WO2002008282A2

WO2002008282A2 - Bstp-ras/rerg protein and related reagents and methods of use thereof

Info

Publication number: WO2002008282A2
Application number: PCT/US2001/023574
Authority: WO
Inventors: David Botstein; Patrick O. Brown; Channing Der; Chuck Perou; Douglas Ross; Douglas Seitz; Fuyu Tamanoi
Original assignee: Stanford University; Applied Genomics, Inc.; The Regents Of The University Of California; University Of North Carolina At Chapel Hill
Priority date: 2000-07-26
Filing date: 2001-07-26
Publication date: 2002-01-31
Also published as: AU2001277202A1; WO2002008282A3

Abstract

The invention provides a protein (BSTP-Ras/Rerg) and polynucleotides which identify and encode BSTP-Ras. The invention also provides expression vectors, host cells, antibodies, agonists, and antagonists. In addition, the invention provides methods for treating or preventing disorders of cell proliferation, particularly breast cancer, by administering a pharmaceutical composition comprising a polypeptide, polynucleotide, or antibody of the invention. The invention also provides methods of classifying diseases, particularly breast cancer, by detecting expression of BSTP-Ras or of a polynucleotide encoding BSTP-Ras, and of providing diagnostic, prognostic, and/or predictive information for a patient based on the detection and/or measurement of BSTP-Ras or of a gene that encodes BSTP-Ras or of a mutation in the BST-RAS/Rerg gene.

Description

BSTP-RAS RERG PROTEIN AND RELATED REAGENTS AND METHODS

OF USE THEREOF

GOVERNMENT SUPPORT The U.S. Government has a paid-up license in this invention and the right in limited circumstances to require the patent owner to license others on reasonable terms as provided for by the terms of Grant Nos. NIH CA77097, CA69577, CA41966, CA41996, and CA42978 awarded by the National Institute of Health.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to provisional applications U.S.S.N 60/220,967, filed July 26, 2000, and U.S.S.N. 60/237,819 filed October 3, 2000, both of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

A major challenge of cancer treatment is to target specific therapies to distinct tumor types in order to maximize efficacy and minimize toxicity. A related challenge lies in the attempt to provide accurate diagnostic, prognostic, and predictive information. At present, breast tumors are described with the tumor-node-metastasis (TNM) system. This system, which uses the size ofthe tumor, the presence or absence of tumor in regional lymph nodes, and the presence or absence of distant metastases, to assign a stage to the tumor is described in the American Joint Committee on Cancer: AJCC Cancer Staging Manual. Philadelphia, Pa: Lippincott- Raven Publishers, 5th ed., 1997, pp 171-180, and further discussion is found in Harris, JR: "Staging of breast carcinoma" in Harris, J.R., Hellman, S., Henderson, LC, Kinne D.W. (eds.): Breast Diseases. Philadelphia, Lippincott, 1991. The assigned stage is used as a basis for selection of appropriate therapy and for prognostic purposes. In addition to the TNM parameters, morphologic appearance is used to further classify tumors and thereby aid in selection of appropriate therapy. However, this approach has serious limitations Tumors with similar histopathologic appearance can exhibit significant variability in terms of clinical course and response to therapy.' For example, some tumors are rapidly progressive while others are not. Some tumors respond readily to hormonal therapy or chemotherapy while others are resistant. Assays for cell surface markers, e.g., using immunohistochernistry, have provided means for dividing certain tumor types into subclasses. For example, one factor considered in prognosis and in treatment decisions for breast cancer is the presence or absence ofthe estrogen receptor (ER) in tumor samples. ER-positive breast cancers typically respond much more readily to hormonal therapies such as tamoxifen, which acts as an anti-estrogen in breast tissue, than ER-negative rumors. Though useful, these analyses are subject to variability and provide only a very crude basis for tumor classification. Therefore, there exists a need for improved methods for classifying tumors.

Mutation or dysregulation of any of a large number of genes contributes to the development and progression of cancer as discussed in Hanahan, D. and Weinberg, R., The Hallmarks of Cancer, Cell, 100, 57-70, 2000. Genes that play a role in cancer can be divided into a number of broad classes including oncogenes, tumor suppressor genes, and genes that regulate apoptosis. Oncogenes such as rαs typically encode proteins whose activities promote cell, growth and/or division, a function that is necessary for normal physiological processes such as development, tissue regeneration, and wound healing. However, inappropriate activity or expression of oncogenes can lead to the uncontrolled cell proliferation that is a feature of cancer. Tumor suppressor genes such as rb act as negative regulators of cell proliferation. Loss of their activity, e.g., due to mutations or decreased expression at the level of mRNA or protein, can lead to unrestrained cell division. A number of familial cancer syndromes and inherited susceptibility to cancer are believed to be caused by mutations in tumor suppressor genes. Apoptosis, or programmed cell death, plays important roles both in normal development and in surveillance to eliminate cells whose survival may be deleterious to the organism, e.g., cells that have acquired DNA damage. Many chemotherapeutic agents are believed to work by activating the endogenous apoptosis pathway in tumor cells. Although a substantial number of genes have been implicated as playing important roles in cancer, the factors responsible for the phenotypic diversity of tumors remain largely unknown. In particular, understanding of he underlying differences in gene expression that may contribute to tumor phenotype is limited. Understanding the differences in gene expression between normal and cancerous tissue and between different tumors ofthe same tissue type is of significant diagnostic, prognostic, and therapeutic utility. There is therefore a need for the identification of genes exhibiting differential expression in tumors. In particular, there is a need for the identification of additional genes and proteins that can be used to classify tumors, especially genes and proteins that can provide diagnostic, prognostic, and/or predictive information in cancer. There is also a need for antibodies and other reagents for the detection and measurement of such genes and proteins.

Most ofthe commonly used chemotherapeutic agents act relatively nonselectively. Rather than specifically killing tumor cells, these agents target any dividing cell, resulting in a variety of adverse effects. In addition, current therapeutic strategies are of limited efficacy, and the mortality rate of breast cancer remains high. There is therefore a need for the identification of additional genes and proteins that can be used as targets for the treatment of cancer. There is also a need for antibodies and other reagents that can modulate, regulate, or interact with these genes and proteins to provide new method of treatment for cancer.

SUMMARY OF THE INVENTION

The present invention relates to the identification of genes of particular import in diagnosis, prognostication and/or therapeutic intervention in breast cancer and other tumors based on their expression profile in human breast tumor samples, their expression in other tissue and normal tissue samples, and in cell lines as assessed using cDNA microarrays. In particular, the genes are identified based on their differential expression across tumor samples.

The invention provides a substantially purified polypeptide and fragments thereof that are encoded by an RNA molecule that is differentially expressed in human breast tumor samples and cell lines. The polypeptide is referred to herein as BSTP-Ras. The polypeptide is also referred to herein as BSTP-Ras/Rerg, or as Rerg (which stands for Ras-like estrogen-regulated growth-inhibitor gene), reflecting features and characteristics ofthe polypeptide and the gene that encodes it as described more fully below. The gene that encodes this polypeptide is referred to herein as BST-RAS, BST- RAS/Rerg, or Rerg.

Thus in one aspect the invention provides a substantially purified polypeptide whose amino acid sequence comprises the amino acid sequence set forth in SEQ ID NO:l. The invention also provides polypeptides possessing homology to the polypeptide having the sequence of SEQ ID NO:l or to fragments of this polypeptide, wherein the polypeptides are significantly similar to the polypeptide of SEQ ID NO:l. In certain embodiments ofthe invention the definition of "significantly similar" can vary, as described further below. In certain embodiments ofthe invention a significantly similar polypeptide has one or more amino acid substitutions, deletions, and/or additions with respect to the sequence of SEQ ID NO: 1. In certain embodiments ofthe invention the polypeptides are expression products of human genes. When referring to polypeptides or polynucleotides whose sequence comprises the sequence set forth in a SEQ ID NO:X, the set of polypeptides or polynucleotides includes those polypeptides or polynucleotides having the particular sequence set forth in the SEQ ID NO:X in addition to other polypeptides or polynucleotides including the sequence of SEQ ID NO:X.

In another aspect, the invention provides a substantially isolated and purified polynucleotide encoding the polypeptide of SEQ ID NO: 1. In particular, the invention provides a substantially isolated and purified polynucleotide comprising a polynucleotide sequence selected from the group consisting of SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, or SEQ ID NO:5. The invention also provides a polynucleotide encoding a polypeptide possessing significant similarity to the polypeptide of SEQ ID NO: 1 , where "significantly similar" is defined below. The invention further provides a polynucleotide having a sequence that is complementary to the sequence of SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, or SEQ ID NO:5. In addition, the invention provides a polynucleotide having a sequence that is complementary to a polypeptide encoding a polypeptide possessing significant similarity to the polypeptide of SEQ ID NO: 1.

In another aspect, the invention provides an isolated and purified polynucleotide that hybridizes under stringent conditions to a polynucleotide encoding a polypeptide comprising or having the amino acid sequence set forth in SEQ ID NO:l. In particular, the invention provides an isolated and purified polynucleotide that hybridizes under stringent conditions to a polynucleotide having the sequence set forth in SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, or fragments of any of these three sequences. In certain embodiments ofthe invention the polynucleotide encodes at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or at least 99%o ofthe polypeptide comprising the amino acid sequence set forth in SEQ ID NO: 1.The invention further provides an isolated an purified polynucleotide that hybridizes under stringent conditions to a polynucleotide encoding a polypeptide having significant similarity to a polypeptide comprising or having the amino acid sequence set forth in SEQ ID NO:l. The invention also provides polynucleotides that hybridize to sequences as set forth above under moderately stringent conditions. In another aspect, the invention provides a substantially purified oligonucleotide that includes a region of nucleotide sequence that hybridizes to at least 8 consecutive nucleotides of sense or antisense sequence of a nucleotide sequence selected from the group consisting of SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, or SEQ ID NO:5. In certain embodiments ofthe invention the oligonucleotide is labeled, e.g., with a fluorescent moiety, enzyme, enzyme substrate, or radioisotope, in order to facilitate detection ofthe oligonucleotide. The oligonucleotide can be used, e.g., as a probe or a primer, to detect the level of a polynucleotide encoding BSTP-Ras/Rerg in cells and/or tissues, e.g., tissues isolated from a patient. The oligonucleotide can also be used to detect mutations in the gene encoding BSTP- Ras/Rerg and/or to detect amplification or altered expression ofthe gene encoding BSTP-Ras/Rerg, in cells and/or tissues. In certain embodiments ofthe invention the oligonucleotide is attached to an oligonucleotide microarray. In certain embodiments ofthe invention the oligonucleotide has a sequence capable of binding specifically with an RNA molecule that encodes a polypeptide comprising an amino acid sequence set forth in SEQ ID NO: 1 so as to prevent appropriate processing, transport, or translation ofthe RNA molecule.

In another aspect the invention provides vectors, e.g. plasmids, containing a polynucleotide encoding a polypeptide comprising the sequence of SEQ ID NO: 1. The invention also provides vectors, e.g., plasmids, comprising a polynucleotide encoding a polypeptide possessing significant similarity to the polypeptide of SEQ ID NO: 1. In certain embodiments ofthe invention the polynucleotide comprises the polynucleotide sequence of SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO: 4, or SEQ ID NO:5. In certain embodiments ofthe invention the vectors contain genetic control elements operably linked to the polynucleotide, wherein the genetic control elements direct transcription ofthe polynucleotide. In certain embodiments ofthe invention the vectors and genetic control elements are adapted for expression ofthe polynucleotide in a bacterial cell, a yeast cell, an insect cell, or a mammalian cell. The invention further provides host cells, e.g., bacterial, yeast, insect, and mammalian cells containing an expression vector containing the polynucleotide encoding the polypeptide having the sequence of SEQ ID NO: 1. The invention further provides host cells, e.g., bacterial, yeast, insect, and mammalian cells containing an expression vector comprising a polynucleotide encoding a polypeptide having significant similarity to the polypeptide of SEQ ID NO : 1.

In another aspect, the invention provides an antibody that specifically bind to a polypeptide whose sequence comprises the amino acid sequence of SEQ ID NO:l. The invention further provides antibodies that specifically bind to a polypeptide having significant similarity to the polypeptide of SEQ ID NO:l. The invention further provides methods of detecting a polypeptide whose sequence comprises the amino acid sequence of SEQ ID NO: 1. The invention further provides methods of detecting a polypeptide having significant similarity to the polypeptide of SEQ ID NO:l. The polypeptides can be detected in a variety of different contexts. For example, the polypeptides can be detected in lysates or extracts derived from cells or tissues, in culture medium, in substantially intact cells or tissue samples (e.g., biopsy specimens), and/or in the blood, urine, serum, ascites, or other body fluids or secretions of a subject.

In another aspect, the invention provides a nonhuman transgenic organism comprising a nonnative DNA molecule encoding a polypeptide comprising an amino acid sequence set forth in SEQ ED NO:l, or an ortholog of such a polypeptide, and including genetic control elements sufficient to direct transcription ofthe DNA molecule in at least a subset ofthe organism's cells. The invention further provides a nonhuman transgenic organism comprising a nonnative DNA molecule encoding a polypeptide having significant similarity to the polypeptide of SEQ ID NO:l and including genetic control elements sufficient to direct transcription ofthe DNA molecule in at least a subset ofthe organism's cells. In yet another aspect, the invention provides a nonhuman organism in which a native DNA sequence encoding a polypeptide having significant similarity to the polypeptide of SEQ ID NO: 1 is deleted, e.g., by homologous recombination.

In another aspect, the invention provides methods for detecting a polynucleotide encoding a polypeptide comprising an amino acid sequence set forth in SEQ ID NO: 1 , or a polypeptide having significant similarity to the polypeptide of SEQ ID NO:l, in a biological sample. The sample may comprise cells, tissue, body fluid, etc., isolated from a subject. The sample may be processed in a variety of ways prior to application ofthe methods. For example, the sample may be subjected to purification, reverse transcription, amplification, etc. One such method comprises steps of: (a) hybridizing a nucleic acid complementary to the polynucleotide encoding a polypeptide comprising an amino acid sequence set forth in SEQ ID NO:l, or a polypeptide having significant similarity to the polypeptide of SEQ ID NO:l, to at least one nucleic acid in the biological sample, thereby forming a hybridization complex; and (b) detecting the hybridization complex, wherein the presence ofthe hybridization complex indicates the presence of a polynucleotide encoding the polypeptide in the biological sample. A second such method comprises steps of: (a) hybridizing a nucleic acid encoding a polypeptide comprising an amino acid sequence set forth in SEQ ID NO:l, or a polypeptide having significant similarity to the polypeptide of SEQ ID NO:l, to at least one nucleic acid complementary to at least one nucleic acid in the biological sample, thereby forming a hybridization complex; and (b) detecting the hybridization complex, wherein the presence ofthe hybridization complex indicates the presence of a polynucleotide encoding the polypeptide in the biological sample.

In yet another aspect, the invention provides kits for detecting a polynucleotide encoding a polypeptide comprising an amino acid sequence set forth in SEQ ID NO:l, or a polypeptide having significant similarity to the polypeptide of SEQ ID NO: 1. The kits can comprise a polynucleotide that hybridizes specifically to the polynucleotide encoding a polypeptide comprising an amino acid sequence set forth in SEQ ID NO:l, or a polypeptide having significant similarity to the polypeptide of SEQ ID NO:l and, optionally, other materials such as suitable buffers, indicators (e.g., fluorophores, chromophores or enzymes providing same), controls (e.g., an appropriate polynucleotide of this invention), controls, and directions for using the kit.

In another aspect, the invention provides methods for detecting a polypeptide comprising an amino acid sequence set forth in SEQ ID NO:l, or a polypeptide having significant similarity to the polypeptide of SEQ ID NO: 1. One such method comprises steps of: (a) contacting the biological sample with an antibody that specifically binds to the polypeptide of SEQ ID NO: 1, or a polypeptide having significant similarity to the polypeptide of SEQ ID NO:l; and (b) determining whether the antibody specifically binds to the sample, the binding being an indication that the sample contains the polypeptide. The invention also provides kits for performing these methods. The kits can comprise an antibody (preferably a monoclonal antibody) that binds to the polypeptide and, optionally, other materials such as suitable buffers, indicators (e.g., fluorophores, chromophores or enzymes providing same), controls (e.g., a polypeptide of this invention) and directions for using the kit. In another aspect, the invention provides methods for producing a polypeptide comprising the amino acid sequence of SEQ ID NO:l, or a polypeptide having significant similarity to the polypeptide of SEQ ID NO:l. In one embodiment the method includes the steps of providing a cell that expresses the polypeptide or polypeptide fragment, e.g., a cell containing an expression vector containing a polynucleotide encoding the polypeptide or polypeptide fragment operably linked to genetic control elements that direct transcription ofthe polynucleotide; maintaining the cell under conditions wherein the polypeptide is produced; harvesting the polypeptide from the cell and/or the culture medium; and, optionally, purifying the polypeptide. In another aspect, the invention provides methods of predicting whether an individual is at risk for a condition featuring inappropriate cell division, e.g., cancer. One such method comprises the step of determining whether there exists, within a cell and/or tissue of an individual, a mutation in a gene encoding a polypeptide having an amino acid sequence selected from the group consisting of SEQ ID NO:l, or a polypeptide having significant similarity to the polypeptide of SEQ ID NO:l, or whether there exists, within a cell and/or tissue of an individual, a mutation in a regulatory sequence for such a gene. A second such method comprises the step of determining whether an individual expresses a particular allele or variant of a gene comprising a nucleotide sequence set forth in SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, such allele or variant being present within the general population and inherited from either ofthe individual's parents rather than constituting a de novo mutation within the organism. A third such method comprises the step of determining whether there exists, within a cell and/or tissue of an individual, inappropriate expression of a polynucleotide encoding a polypeptide having an amino acid sequence set forth in SEQ ID NO:l or a polypeptide having significant similarity to the polypeptide of SEQ ID NO:l. A fourth such method comprises the step of determining whether there exists, within a cell and/or tissue of an individual, inappropriate expression of a polypeptide having an amino acid sequence set forth in SEQ ID NO:l or a polypeptide having significant similarity to the polypeptide of SEQ ID NO:l.

In another aspect, the invention provides methods of classifying a disease, particularly of classifying tumors. One such method includes steps of: (a) obtaining cells or tissue from a site of disease; (b) detecting a polynucleotide encoding a polypeptide having a sequence selected from the group consisting of SEQ ID NO:l or a polypeptide having significant similarity to the polypeptide of SEQ ID NO:l, or a complement of such a polynucleotide; and (c) assigning the disease to one of a set of predetermined categories based on detection ofthe polynucleotide. The method can further comprise the step of providing diagnostic, prognostic, or predictive information based on the category assigned in the assigning step.

In certain embodiments ofthe invention the method is used to classify breast tumors. In certain embodiments ofthe invention the method is based on detecting expression of a single gene, e.g., a gene encoding the polypeptide of SEQ ID NO: 1. Detecting expression of such a gene may comprise detecting the polynucleotide sequence set forth in SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, or SEQ ID NO:5. Detecting expression may comprise measuring either a relative or absolute level of expression. In certain embodiments ofthe invention the method is based on an assessment ofthe expression of multiple polynucleotides as described further in copending U.S. Patent Application "Reagents and Methods for Use in Managing Breast Cancer, filed July 26, 2001 and in U.S. Provisional Patent Application Ser. No. 60/220,967, filed July 26, 2000. These applications are referred to herein as "the gene subset application". The multiple polynucleotides can include all ofthe polynucleotides disclosed therein or any subset thereof.

In another aspect, the invention provides a method of classifying a tumor by detection ofthe polypeptide of SEQ ID NO: 1 or a polypeptide having significant similarity to the polypeptide of SEQ ID NO:l in cells and/or tissue samples obtained from the tumor or from elsewhere in the body (e.g., in blood, urine, ascites, other body fluids or secretions or excretions). In a preferred embodiment the method is used to classify breast tumors. In certain embodiments the method is based on the detection of a single polypeptide, e.g., the polypeptide of SEQ ID NO:l or a polypeptide having significant similarity to the polypeptide of SEQ ID NO:l. However, in other embodiments the method is based on an assessment ofthe expression of multiple polypeptides. The multiple polypeptides can include all ofthe polypeptides disclosed in the gene subset application mentioned above or any subset thereof. In certain embodiments the level ofexpression (either relative or absolute) of the polypeptide is measured. In other embodiments the pattern ofexpression ofthe polypeptide within cells or within a tissue sample is assessed. Regardless ofthe method by which a tumor is assigned to a predetermined category, the assignment may be used as a basis to provide diagnostic, prognostic, and/or predictive information to the patient having the tumor.

In another aspect, the invention provides a microarray for use in classifying tumors, comprising a polynucleotide whose sequence comprises or is complementary to that set forth in SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, or SEQ ID NO:5, or whose sequence is of sufficient length to specifically bind to such a sequence under the microarray hybridization conditions employed. Such conditions may be those described in the Examples, or any conditions appropriate for the particular microarray and detection technology employed. The invention further provides a microarray for use in classifying tumors comprising a polynucleotide, e.g., a cDNA or an oligonucleotide, capable of binding specifically to a polynucleotide encoding the polypeptide having the amino acid sequence set forth in SEQ ID NO: 1, or capable of binding specifically to a polypeptide having significant similarity to the polypeptide of SEQ ID NO : 1 , or complementary to such polynucleotides .

In another aspect, the invention provides a pharmaceutical composition comprising a substantially purified polypeptide having the amino acid sequence set forth in SEQ ID NO:l or a polypeptide having significant similarity to the polypeptide of SEQ ID NO: 1. In certain embodiments ofthe invention the pharmaceutical composition further preferably comprises a pharmaceutically acceptable carrier.

In yet another aspect, the invention provides a pharmaceutical composition comprising a substantially purified antibody that binds to a polypeptide having an amino acid sequence set forth in SEQ ID NO:l or a polypeptide having significant similarity to the polypeptide of SEQ ID NO: 1. In certain embodiments ofthe invention the pharmaceutical composition further preferably comprises a pharmaceutically acceptable carrier. In certain embodiments the antibody is modified, e.g., by attaching a toxic molecule thereto.

The invention provides methods for identifying modulators ofthe expression or activity of a polypeptide comprising the amino acid sequence set forth in SEQ ID NO: 1 or a polypeptide having significant similarity to the polypeptide of SEQ ID

NO:l. The invention further provides agonists and antagonists capable of modulating the expression or activity of a polypeptide comprising the amino acid sequence set forth in SEQ ID NO:l or a polypeptide having significant similarity to the polypeptide of SEQ ID NO: 1. The invention provides pharmaceutical compositions including such modulators and methods of use thereof for the treatment or prevention of cancer, particularly breast cancer.

In another aspect, the invention provides a method for the treatment or prevention of cancer comprising the step of administering to an individual in need thereof, a pharmaceutical composition comprising a polypeptide having an amino acid sequence comprising the sequence of SEQ ID NO: 1 or a polypeptide having significant similarity to the polypeptide of SEQ ID NO: 1. In another aspect, the invention provides a method for the treatment or prevention of cancer comprising the step of administering to an individual in need thereof, a pharmaceutical composition comprising an antibody or a modified antibody that binds to a polypeptide having an amino acid sequence set forth in SEQ ID NO:l, or a polypeptide having significant similarity to the polypeptide of SEQ ID NO:l. In another aspect, the invention provides methods of screening for an inhibitor of cell growth. The methods involve identifying a compound that enhances the expression or activity of a polypeptide comprising the amino acid sequence of SEQ ID NO:l or a polypeptide having significant similarity to the polypeptide of SEQ ID NO:l. According to one embodiment, the method includes steps of: (1) contacting a polypeptide comprising the amino acid sequence of SEQ ID NO: 1 or a polypeptide having significant similarity to the polypeptide of SEQ ID NO:l with a test compound; (2) measuring GTP-binding and/or GTPase activity ofthe polypeptide; and (3) identifying the test compound as an activator ofthe polypeptide if the polypeptide exhibits enhanced GTP-binding activity and/or reduced GTPase activity in the presence ofthe test compound relative to the level of GTP-binding activity and/or GTPase activity in the absence ofthe test compound. In certain embodiments ofthe method the polypeptide includes a GTP-binding domain. The method may be performed in vitro, e.g., using a polypeptide produced using recombinant DNA technology, or may be performed in vivo, e.g., by applying the test compound to a cell that expresses the polypeptide and isolating the polypeptide from the cell. In certain ofthe methods the polypeptide may be a variant that includes a tag, e.g., in order to facilitate isolation.

In another aspect, the invention provides methods of inhibiting growth of a cell comprising enhancing the level or activity of a polypeptide comprising the amino acid sequence of SEQ ID NO: 1 or a polypeptide having significant similarity to the polypeptide of SEQ ID NO:l in the cell. The cell can be a normal cell or a tumor cell, e.g., a breast tumor cell. According to certain ofthe methods the level ofthe polypeptide is enhanced by overexpressing the polypeptide in the cell, e.g., by introducing an expression vector or other nucleotide sequence (e.g., DNA, RNA, or modified nucleotides, etc.) that encodes the polypeptide into the cell. According to certain ofthe methods the activity ofthe polypeptide is enhanced by contacting the cell with a compound that either directly or indirectly increases the GTP-binding activity ofthe polypeptide and/or reduces the GTPase activity ofthe polypeptide. Such a compound may be identified using the inventive screening method described above. According to certain ofthe methods the activity ofthe polypeptide is enhanced by making an appropriate mutation in the coding sequence, such that the resulting variant displays increased GTP-binding activity and/or reduced GTPase activity. As discussed below, a number of such mutations in Ras family members that have predictable effects on GTP-binding activity and/or GTPase activity are well known in the art.

In another aspect, the invention provides a method of treating or preventing a tumor comprising steps of: (i) providing an individual in need of treatment or prevention of a tumor, (ii) administering a compound that enhances the level or activity of a polypeptide comprising the amino acid sequence of SEQ ID NO:l or a polypeptide having significant similarity to the polypeptide of SEQ ID NO: 1. In certain embodiments ofthe method the compound is identified using the screening assay described above. In certain embodiments ofthe invention the compound is provided as a component of a pharmaceutical composition. The invention also includes such a pharmaceutical composition.

In another aspect, the invention provides a method of screening for an activator of cell growth. The methods involve identifying a compound that reduces or inhibits the expression or activity of a polypeptide comprising the amino acid sequence of SEQ ID NO:l or a polypeptide having significant similarity to the polypeptide of SEQ ID NO:l. According to one embodiment, the method includes steps of: (1) contacting a polypeptide comprising the amino acid sequence of SEQ ID NO:l or a polypeptide having significant similarity to the polypeptide of SEQ ID NO: 1 with a test compound; (2) measuring GTP-binding and/or GTPase activity of the polypeptide; and (3) identifying the test compound as an inhibitor ofthe polypeptide if the polypeptide exhibits decreased GTP-binding activity and/or increased GTPase activity in the presence ofthe test compound relative to the level of GTP-binding activity and/or GTPase activity in the absence ofthe test compound. In certain embodiments ofthe method the polypeptide includes a GTP-binding domain. The method may be performed in vitro, e.g., using a polypeptide produced using recombinant DNA technology, or may be performed in vivo, e.g., by applying the test compound to a cell that expresses the polypeptide and isolating the polypeptide from the cell. In certain ofthe methods the polypeptide may be a variant that includes a tag, e.g., in order to facilitate isolation.

In another aspect, the invention provides a method of increasing cell growth comprising: decreasing the level or activity of a polypeptide comprising the amino acid sequence of SEQ ID NO:l or a polypeptide having significant similarity to the polypeptide of SEQ ID NO:l in the cell. Various methods for decreasing the level of a polypeptide in a cell are known in the art. Such methods include, for example, the introduction or expression of antisense nucleic acids or double-stranded RNA (RNA-mediated interference) into the cell. Another such method is introduction or expression of dominant negative polypeptides into the cell. According to certain ofthe methods the activity ofthe polypeptide is decreased by contacting the cell with a compound that either directly or indirectly decreases the GTP-binding activity ofthe polypeptide and/or increases the GTPase activity ofthe polypeptide. Such a compound may be identified using the inventive screening method described above. According to certain ofthe methods the activity ofthe polypeptide is reduced by making an appropriate mutation in the coding sequence, such that the resulting variant displays decreased GTP-binding activity and/or increased GTPase activity. According to one aspect, the invention provides a method of classifying a tumor comprising the steps of (i) providing a tumor sample, (ii) detecting expression or activity of a gene encoding the polypeptide of SEQ ID NO:l in the sample; and (iii) classifying the tumor as belonging to a tumor subclass based on the results ofthe detecting step. The detecting step may comprise detecting the polypeptide. A variety of detection techniques may be employed including, but not limited to, immunohistochemical analysis, ELISA assay, antibody arrays, or detecting modification of a substrate by the polypeptide.

In certain embodiments ofthe methods the tumor is a breast tumor and the tumor subclass is a luminal rumor subclass. The methods may further comprise providing diagnostic, prognostic, or predictive information based on the classifying step. Classifying may include stratifying the tumor (and thus stratifying a subject having the tumor), e.g., for a clinical trial. The methods may further comprise selecting a treatment based on the classifying step. In clinical research, stratification is the process or result of describing or separating a patient population into more homogeneous subpopulations according to specified criteria. Stratifying patients initially rather than after the trial is frequently preferred, e.g., by regulatory agencies such as the U.S. Food and Drug Administration that may be involved in the approval process for a medication. In some cases stratification may be required by the study design. Various stratification criteria may be employed in conjunction with detection ofexpression of one or more basal marker genes. Commonly used criteria include age, family history, lymph node status, tumor size, tumor grade, etc. Other criteria including, but not limited to, tumor aggressiveness, prior therapy received by the patient, ER and/or PR positivity, Her2neu status, p53 status, various other biomarkers, etc., may also be used. Stratification is frequently useful in performing statistical analysis ofthe results of a trial.

In another aspect, the invention provides a method of testing a subject comprising the steps of (i) providing a sample isolated from a subject, (ii) detecting expression or activity of a gene encoding the polypeptide of SEQ ID NO.T in the sample, and (iii) providing diagnostic, prognostic, or predictive information based on the detecting step. The detecting step may comprise detecting the polypeptide. Detection may be performed using any appropriate technique including, but not limited to, immunohistochemistry, ELISA assay, protein array, or detecting modification of a substrate by the polypeptide.

The sample may comprise mRNA, in which case the detecting step may comprise hybridizing the mRNA or cDNA or RNA synthesized from the mRNA to a microarray or detecting mRNA transcribed from the gene or detecting cDNA or RNA synthesized from mRNA transcribed from the gene. In any ofthe above methods, the sample may be a blood sample, a urine sample, a serum sample, an ascites sample, a saliva sample, a cell, and a portion of tissue.

According to another aspect, the invention provides a method of testing a compound or a combination of compounds for activity against tumors comprising steps of (i) obtaining or providing tumor samples taken from subjects who have been treated with the compound or combination of compounds, wherein the tumors fall within a tumor subclass, (ii) comparing the response rate of tumors that fall within the tumor subclass and have been treated with the compound with the overall response rate of tumors that have been treated with the compound or combination of compounds or with the response rate of tumors that do not fall within the subclass and have been treated with the compound or combination of compounds and (iii) identifying the compound or combination of compounds as having selective activity against tumors in the tumor subclass if the response rate of tumors in the subclass is greater than the overall response rate or the response rate of tumors that do not fall within the subclass. In certain embodiments ofthe invention the tumors are breast tumors. In certain embodiments ofthe invention the tumor subclass is a luminal tumor subclass. The tumors may be classified according to any ofthe inventive classification methods described above. In certain embodiments ofthe invention the classification is based on expression ofthe polypeptide of SEQ ID NO:l.

The invention further provides a method of testing a compound or a combination of compounds for activity against tumors comprising steps of (i) treating subjects in need of treatment for tumors with the compound or combination of compounds, (ii) comparing the response rate of tumors that fall within a tumor subclass with the overall response rate of tumors or with the response rate of tumors that do not fall within the subclass, and (iii) identifying the compound or combination of compounds as having selective activity against tumors in the tumor subclass if the response rate of tumors in the subclass is greater than the overall response rate or the response rate of tumors that do not fall within the subclass. The method may further comprise various additional steps. For example, the method may comprise steps of (i) providing tumor samples from subjects in need of treatment for tumors, (ii) determining whether the tumors fall within a tumor subclass, and (iii) stratifying the subjects based on the results ofthe determining step prior to performing the treating step. The method may further comprise the steps of (i) providing tumor samples from subjects in need of treatment for tumors, (ii) detecting expression or activity of a gene encoding the polypeptide of SEQ ID NO:l in the samples, and (iii) stratifying the subjects based on the results ofthe detecting step prior to performing the treating step.

In addition, the invention includes a method of testing a compound or a combination of compounds for activity against tumors comprising steps of (i) treating subjects in need of treatment for tumors with the compound or combination of compounds or with an alternate compound, wherein the tumors fall within a tumor _: subclass, (ii) comparing the response rate of tumors treated with the compound or combination of compounds with the response rate of tumors treated with the alternate compound; and (iii) identifying the compound or combination of compounds as having superior activity against tumors in the tumor subclass, as compared with the alternate compound, if the response rate of tumors treated with the compound or combination of compounds is greater than the response rate of tumors treated with the alternate compound. The method may further comprise various additional steps. For example, the method may comprise steps of (i) providing tumor samples from subjects in need of treatment for tumors, (ii) determining whether the tumors fall within a tumor subclass, and (iii) stratifying the subjects based on the results ofthe determining step prior to performing the treating step. The method may further comprise the steps of (i) providing tumor samples from subjects in need of treatment for tumors, (ii) detecting expression or activity of a gene encoding the polypeptide of SEQ ID NO:l in the samples, and (iii) stratifying the subjects based on the results of the detecting step prior to performing the treating step.

In certain embodiments ofthe invention the alternate compound is a compound approved by the U.S. Food and Drug administration for treatment of rumors. The invention also provides a method of treating a subject comprising steps of (i) identifying a subject as having a tumor in a luminal tumor subclass, and (ii) administering to the subject a compound identified according to any ofthe inventive methods for identifying a subject.

The present application refers to various issued and pending patent applications, provisional patent applications, published articles, books, and other publications. The contents of all of these items are herein incorporated by reference. The present application also incorporates by reference six U.S. patent applications filed by inventors on July 26, 2001. These applications are entitled "REAGENTS AND METHODS FOR USE IN MANAGING BREAST CANCER", "BSTP-ECG1 PROTEIN AND RELATED REAGENTS AND METHODS OF USE THEREOF", "BSTP-CAD PROTEIN AND RELATED REAGENTS AND METHODS OF USE THEREOF", "BASAL CELL MARKERS IN BREAST CANCER AND USES THEREOF", "BSTP-TRANS PROTEIN AND RELATED REAGENTS AND METHODS OF USE THEREOF", "BSTP-5 PROTEINS AND RELATED REAGENTS AND METHODS OF USE THEREOF".

BRIEF DESCRIPTION OF THE DRAWING

Figure 1 presents the sequence of BSTP-Ras/Rerg (SEQ ID NO:l) and the sequences of polynucleotides that include sequences that encode BSTP-Ras/Rerg (SEQ ID NO:2, SEQ ID NO:3, and SEQ ID NO:4). SEQ ID NO:2 is a 599 nucleotide open reading frame that encodes BSTP-Ras/Rerg. The open reading frame is followed by an in-frame termination codon (TAG). In SEQ ID NO:3 and SEQ ID NO:4, the character "N" stands for any nucleotide.

Figure 2 presents the sequence of a full length cDNA that encodes the polypeptide of SEQ ID NO: 1, i.e., BSTP-Ras/Rerg. The sequence is designated as SEQ ID NO:5.

Figure 3 presents a portion ofthe results of a search performed in GenBank using BLASTP with the amino acid sequence of BSTP-Ras/Rerg (SEQ ID NO: 1) as input. The figure identifies polypeptides having homology to BSTP-Ras/Rerg.

Figure 4 presents a Northern blot showing expression of BST-RAS/RERG mRNA in various cell lines.

Figure 5 presents a summary of estrogen modulation microarray experiments showing effects of estrogen or tamoxifen treatment or estrogen deprivation on expression of BST-RAS/RERG and various other genes.

Figure 6 presents an alignment ofthe human BSTP-Ras/Rerg amino acid sequence with the amino acid sequences of various other Ras family members. Figure 7A presents a Western blot showing expression of GFP or a GFP-Rerg fusion protein in various cell lines transiently transfected with DNA constructs encoding GFP or GFP-Rerg.

Figure 7B presents an epifiuorescence micrograph showing expression of GFP or a GFP-Rerg fusion protein in living cells transiently transfected with DNA constructs encoding GFP or GFP-Rerg.

Figure 8A presents a Western blot showing expression of HA-Rerg in MCF-7 cells stably expressing an empty vector and in clones overexpressing HA-Rerg (MCF-7 stably transfected clones) .

Figure 8B presents growth curves for MCF-7 cells stably expressing empty vector and for HA-Rerg overexpressing clones.

Figure 8C presents a graph showing reduced growth in soft agar of HA-Rerg expressing clones relative to MCF-7 cells stably expressing empty vector.

BRIEF DESCRIPTION OF THE TABLES The tables contain the numerical data corresponding to microarray images. Some table present additional information or list the individual genes in the various gene subsets.

Table 1 is a master data table for the 65 microarray experiments performed on individual tumor samples, in which rows represent I.M.A.G.E. clones that identify approximately 1753 genes whose expression varied by at least a factor of 4 and columns represent individual microarray experiments. The first 50 pages ofthe table consist of a reference list in which a descriptive name for each clone (where such a name exists) appears in the column entitled Name, followed by the Genbank accession number for the clone. Each row in the reference list contains a number in the first column that numerically identifies the column. In the subsequent data portion ofthe table (pages 1 - 392), each row is similarly identified by a number in the first column so that the name and Genbank accession number for the clone for which data appears in that row may be determined by consulting the reference list. In the data portion ofthe table, the column headings in the first row identify the tumor samples. Each data cell in the table represents the measured Cy5/Cy3 fluorescence ratio at the corresponding target element on the appropriate array. Empty cells indicate insufficient or missing data. All ratio values are log transformed (base 2) to treat inductions or repressions of identical magnitude as numerically equal but with opposite sign.

Table 2 is a master data table for the 19 microarray experiments performed on cell line samples, in which rows represent I.M.A.G.E. clones that identify approximately 1753 genes whose expression varied by at least a factor of 4 and columns represent individual microarray experiments. This table contains only a data portion, in which the column headings in the first row identify the cell lines. Each row in the table is identified by a number which appears in the first column. The same reference list that forms part of Table 1 may be consulted to determine the name and Genbank accession number for the clone for which data appears in that row. Each data cell in the table represents the measured Cy5/Cy3 fluorescence ratio at the corresponding target element on the appropriate array. Empty cells indicate insufficient or missing data. All ratio values are log transformed (base 2) to treat inductions or repressions of identical magnitude as numerically equal but with opposite sign.

Table 3 presents a listing and description ofthe 11 cell lines used to create the common reference sample.

Table 4 presents a complete listing ofthe 84 experimental samples that were assayed versus the common reference sample. The table includes a list of alternate names (in the column entitled Sample ID/old name) for the same tumors. The alternate names are used to identify the tumor samples in certain contexts, and the table allows conversion between the two sets of names.

Table 5 lists the tumors used in the experiments described herein, along with clinical and pathological information about each tumor/patient.

Table 6 is a master data table for the 84 microarray experiments performed on individual tumor, tissue, and cell line samples, in which rows represent I.M.A.G.E. clones that identify the 496 genes in the intrinsic gene set, and columns represent individual microarray experiments. The first 15 pages ofthe table consist of a reference list in which a descriptive name for each clone (where such a name exists) appears in the column entitled Name, followed by the Genbank accession number for the clone. Each row in the reference list contains a number in the first column that numerically identifies the column. In the subsequent data portion ofthe table (pages 1 - 91), each row is similarly identified by a number in the first column so that the name and Genbank accession number for the clone for which data appears in that row may be determined by consulting the reference list. In the data portion ofthe table, the column headings in the first row identify the tumor samples. Each data cell in the table represents the measured Cy5/Cy3 fluorescence ratio at the corresponding target element on the appropriate array. Empty cells indicate insufficient or missing data. All ratio values are log transformed (base 2) to treat inductions or repressions of identical magnitude as numerically equal but with opposite sign.

Table 7 is a listing ofthe 374 clones that identify genes selected for the epithelial enriched gene set including Genbank accession numbers.

Table 8 is a listing ofthe clones that identify genes that comprise the luminal subset including Genbank accession numbers.

Tables 9-1 and 9-2 are listings ofthe two groups of clones that identify genes that comprise the basal subset including Genbank accession numbers.

Table 10 is a listing ofthe clones that identify genes that comprise the ErbB2 subset including Genbank accession numbers.

Table 11 is a listing ofthe clones that identify genes that comprise the endothelial gene subset including Genbank accession numbers.

Table 12 is a listing ofthe clones that identify genes that comprise the stromal/fibroblast gene subset including Genbank accession numbers.

Table 13 is a listing ofthe clones that identify genes that comprise the B-cell gene subset including Genbank accession numbers.

Table 14 is a listing ofthe clones that identify genes that comprise the adipose- enriched/normal breast gene subset including Genbank accession numbers.

Table 15 is a listing ofthe clones that identify genes that comprise the macrophage gene subset including Genbank accession numbers.

Table 16 is a listing ofthe clones that identify genes that comprise the T-cell gene subset including Genbank accession numbers.

In Table 1, the Genbank accession number for each clone appears in the column entitled "Name", following a brief descriptive name for the gene identified by the clone, where available. In some cases the descriptive name is a number corresponding to an I.M.A.G.E. clone ID number. As is well known and accepted in the art, the Genbank accession number represents a means of definitively identifying a particular clone, since Genbank accession numbers will be maintained permanently or, if changed, the.change will be accomplished in such a manner as to allow unambiguous correlation between any new numbering system and the numbering system currently in use. Note that Tables 1, 2, and 6 are provided for purposes of presenting the clone identifications and the data that was used to perform hierarchical clustering analysis, and that the format ofthe tables may not correspond exactly with the format required by software developed for the analysis ofthe data. Appropriate format will, in general, depend upon the particular computer program. See, for example, the Web site http://genome-www.stanford.edu/~sherlock/tutorial.html for discussion ofthe appropriate format for one particular analysis program.

In Tables 7 - 16, each entry identifies a clone. The first portion of each entry is a brief descriptive name for the gene identified by the clone. The Genbank accession number for the clone appears on the last line ofthe entry for that clone.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

DEFINITIONS

To facilitate understanding ofthe description ofthe invention, the following definitions are provided. It is to be understood that, in general, terms not otherwise defined are to be given their meaning or meanings as generally accepted in the art.

Agonist: As used herein, the term "agonist" refers to a molecule that increases or prolongs the duration ofthe effect of a polypeptide or a nucleic acid. Agonists may include proteins, nucleic acids, carbohydrates, lipids, small molecules, ions, or any other molecules that modulate the effect ofthe polypeptide or nucleic acid. An agonist may be a direct agonist, in which case it is a molecule that exerts its effect by binding to the polypeptide or nucleic acid, or an indirect agonist, in which case it exerts its effect via a mechanism other than binding to the polypeptide or nucleic acid (e.g., by altering expression or stability ofthe polypeptide or nucleic acid, by altering the expression or activity of a target ofthe polypeptide or nucleic acid, by interacting with an intermediate in a pathway involving the polypeptide or nucleic acid, etc.)

Antagonist: As used herein, the term "antagonist" refers to a molecule that decreases or reduces the duration ofthe effect of a polypeptide or a nucleic acid. Antagonists may include proteins, nucleic acids, carbohydrates, or any other molecules that modulate the effect ofthe polypeptide or nucleic acid. An antagonist may be a direct antagonist, in which case it is a molecule that exerts its effect by binding to the polypeptide or nucleic acid, or an indirect antagonist, in which case it exerts its effect via a mechanism other than binding to the polypeptide or nucleic acid (e.g., by altering expression or stability ofthe polypeptide or nucleic acid, by altering the expression or activity of a target ofthe polypeptide or nucleic acid, by interacting with an intermediate in a pathway involving the polypeptide or nucleic acid, etc.) Corresponding to: In general, the phrase "corresponding to" has its commonly accepted meaning indicating, typically, a relationship between two entities, etc. For example, a mRNA corresponds to a gene if the mRNA is transcribed from the gene. A protein corresponds to a gene if the protein is translated from an mRNA transcribed from the gene. A cDNA corresponds to an mRNA if the cDNA is synthesized by reverse transcription ofthe mRNA. In addition, and without limitation, as used herein, an mRNA corresponds to a clone on a microarray when the mRNA (or cDNA derived therefrom) hybridizes specifically (under the experimental conditions described) to the clone or to its complement, e.g., when the sequence ofthe mRNA (or cDNA derived therefrom) and the sequence ofthe clone are sufficiently complementary to one another for specific hybridization to occur. Similarly, a gene corresponds to a clone on a microarray when mRNA transcribed from the gene corresponds to the clone. Note that it is not necessary that the entire mRNA, cDNA, etc. hybridize with the clone or vice versa. For example, the mRNA or cDNA may be longer or shorter than the clone. The clone may be longer or shorter than the mRNA or cDNA. Either or both ofthe mRNA/cDNA and the clone may contain one or more stretches of sequence that is/are not contained within the corresponding nucleic acid.

Diagnostic information: As used herein, diagnostic information or information for use in diagnosis is any information that is useful in determining whether a patient has a disease or condition and/or in classifying the disease or condition into a phenotypic category or any category having significance with regards to the prognosis of or likely response to treatment (either treatment in general or any particular treatment) ofthe disease or condition. Similarly, diagnosis refers to providing any type of diagnostic information, including, but not limited to, whether a subject is likely to have a condition (such as a tumor), information related to the nature or classification of a tumor, information related to prognosis and/or information useful in selecting an appropriate treatment. Selection of treatment may include the choice of a particular chemotherapeutic agent or other treatment modality such as surgery, radiation, etc., a choice about whether to withhold or deliver therapy, etc. Differential expression: A gene exhibits differential expression at the RNA level if its RNA transcript varies in abundance between different samples in a sample set. A gene exhibits differential expression at the protein level, if a polypeptide encoded by the gene varies in abundance between different samples in a sample set. In the context of a microarray experiment, differential expression generally refers to differential expression at the RNA level.

Gene: For the purposes ofthe present invention, the term "gene" has its meaning as understood in the art. However, it will be appreciated by those of ordinary skill in the art that the term "gene" has a variety of meanings in the art, some of which include gene regulatory sequences (e.g., promoters, enhancers, etc.) and/or intron sequences, 3' untranslated regions, etc., and others of which are limited to coding sequences. It will further be appreciated that definitions of "gene" include references to nucleic acids that do not encode proteins but rather encode functional RNA molecules such as tRNAs. For the purpose of clarity we note that, as used in the present application, the term "gene" generally refers to a portion of a nucleic acid that encodes a protein; the term may optionally encompass regulatory sequences. This definition is not intended to exclude application ofthe term "gene" to non-protein coding expression units but rather to clarify that, in most cases, the term as used in this document refers to a protein coding nucleic acid.

Gene product or expression product: A gene product or expression product is, in general, an RNA transcribed from the gene or a polypeptide encoded by an RNA transcribed from the gene.

Homology: The term "homology" refers to a degree of similarity between two or more nucleic acid sequences or between two or more amino acid sequences. As is well known in the art, given any nucleotide or amino acid sequence, homologous sequences may be identified by searching databases (e.g., GenBank, EST [expressed sequence tagjdatabases, GST [gene sequence tag] databases, GSS [genome survey sequence] databases, organism sequencing project databases) using computer programs such as BLASTN for nucleotide sequences and BLASTP, gapped BLAST, and PSI-BLAST for amino acid sequences. These programs are described in Altschul, SF, et al., Basic local alignment search tool, J. Mol. Biol, 215(3): 403-410, 1990, Altchul, SF and Gish, W, Methods in Enzymology, and Altschul, SF, et al., "Gapped BLAST and PSI-BLAST: a new generation of protein database search programs", Nucleic Acids Res. 25:3389-3402, 1997. In addition to identifying homologous sequences, the programs mentioned above typically provide an indication ofthe degree of homology. Determining the degree of identity or homology that exists between two or more amino acid sequences or between two or more nucleotide sequences can also be conveniently performed using any of a variety of other algorithms and computer programs known in the art. Discussion and sources of appropriate programs may be found, for example, in Baxevanis, A., and Ouellette, B.F.F., Bioinformatics : A Practical Guide to the Analysis of Genes and Proteins, Wiley, 1998; and Misener, S. and Krawetz, S. (eds.), Bioinformatics Methods and Protocols (Methods in Molecular Biology, Vol. 132), Humana Press, 1999.

Operably linked: The term "operably linked" refers to a relationship between two nucleic acid sequences wherein the expression of one ofthe nucleic acid sequences is controlled by, regulated by, modulated by, etc. the other nucleic acid sequence. For example, a promoter is operably linked with a coding sequence if the promoter controls transcription ofthe coding sequence. Preferably a nucleic acid sequence that is operably linked to a second nucleic acid sequence is covalently linked, either directly or indirectly, to such a sequence, although any effective three-dimensional association is acceptable.

Prognostic information and predictive information: As used herein the terms prognostic information and predictive information are used interchangeably and somewhat informally to refer to any information that may be used to foretell any aspect ofthe course of a disease or condition either in the absence or presence of treatment. Such information may include, but is not limited to, the average life expectancy of a patient, the likelihood that a patient will survive for a given amount of time (e.g., 6 months, 1 year, 5 years, etc.), the likelihood that a patient will be cured of a disease, the likelihood that a patient's disease will respond to a particular therapy (wherein response may be defined in any of a variety of ways). Prognostic and predictive information are included within the broad category of diagnostic information.

Sample: As used herein, a sample obtained from a subject may include, but is not limited to, any or all ofthe following: a cell or cells, a portion of tissue, blood, serum, ascites, urine, saliva, and other body fluids, secretions, or excretions. The term "sample" also includes any material derived by processing such a sample. Derived samples may include nucleic acids or proteins extracted from the sample or obtained by subjecting the sample to techniques such as amplification or reverse transcription of mRNA, etc.

Specific binding: As used herein, the term refers to an interaction between a target polypeptide (or, more generally, a target molecule) and a binding molecule such as an antibody, agonist, or antagonist. The interaction is typically dependent upon the presence of a particular structural feature ofthe target polypeptide such as an antigenic determinant or epitope recognized by the binding molecule. For example, if an antibody is specific for epitope A, the presence of a polypeptide containing epitope A or the presence of free unlabeled A in a reaction containing both free labeled A and the antibody thereto, will reduce the amount of labeled A that binds to the antibody. It is to be understood that specificity need not be absolute. For example, it is well known in the art that numerous antibodies cross-react with other epitopes in addition to those present in the target molecule. Such cross-reactivity may be acceptable depending upon the application for which the antibody is to be used. Thus the degree of specificity of an antibody will depend on the context in which it is being used. In general, an antibody exhibits specificity for a particular partner if it favors binding of that partner above binding of other potential partners. One of ordinary skill in the art will be able to select antibodies having a sufficient degree of specificity to perform appropriately in any given application (e.g., for detection of a target molecule, for therapeutic purposes, etc). It is also to be understood that specificity may be evaluated in the context of additional factors such as the affinity ofthe binding molecule for the target polypeptide versus the affinity ofthe binding molecule for other targets, e.g., competitors. If a binding molecule exhibits a high affinity for a target molecule that it is desired to detect and low affinity for nontarget molecules, the antibody will likely be an acceptable reagent for immunodiagnostic purposes. Once the specificity of a binding molecule is established in one or more contexts, it may be employed in other, preferably similar, contexts without necessarily re-evaluating its specificity.

Treating a tumor: As used herein, treating a tumor is taken to mean treating a subject who has the tumor.

Tumor sample: The term "tumor sample" as used herein is taken broadly to include cell or tissue samples removed from a tumor, cells (or their progeny) derived from a tumor that may be located elsewhere in the body (e.g., cells in the bloodstream or at a site of metastasis), or any material derived by processing such a sample. Derived tumor samples may include nucleic acids or proteins extracted from the sample or obtained by subjecting the sample to techniques such as amplification or reverse transcription of mRNA, etc.

Tumor subclass: A tumor subclass, also referred to herein as a tumor subset or tumor class, is the group of tumors that display one or more phenotypic or genotypic characteristics that distinguish members ofthe group from other tumors.

Vector: A vector, as used herein, is a nucleic acid molecule that includes sequences sufficient to direct in vivo or in vitro replication ofthe molecule. These may either be self-replication sequences or sequences sufficient to direct integration ofthe vector into another nucleic acid present in a cell (either an endogenous nucleic acid or one introduced into the cell by experimental manipulation), so that the vector sequences are replicated during replication of this nucleic acid. Preferred vectors include a cloning site, at which foreign nucleic acid molecules may be introduced. Vectors may include control sequences that have the ability to direct in vivo or in vitro expression of nucleic acid sequences introduced into the vector. Such control sequences may include, for example, transcriptional control sequences (e.g., promoters, enhancers, terminators, etc.), splicing control sequences, translational control sequences, etc. Vectors may also include a coding sequence, so that transcription and translation of sequences introduced into the vector results in production of a fusion protein.

I. Overview

The invention is based on the identification of polynucleotides (cDNAs) corresponding to human genes that are differentially expressed in human breast tumor samples, the polypeptides encoded by these polynucleotides, and antibodies raised against these polypeptides. The invention encompasses the use of these polynucleotides, polypeptides, and antibodies as well as compositions containing them, either singly or in combination, in the prediction, diagnosis, treatment, or prevention of cancer and in the provision of prognostic and predictive information related to cancer.

Nucleic acids encoding BSTP-Ras/Rerg were identified based on expression profiles gathered in a series of cDNA microarray experiments. As described in more detail in Examples 1, 2, and 4, cDNA microarrays each representing the same set of approximately 8100 different human genes were produced. The human cDNA clones used to produce the microarrays contained approximately 4000 named genes, 2000 genes with homology to named genes in other species, and approximately 2000 ESTs of unknown function. An mRNA sample was obtained from each of a set of 84 tissue samples or cell lines. The expression levels ofthe approximately 8100 genes were measured in each mRNA sample by hybridization to an individual microarray, yielding an expression profile for each gene across the experimental samples. These expression profiles were studied and compared and were used to identify nucleic acids encoding BSTP-Ras/Rerg. Although more details will be found in the Examples, a description of cDNA microarray technology and a description ofthe experimental approach employed in the identification ofthe polynucleotides that encode BSTP- Ras/Rerg is presented here so that the invention may be better understood. Certain aspects ofthe invention are then described in detail.

II. cDNA Microarray Technology cDNA microarrays consist of multiple (usually thousands) of different cDNAs spotted (usually using a robotic spotting device) onto known locations on a solid support, such as a glass microscope slide. After spotting, the cDNAs are usually cross-linked to the support, e.g., by UV irradiation. The cDNAs are typically obtained by PCR amplification of plasmid library inserts using primers complementary to the vector backbone portion ofthe plasmid or to the gene itself for genes where sequence is known. PCR products suitable for production of microarrays are typically between 0.5 and 2.5 kB in length. Full length cDNAs, expressed sequence tags (ESTs), or randomly chosen cDNAs from any library of interest can be chosen. ESTs are partially sequenced cDNAs as described, for example, in L. Hillier, et al., Generation and analysis of

280,000 human expressed sequence tags, Genome Research, 6, 807-828, 1996. The afore-mentioned article is herein incorporated by reference, as are the entire teachings of all other patents and journal articles mentioned herein, for all purposes and not just those related to the particular context in which they are mentioned. Although some ESTs correspond to known genes, frequently very little or no information regarding any particular EST is available except for a small amount of 3' and/or 5' sequence and, possibly, the tissue of origin ofthe mRNA from which the EST was derived. As will be appreciated by one of ordinary skill in the art, in general the cDNAs contain sufficient sequence information to uniquely identify a gene within the human genome. Furthermore, in general the cDNAs are of sufficient length to hybridize specifically to cDNA obtained from mRNA derived from a single gene under the hybridization conditions ofthe experiment.

In a typical microarray experiment, a microarray is hybridized with differentially labeled RNA or DNA populations derived from two different samples. Most commonly RNA (either total RNA or poly A⁺ RNA is isolated from cells or tissues of interest and is reverse transcribed to yield cDNA. Labeling is usually performed during reverse transcription by incorporating a labeled nucleotide in the reaction mixture. Although various labels can be used, most commonly the nucleotide is conjugated with the fluorescent dyes Cy3 or Cy5. For example, Cy5- dUTP and Cy3-dUTP can be used. cDNA derived from one sample (representing, for example, a particular cell type, tissue type or growth condition) is labeled with one fluor while cDNA derived from a second sample (representing, for example, a different cell type, tissue type, or growth condition) is labeled with the second fluor. Similar amounts of labeled material from the two samples are cohybridized to the microarray. In the case of a microarray experiment in which the samples are labeled with Cy5 (which fluoresces red) and Cy3 (which fluoresces green), the primary data (obtained by scanning the microarray using a detector capable of quantitatively detecting fluorescence intensity) are ratios of fluorescence intensity (red/green, R G). These ratios represent the relative concentrations of cDNA molecules that hybridized to the cDNAs represented on the microarray and thus reflect the relative expression levels ofthe mRNA corresponding to each cDNA/gene represented on the microarray.

Each microarray experiment can provide tens of thousands of data points, each representing the relative expression of a particular gene in the two samples. Appropriate organization and analysis ofthe data is of key importance. Various computer programs have been developed to facilitate data analysis. One basis for organizing gene expression data is to group genes with similar expression patterns together into clusters. A method for performing hierarchical cluster analysis and display of data derived from microarray experiments is described in Eisen, M., Spellman, P., Brown, P., and Botstein, D., Cluster analysis and display of genome- wide expression patterns, Proc. Natl. Acad. Sci. USA, 95: 14863-14868, 1998. As described therein, clustering can be combined with a graphical representation ofthe primary data in which each data point is represented with a color that quantitatively and qualitatively represents that data point. By converting the data from a large table of numbers into a visual format, this process facilitates an intuitive analysis ofthe data. Additional information and details regarding the mathematical tools and/or the clustering approach itself may be found, for example, in Sokal, R.R. & Sneath, P.H.A. Principles of numerical taxonomy, xvi, 359, W. H. Freeman, San Francisco, 1963; Hartigan, J.A. Clustering algorithms, xiii, 351, Wiley, New York, 1975; Paull, K.D. et al. Display and analysis of patterns of differential activity of drugs against human tumor cell lines: development of mean graph and COMPARE algorithm. JNatl Cancer Inst 81, 1088-92,1989; Weinstein, J.N. et al. Neural computing in cancer drug development: predicting mechanism of action. Science 258, 447-51, 1992; van Osdol, W.W., Myers, T.G., Paull, K.D., Kohn, K.W. & Weinstein, J.N. Use ofthe Kohonen self- organizing map to study the mechanisms of action of chemotherapeutic agents. JNatl Cancer Inst 86, 1853-9, 1994; and Weinstein, J.N. et al. An information-intensive approach to the molecular pharmacology of cancer. Science, 275, 343-9, 1997.

Further details ofthe experimental methods used in the present invention are found in the Examples. Additional information describing methods for fabricating and using microarrays is found in U.S. Patent No. 5,807,522, which is herein incorporated by reference. Instructions for constructing microarray hardware (e.g., arrayers and scanners) using commercially available parts can be found at http://cmgm.stanford.edu/pbrown/ and in Cheung, V., Morley, M., Aguilar, F., Massimi, A., Kucherlapati, R., and Childs, G., "Making and reading microarrays", Nature Genetics Supplement, 21:15-19, 1999. Additional discussions of microarray technology and protocols for preparing samples and performing microrarray experiments are found in, for example, DNA arrays for analysis of gene expression, Methods Enzymol, 303:179-205, 1999; Fluorescence-based expression monitoring using microarrays, Methods Enzymol, 306: 3-18, 1999; and M. Schena (ed.), DNA Microarrays: A Practical Approach, Oxford University Press, Oxford, UK, 1999. Descriptions of how to use an array er and the associated software are found at http://cmgm.stanford.edu/pbrown/mguide/arrayerHTML/ArrayerDocs.html, which is herein incorporated by reference.

III. Experimental Approach ofthe Invention

The present invention encompasses the realization that genes that are differentially expressed in tumors are of use in tumor classification and are targets for the development of diagnostic and therapeutic agents. Differentially expressed genes are likely to be responsible for the different phenotypic characteristics of tumors. The present invention identifies one such gene. In general, a differentially expressed gene is a gene whose transcript abundance varies between different tumor samples. For example, and without intending to be limiting, the transcript level of a differentially expressed gene may vary by at least fourfold from its average abundance in a given sample set in at least 1 sample, at least two samples, at least three samples, etc. Of course other criteria for differential expression may be employed.

While analysis of multiple genes is of use in developing a robust classification of tumors, each ofthe differentially expressed genes and their encoded proteins is a target for the development of diagnostic and therapeutic agents. Investigation of variation in individual genes in breast tumors reveals that molecular variation can be related to important features of clinical variation. For example, expression ofthe estrogen receptor alpha gene (ESR1), the Erb-B2/HER2/neu oncogene (the target for the monoclonal antibody Herceptin^® (Trastuzumab), a recently approved treatment for certain patients with metastatic breast cancer), and the mutational status at the TP53, BRCA1 and BRCA2 loci have shown that molecular variation can be related to important features of clinical variation. (Discussed, for example, in Osborne, C.K., et ah, The value of estrogen and progesterone receptors in the treatment of breast cancer, Cancer 46, 2884-2888, 1980; Ingvarsson, S., Molecular genetics of breast cancer progression, Seminars in Cancer Biology, 9, 277-288, 1999; Breast Cancer Linkage Consortium, Pathology of familial breast cancer: differences between breast cancers in carriers of BRCA1 andBRCA2 mutations and sporadic cases, Lancet, 349, 1505-1510, 1997; Anderson, T. I., et al., Prognostic significance of TP53 alterations in breast carcinoma. Br J Cancer, 68, 540-548, 1993 and references cited in these articles). In particular, approximately 60% to 70% of breast tumors express the estrogen receptor, and this expression has been shown to be a favorable prognostic factor (reviewed in Alfred, D.C., et al. Prognostic and Predictive Factors in Breast Cancer by Immunohistochemical Analysis, Modern Pathology, 11(2), 155-168, 1998). As these examples demonstrate, the study of genetic variation in breast cancer has the potential to contribute to improved classification, diagnosis, and therapy for patients.

As described in more detail in Examples 1, 2, and 4, in order to identify genes that are differentially expressed in breast tumors, cDNA microarrays each representing the same set of approximately 8100 different human genes were produced. The human cDNA clones used to produce the microarrays contained approximately 4000 named genes, 2000 genes with homology to named genes in other species, and approximately 2000 ESTs of unknown function. An mRNA sample was obtained from each of a set of 84 tissue samples or cell lines. The expression levels of the approximately 8100 genes were measured in each mRNA sample by hybridization to an individual microarray, yielding an expression profile for each gene across the experimental samples. Although more details will be found in the Examples, an overview ofthe experimental procedure is presented here so that the invention may be better understood.

Variation in patterns of gene expression were characterized in 62 breast tumor samples from 40 different patients, 3 normal breast tissue samples, and 19 samples from 17 cultured human cell lines (one of which was sampled 3 times under different conditions). Twenty ofthe tumors had been sampled twice, before and after a 16 week course of doxorubicin chemotherapy, and two tumors were paired with a lymph node metastasis from the same patient. The other 18 tumor samples were single samples from individual tumors. A detailed listing ofthe tumor samples and various characteristics including clinical estrogen receptor and Erb-B2 status as assessed using antibody staining, estrogen receptor and Erb-B2 status as assessed by microarray result, tumor grade, differentiation, survival status and time, age at diagnosis, doxorubicin response, and p53 status is presented in Table 5 ofthe gene subset application. A listing ofthe cell lines including description and ATCC (American Tissue Culture Collection) number or reference is presented in Table 3 ofthe gene subset application. The cell lines provided a framework for interpreting the variation in gene expression patterns seen in the tumor samples and included gene expression models for many ofthe cell types encountered in tumors.

As described in more detail in Example 2, mRNA was isolated from each sample. cDNA labeled with the fluorescent dye Cy5 was prepared from each experimental sample separately. Fluorescently labeled cDNA, labeled using a second distinguishable dye (Cy3), was prepared from a pool of mRNAs isolated from 11 different cultured cell lines. The pooled mRNA sample served as a reference to provide a common internal standard against which each gene's expression in each experimental sample was measured.

Comparative expression measurements were made by separately mixing Cy5- labeled experimental cDNA derived from each ofthe 84 samples with a portion ofthe Cy3 -labeled reference cDNA, and hybridizing each mixture to an individual cDNA microarray. The ratio of Cy5 fluorescence to Cy3 fluorescence measured at each cDNA element on the microarray was then quantitatively measured. The use of a common reference standard in each hybridization allowed the fluorescence ratios to be treated as comparative measurements ofthe expression level of each gene across all the experimental samples. A hierarchical clustering method (Eisen, et al, 1998) was used to group genes based on similarity in the pattern with which their expression varied over all experimental samples. The same clustering method was used to group the experimental samples (tissue and cell lines separately) based on the similarity in their patterns ofexpression. Interpretation ofthe data obtained from the clustering algorithm was facilitated by displaying the data in the form of tumor and gene dendrograms. In the tumor dendrograms, the pattern and length ofthe branches reflects the relatedness ofthe tumor samples with respect to their expression of genes represented on the microarray. Microarray images may be found in Perou, et al, Nature, 2000, and on inventors' Web site (http://genome- www.stanford.edu/molecularportraits/).

The similarity ofthe gene expression profiles of individual tumor samples or groups of tumor samples to one another is inversely related to the length ofthe branches that connect them. Thus, for example, adjacent tumor samples connected to one another by short vertical branches descending from a common horizontal branch (e.g., tumor samples Norway 48-BE and Norway 48-AF close to the right ofthe tumor dendrogram) are more closely related to one another in terms of their gene expression profiles than adjacent tumor samples connected to one another by longer vertical branches descending from a common horizontal branch (e.g., tumor samples Norway 100-BE and Norway 100-AF at the left side ofthe tumor dendrogram). To the extent that the gene expression programs dictate the biological properties and behavior ofthe tumors and reflect their physiological state and environment, it is expected that the clustering ofthe tumors reflects phenotypic relationships among them, e.g., tumor samples connected by short horizontal branches (i.e., located in close proximity to one another) are expected to exhibit similar phenotypic features. In the gene dendrograms, the pattern and length ofthe branches reflects the relatedness ofthe genes with respect to their expression profiles across the tumor samples. Similarly to the tumor samples, genes connected by short vertical branches are more similar to one another in terms ofexpression profile than genes connected by longer vertical branches.

The expression patterns ofthe genes were also displayed using a matrix format, with each row representing all ofthe hybridization results for a single cDNA element on the array and each column representing the measured expression levels for all genes in a single sample. In this format, tumor samples with similar patterns of expression across the gene set are close to each other along the horizontal dimension. Similarly, genes with similar expression patterns across the set of samples are close to each other along the vertical dimension. To allow the patterns ofexpression to be visualized, the normalized expression value of each gene was represented by a colored box, using red to represent expression levels greater than the median and green to represent expression levels less than the median. In all microarray images, the brightest red color represents transcript levels at least 16-fold greater than the median, and the brightest green color represents transcript levels at least 16-fold below the median. This display format facilitates comparisons between genes and the recognition of significant patterns. Certain gene subsets of particular interest are indicated by colored bars along the right side ofthe matrices. These subsets are discussed further in the gene subset application.

IV. Identification of BSTP-Ras/Rerg and Studies Thereof A. Identification of BSTP-Ras/Rerg

I.M.A.G.E. clone 503581 was identified based on the expression pattern of its corresponding mRNA among the 84 samples analyzed by microarray hybridization. In particular, transcripts corresponding to clone 503581 varied in abundance by at least 4-fold from their median abundance in the sample set, among at least 3 ofthe 84 samples. Thus the polynucleotide corresponding to clone 503581 was differentially expressed among the tumor samples, indicating its potential utility for classifying tumors. Numerical data indicating the measured expression of mRNA corresponding to clone 503581 (i.e., mRNA hybridizing to clone 503581) appear in Table 1. In addition, the expression profile and additional data related to clone 503581 are available at Applicants' Web site (http.V/genome- www.stanford.edu/molecularportraits/). As shown therein, the expression level of mRNA corresponding to clone 503581 varied significantly among tumor samples. For example, mRNA corresponding to clone 503581 was particularly highly expressed in tumor samples Norway 27-BE, Norway 27-AF, and Stanford 24. The relative expression level was also high in tumors Norway 100-BE, Norway 100-AF, Norway 111, and Norway 19, among others. However, the relative expression level of mRNA corresponding to clone 503581 was particularly low in tumor sample Norway 14-BE and was also low in tumor samples Norway 109-BE, Norway 109-AF, Norway 101 -BE, Stanford 2-LN, among others. As is evident from the discussion above, the presence of mRNA corresponding to clone 503581 reflects the expression ofthe gene from which the mRNA is transcribed.

The expression profile of mRNA corresponding to clone 503581 was particularly noteworthy in that it closely resembled that ofthe estrogen receptor 1 (ESR1) gene. Previous studies have demonstrated genes that have similar patterns of expression when measured across many samples of varying biology are significantly enriched for those genes that share roles in common biologic processes (DeRisi, et al, Iyer, et al., Ross, et al, Brown, et al., Spellman, et al, Eisen, et al). For example, Ross, et al. demonstrated that the pattern of gene expression measured across sixty unrelated cell lines identified a set of genes that varied in a manner correlated with the measured doubling time ofthe cell lines. The correlated set of genes was highly enriched for those genes known to play roles in transiting the cell cycle. However, the fine patterns of gene expression within the larger set that varied in a manner correlated with the variation in measured cell doubling time (approximately 1500 genes) distinguished genes involved in RNA splicing from those involved in protein translation. The subtle regulation of gene expression that differed between these sets of genes involved in similar but aspects of cell physiology and allowed accurate functional categorization of known genes and likely those genes of unknown function that share expression patterns. While not wishing to be bound by any theory, Applicants suggest that the measurement of gene expression across many breast tumor samples such as that described above is likely to identify genes that act in common physiologic processes that vary amongst the tumor samples. The co-variation of clone 503581 with the estrogen receptor gene suggests that these two genes (and potentially other genes that show similar patterns ofexpression in the microarray experiments described herein) might have common roles in breast physiology.

The similarity in the expression profiles of clone 503581 and ESRl is evident in the microarray images and in Table 1. For example, the relative expression level of ESRl was high in tumor samples Norway 27-BE, Norway 27-AF, Norway 100-BE and Norway 100-AF, among others, as was the expression of mRNA corresponding to clone 503581, and the relative expression level of ESRl was low in tumor samples Norway 14-BE, Norway 48-AF, and Stanford 2-LN. The similarity in the expression profiles ofthe gene corresponding to clone 503581 and ESRl is evidenced by the fact that the correlation coefficient (a well known measure of statistical similarity) between the dataset representing expression ofthe gene corresponding to clone 503581 and the dataset representing expression of ESRl is greater than the correlation coefficient between the dataset representing expression ofthe gene corresponding to clone 503581 and the dataset representing expression of any other gene among the genes represented on the microarray. In addition, the similarity in the expression profiles ofthe gene corresponding to clone 503581 and ESRl is confirmed by the results of application ofthe hierarchical clustering algorithm to the entire set of tumor samples analyzed. While not wishing to be bound by any theory, these results suggest that clone 503581 may share a role in biologic processes related to those in which the estrogen receptor is involved.

B. Cloning and Sequence Analysis of BST-Ras/Rerg

A search of Genbank revealed that only a small portion at the 3' end and a small portion at the 5' end of clone 503581 had been sequenced. Therefore, clone 503581 was sequenced and the full length sequence (SEQ ID NO: 3) was obtained. An overlapping clone (I.M.A.G.E. clone 28777) was identified by searching Genbank for clones homologous to clone 503581. A consensus nucleotide sequence, SEQ ID NO: 4 was derived based on sequencing and analysis of overlapping I.M.A.G.E. clone 28777. In SEQ ID NO: 3 and SEQ ID NO: 4, the abbreviation N stands for any nucleotide. The consensus sequence (SEQ ID NO: 4) was used as input for a search of Genbank with the BLASTX program (which translates a nucleotide sequence in each ofthe possible six reading frames and then searches for homologous amino acid sequences). The search indicated the presence of a region encoding an amino acid sequence with homology to the Ras family of small guanine nucleotide-binding (GTP- binding) proteins. A corresponding open reading frame (SEQ ID NO: 2) was identified within the consensus sequence. The predicted amino acid sequence for the polypeptide encoded by this open reading frame is presented as SEQ ID NO: 1. A full length cDNA encoding the polypeptide of SEQ ID NO:l, i.e., BSTP-Ras/Rerg, was assembled from the I.M.A.G.E. clones listed above and publicly available ESTs. The sequence ofthe full length cDNA is presented in Figure 2 as SEQ ID NO:5. Thus in one embodiment, the invention encompasses a polypeptide comprising the amino acid sequence of SEQ ID NO: 1. The polypeptide is 199 amino acids in length. As shown in Figure 3, a search ofthe GenBank database using the BLASTP computer program (Altschul, Stephen F., Thomas L. Madden, Alejandro A. Schaffer, Jinghui Zhang, Zheng Zhang, Webb Miller, and David J. Lipman (1997), "Gapped BLAST and PSI-BLAST: a new generation of protein database search programs", Nucleic Acids Res. 25:3389-3402) performed with this sequence indicated that this polypeptide displays a high level of homology with members ofthe Ras family, consistent with the information obtained from the BLASTX search described above.

As discussed below, expression ofthe gene encoding the polypeptide of SEQ ID NO:l is regulated by estrogen, and the polypeptide exhibits growth-inhibitory effects. For these reasons the gene that encodes the polypeptide of SEQ ID NO: 1 is also known as Rerg (Ras-related and estrogen-regulated growth-inhibitory gene), and the polypeptide is known as Rerg. To reflect these names, the polypeptide comprising the amino acid sequence presented in SEQ ID NO:l will be referred to herein interchangeably as BSTP-Ras, BSTP-Ras/Rerg, or Rerg, and the gene encoding the polypeptide will be referred to herein interchangeably as BST-RAS, BST-RAS/Rerg, or

Rerg. The BST-RAS/Rerg gene is located on chromosome 12 within two overlapping

BAC clones (AC007543 and AA022334) and is in close proximity to the K-Ras gene.

The gene is spread out over approximately 110 kB of genomic DNA and is contained in four exons. The first exon of at least 170 bp is separated from the second 57 base pair exon by an intron of over 95 kB. While the cloned cDNA sequence starts at position -109 relative to the putative initiator methionine, the predicted transcription start site as determined from analysis ofthe genomic sequence suggests that the actual start site may be at position -780. Analysis ofthe BST-RAS/Rerg gene sequence identified two consensus ER binding sites within the 5' upstream region.

GTP-binding proteins play a key role in cell cycle control and also in a number of other physiological and regulatory processes including cell signaling, growth, differentiation, protein synthesis, and cytoskeletal dynamics, and cell movement. For example, Ras proteins play a major role in transducing extracellular signals to the nucleus to stimulate cell proliferation or differentiation. The Ras proteins belong to the large Ras superfamily of monomeric GTPases, which also contains three other subfamilies: (1) the Rho and Rac proteins, which transduce signals from receptors on the cell surface to the actin cytoskeleton; (2) the Rab family, involved in regulating the movement of intracellular transport vesicles; and (3) the Ran family, involved in the regulation of cell cycle progression, nuclear envelope structure and function, and nucleocytoplasmic transport. Despite sequence differences between subfamily members, Ras-related

GTPases contain five highly conserved domains (G1-G5) and function as guanine- nucleotide-dependent molecular switches. Recently several novel Ras-related GTPases have been identified that exhibit amino acid sequence features that distinguish them from Ras proteins (reviewed in Reuther, G. W., and Der, C. J., Curr Opin Cell Biol 12(2), 157-65, 2000). These include ARH1, an imprinted tumor suppressor gene in breast and ovarian carcinomas; expression of ARH1 in cancer cells inhibited cell growth and was associated with down-regulation of cyclin Dl promoter activity and induction of p21 ^{AF1 CIP1} (Yu, Y., Xu, F., Peng, H., Fang, X., Zhao, S, Li, Y., Cuevas, B., Kuo, W. L., Gray, J. W., Siciliano, M., Mills, G. B., and Bast, R. C, Jr., Proc Natl Acad Sci USA 96(1), 214-9, 1999).

Like other monomeric GTP-binding proteins and G proteins, Ras functions as a molecular switch, cycling between two conformational states: a GTP-bound active form and an inactive GDP-bound form (Bourne, H. R., Sanders, D. A., and McCormick, F. (1991) Nature 349(6305), 117-27). Transitions between these states are regulated by two classes of proteins. GTPase-activating proteins (GAPs) inactivate Ras by increasing the rate of hydrolysis of bound GTP by Ras. Guanine nucleotide releasing proteins (GNRPs) stimulate the exchange of bound GDP for GTP, thus leading to activation of Ras. GAPs and GNRPs are regulated, either directly or indirectly, through interactions with receptor and nonreceptor tyrosine kinases. GTP-bound Ras is active and capable of interacting (e.g.,via a Ras effector domain) with downstream effectors such as the kinases Raf and phosphatidyl inositol (3) kinase, which leads to a signal transduction cascade involving proteins ofthe mitogen-activated protein (MAP) kinase family (among others) that ultimately modulates the activity of transcription factors in the nucleus. Additional information on Ras and other members ofthe Ras superfamily may be found, for example, in Rommel, C. and Hafen, C, Ras - a versatile cellular switch, Curr. Op. Genet. & Dev., 8: 412-418, 1998 and references therein, and in Hesketh, Robin, The Oncogene and Tumor Suppressor Gene Factsbook (Factsbook Series), 2^nd edition, Academic Press, San Diego, 1997).

Mutations in genes ofthe Ras family play a significant role in a variety of cancer types including cancers ofthe lung, pancreas, colon, and myeloid systems and various other organs. In general, mutations that convert a normal Ras gene into an oncogenic (cancer-causing) form result in activation ofthe protein, e.g., by locking it in the GTP-bound state. An extensive discussion of Ras and the role of mutated Ras genes in cancer may be found in Franz Watzinger, Thomas Lion, "RAS family", Atlas Genet Cytogenet Oncol Haematol, March 1999, which is reproduced at http://www.infobiogen.fr/services/chromcancer/Deep/ras.html. Activating Ras mutations can be found in human malignancies with an overall frequency of 15-20%. The three human Ras family members that have been most widely associated with cancer are known as H-Ras, K-Ras, and N-Ras. A high incidence of Ras gene mutations has been reported in malignant tumors ofthe pancreas (80-90%, K-ras) (Almoguera C et al. Most human carcinomas ofthe exocrine pancreas contain mutant c-K-ras genes. Cell 53: 549, 1988; Smit VT et al. K-RAS codon 12 mutations occur very frequently in pancreatic adenocarcinomas. Nucleic Acids Res, 16: 7773, 1988), in colorectal carcinomas (30-60%, K-ras) (Breivik J et al. K-ras mutation in colorectal cancer: relations to patient age, sex and tumour location. Br J Cancer 1994; 69: 361, 1994; Spandidos DA et al. Ras oncogene activation in benign and malignant colorectal tumours. Tumor , 81(3 Suppl):7, 1995), in lung (25-60%, K-ras) (HusgafVel-Pursiainen K et al. Detection of ras gene mutations in human lung cancer: comparison of two screening assays based on the polymerase chain reaction. Environ Health Perspect 98: 183-5: 183, 1992; Rodenhuis S, Slebos RJ. Clinical significance of ras oncogene activation in human lung cancer. Cancer Res, 52: 2665s, 1992; Sagawa M et al. K-ras point mutation occurs in the early stage of carcinogenesis in lung cancer. BrJ Cancer 11: 720, 1998) in hematopoietic neoplasia of myeloid origin (18-30%), K-and N-ras) (Nakagawa T et al. Multiple point mutation of N-ras and K-ras oncogenes in myelodysplastic syndrome and acute myelogenous leukemia. Oncology 1992; 49: 114, 1992; Neubauer A et al. Prognostic importance of mutations in the ras proto-oncogenes in de novo acute myeloid leukemia. Blood, 83: 1603, 1994). Ras mutation or overexpression has also been implicated in breast cancer (Miyakis, S. et al., Differential expression and mutation ofthe ras family genes in human breast cancer, Biochem Biophys Res Commun, 251(2):609, 1998; Rochlitz CF et al. Incidence of activating ras oncogene mutations associated with primary and metastatic human breast cancer. Cancer Res 49: 357, 1989; Spandidos DA. Oncogene activation in malignant transformation: a study of H-ras in human breast cancer. Anticancer Res; 1: 99, 1987). It is noted that the term "activity" in reference to Ras family members may refer to either the biological activity or activities ofthe protein, e.g., its effects on some aspect ofthe phenotype of a cell or organism, or to particular biochemical activities of binding GTP or hydrolyzing GTP. Thus reference to an increase or decrease in Ras "activity" can be ambiguous unless it is understood which activity is being referred to, which can usually be ascertained from the context. In general, unless otherwise stated, a reference to Ras "activity" herein refers to the effect ofthe Ras protein on cell or organism phenotype rather than to a particular biochemical activity. For example, the increased activity of 'activated' H-Ras proteins refers to an increased ability to enhance cell proliferation and/or tumorogenicity. Such activation is mediated by Ras mutants that have reduced GTPase activity. Conversely, increased activity of BSTP-Ras/Rerg refers to increased ability to inhibit cell proliferation and/or tumorigenicity. Such activation may be mediated by BSTP-Ras/Rerg mutants or variants that have reduced GTPase activity. The growth inhibitory activity demonstrated in Figure 8 is consistent with the biologic activity of other Ras family members thathave been implicated directly in second messanger pathways that regulate cell growth. However, the specific pathways modulated by BSTP-Ras/Rerg remain to be defined and may include activities whose secondary effect is modulation of cellular growth.

Figure 6 presents an alignment of BSTP-Ras/Rerg with several other Ras family members. The alignment was performed with the CLUSTAL W1.6 program (Thompson, J. D., Higgins, D. G., and Gibson, T. J., Nucleic Acids Res 22(22), 4673- 80, 1994). Hyphens represent gaps introduced for optimal alignment. Numbers are residue numbers. Amino acid residues that were conserved in at least four ofthe five proteins in the alignment are placed in shaded boxes and amino acid similarity is indicated by line boxes. Consensus sequences for GTP-binding regions (G1-G5) (heavy overline) and the position of conserved C AAX motif (dashed underline) are labeled and highlighted. Similar alignments with other Ras family members can be readily obtained, thus providing additional information about which sites in BSTP- Ras/Rerg correspond to well-studied sites in other Ras proteins.

The predicted amino acid sequence ofthe Rerg protein is 50% and 47% identical to the Dictyostelium Ras-D and Ras-S proteins respectively, and 44% to 45% identical to human Rit, TC21/R-Ras2, M-Ras/R-Ras3, Rin, and Raplb. Although Rerg shares significant sequence identity and organization with Ras, it also contains a number of unique features. First, Rerg has an alanine at the position corresponding to the glycine at position 12 of Ras. Substitution of this residue with alanine results in the constitutive activation of Ras (Barbacid, M. (1987) Annu Rev Biochem 56, 779- 827). Another unique feature of Rerg is that it lacks any known COOH-terminal prenylation motif suggesting that it is not subject to post-translational prenylation (Casey, P. J., and Seabra, M. C. (1996) JBiol Chem 271(10), 5289-92; Glomset, J. A., and Farnsworth, C. C. (1994) Annu Rev Cell Biol 10, 181-205). Prenylation facilitates the association of Ras with the plasma membrane and nonprenylated mutants of Ras are rendered completely inactive. Instead, stretches of basic residues are found in the Rerg COOH-terminal region. These unique COOH-terminal features of Rerg are similar to those of Rit and Rin (Wes, P. D., Yu, M., and Montell, C, Embo J 15(21), 5839-48, 1996; Lee, C. H., Delia, N. G., Chew, C. E., and Zack, D. J., JNeurosci 16(21), 6784-94, 1996).

C. Biological Characterization of BSTP-Ras/Rerg While not wishing to be bound by any theory, as discussed in Examples 12 and 13, the BST-RAS/Rerg gene and its encoded polypeptide display various characteristics that suggest a role for BSTP-Ras/Rerg in inhibiting cell growth and/or tumor development or growth. As demonstrated in Example 12, both stable and transient over-expression of BSTP-Ras/Rerg in MCF-7 cells inhibited their proliferation. Based on the results of two widely used assays for oncogenicity (colony growth in soft agar and tumor formation in nude mice), cells overexpressing BSTP- Ras/Rerg have significantly reduced tumorigenicity. MCF-7 cells stably overexpressing BSTP-Ras/Rerg showed greatly reduced colony forming efficiency (50-80%) reduction) in soft agar as compared to control MCF-7 cells not overexpressing BSTP-Ras/Rerg. Furthermore, as demonstrated in Example 13, MCF- 7 cells stably overexpressing BSTP-Ras/Rerg at high levels showed decreased tumorigenicity in nude mice as compared to control MCF-7 cells in that nude mice injected with MCF-7 cells overexpressing BSTP-Ras/Rerg at high levels remained tumor free for significantly longer than mice injected with control MCF-7 cells.

In addition to the biological data in cell lines and animals, the expression of BST-RAS/Rerg across the tumor samples was compared with the expression pattern of the "proliferation" cluster of genes described in more detail in copending U.S. Patent Application "Reagents and Methods for Use in Managing Breast Cancer, filed July 26, 2001 and in U.S. Provisional Patent Application Ser. No. 60/220,967, filed July 26, 2000. As described therein, the "proliferation" cluster is a group of approximately 120 genes whose level ofexpression correlates with cellular proliferation rates (See Perou, C, et al, 1999; Ross, D., et al, Nature Genetics, 24(3): 227-35, 2000.). Expression of this subset of genes varied widely among the tumor samples, and was generally well correlated with a standard pathological index of tumor cell proliferation, namely the mitotic index. Tumors that most highly express BST- RAS/Rerg tend to be the least proliferative, and the ones with low to no BST-RAS/Rerg expression tend to be the most proliferative. BST-RAS/Rerg expression was decreased or lost in a significant percentage of tumors that show a poor clinical prognosis. BST- RAS/Rerg is a member ofthe "luminal epithelial/ER+" gene cluster, which contains most ofthe genes whose high expression was associated with a good prognosis (i.e., long survival times). The luminal gene subset includes a number of genes known to be expressed in luminal epithelial cells ofthe normal mammary gland (e.g., the ER and the prolactin receptor) and is characterized in that certain ofthe genes in the subset are overexpressed at the RNA level in samples obtained from a subset of tumors that had a good prognosis relative to the entire group of tumors (the luminal group is further described in copending U.S. Patent Application "Reagents and Methods for Use in Managing Breast Cancer, filed July 26, 2001 and in U.S. Provisional Patent Application Ser. No. 60/220,967, filed July 26, 2000). The luminal gene subset is identified with a purple bar along the side ofthe color matrix in part b and is shown in expanded form in part c. The clones that identify the genes in the luminal subset are listed by their Genbank accession numbers in Table 8.

Thus a number of lines of evidence indicate that BSTP-Ras/Rerg has growth- inhibitory effects. The invention therefore provides methods for inhibiting growth of a cell comprising increasing the activity of BSTP-Ras/Rerg. In certain embodiments ofthe invention the methods comprise increasing the GTP-binding activity and/or decreasing the GTPase activity of BSTP-Ras/Rerg. Increasing the GTP-binding activity and/or decreasing the GTPase activity of BSTP-Ras/Rerg can be accomplished in any of a variety of ways. For example, these effects may be achieved by making certain mutations in the BSTP-Ras/Rerg coding sequence. Such mutations may be made based on the homology of BSTP-Ras/Rerg with other Ras family members. The mutations may be made and tested in vitro, e.g., in an expression construct, which may then be introduced into the cell. The effects can also be achieved by contacting BSTP-Ras/Rerg with a compound that activates or inhibits BSTP-Ras/Rerg level or activity. Methods for identifying such compounds are described above. Methods for early detection of cancer by screening for mutations in Ras genes are currently being explored (K-ras mutation: early detection in molecular diagnosis and risk assessment of colorectal, pancreas, and lung cancers—a review, Cancer Detect Prev. 24(1):1-12, 2000). Ras proteins are also targets for the development of new therapeutic agents for cancer Taveras, AG, et al., Bioorg Med Chem Ras oncoprotein inhibitors: the discovery of potent, Ras nucleotide exchange inhibitors and the structural determination of a drug-protein complex, 5(l):125-33, 1997. In addition, as mentioned above, the gene expression profile ofthe gene encoding BSTP- Ras Rerg (i.e., BST-RAS/Rerg) closely parallels the expression profile ofthe estrogen receptor gene ESRl. As is well known in the art, tumors that express the estrogen receptor (ER) have a better prognosis than tumors that do not express ER (reviewed in Alfred, D.C., et al). In addition, measurement of estrogen receptor levels in breast tumor samples is used clinically for prognostic and therapeutic decisions. Since the expression profile ofthe BST-RAS/Rerg gene closely resembles that ofthe estrogen receptor gene, determining the expression of BST-RAS/Rerg may be used to provide prognostic information for breast cancer patients. Determining the expression of BST- RAS/Rerg may include measuring mRNA transcribed from BST-RAS/Rerg, e.g., mRNA comprising a nucleotide sequence set forth in SEQ ID NO:2, 3, 4, SEQ ID NO:5, or portions or variants thereof. Such measurements can be made using a variety of techniques including, but not limited to, Northern analysis and microarray hybridization. Determining the expression of BST-RAS/Rerg may include detecting (qualitatively or quantitatively) a translation product of BST-RAS/Rerg, e.g., a polypeptide comprising an amino acid sequence set forth in SEQ ID NO:l or a polypeptide having significant similarity to the polypeptide of SEQ ID NO:l . A wide variety of methods for detecting and measuring protein levels are known in the art. For example, the detecting can be performed using immunohistochemistry or other antibody-based approaches including Western blots, use of antigen-antibody protein arrays, etc.

The discovery and characterization of BSTP-Ras/Rerg and the discovery ofthe differential expression ofthe gene encoding BSTP-Ras/Rerg satisfy a need in the art by providing compositions useful in the diagnosis, treatment, and prevention of cancer and by providing methods useful in the classification of cancer, the provision of prognostic information to patients with cancer, and the identification of new compounds for inhibiting cell growth and for the treatment of cancer. BST-RAS/Rerg shares a pattern ofexpression similar to the estrogen receptor gene, a gene known to play a role in growth control of normal and tumor breast cells, and already targeted for inhibition in both prevention and treatment of breast cancer. Overexpression of BSTP-Ras/Rerg inhibits cell growth in vitro and tumor formation in an animal model. These results suggest that BST-RAS/Rerg may be a useful gene to target for therapeutic intervention in subsets of breast cancer and a useful gene to distinguish between different subsets of breast cancer.

V. Further Aspects ofthe Invention

A. Polynucleotides, polypeptides, antibodies, vectors, and host cells The invention also encompasses polypeptides possessing significant similarity to BSTP-Ras/Rerg, i.e., polypeptides whose sequence possesses signficant similarity to the sequence of SEQ ID NO: 1. In certain embodiments ofthe invention a significantly similar polypeptide is encoded by a human gene. Definitions of "significantly similar" make reference to the BLAST algorithm and BLOSUM substitution matrix, which are described in Altschul, SF, et al., "Gapped BLAST and PSI-BLAST: a new generation of protein database search programs", Nucleic Acids Res. 25:3389-3402, 1997 and Henikoff, S. and Henikoff, J., "Amino acid substitution matrices from protein blocks", Proc. Natl. Acad. Sci. 89, 10915-10919, 1992. In certain embodiments ofthe invention a polypeptide is considered significantly similar if, when the amino acid sequence ofthe polypeptide is compared with the amino acid sequence ofthe polypeptide of SEQ ID NO:l using the BLAST algorithm and the BLOSUM substitution matrix with default parameters, the result is a % identity greater than 60 or a % positive greater than 70 encompassing at least 25% ofthe length of SEQ ID NO:l, or both. In other embodiments ofthe invention a polypeptide is considered significantly similar if, when the amino acid sequence ofthe polypeptide is compared with the amino acid sequence ofthe polypeptide of SEQ ID NO:l using the BLAST algorithm and the BLOSUM substitution matrix with default parameters, the result is a % identity greater than 60 or a % positive greater than 70 encompassing at least 50% ofthe length of SEQ ID NO:l, or both. In other embodiments ofthe invention a polypeptide is considered significantly similar if, when the amino acid sequence ofthe polypeptide is compared with the amino acid sequence ofthe polypeptide of SEQ ID NO:l using the BLAST algorithm and the BLOSUM substitution matrix with default parameters, the result is a % identity greater than 60 or a % positive greater than 70 encompassing at least 75% ofthe length of SEQ ID NO: 1, or both. In other embodiments ofthe invention a polypeptide is considered significantly similar if, when the amino acid sequence ofthe polypeptide is compared with the amino acid sequence ofthe polypeptide of SEQ ID NO:l using the BLAST algorithm and the BLOSUM substitution matrix with default parameters, the result is a % identity greater than 60 or a % positive greater than 70 encompassing at least 90% ofthe length of SEQ ID NO:l, or both. In other embodiments ofthe invention a polypeptide is considered significantly similar if, when the amino acid sequence ofthe polypeptide is compared with the amino acid sequence ofthe polypeptide of SEQ ID NO:l using the BLAST algorithm and the BLOSUM substitution matrix with default parameters, the result is a % identity greater than 60 or a % positive greater than 70 encompassing at least 95% ofthe length of SEQ ID NO:l, or both. In other embodiments ofthe invention a polypeptide is considered significantly similar if, when the amino acid sequence ofthe polypeptide is compared with the amino acid sequence ofthe polypeptide of SEQ ID NO:l using the BLAST algorithm and the BLOSUM substitution matrix with default parameters, the result is a % identity greater than 70 or a % positive greater than 80 encompassing at least 25% ofthe length of SEQ ID NO:l, or both. In other embodiments ofthe invention a polypeptide is considered significantly similar if, when the amino acid sequence ofthe polypeptide is compared with the amino acid sequence ofthe polypeptide of SEQ ID NO:l using the BLAST algorithm and the BLOSUM substitution matrix with default parameters, the result is a % identity greater than 70 or a % positive greater than 80 encompassing at least 75% ofthe length of SEQ ID NO: 1, or both. In other embodiments ofthe invention a polypeptide is considered significantly similar if, when the amino acid sequence ofthe polypeptide is compared with the amino acid sequence ofthe polypeptide of SEQ ID NO:l using the BLAST algorithm and the BLOSUM substitution matrix with default parameters, the result is a % identity greater than 70 or a % positive greater than 80 encompassing at least 90% ofthe length of SEQ ID NO:l, or both. In other embodiments ofthe invention a polypeptide is considered significantly similar if, when the amino acid sequence ofthe polypeptide is compared with the amino acid sequence ofthe polypeptide of SEQ ID NO: 1 using the BLAST algorithm and the BLOSUM substitution matrix with default parameters, the result is a % identity greater than 70 or a % positive greater than 80 encompassing at least 95% ofthe length of SEQ ID NO:l, or both. In other embodiments ofthe invention a polypeptide is considered significantly similar if, when the amino acid sequence ofthe polypeptide is compared with the amino acid sequence ofthe polypeptide of SEQ ID NO:l using the BLAST algorithm and the BLOSUM substitution matrix with default parameters, the result is a % identity greater than 80 or a % positive greater than 90 encompassing at least 25% ofthe length of SEQ ID NO: 1, or both. In other embodiments ofthe invention a polypeptide is considered significantly similar if, when the amino acid sequence ofthe polypeptide is compared with the amino acid sequence ofthe polypeptide of SEQ ID NO:l using the BLAST algorithm and the BLOSUM substitution matrix with default parameters, the result is a % identity greater than 80 or a % positive greater than 90 encompassing at least 75% ofthe length of SEQ ID NO:l, or both. In other embodiments ofthe invention a polypeptide is considered significantly similar if, when the amino acid sequence ofthe polypeptide is compared with the amino acid sequence ofthe polypeptide of SEQ ID NO:l using the BLAST algorithm and the BLOSUM substitution matrix with default parameters, the result is a % identity greater than 80 or a % positive greater than 90 encompassing at least 90% ofthe length of SEQ ID NO: 1, or both. In other embodiments ofthe invention a polypeptide is considered significantly similar if, when the amino acid sequence ofthe polypeptide is compared with the amino acid sequence ofthe polypeptide of SEQ ID NO:l using the BLAST algorithm and the BLOSUM substitution matrix with default parameters, the result is a % identity greater than 80 or a % positive greater than 90 encompassing at least 95% ofthe length of SEQ ID NO: 1, or both.

In other embodiments ofthe invention a polypeptide is considered significantly similar if, when the amino acid sequence ofthe polypeptide is compared with the amino acid sequence ofthe polypeptide of SEQ ID NO: 1 using the BLAST algorithm and the BLOSUM substitution matrix with default parameters, the result is a % identity greater than 90 or a % positive greater than 95 encompassing at least 25% ofthe length of SEQ ID NO:l, or both. In other embodiments ofthe invention a polypeptide is considered significantly similar if, when the amino acid sequence ofthe polypeptide is compared with the amino acid sequence ofthe polypeptide of SEQ ID NO:l using the BLAST algorithm and the BLOSUM substitution matrix with default parameters, the result is a % identity greater than 90 or a % positive greater than 95 encompassing at least 75% ofthe length of SEQ ID NO:l, or both. In other embodiments ofthe invention a polypeptide is considered significantly similar if, when the amino acid sequence ofthe polypeptide is compared with the amino acid sequence ofthe polypeptide of SEQ ID NO:l using the BLAST algorithm and the BLOSUM substitution matrix with default parameters, the result is a % identity greater than 90 or a % positive greater than 95 encompassing at least 90% ofthe length of SEQ ID NO:l, or both. In other embodiments ofthe invention a polypeptide is considered significantly similar if, when the amino acid sequence ofthe polypeptide is compared with the amino acid sequence ofthe polypeptide of SEQ ID NO: 1 using the BLAST algorithm and the BLOSUM substitution matrix with default parameters, the result is a % identity greater than 90 or a % positive greater than 95 encompassing at least 95% ofthe length of SEQ ID NO:l, or both. By "encompassing at least X% ofthe length of SEQ ID NO: 1 " (or, in general, SEQ ID NO:Y) is meant that the length ofthe portion of SEQ ID NO:l that is being compared with a potentially similar protein is at least X% ofthe length of SEQ ID NO: 1 (or, in general, SEQ ID NO:Y).

In certain embodiments ofthe invention a polypeptide having significant similarity to the polypeptide of SEQ ID NO:l includes one or more conservative amino acid substitutions. Examples of conservative substitutions are well known in the art. See, for example, Biochemistry, 4th Ed., Stryer, L., et al, W. Freeman and

Co., 1995 and U.S. Patent No. 6,015,692. The invention also encompasses variants of the polypeptide of SEQ ID NO:l and variants of significantly similar polypeptide, wherein the variants have one or more altered or modified amino acids. Alterations and modifications may include the replacement of an L- amino acid with a D-amino acid, or various modifications including, but not limited to, phosphorylation, carboxylation, alkylation, etc.

Certain polypeptides having significant similarity to the polypeptide of SEQ ID NO:l contain at least one functional or structural characteristic of BSTP-Ras/Rerg. For example, certain ofthe polypeptides contain an epitope that binds an antibody that binds to BSTP-Ras/Rerg. Certain ofthe polypeptides have amino acid sequences that differ by less than 20, less than 10, or less than 5 amino acids from the amino acid sequence of SEQ ID NO: 1. Certain or the polypeptides contain a GTP-binding domain and/or a Ras effector domain. Certain ofthe polypeptides retain at least one biological activity, structural feature, or immunological activity of BSTP-Ras/Rerg.

The invention also includes fragments of a polypeptide comprising the sequence of SEQ ID NO:l and fragments of polypeptides having significant similarity to the polypeptide of SEQ ID NO: 1. In certain embodiments ofthe invention the fragments are between 5 and 15 amino acids in length, inclusive. In certain embodiments ofthe invention the fragments are between 10 and 15 amino acids in length, inclusive. In certain embodiments ofthe invention the fragments are between 10 and 20 amino acids in length, inclusive. In certain embodiments ofthe invention the fragments are between 20 and 30 amino acids in length, inclusive. Such fragments are useful, for example, as antigens for the generation of antibodies. In other embodiments ofthe invention the fragments include a characteristic feature of a Ras family member such as a GTP-binding domain or a Ras effector domain. In certain embodiments ofthe invention the length ofthe fragments is at least 50%, at least 75%, at least 90%, or at least 95% ofthe full length of BSTP-Ras/Rerg.

The invention also includes polynucleotides that encode BSTP-Ras/Rerg, i.e., polynucleotides that encode a polypeptide comprising the sequence of SEQ ID NO:l. In one embodiment the invention encompasses a polynucleotide comprising the polynucleotide sequence of SEQ ID NO:2. In other embodiments the invention encompasses a polynucleotide comprising the polynucleotide sequence of SEQ ID NO: 3, SEQ ID NO: 4, or SEQ ID NO:5. The invention further includes polynucleotides that encode the polypeptides having significant similarity to the polypeptide of SEQ ID NO: 1 described above. In addition, the invention includes fragments ofthe foregoing polynucleotides, wherein the fragments are at least twelve nucleotides in length, at least 15 nucleotides in length, at least 20 nucleotides in length, or at least 25 nucleotides in length. In certain embodiments ofthe invention the length of a fragment is at least 50%, at least 60%, at least 60%, at least 80%, at least 90%, at least 95%, or at least 99% ofthe full length ofthe corresponding polynucleotide. As is well known in the art, due to the degeneracy ofthe genetic code (i.e., the fact that in many cases multiple different codons can code for the same amino acid), multiple different polynucleotide sequences encode BSTP-Ras/Rerg ofthe present invention. The invention encompasses all ofthe sequences that can be made by substituting alternative codons in accordance with the genetic code. It is noted that such substitution must be made appropriately in view ofthe reading frame ofthe polynucleotide. It is further noted that many of these polynucleotide sequences will display little or no homology with the sequences in SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4or SEQ ID NO: 5. In certain embodiments ofthe invention it may be preferred to employ polynucleotides encoding BSTP-Ras/Rerg having a significantly different codon usage to that found in naturally occurring BSTP-Ras/Rerg. For example, if the inventive polynucleotides are to be used to express BSTP-Ras/Rerg in a heterologous system such as a bacterial or yeast expression system, it may be desirable to employ polynucleotides having a codon usage preferred for optimal expression in the heterologous system. Such codon usage preferences are well known in the art. Altering the nucleotide sequence encoding BSTP-Ras/Reegg may have additional uses such as maximizing RNA stability, as it is well known in the art that RNA stability can be affected by the sequence ofthe RNA.

The invention also includes polynucleotides having a complementary nucleotide sequence to any ofthe inventive polynucleotides described above. Such complementary polynucleotides are useful as probes, e.g., to detect expression ofthe inventive polynucleotides at the RNA level. Such complementary polynucleotides are also useful as antisense reagents, to inhibit the expression ofthe corresponding genes at the protein level, e.g., by interfering with mRNA translation. Inhibiting gene expression has a variety of applications, e.g., it may be used to gain information about the function ofthe encoded protein. In addition, antisense inhibition of gene expression may be used therapeutically. The invention encompasses polynucleotides that are able to hybridize to any of the inventive polynucleotide sequences discussed above under various conditions of stringency. In general, a hybridizing polynucleotide will have a sequence either partially or fully complementary with the polynucleotide to which it hybridizes. Hybridization conditions of various stringency are well known in the art and are, in general, governed by the concentration of reagents such as salts and formamide in the hybridization buffer as well as by the temperature at which hybridization is performed. For example, a stringent hybridization can be performed by use of a hybridization buffer comprising 30% formamide in 0.9M saline/0.09M sodium citrate (SSC) buffer at a temperature of 45° C followed by washing twice with that SSC buffer at 45° C. A moderately stringent hybridization condition could include use of a hybridization buffer comprising 20% formamide in 0.8M saline/0.08M SSC buffer at a temperature of 37° C. followed by washing once with that SSC buffer at 37° C. The selection of appropriate hybridization conditions will typically be determined by the purpose for which hybridization is to be carried out and is a matter of choice for the practitioner. When the polynucleotide is present on an array, the hybridization conditions may be chosen as described in Example 4. The invention further includes oligonucleotides comprising a fragment of a polynucleotide encoding BSTP-Ras/Rerg or comprising a fragment of a polynucleotide complementary to such a polynucleotide. In certain embodiments of the invention the oligonucleotides are between 6 nucleotides and 60 nucleotides in length. In certain embodiments ofthe invention the oligonucleotides are between about 15 to 30 nucleotides in length, while in certain other embodiments ofthe invention the oligonucleotides are between about 20 and 25 nucleotides in length. Such oligonucleotides are useful, for example, as primers in PCR amplification or in hybridization assays including microarray assays.

The invention contemplates the production of any ofthe polynucleotides,fragments, and variants thereof described herein by chemical synthesis, by PCR, or by use ofexpression vectors including the polynucleotides. Such expression vectors and methods of their use are well known in the art. The inventive polynucleotides and fragments thereof can be produced using an in vitro transcription system or within a host cell containing a vector comprising the inventive polynucleotide sequence and appropriate genetic control elements (e.g., enhancers, promoters, terminators) operatively linked to the polynucleotide sequence so as to direct transcription therefrom. In vitro transcription systems are well known in the art as are vectors containing appropriate genetic control elements for directing transcription of an inserted polynucleotide sequence and host cells in which such vectors are maintained. The invention encompasses the production of either DNA or RNA having the sequence of an inventive polynucleotide. One of ordinary skill in the art will be able to select appropriate vectors and synthesis conditions depending upon whether it is desired to produce DNA or RNA. It is noted that the inventive polynucleotides and fragments thereof can also be synthesized entirely through chemical means. Techniques and machines for chemical synthesis of polynucleotides are well known in the art. The polynucleotides can be labeled or conjugated with detectable moieties including radionuclides, enzymes, chromogenic substrates, fluorescent substances, etc., using any of a variety of techniques.

Polynucleotides encoding BSTP-Ras Rerg can be extended, e.g., to identify upstream elements such as promoters or other regulatory elements, using techniques that are well known in the art. Such techniques are described, for example, in U.S. Patent No. 6,008, 337, which is herein incorporated by reference, and include a variety of PCR-based methods, screening of cDNA libraries, primer extension, etc. Genomic sequence such as introns can also be obtained. Discovery of additional sequence may also be performed using computer-based searches of sequenced human DNA. As is well known, large portions ofthe human genome have been sequenced, but relatively little information exists as to the structure and organization of much of the sequence. Thus extension of the inventive polynucleotide sequences may be performed by careful examination of previously sequenced genomic DNA. Preferably any predictions based on examination of genomic sequence are verified experimentally, since it is well known in the art that a significant number of errors exist in the genomic sequence and in the predictions (e.g., predictions of genes and open reading frames) based thereon.

It is well known in the art that different cell types, cells at different stages of differentiation, and/or cells within organisms at different developmental stages may express variants ofthe same gene, e.g., variants derived by alternative splicing. Therefore, multiple different mRNAs corresponding to the same gene may exist.

Such mRNAs are transcribed from the same region of genomic DNA but may vary in sequence, usually lacking or containing domains corresponding to introns or regions at the 5' and/or 3' end ofthe message. The present invention encompasses such variant polynucleotides and their encoded polypeptides. Variant polynucleotides can be identified and cloned by screening cDNA libraries produced using mRNA from cells of various different types, differentiation states, or from tissues at different developmental stages. The invention contemplates production of any ofthe BSTP-Ras/Rerg polypeptides or fragments thereof using any of a variety of techniques including both in vivo or in vitro synthesis. For example, polynucleotides encoding an inventive polypeptide can be inserted into an expression vector, which can then be introduced into an appropriate host cell (e.g., a bacterial, yeast, insect, or mammalian cell). Thus the invention includes an expression vector comprising a polynucleotide comprising a nucleotide sequence set forth in SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, or SEQ ID NO:5. The invention further includes an expression vector comprising a polynucleotide that encodes the polypeptide of SEQ ID NO:l or encodes a significantly similar polypeptide. The invention further includes a host cell comprising any ofthe afore-mentioned vectors. A wide variety of vector/host expression systems are known in the art. In general, vectors contain necessary control and regulatory sequences (e.g., enhancers, promotors, polyadenylation sequence, etc.) operatively linked to an inserted polynucleotide so as to direct expression ofthe polypeptide in the appropriate host cell. Depending upon the host cell to be employed, appropriate vectors may include phages, viruses, or plasmids. The invention encompasses any available vector/host expression system and specifically includes vectors that direct expression of an inventive polynucleotide, vectors that direct expression of an inventive polypeptide (e.g., expression vectors), in addition to cells and cell lines transformed with such vectors. In certain embodiments ofthe invention the inventive polypeptide is secreted from a cell transformed with an expression vector, thereby allowing purification from the medium rather than by harvesting the cells. The invention also encompasses the production of inventive polypeptides in cells that have been engineered to express such polypeptides according to the methods described in U.S. Patent No. 6,063,630, which discloses methods of "turning on" an endogenous gene in cells that normally express the gene at low or undetectable levels. Methods for harvesting, isolating, purifying, etc., polypeptides from cells expressing such polypeptides are well known in the art. BSTP-Ras/Rerg and polypeptides that are significantly similar to BSTP-

Ras/Rerg can also be produced in animals or plants that are transgenic for a polynucleotide sequence encoding the polypeptide. The invention includes such animals and plants. In addition to their potential use as sources for the inventive polypeptides, transgenic animals may be used to study the function ofthe inventive polypeptides. Methods for the production of transgenic animals and plants, as well as methods for purifying and harvesting inventive polypeptides from such animals and plants are well known in the art and are within the scope ofthe invention. The invention also encompasses cells and transgenic animals that have been engineered to lack expression ofthe inventive polynucleotides. Methods for "knocking out" a gene using the technique of homologous recombination and methods of creating cells and organisms lacking expression ofthe knocked out gene are well known in the art and are described, for example, in U.S. Patent No. 5,464,764, U.S. Patent No. 5,487,992, U.S. Patent No. 5,627,059, and U.S. Patent No. 5,631,153.

As will be appreciated by one of ordinary skill in the art, in certain circumstances it may be advantageous to modify an inventive polynucleotide sequence by ligating it to a heterologous sequence, thereby enabling the production of a fusion protein. Certain vectors are designed to incorporate such heterologous sequences so that insertion of a polynucleotide into the vector at an appropriate location results in an in-frame fusion to the heterologous sequence, which may be either upstream or downstream from the inserted polynucleotide. Such heterologous sequences may encode tags or cleavable linker sequences such as glutathione S- transferase (GST), the hemaglutinin epitope known as HA tag, a short stretch ofthe Myc protein (Myc tag), FLAG tag, 6X His tag, maltose binding protein tag, etc. In general, many of these tags are useful for the purification and/or detection ofthe polypeptide using an antibody or other reagent that binds to the tag. Other useful heterologous sequences include that of green fluorescent protein (GFP), which allows visualization ofthe fusion protein. The present invention encompasses all such BSTP-Ras/Rerg fusion proteins.

The presence of a consensus sequence for GTP-binding regions in BSTP- Ras/Rerg indicates that the protein binds GTP and strongly suggests that its growth- inhibitory functions are mediated by the GTP-bound form. A decrease in the GTPase activity of BSTP-Ras/Rerg may therefore be expected to have similar growth- inhibitory effects to those induced by overexpressing BSTP-Ras/Rerg. The invention provides fragments and variants (e.g., mutants) of BSTP-Ras/Rerg that have increased activity. Certain ofthe fragments or variants have increased GTP-binding activity and/or decreased GTPase activity. The invention also provides fragments or variants of BSTP-Ras/Rerg that have decreased activity. Certain ofthe fragments or variants have decreased GTP-binding activity and/or increased GTPase activity. Activating point mutations have been localized in codons 12, 13, 59, 61, 63,

116, 117, 119, and 146 of the H-Ras protein (See, e.g., Der, C. J., Finkel, T., and Cooper, G. M., Cell 44(1), 167-76, 1986; Barbacid M., Eur J Clin Invest, 20: 225, 1990). All of these alterations occur at or near the guanine nucleotide binding sites. The effects of these point mutations are either reduced GTPase activity (if amino acids 12, 13, 59, 61, 63 are involved), so that oncogenic RAS mutants are locked in the active GTP-bound state, or decreased nucleotide affinity, and hence, increased exchange of bound GDP for cytosolic GTP (if amino acids 116, 117, 119 or 146 are affected). The inefficient deactivation ofthe active GTP-bound RAS proteins is intensified by the inability of GAPs to stimulate the conversion to the inactive, GDP- bound state. These point mutations cause an accumulation of activated RAS-GTP complexes, leading to continuous signal transduction by facilitating accumulation of constitutively active, GTP-bound RAS protein.

The alignment of BSTP-Ras/Rerg with other Ras family members provides a basis for rational selection of mutations that are likely to increase or decrease BSTP- Ras/Rerg activity. However, the mutations are not limited to point mutations identical to those identified in other Ras family members but may include different single amino acid substitutions. Multiple amino acid substitutions may also be made. In certain embodiments ofthe invention less than five amino acid substitutions are made. In certain other embodiments ofthe invention less than ten amino acid substitutions are made. In certain other embodiments ofthe invention less than 20 amino acid substitutions are made. Activating mutations may also include deletions and/or additions. In certain embodiments ofthe invention the deletion or addition is a single amino acid. In other embodiments ofthe invention the deletion or addition is less than five amino acids in length. In certain other embodiments ofthe invention the deletion or addition is less than ten amino acids in length. In certain other embodiments ofthe invention the deletion or addition is less than 20 amino acids in length. Combinations ofthe foregoing mutations are also included in the invention. While the range of possible mutations is broad, since the number of amino acids is limited it is possible to list all mutations that meet the various criteria outlined above. In addition, the range of mutations is limited in that the effects of mutations on the GTP-binding and/or GTPase activity ofthe mutated polypeptide may readily be tested according to standard methods that are well known in the art. For example, the time dependence and/or concentration dependence of guanine nucleotide binding to BSTP-Ras/Rerg or a fragment or variant thereof, or to a significantly similar polypeptide, the nucleotide specificity, and/or the guanine nucleotide dissociation rate may be determined by incubating the polypeptide with appropriate radiolabeled nucleotide (e.g., [³⁵S]GTPγS or [³H]GDP) and performing an appropriate filtration assay with detection of label. GTPase activity may be measured by incubation with appropriate radiolabeled nucleotide (e.g., [ -³²P]GTP and analyzing reaction products using thin layer chromatography.

The invention provides an antibody that binds to BSTP-Ras/Rerg or to a polypeptide having significant similarity to BSTP-Ras/Rerg. Antibodies to these polypeptides may be generated, for example, as described in Example 6 below. In general, such antibodies may be generated by methods well known in the art and described, for example, in Harlow, E., and Lane, D., Antibodies: A Laboratory Manual, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, 1988. Details and references for the production of antibodies based on an inventive polypeptide may also be found in U.S. Patent No. 6,008,337. Antibodies may include, but are not limited to, polyclonal, monoclonal, chimeric (e.g., "humanized"), and single chain antibodies, and Fab fragments. The invention encompasses "fully human" antibodies produced using the XenoMouse™ technology (AbGenix Corp., Fremont, CA) according to the techniques described in U.S. Patent No. 6,075,181.

B. Diagnostics and methods of use thereof

The invention provides reagents and methods for detecting the inventive polynucleotides and polypeptides described above. The reagents are useful for diagnostic purposes among others. In one aspect, the invention provides a method of classifying tumors by detecting the presence of one or more ofthe inventive polypeptides or polynucleotides, e.g., polypeptides or polynucleotides comprising a sequence set forth in SEQ ID NO:l, SEQ ID NO: 2, SEQ ID NO:3, SEQ ID NO: 4, or SEQ ID NO:5, or polypeptides having significant similarity to the polypeptide of SEQ ID NO: 1. As is well known in the art, a polypeptide may be detected using a variety of techniques that employ an antibody that binds to the polypeptide. In addition, in certain embodiments ofthe invention the polypeptides are detected using other modalities known in the art for the detection of polypeptides, such as aptamers (Aptamers, Molecular Diagnosis, Vol.4, No.4, 1999), reagents derived from combinatorial libraries for specific detection of proteins in complex mixtures, random peptide affinity reagents, etc. In general, any appropriate method for detecting a polypeptide may be used in conjunction with the present invention, although antibodies may represent a particularly appropriate modality.

Thus the invention provides a method for classifying a disease comprising the steps of: (a) obtaining cells or tissue from a site of disease; (b) detecting a polypeptide having a sequence selected from the group consisting of SEQ ID NO:l, or a polypeptide having significant similarity to the polypeptide of SEQ ID NO: 1 ; and (c) placing the disease into one of a set of predetermined categories based on detection of the polypeptide. The predetermined categories are, in general, characterized by differences in their expression of BSTP-Ras/Rerg and also by differences in some aspect of tumor phenotype. For example, and without intending to be limiting, one predetermined category may be characterized by a good prognosis; one predetermined category may be characterized by a poor prognosis; and one predetermined category may be characterized by a non-responder phenotype. In addition to differences in phenotype, the predetermined categories also feature differences in the expression of BSTP-Ras, thus allowing the placement of a tumor into one ofthe categories based on the detection (which may include measurement) of BSTP-Ras/Rerg in a sample from the tumor. Thus the assignment may be used as a basis for providing diagnostic, prognostic, and/or predictive information to a patient having the tumor. The assignment may be used to stratify a patient for a clinical trial, to select a particular treatment, etc. The invention also provides additional methods for classifying a disease. One such method comprises the steps of: (a) obtaining a sample containing cells or tissue from a subject; (b) detecting the presence of a polynucleotide that encodes a polypeptide having the sequence of SEQ ID NO:l or a polypeptide having significant similarity to the polypeptide of SEQ ID NO:l within the sample; and (c) assigning the disease to one of a set of predetermined categories based on detection ofthe polynucleotide. Any appropriate technique can be used to perform the detection step including, but not limited to, the various hybridization-based assays described herein. It is to be understood that nucleic acids within the cell or tissue sample may be subjected to various procedures such as purification, reverse transcription, amplification, etc., prior to the actual detection. Thus the detection itself may be performed on a sample derived from the cell or tissue sample through such a procedure and may involve detection of a complementary polynucleotide. Detection within such a derived sample indicates the presence ofthe polynucleotide within the cell or tissue sample. Similarly, the methods that involve detecting the presence of a polypeptide within a cell or tissue sample may involve detection ofthe polypeptide within a sample derived from the cell or tissue sample.

The invention encompasses a number of uses for antibodies that bind to BSTP-Ras/Rerg. In a broad aspect, antibodies that bind to BSTP-Ras/Rerg can be used to provide information useful for diagnosis, prognosis, classification, or monitoring of a disorder characterized by the inappropriate expression ofthe polypeptide. The term "inappropriate expression", as used herein, can include, but is not limited to, underexpression, overexpression, or expression in a cell type or organ in which the polypeptide is not normally expressed. Inappropriate expression can include (1) underexpression relative to normal for that cell or tissue, (2) overexpression relative to normal for that cell or tissue, or (3) mislocalization within a cell or tissue relative to normal for that cell or tissue. In order to provide a basis for diagnosis, prognosis, classification, or monitoring of a disorder characterized by the inappropriate expression ofthe BSTP-Ras/Rerg polypeptide, a normal or standard expression profile can first be established by measuring the expression of BSTP- Ras/Rerg in cells, tissues, body fluids, etc., obtained from subjects not suffering from the disorder. In general, a range of values may be considered normal, and departure from within this range of values may be taken to indicate that an individual suffers from or is at increased likelihood to develop the disorder. Of course in certain cases the information will simply consist of an indication ofthe presence or absence of BSTP-Ras/Rerg in a cell or tissue sample (e.g., a sample of breast cancer cells or tissue), regardless of whether BSTP-Ras/Rerg expression is considered "inappropriate". As used herein the term "diagnostic information" includes, but is not limited to, any type of information that is useful in determining whether a patient has, or is at increased risk for developing, a disease or disorder; for providing a prognosis for a patient having a disease or disorder; for classifying a disease or disorder; for monitoring a patient for recurrence of a disease or disorder; for selecting a preferred therapy; for predicting the likelihood of response to a therapy, etc. In certain embodiments ofthe invention, antibodies to BSTP-Ras/Rerg are used for providing diagnostic information for cancer, particularly for breast cancer. In general, diagnostic assays in which the antibodies may be employed include methods that use the antibody to detect BSTP-Ras/Rerg in a tissue sample, cell sample, body fluid sample (e.g., serum), cell extract, etc. Thus the invention provides a method for detecting a polypeptide comprising an amino acid sequence set forth in SEQ ID NO: 1 or a polypeptide having significant similarity to the polypeptide of SEQ ID NO: 1 in a biological sample comprising steps of: (a) contacting the biological sample with an antibody that binds to the polypeptide of SEQ ID NO:l; and (b) determining whether the antibody specifically binds to the sample, the binding being an indication that the sample contains the polypeptide. The biological sample can be processed in any of a variety of ways prior to being placed in contact with the antibody.

Many detection methods typically involve the use of a labeled secondary antibody that recognizes the primary antibody (i.e., the antibody that binds to the polypeptide being detected). Depending upon the nature ofthe sample, appropriate methods include, but are not limited to, immunohistochemistry, radioimmunoassay, ELISA, immunoblotting, and FACS analysis. Assays for an activity such as GTP binding or hydrolysis may also be employed. In the case where the polypeptide is to be detected in a tissue sample, e.g., a biopsy sample, immunohistochemistry may be a particularly appropriate detection method. Techniques for obtaining tissue and cell samples and performing immunohistochemistry and FACS are well known in the art. Such techniques are routinely used, for example, to detect the ER in breast tumor tissue or cell samples. In general, such tests will include a negative control, which can involve applying the test to normal tissue so that the signal obtained thereby can be compared with the signal obtained from the sample being tested. In tests in which a secondary antibody is used to detect the antibody that binds to the polypeptide of interest, an appropriate negative control can involve performing the test on a portion ofthe sample with the omission ofthe antibody that binds to the polypeptide to be detected, i.e., with the omission ofthe primary antibody. Antibodies suitable for use as diagnostics generally exhibit high specificity for the target polypeptide and low background. In general, monoclonal antibodies are preferred for diagnostic purposes. The invention encompasses the use of protein arrays, including antibody arrays, for detection ofthe polypeptide. The use of antibody arrays is described, for example, in Haab, B., et al, "Protein microarrays for highly parallel detection and quantitation of specific proteins and antibodies in complex solutions", Genome Biol. 2001;2(2), 2001. Other types of protein arrays are known in the art. In general, the results of such a test can be presented in any of a variety of formats. The results can be presented in a qualitative fashion. For example, the test report may indicate only whether or not a particular polypeptide was detected, perhaps also with an indication ofthe limits of detection. The results may be presented in a semi-quantitative fashion. For example, various ranges may be defined, and the ranges may be assigned a score (e.g., 1+ to 4+) that provides a certain degree of quantitative information. Such a score may reflect various factors, e.g., the number of cells in which the polypeptide is detected, the intensity ofthe signal (which may indicate the level ofexpression ofthe polypeptide), etc. The results may be presented in a quantitative fashion, e.g., as a percentage of cells in which the polypeptide is detected, as a protein concentration, etc. As will be appreciated by one of ordinary skill in the art, the type of output provided by a test will vary depending upon the technical limitations ofthe test and the biological significance associated with detection ofthe polypeptide. For example, in the case of certain polypeptides a purely qualitative output (e.g., whether or not the polypeptide is detected at a certain detection level) provides significant information. In other cases a more quantitative output (e.g., a ratio ofthe level ofexpression ofthe polypeptide in the sample being tested versus the normal level) is necessary. A particular use for antibodies that bind to BSTP-Ras/Rerg is to classify breast tumors based on the association between the expression level ofthe BST-RAS/Rerg gene, or the association between a gene subset that includes the BST-RAS/Rerg gene, and a tumor subset having a particular phenotype (e.g., a good prognosis phenotype, a poor prognosis phenotype, a non-responder phenotype, etc.). Immunohistochemistry using an antibody that binds to BSTP-Ras/Rerg can be employed to detect BSTP- Ras/Rerg in a tumor tissue or cell sample, thereby providing information useful in determining whether the tumor expresses or overexpresses the polypeptide. Additional detection methods including RIA, ELISA, immunoblotting, and FACS analysis. Thus the present invention provides a test for classifying tumors. The result of such a test (e.g., whether a given tumor expresses or overexpresses BSTP-Ras/Rerg, quantitative expression level of BSTP-Ras/Rerg, etc.) can be used to provide information about the prognosis ofthe tumor or the likelihood that the tumor will respond to therapy. In certain embodiments ofthe inventive methods a single antibody is used whereas in other embodiments ofthe invention multiple antibodies, directed either against the same or against different polypeptides can be used to increase the sensitivity or specificity ofthe test or to provide more detailed information than that provided by a single antibody. Thus the invention encompasses the use of a battery of antibodies, one or more of which binds to BSTP- Ras/Rerg.

Although in many cases detection of polypeptides using antibodies represents the most convenient means of determining whether BST-RAS/Rerg is expressed (or overexpressed) in a particular sample, the invention also encompasses the use of polynucleotides for this purpose. The invention provides methods for detecting a polynucleotide encoding a polypeptide comprising an amino acid sequence set forth in SEQ ID NO:l, or a polypeptide having significant similarity to the polypeptide of SEQ ID NO:l, in a biological sample. One such method comprises steps of: (a) hybridizing a nucleic acid complementary to the polynucleotide encoding a polypeptide comprising an amino acid sequence set forth in SEQ ID NO:l, or a polypeptide having significant similarity to the polypeptide of SEQ ID NO: 1 , to at least one nucleic acid in the biological sample, thereby forming a hybridization complex; and (b) detecting the hybridization complex, wherein the presence ofthe hybridization complex indicates the presence of a polynucleotide encoding the polypeptide in the biological sample. A second such method comprises steps of: (a) hybridizing a nucleic acid encoding a polypeptide comprising an amino acid sequence set forth in SEQ ID NO:l, or a polypeptide having significant similarity to the polypeptide of SEQ ID NO: 1, to at least one nucleic acid complementary to a nucleic acid in the biological sample, thereby forming a hybridization complex; and (b) detecting the hybridization complex, wherein the presence ofthe hybridization complex indicates the presence of a polynucleotide encoding the polypeptide in the biological sample. In other words, detection can comprise detecting either a polynucleotide encoding a polypeptide comprising an amino acid sequence set forth in SEQ ID NO:l or a polypeptides having significant similarity to the polypeptide of SEQ ID NO:l, or detecting the complement of such a polynucleotide. For example, in certain embodiments ofthe inventive method mRNA in the biological sample is detected while in other embodiments ofthe invention cDNA synthesized from mRNA in the biological sample is detected.

The hybridization complex can be detected in any of a variety of ways. For example, the hybridization complex may be formed on a microarray (e.g., a cDNA array or an oligonucleotide array) and detected using techniques such as those described herein or related techniques well known in the art. Microarray analysis is but one means by which polynucleotides can be used to detect or measure BST- RAS/Rerg expression. Expression of BST-RAS/Rerg can also be measured by a variety of other techniques that make use of a polynucleotide corresponding to part or all ofthe BST-RAS/Rerg gene rather than an antibody that binds to a polypeptide encoded by the gene. Appropriate techniques include, but are not limited to, in situ hybridization, Northern blot, and various nucleic acid amplification techniques such as PCR, quantitative PCR, and the ligase chain reaction. Various additional techniques for detecting nucleic acids may be employed in the practice ofthe invention. See, for example, U.S. Patent No. 6,057,105.

Another aspect ofthe invention comprises a kit to test for the presence of any ofthe inventive polynucleotides or polypeptides, e.g., in a cell or tissue sample or in a body fluid. The kit can comprise, for example, an antibody for detection of a polypeptide (e.g., the polypeptide of SEQ ID NO:l or a polypeptide having significant similarity to the polypeptide of SEQ ID NO:l) or a probe for detection of a polynucleotide. In addition, the kit can comprise a reference sample, instructions for processing samples, performing the test and interpreting the results, buffers and other reagents necessary for performing the test. In certain embodiments the kit can comprise a panel of antibodies. In certain embodiments the kit comprises a cDNA or oligonucleotide array for detection ofexpression ofthe gene encoding BSTP-Ras, e.g., for detecting the presence of a polynucleotide comprising the nucleotide sequence set forth in SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, or SEQ ID NO:5. Yet another aspect ofthe invention comprises detecting mutations in the gene encoding BSTP-Ras/Rerg and/or in regulatory regions ofthe gene. The invention further encompasses detecting allelic variants ofthe gene encoding BSTP-Ras/Rerg. As mentioned above, mutations in certain genes (e.g., BRCA-1, BRCA-2) have been associated with an increased risk of breast cancer. Mutations within regulatory regions and/or within the BSTP-Ras/Rerg coding sequence may affect expression levels or activity of BSTP-Ras/Rerg. Detection of such mutations may be used to provide prognostic information, diagnostic information, and/or to guide treatment decisions for breast cancer. For example, the fact that BST-RAS/Rerg is an estrogen- responsive gene (as demonstrated in Example 10) and the presence of two potential ER binding sites within the BST-RAS/Rerg promoter region suggest that expression of ^■ BSTP-Ras/Rerg is regulated by the ER and that mutations in these sites that affect the ability of ER to bind may affect BSTP-Ras/Rerg expression. Thus the invention provides methods for obtaining prognostic, diagnostic, or therapeutic information comprising (i) obtaining a sample containing cells or tissue from a subject, and (ii) detecting, within the sample, a mutation in a regulatory or coding region ofthe gene that encodes BSTP-Ras/Rerg. In certain ofthe methods the mutation is in an ER binding site. In certain ofthe methods the mutation is in a site that encodes a GTPase domain. Techniques for detecting mutations and allelic variants are well known in the art, and the inventive methods encompass the use of any appropriate technique. Such techniques include use of microarrays (e.g., oligonucleotide arrays) to detect single nucleotide polymorphisms (SNPs) associated with a particular allele, use of microarrays (e.g.,oligonucleotide arrays) to detect substitutions, deletions, etc., detection of restriction fragment length polymorphisms (RFLPs), direct sequencing of DNA isolated from an individual, etc.

For example, to determine whether there is a mutation in a particular region of a gene the region may be amplified using PCR and then sequenced. Alternately, the region may be amplified using PCR and hybridized to an oligonucleotide array containing probes that represent different sequence variants as described, for example, in Hacia, J., "Resequencing and mutational analysis using oligonucleotide arrays", Nature Genetics, Supplement, 21, pp. 42-47, 1999, and references therein. Since BSTP-Ras/Rerg is growth-inhibitory, mutations that result in decreased BSTP- Ras/Rerg activity, e.g., tumors whose cells harbor mutations that result in decreased GTP-binding activity or increased GTPase activity may be associated with a worse prognosis and/or more a aggressive phenotype than tumors whose cells do not harbor such mutations.

C. Compositions and Therapeutic Agents

The invention includes the use ofthe polynucleotides, polypeptides, and antibodies described herein as therapeutic agents for the treatment of cancer among other uses. In particular, the invention contemplates the use ofthe polynucleotides, polypeptides, and antibodies described herein for the treatment of breast cancer, although their use for the treatment of other forms of cancer is also within the scope of the invention. In addition to use as therapeutics, certain ofthe compositions are useful for altering cell phenotypes including cell growth properties. The invention encompasses agonists and antagonists to BSTP-Ras/Rerg. Such agents (which include, but are not limited to, antibodies, small molecules, antisense nucleic acids) may be produced or identified using any of a variety of methods known in the art. For example, a purified inventive BSTP-Ras/Rerg polypeptide or fragment thereof may be used to raise antibodies or to screen libraries of compounds to identify those that specifically bind to the polypeptide.

Preferably antibodies suitable for use as therapeutics exhibit high specificity for the target polypeptide and low background binding to other polypeptides. In general, monoclonal antibodies are preferred for therapeutic purposes. In the case of breast cancer, antibodies against the HER2/neu/ErbB2 polypeptide (a polypeptide homologous to the epidermal growth factor receptor) represent a paradigm in terms of the development of therapeutic antibodies. The HER2/neu/ErbB2 gene is overexpressed in approximately 25 to 30 percent of metastatic breast tumors, and an antibody against the HER2/neu/ErbB2 polypeptide, Herceptin^® (Trastuzumab) is approved for the treatment of certain patients with metastatic breast cancer, confirming the utility of therapeutic antibodies directed against polypeptides that are specifically overexpressed in particular tumors subsets. Antibodies directed against a polypeptide expressed by a cell may have a number of mechanisms of action. In certain instances, e.g., in the case of a polypeptide that exerts a growth stimulatory effect on a cell, antibodies may directly antagonize the effect ofthe polypeptide and thereby arrest tumor progression, trigger apoptosis, etc. In certain embodiments ofthe invention the antibody may serve to target a toxic moiety to the cell. Thus the invention encompasses the use of antibodies that have been conjugated with a cytotoxic agent, e.g., a toxin such as ricin or diphtheria toxin, a radioactive moiety, etc. Such antibodies can be used to direct the cytotoxic agent specifically to cells that express the inventive polypeptide.

Although certain modulators may function through direct interaction with a polypeptide such as BSTP-Ras/Rerg, e.g., by stimulating or inhibiting its activity, others may function by affecting expression ofthe polypeptide. It may be desirable to increase the expression of a gene encoding BSTP-Ras/Rerg or to increase the activity of BSTP-Ras/Rerg. For example, in the case of genes (such as that encoding BSTP- Ras/Rerg), whose expression correlates with that ofthe estrogen receptor and therefore is associated with a good prognosis and/or which exhibit growth-inhibitory effects, it may be desirable to increase the expression of such genes or the activity of the corresponding polypeptides in tumors that fail to express these genes or express them at low levels relative to normal cells.

Modulators (e.g., inhibitors or activators) of BST-RAS/Rerg gene expression are within the scope ofthe invention and may be detected by screening libraries of compounds using, for example, cell lines that express the polypeptide or a version of the polypeptide that has been modified to include a readily detectable moiety. Methods for identifying compounds capable of modulating gene expression are described, for example, in U.S. Patent No. 5,976,793. The screening methods described therein are particularly appropriate for identifying compounds that do not naturally occur within cells and that modulate the expression of genes of interest whose expression is associated with a defined physiological or pathological effect within a multicellular organism. The invention encompasses methods for identifying compounds that modulate the activity of a polypeptide encoding BSTP-Ras/Rerg. Methods of screening for such interacting compounds are well known in the art and depend, to a certain degree, on the particular properties and activities ofthe polypeptide encoded by the gene. The invention provides methods for identifying a compound that increases the activity of BSTP-Ras/Rerg and methods for identifying a compound that decreases the activity of BSTP-Ras/Rerg. In addition, the invention provides compounds that increase BSTP- Ras/Rerg activity and compounds that decrease BSTP-Ras/Rerg activity. The methods involve identifying a compound that enhances the expression or activity of a polypeptide comprising the amino acid sequence of SEQ ID NO:l or of a polypeptide having significant similarity to the polypeptide of SEQ ID NO: 1. According to one embodiment, the method includes steps of: (1) contacting a polypeptide comprising the amino acid sequence of SEQ ID NO:l or a polypeptide having significant similarity to the polypeptide of SEQ ID NO:l with a test compound; (2) measuring GTP-binding and/or GTPase activity ofthe polypeptide; and (3) identifying the test compound as an activator ofthe polypeptide if the polypeptide exhibits enhanced GTP-binding activity and/or reduced GTPase activity in the presence ofthe test compound relative to the level of GTP-binding activity and/or GTPase activity in the absence ofthe test compound. In certain embodiments ofthe method the polypeptide includes a GTP-binding domain. The method may be performed in vitro, e.g., using a BSTP-Ras/Rerg polypeptide or significantly similar polypeptide or fragment thereof produced using recombinant DNA technology, or may be performed in vivo, e.g., by applying the test compound to a cell that expresses the polypeptide and isolating the polypeptide from the cell. In certain ofthe methods the polypeptide may be a variant that includes a tag (e.g., an HA tag, 6XHis tag, Flag tag, etc.) which may be used, for example, to facilitate isolation or the variant may be a fusion protein. Any suitable assay for GTP binding and/or GTPase activity may be used including, but not limited to, those described above. Suitable assays are described, for example, in Self AJ, Hall A, "Measurement of intrinsic nucleotide exchange and GTP hydrolysis rates" in Methods Enzymol, 256:67-76, 1995.

Compounds suitable for screening according to the above methods include small molecules, natural products, peptides, nucleic acids, etc. Sources for compounds include natural product extracts, collections of synthetic compounds, and compound libraries generated by combinatorial chemistry. Libraries of compounds are well known in the art. One representative example is known as DIVERSet™, available from ChemBridge Corporation, 16981 Via Tazon, Suite G, San Diego, CA 92127. DIVERSet™ contains between 10,000 and 50,000 drug-like, hand- synthesized small molecules. The compounds are pre-selected to form a "universal" library that covers the maximum pharmacophore diversity with the minimum number of compounds and is suitable for either high throughput or lower throughput screening. For descriptions of additional libraries, see, for example, Tan, et al, "Stereoselective Synthesis of Over Two Million Compounds Having Structural Features Both Reminiscent of Natural Products and Compatible with Miniaturized Cell-Based Assays", Am. Chem Soc.120, 8565-8566, 1998; Floyd CD, Leblanc C, Whittaker M, Prog Med Chem 36:91-168, 1999. Numerous libraries are commercially available, e.g., from AnalytiCon USA Inc., P.O. Box 5926, Kingwood, TX 77325; 3- Dimensional Pharmaceuticals, Inc., 665 Stockton Drive, Suite 104, Exton, PA 19341- 1151; Tripos, Inc., 1699 Hanley Rd., St. Louis, MO, 63144-2913, etc. In certain embodiments ofthe invention the methods are performed in a high-throughput format using techniques that are well known in the art, e.g., in multiwell plates, using robotics for sample preparation and dispensing, etc. Representative examples of various screening methods may be found, for example, in U.S. Patent No. 5,985,829, U.S. Patent No. 5,726,025, U.S. Patent No. 5,972,621, and U.S. Patent No. 6,015,692. The skilled practitioner will readily be able to modify and adapt these methods as appropriate for BSTP-Ras/Rerg.

The invention includes compounds identified using the above methods, i.e., compounds that increase or decrease one or more activities of BSTP-Ras/Rerg or that increase or decrease a polypeptide having significant similarity to the polypeptide of SEQ ID NO: 1. Reduction in expression of an endogenously produced polypeptide may be achieved by the administration of antisense nucleic acids (e.g., oligonucleotides, RNA, DNA, most typically oligonucleotides that have been modified to improve stability or targeting) or peptide nucleic acids comprising sequences complementary to those ofthe mRNA that encodes the polypeptide. Antisense technology and its applications are described in Phillips, MJ. (ed.) Antisense Technology, Methods Enzymol., Volumes 313 and 314, Academic Press, San Diego, 2000, and references mentioned therein. Ribozymes (catalytic RNA molecules that are capable of cleaving other RNA molecules) represent another approach to reducing gene expression. Such ribozymes can be designed to cleave specific mRNAs corresponding to a gene of interest. Their use is described in U.S. Patent No. 5,972,621, and references therein. The invention encompasses the delivery of antisense and/or ribozyme molecules via a gene therapy approach in which vectors or cells expressing the antisense molecules are administered to an individual. The invention also encompasses the use of polynucleotides encoding BSTP-

Ras, or fragments thereof, as DNA vaccines. Such vaccines comprise polynucleotide sequences, typically inserted into vectors, that direct the expression of an antigenic polypeptide within the body ofthe individual being immunized. Details regarding the development of vaccines, including DNA vaccines, for various forms of cancer may be found, for example, in Brinckerhoff L.H., Thompson L.W., Slingluff C.L., Jr., Melanoma Vaccines, Curr Opin Oncol, 12(2): 163-73, 2000 and in Stevenson, F.K., DNA vaccines against cancer: from genes to therapy, Ann. Oncol., 10(12): 1413-8, 1999 and references therein. BSTP-Ras/Rerg polypeptides, or fragments thereof, that may also find use as cancer vaccines. Any of these vaccines may be used for the prevention and/or the treatment of cancer.

The invention includes pharmaceutical compositions comprising the inventive polypeptides, polynucleotides, antibodies, inhibitors, agonists, or antagonists described above. In general, a pharmaceutical composition will include an active agent in addition to one or more inactive agents such as a sterile, biocompatible carrier including, but not limited to, sterile water, saline, buffered saline, or dextrose solution. The pharmaceutical compositions may be administered either alone or in combination with other therapeutic agents including other chemotherapeutic agents, hormones, vaccines, and/or radiation therapy. By "in combination with", it is not intended to imply that the agents must be administered at the same time or formulated for delivery together, although these methods of delivery are within the scope ofthe invention. In general, each agent will be administered at a dose and on a time schedule determined for that agent. Additionally, the invention encompasses the delivery ofthe inventive pharmaceutical compositions in combination with agents that may improve their bioavailability, reduce or modify their metabolism, inhibit their excretion, or modify their distribution within the body. The invention encompasses treating cancer, particularly breast cancer, by administering the pharmaceutical compositions ofthe invention. Although the pharmaceutical compositions ofthe present invention can be used for treatment of any subject (e.g., any animal) in need thereof, they are most preferably used in the treatment of humans.

The pharmaceutical compositions of this invention can be administered to humans and other animals by a variety of routes including oral, intravenous, intramuscular, intraarterial, subcutaneous, intraventricular, transdermal, rectal intravaginal, intraperitoneal, topical (as by powders, ointments, or drops), bucal, or as an oral or nasal spray or aerosol. In general the most appropriate route of administration will depend upon a variety of factors including the nature ofthe compound (e.g., its stability in the environment ofthe gastrointestinal tract), the condition ofthe patient (e.g., whether the patient is able to tolerate oral administration), etc. At present the intravenous route is most commonly used to deliver therapeutic antibodies and nucleic acids. However, the invention encompasses the delivery ofthe inventive pharmaceutical composition by any appropriate route taking into consideration likely advances in the sciences of drug delivery. General considerations in the formulation and manufacture of pharmaceutical agents may be found, for example, in Remington 's Pharmaceutical Sciences, 19^th ed., Mack Publishing Co., Easton, PA, 1995. It will be appreciated that certain ofthe compounds ofthe present invention can exist in free form for treatment, or, where appropriate, in salt form, as discussed in more detail below. Compounds to be utilized in the pharmaceutical compositions include compounds existing in free form or pharmaceutically acceptable derivatives thereof, as defined herein, such as pharmaceutically acceptable salts, esters, salts of such esters, or any other adduct or derivative, which upon administration to a patient in need, is capable of providing, directly or indirectly, a compound as otherwise described herein, or a metabolite or residue thereof, e.g., a prodrug. Thus, as used herein, the term "pharmaceutically acceptable salt" refers to those salts which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of humans and lower animals without undue toxicity, irritation, allergic response and the like, and are commensurate with a reasonable benefit/risk ratio. Pharmaceutically acceptable salts are well known in the art. For example, S. M. Berge, et al. describe pharmaceutically acceptable salts in detail in J. Pharmaceutical Sciences, 66: 1-19 (1977), incorporated herein by reference. The salts can be prepared in situ during the final isolation and purification ofthe compounds ofthe invention, or separately by reacting the free base function with a suitable organic acid. Examples of pharmaceutically acceptable, nontoxic acid addition salts are salts of an amino group formed with inorganic acids such as hydrochloric acid, hydrobromic acid, phosphoric acid, sulfuric acid and perchloric acid or with organic acids such as acetic acid, oxalic acid, maleic acid, tartaric acid, citric acid, succinic acid, or malonic acid or by using other methods used in the art such as ion exchange. Other pharmaceutically acceptable salts include adipate, alginate, ascorbate, aspartate, benzenesulfonate, benzoate, bisulfate, borate, butyrate, camphorate, camphorsulfonate, citrate, cyclopentanepropionate, digluconate, dodecylsulfate, ethanesulfonate, formate, fumarate, glucoheptonate, glycerophosphate, gluconate, hemisulfate, heptanoate, hexanoate, hydroiodide, 2-hydroxy- ethanesulfonate, lactobionate, lactate, laurate, lauryl sulfate, malate, maleate, malonate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, oleate, oxalate, palmitate, pamoate, pectinate, persulfate, 3-phenylpropionate, phosphate, picrate, pivalate, propionate, stearate, succinate, sulfate, tartrate, thiocyanate, p- toluenesulfonate, undecanoate, valerate salts, and the like. Representative alkali or alkaline earth metal salts include sodium, lithium, potassium, calcium, magnesium, and the like. Further pharmaceutically acceptable salts include, when appropriate, nontoxic ammonium, quaternary ammonium, and amine cations formed using counterions such as halide, hydroxide, carboxylate, sulfate, phosphate, nitrate, lower alkyl sulfonate and aryl sulfonate.

Additionally, as used herein, the term "pharmaceutically acceptable ester" refers to esters that hydrolyze in vivo and include those that break down readily in the human body to leave the parent compound or a salt thereof. Suitable ester groups include, for example, those derived from pharmaceutically acceptable aliphatic carboxylic acids, particularly alkanoic, alkenoic, cycloalkanoic and alkanedioic acids, in which each alkyl or alkenyl moiety advantageously has not more than 6 carbon atoms. Examples of particular suitable esters includes formates, acetates, propionates, butyrates, acrylates and ethylsuccinates.

Furthermore, the term "pharmaceutically acceptable prodrugs" as used herein refers to those prodrugs ofthe compounds ofthe present invention that are, within the scope of sound medical judgment, suitable for use in contact with the tissues of humans and lower animals without undue toxicity, irritation, allergic response, and the like, commensurate with a reasonable benefit/risk ratio, and effective for their intended use, as well as the zwitterionic forms, where possible, ofthe compounds of the invention. The term "prodrug" refers to compounds that are rapidly transformed in vivo to yield a particular active compound, for example by hydrolysis in blood. A thorough discussion is provided in T. Higuchi and V. Stella, "Pro-drugs as Novel Delivery Systems", Vol. 14 ofthe A.C.S. Symposium Series, and in Edward B. Roche, ed., Bioreversible Carriers in Drug Design, American Pharmaceutical Association and Pergamon Press, 1987, both of which are incorporated herein by reference.

As mentioned above, the pharmaceutical compositions ofthe present invention additionally comprise a pharmaceutically acceptable carrier, which, as used herein, means a non-toxic, inert solid, semi-solid or liquid filler, diluent, encapsulating material, or formulation auxiliary of any type. Some examples of materials which can serve as pharmaceutically acceptable carriers are sugars such as lactose, glucose and sucrose; starches such as com starch and potato starch; cellulose and its derivatives such as sodium carboxymethyl cellulose, ethyl cellulose and cellulose acetate; powdered tragacanth; malt; gelatin; talc; excipients such as cocoa butter and suppository waxes; oils such as peanut oil, cottonseed oil; safflower oil; sesame oil; olive oil; corn oil and soybean oil; glycols; such a propylene glycol; esters such as ethyl oleate and ethyl laurate; agar; buffering agents such as magnesium hydroxide and aluminum hydroxide; alginic acid; water; isotonic saline; Ringer's solution; ethyl alcohol, and phosphate buffer solutions, dextrose solutions, as well as other non-toxic compatible lubricants such as sodium lauryl sulfate and magnesium stearate, as well as coloring agents, releasing agents, coating agents, sweetening, flavoring and perfuming agents, preservatives and antioxidants can also be present in the composition, according to the judgment ofthe formulator.

Liquid dosage forms for oral administration include pharmaceutically acceptable emulsions, microemulsions, solutions, suspensions, syrups and elixirs. In addition to the active compounds, the liquid dosage forms may contain inert diluents commonly used in the art such as, for example, water or other solvents, solubilizing agents and emulsifiers such as ethyl alcohol, isopropyl alcohol, ethyl carbonate, ethyl acetate, benzyl alcohol, benzyl benzoate, propylene glycol, 1,3-butylene glycol, dimethylformamide, oils (in particular, cottonseed, groundnut, com, germ, olive, castor, and sesame oils), glycerol, tetrahydrofurfuryl alcohol, polyethylene glycols and fatty acid esters of sorbitan, and mixtures thereof. Besides inert diluents, the oral compositions can also include adjuvants such as wetting agents, emulsifying and suspending agents, sweetening, flavoring, and perfuming agents.

Injectable preparations, for example, sterile injectable aqueous or oleaginous suspensions may be formulated according to the known art using suitable dispersing or wetting agents and suspending agents. The sterile injectable preparation may also be a sterile injectable solution, suspension or emulsion in a nontoxic parenterally acceptable diluent or solvent, for example, as a solution in 1,3-butanediol. Among the acceptable vehicles and solvents that may be employed are water, Ringer's solution, U.S.P. and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose any bland fixed oil can be employed including synthetic mono- or diglycerides. In addition, fatty acids such as oleic acid are used in the preparation of injectables.

The injectable formulations can be sterilized, for example, by filtration through a bacterial-retaining filter, or by incorporating sterilizing agents in the form of sterile solid compositions which can be dissolved or dispersed in sterile water or other sterile injectable medium prior to use.

In order to prolong the effect of a drug, it is often desirable to slow the absorption ofthe drug from subcutaneous or intramuscular injection. This may be accomplished by the use of a liquid suspension of crystalline or amorphous material with poor water solubility. The rate of absorption ofthe drug then depends upon its rate of dissolution which, in turn, may depend upon crystal size and crystalline form. Alternatively, delayed absorption of a parenterally administered drug form is accomplished by dissolving or suspending the drag in an oil vehicle. Injectable depot forms are made by forming microencapsulated matrices ofthe drag in biodegradable polymers such as polylactide-polyglycolide. Depending upon the ratio of drug to polymer and the nature ofthe particular polymer employed, the rate of drug release can be controlled. Examples of other biodegradable polymers include poly(orthoesters) and poly(anhydrides). Depot injectable formulations are also prepared by entrapping the drug in liposomes or microemulsions which are compatible with body tissues.

Compositions for rectal or vaginal administration are preferably suppositories which can be prepared by mixing the compounds of this invention with suitable non- irritating excipients or carriers such as cocoa butter, polyethylene glycol or a suppository wax which are solid at ambient temperature but liquid at body temperature and therefore melt in the rectum or vaginal cavity and release the active compound.

Solid dosage forms for oral administration include capsules, tablets, pills, powders, and granules. In such solid dosage forms, the active compound is mixed with at least one inert, pharmaceutically acceptable excipient or carrier such as sodium citrate or dicalcium phosphate and/or a) fillers or extenders such as starches, lactose, sucrose, glucose, mannitol, and silicic acid, b) binders such as, for example, carboxymethylcellulose, alginates, gelatin, polyvinylpyrrolidinone, sucrose, and acacia, c) humectants such as glycerol, d) disintegrating agents such as agar~agar, calcium carbonate, potato or tapioca starch, alginic acid, certain silicates, and sodium carbonate, e) solution retarding agents such as paraffin, f) absorption accelerators such as quaternary ammonium compounds, g) wetting agents such as, for example, cetyl alcohol and glycerol monostearate, h) absorbents such as kaolin and bentonite clay, and i) lubricants such as talc, calcium stearate, magnesium stearate, solid polyethylene glycols, sodium lauryl sulfate, and mixtures thereof. In the case of capsules, tablets and pills, the dosage form may also comprise buffering agents. Solid compositions of a similar type may also be employed as fillers in soft and hard-filled gelatin capsules using such excipients as lactose or milk sugar as well as high molecular weight polyethylene glycols and the like. The solid dosage forms of tablets, dragees, capsules, pills, and granules can be prepared with coatings and shells such as enteric coatings and other coatings well known in the pharmaceutical formulating art. They may optionally contain opacifying agents and can also be of a composition that they release the active ingredient(s) only, or preferentially, in a certain part ofthe intestinal tract, optionally, in a delayed manner. Examples of embedding compositions that can be used include polymeric substances and waxes. Solid compositions of a similar type may also be employed as fillers in soft and hard- filled gelatin capsules using such excipients as lactose or milk sugar as well as high molecular weight polethylene glycols and the like.

The active compounds can also be in micro-encapsulated form with one or more excipients as noted above. The solid dosage forms of tablets, dragees, capsules, pills, and granules can be prepared with coatings and shells such as enteric coatings, release controlling coatings, and other coatings well known in the pharmaceutical formulating art. In such solid dosage forms the active compound may be admixed with at least one inert diluent such as sucrose, lactose or starch. Such dosage forms may also comprise, as is normal practice, additional substances other than inert diluents, e.g., tableting lubricants and other tableting aids such a magnesium stearate and microcrystalline cellulose. In the case of capsules, tablets and pills, the dosage forms may also comprise buffering agents. They may optionally contain opacifying agents and can also be of a composition that they release the active ingredient(s) only, or preferentially, in a certain part ofthe intestinal tract, optionally, in a delayed manner. Examples of embedding compositions that can be used include polymeric substances and waxes.

Dosage forms for topical or transdermal administration of a compound of this invention include ointments, pastes, creams, lotions, gels, powders, solutions, sprays, inhalants or patches. The active component is admixed under sterile conditions with a pharmaceutically acceptable carrier and any needed preservatives or buffers as may be required. Ophthalmic formulation and ear drops are also contemplated as being within the scope of this invention. The ointments, pastes, creams and gels may contain, in addition to an active compound of this invention, excipients such as animal and vegetable fats, oils, waxes, paraffins, starch, tragacanth, cellulose derivatives, polyethylene glycols, silicones, bentonites, silicic acid, talc and zinc oxide, or mixtures thereof. Powders and sprays can contain, in addition to the compounds of this invention, excipients such as lactose, talc, silicic acid, aluminum hydroxide, calcium silicates and polyamide powder, or mixtures of these substances. Sprays can additionally contain propellants known in the art such as chlorofiuorohydrocarbons.

Transdermal patches have the added advantage of providing controlled delivery of a compound to the body. Such dosage forms can be made by dissolving or dispensing the compound in the proper medium. Absoφtion enhancers can also be used to increase the flux ofthe compound across the skin. The rate can be controlled by either providing a rate controlling membrane or by dispersing the compound in a polymer matrix or gel.

In yet another aspect, the present invention also provides a pharmaceutical pack or kit comprising one or more containers filled with one or more ofthe ingredients ofthe pharmaceutical compositions ofthe invention, and in certain embodiments, includes an additional approved therapeutic agent for use as a combination therapy. Optionally associated with such container(s) can be a notice in the form prescribed by a governmental agency regulating the manufacture, use or sale of pharmaceutical products, which notice reflects approval by the agency of manufacture, use or sale for human administration. Instructions for use ofthe compound(s) may also be included.

According to the methods of treatment ofthe present invention, cancer, particularly breast cancer, is treated or prevented in a patient such as a human or other mammal by administering to the patient a therapeutically effective amount of a compound ofthe invention, in such amounts and for such time as is necessary to achieve the desired result. By a "therapeutically effective amount" of a compound of the invention is meant a sufficient amount ofthe compound to treat (e.g. to ameliorate the symptoms of, delay progression of, prevent recurrence of, cure, etc.) cancer, particularly breast cancer, at a reasonable benefit/risk ratio, which involves a balancing ofthe efficacy and toxicity ofthe compound. In general, therapeutic efficacy and toxicity may be determined by standard pharmacological procedures in cell cultures or with experimental animals, e.g., by calculating the ED₅₀ (the dose that is therapeutically effective in 50% ofthe treated subjects) and the LD₅₀ (the dose that is lethal to 50% of treated subjects). The ED₅₀/LD₅₀ represents the therapeutic index ofthe compound. Although in general drugs having a large therapeutic index are preferred, as is well known in the art, a smaller therapeutic index may be acceptable in the case of a serious disease, particularly in the absence of alternative therapeutic options. Ultimate selection of an appropriate range of doses for administration to humans is determined in the course of clinical trials.

It will be understood that the total daily usage ofthe compounds and compositions ofthe present invention for any given patient will be decided by the attending physician within the scope of sound medical judgment. The specific therapeutically effective dose level for any particular patient will depend upon a variety of factors including the disorder being treated and the severity ofthe disorder; the activity ofthe specific compound employed; the specific composition employed; the age, body weight, general health, sex and diet ofthe patient; the time of administration, route of administration, and rate of excretion ofthe specific compound employed; the duration ofthe treatment; drugs used in combination or coincidental with the specific compound employed; and like factors well known in the medical arts. The total daily dose ofthe compounds of this invention administered to a human or other mammal in single or in divided doses can be in amounts, for example, from 0.01 to 50 mg/kg body weight or more usually from 0.1 to 25 mg/kg body weight. Single dose compositions may contain such amounts or submultiples thereof to make up the daily dose. In general, treatment regimens according to the present invention comprise administration to a patient in need of such treatment from about 0.1 μg to about 2000 mg ofthe compound(s) ofthe invention per day in single or multiple doses. EXAMPLES Note: A numbered list of references for the Examples appears following the Examples, all of which are incoφorated herein by reference.

Example 1

Preparation of Microarrays Containing 8498 Human cDNAs

The human cDNA clones used in this study were obtained from Research Genetics (Huntsville AB, USA) as bacterial colonies in 96-well microtiter plates. The clones were chosen from a set of 15,000 cDNA clones that corresponded to the Research Genetics Human Gene Filters sets GF200-202 (http://www.resgen.com/). These clones form part of a set of clones assembled by the I.M.A.G.E. consortium (Lennon, G.G., Auffray, C, Polymeropoulos, M., Soares, M.B. The I.M.A.G.E. Consortium: An Integrated Molecular Analysis of Genomes and their Expression. Genomics 33: 151-152,1996) and are identified by I.M.A.G.E. clone ID numbers. All clones printed on these arrays were sequence validated as part of a product offered at Research Genetics, Inc. We estimate that greater than 97% ofthe clones on the array are correctly identified.

A detailed protocol for the production ofthe cDNA microarrays used in this study is available at http://cmgm.stanford.edu/pbrown/protocols.html and is reproduced below with insubstantial changes. As described below, the protocol includes steps of (1) cleaning the glass slides onto which the DNAs (e.g., products of PCR reactions) are to be spotted; (2) spotting the DNAs onto the glass slides with an arrayer; (3) Post processing to prepare arrays containing spotted DNAs for hybridization. All procedures are done at room temperature and with double distilled water unless otherwise stated. Unless otherwise stated, in this Example and the following Examples, reagents are prepared according to protocols available in Maniatis, T., Sambrook, J. and Fritsch, E., Molecular Cloning: A Laboratory Manual (3 Volume Set), Cold Spring Harbor Laboratory Press, Cold Spring Harbor, 1989, the contents of which are herein incoφorated by reference.

Cleaning Slides Use 30 slide racks in 350mL glass dishes

1. Dissolve 50g of NaOH pellets into 150ml ddH2O

2. Add 200ml of 95% EtOH, stir until completely mixed

3. If solution remains cloudy, add ddH2O until clear 4. Pour solution into glass slide box.

5. Drop in 30 slides in a metal rack. (Gold Seal slides, Cat. 3010)

6. Let soak on an orbital shaker for at least two hours

7. Rinse slides by transferring rack to slide dish filled with ddH2O

8. Repeat ddH2O rinses x3. It's important to remove all traces ofthe NaOH-ethanol.

9. Prepare Poly-1-lysine solution: Use Sigma Poly-1-lysine solution. Cat. No. 8920

10. Add 70mL poly-1-lysine to 280ml of water

11. Transfer slides to poly-1-lysine solution and let soak for 1 hour. 12. Remove excess liquid from slides by spinning the rack of slides on microtiter plate carriers at 500φm.

13. Dry slides at 40 degrees C for 5 minutes in a vacuum oven.

14. Store slides in a closed box for at least two weeks prior to use. 15. Before printing arrays, check a sample slide to make sure it's hydrophobic

(water should bead off it) but the lysine coating is not turning opaque.

Arraying

1. Transfer PCR reactions to 96-well V-bottom tissue culture plates (Costar). Add 1/10 vol. 3M sodium acetate (pH 5.2) and equal volume isopropanol. Store at -20 C for a few hours.

2. Centrifuge in Sorvall at 3500 RPM for 45 min. Rinse with 70% EtOH, centrifuge again and dry.

2. Resuspend DNA in 12ul 3X SSC for a few hours and transfer to flexible U-bottom printing plates.

4. Spot DNA onto poly-1-lysine slides with an arrayer. Post processing

1. Rehydrate arrays by suspending slides over a dish of warm ddH2O. (~1 minute)

2. Snap-dry each array (DNA side up) on a 100C hot plate for 3 seconds. 3. UV cross-link DNA to the glass by using a Stratalinker set for 60 milli Joules

4. Dissolve 5g of succinic anhydride (Aldrich) in 315mL of n-methyl-pyrrolidinone.

5. To this, add 35mL of 0.2M NaBorate pH 8.0 (made by dissolving boric acid in water and adjusting the pH with NaOH), and stir until dissolved. 6. Soak arrays in this solution for 15 minutes with shaking.

7. Transfer arrays to 95C water bath for 2 minutes

8. Quickly transfer arrays to 95% EtOH for 1 minute.

9. Remove excess liquid from slides by spinning the rack of slides on microtiter plate carriers at 500rpm.

10. Arrays can be used immediately.

Reagent Suppliers

Microscope slides Goldseal brand. (Cat. 3010)

Poly-1-lysine solution Sigma product number P8920 Succinic Anhydride Aldrich product number 23,969-0 N-Methyl-Pyrrolidinone Aldrich product number 32,863-4

Microarrays were prepared according to the above protocol using the 8498 cDNA clones described above. All microarrays used in the experiments described herein were from a single print run batch of microarrays.

Example 2 Cell Lines, Breast Tissue, and Breast Tumor Samples for Microarray Analysis and

Preparation of mRNA Samples

Common Reference Sample Each ofthe 84 experimental samples tested here was analyzed by a comparative hybridization, using a common reference RNA pool as a standard; this reference sample was composed of equal mixtures of mRNA isolated from 11 established cell lines derived from human tissue (MCF7, Hs578T, OVCAR3, HepG2, NTERA2, MOLT4, RPMI-8226, NB4+ATRA, UACC-62, SW872, and Colo205: also see Table 2 for more details). The 11 cell lines were all grown to 70-90% confluence in RPMI medium, containing 10% Fetal Calf Serum and Penicillin/Streptomycin. The cells were harvested either by scraping or centrifugation, quickly resuspended in RNA lysis buffer and mRNA prepared using the FastTrack™ 2.0 mRNA Isolation Kit (Invitrogen, Carlsbad, CA) according to the manufacturer's instructions. In each case, multiple individual mRNA preparations were collected for each cell line, which were then pooled together and analyzed via Northern analysis before final mixing to ensure the quality ofthe input mRNAs (e.g., to confirm that the mRNA exhibited a size distribution indicating that it was substantially nondegraded). The 11 mRNA samples were then mixed together in equal amounts, aliquoted in lOmM Tris (7.4), and stored at -80 C until use (2 micrograms of common reference sample was used per microarray hybridization and was always labeled using Cy3).

Normal Breast Tissue

Three samples of normal breast tissue were analyzed. Two ofthe samples were obtained from Clontech (Palo Alto, CA) and were pools of six (Normall) or two (Normal2) whole normal breasts. The third sample (NormaB) was obtained from a single individual.

Breast Tumor Samples The 40 individual breast tumor samples were collected at either Stanford

University in Stanford CA, USA, or in the Haukeland University Hospital in Bergen, Norway. Twenty ofthe forty breast tumors were sampled twice as part of a larger Norwegian study on locally advanced breast cancers (T3/T4 and/or N2 tumors) and have been described previously (Aas, T., et al., Nat. Med., 2, 811-814, 1996, the contents of which are incoφorated herein by reference) ; these patients underwent an open surgical biopsy before treatment with doxorubicin monotherapy (range 12-23 weeks), followed by the definitive surgical resection ofthe remaining tumor after therapy, and were evaluated for clinical responses according to UICC criteria (Hayward, J., et al., Br. J. Cancer, 35, 292-298, 1977). In addition to the 20 pairs, there were 8 additional "before" specimens from Norway and 10 tumor specimens from Stanford (all Stanford tumors tested had a diameter of 3 cm or larger). Finally, 2 of the 10 Stanford tumor specimens assayed were also paired with a lymph node metastasis from the same patient.

mRNA Isolation from Breast Tumor and Tissue Samples

Following their excision, breast tumor samples were rapidly frozen in liquid N2 and then stored at -80 C until use. mRNA was isolated from breast tumors and normal breast tissue using the Trizol Reagent (Gibco-BRL) and Invitrogen FastTrack 2.0 Kit (all Stanford samples, and see http://genome- www.stanford.edu/sbcmp/web.shtml for the detailed protocol) or using the Trizol Reagent followed by Dynal bead separation for the mRNA purification step (all Norway tissue samples). Briefly, frozen tumor samples were cut into small pieces and immediately placed into 12 ml of Trizol Reagent. Each tumor sample in Trizol was homogenized using a PowerGen 125 Tissue Homogenizer (Fisher Scientific), and total RNA was isolated according to the Trizol reagent manufacturer's protocol. Tumor mRNA was isolated according to the manufacturer's protocols using the FastTrack 2.0 Kit (Invitrogen) or Dynal beads.

Example 3

Characterization of Breast Tissue and Tumor Samples For all but two ofthe tumor specimens (i.e. New York 1 and New York 2), the mutational status ofthe TP53 gene was determined using published methods (Aas, T., et al).

A single pathologist (applicant Matt van de Rijn) reviewed hematoxylin and eosin (H&E) sections of each tumor, including all before and after pairs, and made a histological evaluation of each while blinded to the source. Tumors were graded using a modified version ofthe Bloom-Richardson method (Robbins, P., et al., Hum Pathol, 26, 873-879, 1995). These data are displayed in Table 4. Representative H&E sections of each tumor are posted on Applicants' website at http://genome- www.stanford.edu/molecularportraits/.

Immunohistochemistry was performed as described previously (Perou, C, et al., 1999; Bindl, J. and Warnke, R., Am J Clin Pathol, 85, 490-493, 1986, and Natkunam, Y., et al, Am. J. Path., 156(1), 2000, the contents of which are incorporated herein by reference). The antibodies used included the commercially available monoclonal antibodies CAM5.2 (specific for keratins 8/18, available from Becton Dickinson), anti-keratin 5/6 (available originally from Boehringer Mannheim, Indianapolis, IN, cat. no. 1273396 and now from Chemicon International, Temekula, CA ), anti-keratin 17 (clone E3, available from Dako, Caφinteria, CA, cat. no. M7046), anti-CD3 (available from Dako), and anti-immunoglobulin light chain (A191, A193, available from Dako). These immunohistochemical methods were applied for all the immunohistochemical studies described in the present application unless otherwise stated.

Example 4 cDNA Synthesis and Labeling and Microarray Hybridization

mRNA was isolated from breast tissue, breast tumor samples, and cell lines as described in Example 2. Fluorescently labeled cDNA was synthesized from the mRNA using a reverse transcriptase reaction that included dUTP labeled with either Cy3 or Cy5. For each hybridization experiment differentially labeled cDNA samples (an experimental sample and a reference sample) were pooled and hybridized to a cDNA microarray, which was then scanned as described in Example 4. The protocol below provides details ofthe steps performed for cDNA synthesis and labeling and for microarray hybridization.

I . To set up for the reverse transcriptase (RT) reaction, combine the following (e.g., in an Eppendorf tube):

(a) Anchored Oligo dT primer - 2 microliters at 2.5 micrograms/microliter or control - 2 microliters

(b) mRNA - (whatever volume is needed to reach 1.5-2 micrograms)

(c) DEPC/H2O - add sufficient volume so that final volume is 16 microliters 2. Heat at 70° C for 10 minutes

3. Chill on ice for 1-2 minutes

4. Add the following RT reaction components to each individual tube:

(a) 5X RT Buffer - 6 microliters

(b) 50X dNTPs - 0.7 microliters - (500mm A,C,G, 200mm T) (c) Cy Dyes dUTP - 3 microliters - (either Cy3 or Cy5)

(d) DTT Stock - 3 microliters - (comes with RT setup)

(e) Superscript II RT--1.7 microliters - (cat# 18064-014 Gibco-BRL)

5. Mix well

6. Incubate at 42° C for 1 hour 7. Add another 1 microliter of Superscript II RT and mix

8. Incubate at 42° C for 1 more hour

9. Degrade mRNA with 1.5 microliters of 1M NaOH / 2mM EDTA

10. Incubate at 65° C for 8 minutes (do NOT go TOO long here)

I I. Add 15 microliters of 0.1M HCL 12. Add 450 microliters of TE (pH 7.4) to each sample and place each sample into a microcon-30 filter.

13. Add 15 microliters of Human COT1 DNA (Gibco-BRL = 1 microgram/microliter) to each sample in the microcon filter.

14. Spin in Eppendorf centrifuge until volume equals about 50 microliters (8-10') 15. Remove flowthroughs, and pool Cy3 and Cy5 flowthroughs together for future recovery of Cy dyes (store at -20 ° C). 16. Invert microcons, recover labeled samples, and pool Cy3 and Cy5 samples together that will be used for an individual experiment, in a single microcon filter that was used in step 15.

17. Add 500 microliters of T.E again, and spin until final volume equals 8 microliters or less (BE VERY CAREFUL TO NOT SPIN THE SAMPLE DRY! ! !)

18. To the 8 microliter combined Cy3 + Cy5 sample, add the following:

(a) Yeast tRNA - 1 microliter - (10 micrograms/microliter)

(b) PolyA DNA - 2 microliters - (10 micrograms/microliter)

(c) 20XSSC - 2 microliters - (FINAL SSC concentration approximately 3X) (d) 10% SDS - 0.3 microliters

FINAL VOLUME = 13.3 MICROLITERS

19. Mix well.

20. Heat sample at 100° C for 2 minutes, spin very briefly.

21. Place samples at 42° C for 20-30 minutes. 22. During Step 21, prepare the necessary number of hybridization chambers (Custom made by Die-Tech, San Jose, CA (see "Drawings for custom parts at http://cmgm.stanford.edu/pbrown/mguide/HybChamber.pdf) or purchased at Coming Costar, Acton, MA (CTM™ Hybridization Chamber, #2551), get 22mm X 22mm coverslips ready, and get arrays ready. 23. Add the 13 microliters of probe (i.e., labeled cDNA mixture) onto the center ofthe array while NOT actually touching the array face with the pipette tip.

24. Quickly and gently place the 22mm X 22mm glass#l coverslip onto the array face.

25. Add about 15-20 microliters of 3XSSC in two drops onto the end ofthe array slide away from the actual array for hydration puφoses.

26. Assemble the hybridization chamber with the array slide in it, and place into a 65 C water bath overnight.

27. Pull out the hybridization chamber and dry off the excess H₂O.

28. Disassemble the hybridization chamber, and quickly place the slides into a slide washing chamber that contains 2XSSC/0.05%SDS. Jiggle the slide holder up and down until the slide coverslip falls off. Repeat this individually for each array, one at a time, until all are done 29. Wash slides in 1XSSC for 3-5 minutes.

30. Wash slides in 50 C 0.2XSSC for 3-5 minutes, twice.

31. Spin slides down in centrifuge at 200 RPM for 2 minutes. 32.SCAN immediately.

Example 5 Collection, Processing, and Analysis of Data from Microarray Hybridizations

The cDNA microarrays were scanned with either a General Scanning (Watertown, MA) ScanArray 3000 at 20 microns resolution, or with a prototype Axon Instruments (Foster City, CA) GenePix Scanner at 10 micron resolution. The output files, which were TIFF images, were then analyzed using the program ScanAlyze (M. Eisen; available at http://www.microarrays.org/software). Fluorescent ratios and quantitative data on spot quality (see ScanAlyze manual) were stored in a prototype of the AMAD database (M. Eisen; available at http://www.microarrays.org/software). Areas ofthe array with obvious blemishes were manually flagged and excluded from subsequent analyses. The primary data tables can be downloaded at http://genome- www.stanford.edu/molecularportraits/, in text/tab delimited format after obtaining a password. Data were extracted from the database in a single table, with each row representing an array element, each column a hybridization, and each cell the observed fluorescent ratio for the array element in the appropriate hybridization. Previously flagged spots were excluded, as were spots that did not pass quality control. This table had 9216 rows and 84 columns. Array elements were removed if they were not well measured in at least 80% ofthe hybridizations. The data table was split into tumors and cell lines, and the two subtables were separately median polished (the rows and columns were iteratively adjusted to have median 0) before being rejoined into a single table. Genes whose expression varied by at least 4-fold from the median in this sample set in at least three ofthe samples tested were selected for the analyses that led to the identification of polynucleotides encoding BSTP-Ras/Rerg (1753 genes satisfied these conditions). Average-linkage hierarchical clustering, as implemented in the program Cluster (M. Eisen; http://www.microarrays.org/software), was applied separately to both the genes and arrays. The results were analyzed, and figures generated, using Tree View (M. Eisen; http://www.microarrays.org/software).

Example 6 Producing Antibodies to the BSTP-Ras/Rerg Polypeptide

This example describes the preparation of a polyclonal antibody that binds to the BSTP-Ras polypeptide, i.e., an antibody that binds to a polypeptide comprising an amino acid sequence as set forth in SEQ ID NO: 1. The example further describes affinity purification ofthe antibody.

Materials

Anisole (Cat. No. A4405, Sigma)

2,2'-azino-di-(3-ethyl-benzthiazoline-sulfonic acid) (ABTS) (Cat. No. A6499,

Molecular Probes Eugene, OR)

Activated Maleimide Keyhole Limpet Cyanin (Cat. No. 77106, Pierce Chemical

Co. Rockford, IL)

Biotin (Cat. No. B2643, Sigma)

Boric acid (Cat. No. B0252, Sigma)

Sepharose 4b (Cat. No. 17-0120-01, LKB/Pharmacia, Uppsala, Sweden)

Bovine Serum Albumin (LP) (Cat. No. 100 350, Boehringer Mannheim,

Indianapolis, IN)

Cyanogen bromide (Cat. No. C6388 Sigma, St. Louis, MO)

Dialysis tubing Spectra/Por Membrane MWCO: 6-8,000 (Cat. No. 132 665,

Spectrum Industries Inc., Laguna Hills, CA)

Dimethyl formamide (DMF) (Cat. No. 22705-6, Aldrich Chemical Company,

Milwaukee, Wl)

DIC (Cat. No. BP 592-500, Fisher)

Ethanedithiol (Cat. No. 39,802-0, Aldrich Chemicals, Milwaukee, Wl) Ether (Cat. No. TX 1275-3, EM Sciences)

Ethylenediaminetetraacetatic acid (EDTA)(Cat No. BP 120-1, Fisher Scientific,

Springfield, NJ) l-ethyl-3-(3'dimethylaminopropyl)-carbodiimide, HCL (EDC) (Cat No. 341-006,

Calbiochem, San Diego, CA)

Freund's Adjuvant, complete (Cat. No. M-0638-50B, Lee Laboratories, Grayson,

GA)

Freund's Adjuvant, incomplete (Cat. No. M0639-50B, Lee Laboratories) Fritted chromatography columns (Column part No. 12131011; Frit: Part No. 12131029, Varian Sample Preparation Products, Harbor City, CA)

Gelatin from Bovine Skin (Cat. No. G9382, Sigma)

Glycine (Cat. No. BP381-5, Fisher)

Goat anti-rabbit IgG, biotinylated (Cat No. A 0418, Sigma)

HOBt (Cat. No. 01-62-0008, Calbiochem-Novabiochem)

Horseradish peroxidase (HRP) (Cat. No. 814 393, Boehringer Mannheim)

HRP-Streptavidin (Cat. No. S 5512, Sigma)

Hydrochloric Acid (Cat No. 71445-500, Fisher)

Hydrogen Peroxide 30% w/w (Cat. No. HI 009, Sigma)

Methanol (Cat. No. A412-20, Fisher)

Microtiter plates, 96 well (Cat. No.2595, Corning-Costar Pleasanton, CA)

N-α-Fmoc protected amino acids available from Calbiochem-Novabiochem, San

Diego, CA. See 1997-1998 catalog pages 1-45.

N-α-Fmoc protected amino acids attached to Wang Resin available from

Calbiochem-Novabiochem. See 1997-1998 catalog pages 161-164.

NMP (Cat. No. CAS 872-50-4, Burdick and Jackson, Muskegon, MI)

Peptide (Synthesized by Research Genetics, Inc. Details given below)

Piperidine (Cat. No. 80640, Fluka, available through Sigma)

Sodium Bicarbonate (Cat. No. BP328-1, Fisher)

Sodium Borate (Cat. No. B9876, Sigma)

Sodium Carbonate (Cat. No. BP357-1, Fisher)

Sodium Chloride (Cat. No. BP 358-10, Fisher)

Sodium Hydroxide (Cat. No. SS 255-1, Fisher) • Streptavidin (Cat. No. 1 520, Boehringer Mannheim)

• Thioanisole (Cat. No. T-2765, Sigma)

• Trifluoroacetic acid (Cat. No. TX 1275-3, EM Sciences)

• Tween-20 (Cat. No. BP 337-500, Fisher) • Wetbox-(Rubbermaid Rectangular Servin' Saver™ Part No. 3862 Wooster, OH)

Solutions

• BBS - Borate Buffered Saline with EDTA dissolved in distilled water (pH 8.2 to 8.4 with HCl or NaOH) -25 mM Sodium borate (Borax)

-100 mM Boric Acid -75 mM NaCl -5 mM EDTA

• 0.1 N HCl in saline -concentrated HCl (8.3 mL/0.917 L distilled water)

-0.154 M NaCl

• Glycine (pH 2.0 and pH 3.0) dissolved in distilled water and adjusted to the desired pH.

-0.1 M glycine -0.154 M NaCl

• 5X Borate IX Sodium Chloride dissolved in distilled water.

-0.11 M NaCl -60 mM Sodium Borate -250 mM Boric Acid • Substrate Buffer in distilled water adjusted to pH 4.0 with sodium hydroxide: -50 to 100 mM Citric Acid

Peptide Synthesis Solutions

• AA solution: HOBt is dissolved in NMP (8.8 grams HOBt to 1 liter NMP). Fmoc-N-a-amino at a concentration at .53 M.

• DIC solution: 1 part DIC to 3 parts NMP.

• Deprotecting solution: 1 part Piperidine to 3 parts DMF • Reagent R: 2 parts anisole, 3 parts ethanedithiol, 5 parts thioanisole, 90 parts trifluoroacetic acid.

Equipment • MRX Plate Reader (Dynatech Inc., Chantilly, VA)

• Hamilton Eclipse (Hamilton Instruments, Reno, NV)

• Beckman TJ-6 Centrifuge, Refrigerated (Model No. TJ-6, Beckman Instruments, Fullerton, CA)

• Chart Recorder (Recorder 1 Part No. 18-1001-40, Pharmacia LKB Biotechnology) • UV Monitor (Uvicord SII Part No. 18-1004-50, Pharmacia LKB Biotechnology)

• Amicon Stirred Cell Concentrator (Model 8400, Amicon Inc., Beverly, MA)

• 30 kD MW cut-off filter (Cat. No. YM-30 Membranes Cat. No. 13742, Amicon Inc., Beverly, MA)

• Multi-channel Automated Pipettor (Cat. No. 4880, Coming Costar Inc., Cambridge, MA)

• pH Meter Coming 240 (Corning Science Products, Coming Glassworks, Corning, NY)

• ACT396 peptide synthesizer (Advanced ChemTech, Louisville, KY)

• Vacuum dryer (Box is from Labconco, Kansas City, MO; Pump is from Alcatel, Laurel MD).

• Lyophilizer (Unitop 600sl in tandem with Freezemobile 12, both from Virtis, Gardiner, NY)

Methods Peptides were selected using the program Omiga ™1.1 (Oxford Molecular Group,

Inc., 2105 So. Bascom Ave., Suite 200, Campbell, CA 95008) using the Hopp/Woods method, which is described in Hopp TP, Woods KR, Mol Immunol, Apr;20(4):483-9 A computer program for predicting protein antigenic determinants, 1983, and Hopp TP and Woods KR, Proc. Nat. Acad. Sci. U.S.A. 78, 3824-3828, 1981. Three peptide sequences were selected. The sequences were selected from regions ofthe polypeptide that displayed minimal homology with known proteins. The sequences of the three peptides were as follows: Peptide 1 (SEQ ID NO: 5): MAKSAEVKLAIFGRAGVGK Peptide 2 (SEQ ID NO: 6): VLPLKNILDEIKKPKN Peptide 3 (SEQ ID NO: 7): YELCREVRRRRMVQGKT

Synthesis of Peptides

Each ofthe three peptides listed above was synthesized according to the following protocol:

Incubate: Resin was immersed in appropriate solution. All incubation steps occurred with mixing.

Wash: Added 2 mis. DMF, incubated 5 minutes and drained. Wash Cycle: Five washes.

Machine Synthesis The sequence ofthe desired peptide was provided to the peptide synthesizer. The C- terminal residue was determined and the appropriate Wang Resin was attached to the reaction vessel. The peptides were synthesized C-terminus to N-terminus by adding one amino acid at a time using a synthesis cycle. Which amino acid is added was controlled by the peptide synthesizer, which looks to the sequence ofthe peptide entered into its database.

Step 1 - Resin Swelling: Added 2 mL DMF, incubated 30 minutes, drained DMF. Step 2 - Synthesis cycle

2a - Deprotection: 1 mL deprotecting solution was added to the reaction vessel and incubated for 20 minutes.

2b - Wash Cycle

2c - Coupling: 750 mL of amino acid solution and 250 mL of DIC solution were added to the reaction vessel. The reaction vessel was incubated for thirty minutes and washed once. The coupling step was repeated once. 2d - Wash Cycle

Step 2 was repeated over the length ofthe peptide. The amino acid solution changed as the sequence listed in peptide synthesizer dictated. Step 3 - Final Deprotection: Steps 2a and 2b were performed one last time.

Resins were deswelled in methanol — rinsed twice in 5 mL methanol, incubated 5 minutes in 5 mL methanol, rinsed in 5 mL methanol — and then vacuum dried.

Peptide was removed from the resin by incubating 2 hours in reagent R and then precipitated into ether. Peptide was washed in ether and then vacuum dried. Peptide was resolubilized in diH20, frozen, and lyophilized overnight.

Conjugation of Peptide with Keyhole Limpet Hemocyanin

Peptide (6 mg) was dissolved in PBS (6 mL) and mixed with 6 mg of maleiimide activated KLH carrier in 6 mL of PBS for a total volume of 12 mL. The entire solution was mixed for two hours, dialyzed in IL PBS, and lyophilized.

Immunization of Rabbits

Two New Zealand White Rabbits were injected with 250 μg keyhole limpet hemocyanin (KLH) conjugated peptide in an equal volume of complete Freund's adjuvant and saline in a total volume of 1 mL. Antigens (KLH-Peptide, 100 μg each) in an equal volume of incomplete Freund's Adjuvant and saline were injected into three to four subcutaneous dorsal sites for a total volume of 1 mL two, four, and six weeks after the first immunization. The three peptides were injected together.

The immunization schedule was as follows:

Day O Pre-immune bleed, primary immunization

Day 15 1st Boost

Day 27 1st Bleed

Day 44 2nd Boost

Day 57 2nd Bleed and 3rd Boost

Day 69 3rd Bleed

Day 84 4th boost

Day 98 4th bleed The Collection of Rabbit Serum

The rabbits were bled (30 to 50 mL) from the auricular artery. The blood was allowed to clot at room temperature for 15 minutes and the serum was separated from the clot using an IEC DPR-6000 centrifuge at 5000 x g. Cell-free serum was decanted gently into a clean test tube and stored at -20°C for affinity purification.

Determination of Antibody Titer

All solutions with the exception of wash solution were added by the Hamilton Eclipse, a liquid handling dispenser. The antibody titer was determined in the rabbits using an ELISA assay with peptide on the solid phase. Flexible high binding ELISA plates were passively coated with peptide diluted in BBS (100 μL, 1 μg/well) and the plate was incubated at 4°C in a wetbox overnight (air-tight container with moistened cotton balls). The plates were emptied and then washed three times with BBS containing 0.1% Tween-20 (BBS-TW) by repeated filling and emptying using a semi- automated plate washer. The plates were blocked by completely filling each well with BBS-TW containing 1% BSA and 0.1% gelatin (BBS-TW-BG) and incubating for 2 hours at room temperature. The plates were emptied and sera of both pre- and post- immune serum were added to wells. The first well contained sera at 1:50 in BBS. The sera were then serially titrated eleven more times across the plate at a ratio of 1 : 1 for a final (twelfth) dilution of 1 :204,800. The plates were incubated overnight at 4°C. The plates were emptied and washed three times as described.

Biotinylated goat anti-rabbit IgG (100 μL) was added to each microtiter plate test well and incubated for four hours at room temperature. The plates were emptied and washed three times. Horseradish peroxidase-conjugated Streptavidin (100 μL diluted 1:10,000 in BBS-TW-BG) was added to each well and incubated for two hours at room temperature. The plates were emptied and washed three times. The ABTS was prepared fresh from stock by combining 10 mL of citrate buffer (0.1 M at pH 4.0), 0.2 mL ofthe stock solution (15 mg/mL in water) and 10 μL of 30% H₂O₂. The ABTS solution (lOOμL) was added to each well and incubated at room temperature. The plates were read at 414 λ, 20 minutes following the addition of substrate. Preparation ofthe Peptide Affinity Purification Column: The affinity column was prepared by conjugating 5 mg of peptide to 10 mL of cyanogen bromide-activated Sepharose 4B, and 5 mg of peptide to hydrazine- Sepharose 4B. Briefly, 100 uL of DMF was added to peptide (5 mg) and the mixture was vortexed until the contents were completely wetted. Water was then added (900 μL) and the contents were vortexed until the peptide dissolved. Half of the dissolved peptide (500 μL) was added to separate tubes containing 10 mL of cyanogen-bromide activated sepharose 4B in 0.1 mL of borate buffered saline atpH 8.4 (BBS), and 10 mL of hydrazine-Sepharose 4B in 0.1 M carbonate buffer adjusted to pH 4.5 using excess EDC in citrate buffer pH 6.0. The conjugation reactions were allowed to proceed overnight at room temperature. The conjugated sepharose was pooled and loaded onto fritted columns, washed with 10 mL of BBS, blocked with 10 mL of 1 M glycine, and washed with 10 mL 0.1 M glycine adjusted to pH 2.5 with HCl and re- neutralized in BBS. The column was washed with enough volume for the optical density at 280λ to reach baseline.

Affinity Purification ofthe Antibody

The peptide affinity column was attached to a UV monitor and chart recorder.

The titered rabbit antiserum was thawed and pooled. The serum was diluted with one volume of BBS and allowed to flow through the columns at 10 mL per minute. The non-peptide immunoglobulms and other proteins were washed from the column with excess BBS until the optical density at 280 λ reached baseline. The columns were disconnected and the affinity purified column was eluted using a stepwise pH gradient from pH 7.0 to pH 1.0. The elution was monitored at 280 nM, and fractions containing antibody (pH 3.0 to pH 1.0) were collected directly into excess 0.5 M BBS. Excess buffer (0.5 M BBS) in the collection tubes served to neutralize the antibodies collected in the acidic fractions ofthe pH gradient.

The entire procedure was repeated with "depleted" serum to ensure maximal recovery of antibodies. The eluted material was concentrated using a stirred cell apparatus and a membrane with a molecular weight cutoff of 30 kD. The concentration ofthe final preparation was determined using an optical density reading at 280 nM. The concentration was determined using the following formula: mg/mL = OD₂₈₀/1.4.

Example 7

SDS-PAGE and Immunoblot Analysis of BSTP-Ras

This example describes in detail one approach to investigating the expression pattern of BSTP-Ras. Example X describes similar experiments that have been performed.

Extracts are made from a variety of different cell lines and subjected to SDS- PAGE followed by immunoblotting according to the protocol below, using an affinity purified polyclonal antibody to BSTP-Ras prepared as described in Example 6.

Materials

Acetic acid, Glacial (Cat. No. A38°-212, Fisher)

Acrylamide (Cat. No. A-3553, Sigma)

Anti-Rabbit IgG (H&L) (Cat. No. 31460ZZ, Pierce)

Bis-acrylamide (Cat. No. M-7279, Sigma)

Blotting paper (Cat. No. 170-3960, Bio-Rad, Hercules, CA)

Bovine Serum Albumin (LP) (Cat. No. 100-350, Boehringer Mannheim,

Indianapolis, IN)

Brilliant Blue R-250 (Cat. No. BP101-25, Fisher)

Complete™ Mini (Cat. No. 1836153, Boehringer Mannheim)

ECL Western Blotting Detection Reagents (Cat. No. RPN2106, Amersham

Pharmacia Biotech, Piscataway, NJ)

Ethyl alcohol (AAPER Alcohol and Paper Chemical Co., Shelbyville, KY)

Gelplate Clean (Cat. No. 786-140RF, Geno Technology, Inc., St. Louis)

Gelatin (Cat. No. G-2500, Sigma)

Glycerol (Cat. No. BP229-1, Fisher)

Glycine (Cat. No. G-8898, Sigma)

Hybond ECL (Cat. No. RPN303D, Amersham Pharmacia Biotech) Lauryl Sulfate (SDS) (Cat. No. L-3771, Sigma)

Methanol (Cat. No. BP1105-4, Fisher)

M-Per (Cat. No. 78501, Pierce, Rockford, IL)

Nalgene bottle top filters (Cat. No. 09-740-62B, Fisher)

Nonfat dry milk (Kroger Co., Cincinnati, OH)

Ponceau-S (Cat. No. P-07170, Sigma)

Potassium phosphate (Cat. No. P-0662, Sigma)

2X SDS gel loading buffer (Cat. No. 750006, Research Genetics, Huntsville, AL)

Size markers (Cat. No. M-3913, M-4038, M-3788, Sigma)

Sodium azide (Cat. No. S227I-25, Fish)

Sodium chloride (Cat. No. S271-3, Fisher)

Sodium phosphate, Dibasic, Anhydrous (Cat. No. BP332-1, Fisher) t-amyl alcohol (Cat. No. A- 16852, Sigma)

TEMED (Cat. No. T-9281, Sigma)

Trizma® Base (Cat. No. T-6066, Sigma)

Tween-20 (Cat. No. BP337-500, Fisher)

Solutions

• PBS - Phosphate Buffered Saline dissolved in distilled water -136 mM NaCl

-2.7 mM KC1

-10.1 mM Na₂HPO₄

-1.8 mM KH₂PO₄

• Acrylamide/Bis (30% T, 2.67% C) dissolved in distilled water -4.1 M acrylamide

-51.9 mM N,N'-

• 1.5 M Tris-HCl (pH 8.8) dissolved in distilled water

• 0.5 M Tris-HCl (pH 6.8) dissolved in distilled water

• 10% SDS - dissolve 10 grams SDS in 100 mis distilled water • Running Buffer

-24.8 mM Tris base -191.9 mM glycine -3.5 mM SDS

• Towbin transfer buffer (pH 8.3) dissolved in distilled water -20% methanol

-25 mM Tris -192 mM glycine

• Equilibrating buffer for gel drying, mixed in distilled water -20% ethanol

-10% glycerol

• Gel staining solution dissolved in distilled water -0.3 mM Coomassie brilliant blue R-250

-40% methanol

-7% glacial acetic acid

• Gel destaining solution mixed in distilled water -25% methanol -7% glacial acetic acid

• 10% Tween^®20 in PBS

• 5% Nonfat dry milk in PBS

• 0.2% BSA Blocking Buffer dissolved in PBS -0.2% BSA -0.1%) gelatin

-0.05% Tween^®20

• Wash Buffer -0.05% Tween^®20 -IX PBS Equipment

• Microcentrifuge (Model 5415, Eppendorf)

• Power Pak 200 (Cat. No. 165-5052, Bio-Rad)

• Power Pak 3000 (Cat. No. 165-5056, Bio-Rad)

• Protean II xi Cell (Cat. No. 165-1813, Bio-Rad) • Recirculating chiller (Cat. No. CFT33D 115 V, Neslab Instruments, Inc.. Portsmouth, NH)

• 20-Well comb (Cat. No. 165-1867, Bio-Rad) • pH Meter Corning 240 (Corning Science Products, Corning Glasswares, Corning, NY)

• Air Cadet vacuum pump (Cat. No. P-07530-50, Cole-Palmer Instruments Co., Chicago, IL) • Tissue Tearor tissue homogenizer (Cat. No. 985370-07, BioSpec Products Inc., Bartletsville, OK)

Methods

Sample Preparation Preferably a variety of cell lines known in the art are used for the experiment, including cell lines derived from breast tumors, cell lines derived from normal breast . tissue, cell lines derived from other cancer types, etc. A selection of appropriate cancer cell lines for investigation ofthe expression of BSTP-Ras is found in reference

21. A selection of noncancer cell lines appropriate for investigation ofthe expression of BSTP-Ras is found in Perou, et al., Molecular portraits of human breast tumours,

Nature, 406(6797):747-52, 2000. Cell lines are maintained under standard growth conditions and in standard tissue culture media as appropriate for the particular cell line. Cells are collected according to standard techniques (e.g., trypsinization in the case of adherent cells), and the resulting cell suspension is prepared as follows: -The cell suspension is pelleted by centrifugation at 3000 RPM for 10 minutes, and the supernatant discarded.

-The pellet is washed with 1ml PBS, centrifuged at 10000 RPM for 10 minutes, and the supernatant discarded.

-An appropriate volume of M-Per™ Reagent is added to the cell pellet and mixed gently for 10 minutes in an ice bath. The mixture is centrifuged at 13200 RPM for 15 minutes, and the supernatant is saved.

The protein concentration in the supernatant is measured according to standard techniques.

All samples are mixed at 1:1 with gel loading buffer and boiled for 5 minutes before loading. SDS PAGE

Standard SDS-PAGE stacking and running gels are prepared and placed in an electrophoresis apparatus. After filling the upper and lower chambers with running buffers the samples (60 μg/lane) are loaded. The inner core is placed in the lower chamber and the lid placed on top. The apparatus is connected to the power supply and recirculating system. The temperature setting is 10°C. The stacking gel is run at 14mA per gel for 1 hour. The separating gel is run at 0.58mA per gel per hour for 16 hours.

Transfer to nitrocellulose

After electrophoresis is complete, the gel is equilibrated in Towbin Buffer for 15-30 minutes. The assembly for transfer is as follows: cathode pre-soaked blotting paper gel pre-wetted nitrocellulose pre-soaked blotting paper anode The transfer is performed at 20V for 25 minutes, then 25V for 20 minutes. After the transfer is complete, the gel is stained with Coomassie and the blot is stained with Ponceau-S.

Western Blotting

Primary and secondary antibodies All primary and secondary antibodies are diluted in 0.2% BSA blocking buffer. All incubation steps are done with gentle mixing.

Blots are blocked in 5% milk overnight at room temperature. The blots are rinsed with wash buffer before adding the primary antibody and incubating for two hours at room temperature. One wash cycle is performed. One wash cycle consists of: Wash 5 min, rinse Wash 5 min, rinse Wash 10 min, rinse

Wash 5 min, rinse

Wash 5 min, rinse The secondary antibody is added and incubated for one hour at room temperature. One wash cycle is then performed. Peptide Block

As a control to demonstrate the specificity ofthe antibody, equal amounts (w/w) of peptide and antibody are added to 1/10 ofthe final volume of blocking buffer and incubated overnight at 4°C. The volume of blocking buffer is then brought up to the final volume, and the membrane is incubated for an additional two hours at room temperature.

Developing

The blots are placed in a Ziploc® bag. Equal volumes of ECL western blotting detection reagents are mixed and distributed evenly over the blots. The blots are placed in an autoradiography cassette, covered with a piece of film, and exposed.

Example 8 Detection of BSTP-Ras in Breast Cancer Samples by Immunohistochemistry

A breast cancer tissue microarray consisting of tissue samples from a large number of breast cancer biopsies is prepared essentially as described in Kononen, J., et al., Tissue microarrays for high-throughput molecular profiling of tumor specimens, Nature Medicine, 4(7), 844-847, 1998. Briefly, several hundred archival paraffin- embedded breast tumor samples were obtained from the Pathology Department at Stanford University Medical Center. The samples were reviewed by a pathologist (applicant MVR) to ensure that they met pathological criteria for breast cancer. Small tissue cores were removed from the samples and embedded in a single paraffin block to produce a tissue array. Immunohistochemistry is performed as described previously (Perou, C, et al, 1999; Bind], J. and Warnke, R., Am J Clin Pathol, 85, 490-493, 1986, and Natkunam, Y., et al, Am. J. Path., 156(1), 2000, using an antibody to BSTP-Ras/Rerg generated as described in Example 6. Example 9 BST-RAS/RERG Expression in Primary Breast Tumors, Breast-Derived Cell Lines, and Human Tissues

Materials and Methods Microarray Data Analysis

A new analytical method called Statistical Analysis of Microarrays (SAM; described in Tusher, V., Tibshirani, R., and Chu, G., Proc Natl Acad Sci USA 98(9), 5116-5121, 2001) was used to analyze microarray data from 1753 differentially expressed genes, obtained as described in Example 5. The 1753 genes and their relative expression levels are presented in Table 1.

RNA Isolation and Northern Blot Analysis Human breast-derived cell lines were obtained from the American Type Culture

Collection (ATCC) and were maintained in either RPMI or αMEM with 10% fetal calf serum. To analyze Rerg expression, RNA was isolated by acid-phenol extraction as described (Chirgwin, J. M., Przybyla, A. E., MacDonald, R. J., and Rutter, W. J. (1979) Biochemistry 18(24), 5294-9). Total RNA (-25 μg) was resolved on a 1.3% agarose/formaldehyde gel, denatured, and transferred to Hybond-N (Amersham Pharmacia Biotech). [α³²P]dCTP labeled Rerg or GAPDH cDNA was prepared with Random Prime Kit (BMB), purified with Sephadex G50 "NICK" column (Pharmacia), and hybridized to the RNA samples using PerfectHyb (Sigma), all according to the instructions ofthe respective manufacturers. To further analyze Rerg mRNA expression, a similar process to that described above was used to probe a human multiple tissue Northern blot (Clontech). In addition, Rerg expression was investigated by screening the dbest database.

Results Data analysis using SAM resulted in the identification of 264 genes whose expression correlated with overall patient survival. Of particular interest were genes in which high expression was associated with favorable patient outcomes and the longest relapse free survival times. A single cluster of genes, the "luminal epithelial/ER+" cluster, described more fully in copending U.S. Patent Application "Reagents and Methods for Use in Managing Breast Cancer, filed July 26, 2001 and in U.S. Provisional Patent Application Ser. No. 60/220,967, filed July 26, 2000, contained most ofthe genes whose high expression was associated with long survival times. Thus data analysis using SAM confirmed the initially recognized correlation between longer survival times and high expression of genes in the luminal epithelial/ER+ cluster. Tumors that most highly expressed the luminal/epithelial set of genes were, on average, some ofthe least proliferative tumors. BST-RAS/RERG was included in both the "luminal epithelial/ER+" gene cluster and the 264 gene survival-associated cluster. In addition to Rerg, these clusters included the ER and also a known estrogen-regulated gene (LIV-1). The mRNA expression pattern of Rerg across the 78 breast tumors described in Example 2 was a statistically significant predictor of patient outcome in a univariate analysis (p=0.0037), however, as would be expected based on its expression pattern, it was not an independent predictor of outcome in a multivariate analysis due to its correlation with ER expression (p=0.0001).

As shown in the upper panel of Figure 4 (lanes 3, 5, 6, and 7), Rerg mRNA was detected in all ofthe estrogen receptor positive breast derived cell lines (MCF- 10A, BT474, MCF-7, and T47D). As shown in lanes 4, 8, 9, and 10, Rerg mRNA was not detected in any ofthe ER negative cell lines examined (SK-BR-3, MDA-MB- 231, Hs578T, and BT-549). Rerg mRNA was also not detected in rat intestinal epithelial cells (RIE-1, lane 2). The lower panel of Figure 5, probed with labeled GAPDH cDNA, shows that equal amounts of RNA were loaded in each lane. Rerg mRNA was detected by Northern analysis in human heart, brain, placenta, lung, liver, skin, kidney, and pancreas, with the highest levels ofexpression in heart, kidney, and pancreas. A potentially ubiquitous pattern ofexpression was supported by Unigene/EST expression data (Hs.127756 and Hs.21594), which indicated that Rerg is found in brain, kidney, muscle, prostate, uterus, adrenal gland, aorta, eye, lung, placenta, stomach, and testis.

Example 10 Microarray Analysis Demonstrates that Rerg is an Estrogen-responsive Gene Materials and Methods

All cDNA microarrays were produced and hybridized as described in Example land in either Perou, C. M., et al., Nature 406, 747-752, 2000 or Perou, C. M., et al. Proc Natl Acad Sci USA 96(16), 9212-9217, 1999. For the MCF-7 estrogen add back experiments, the parental vector only MCF-7 control cell line (MCF-7-pCDNA3) generated as described in Example 11 was used and was first grown up to 50-70% confluency in RPMI + 10% Fetal Calf Serum (FSC) + pen/strep, at which point the cells were switched to phenol-red free RPMI medium that contained 10% dextran-charcoal stripped FCS (Hyclone, Logan UT) plus pen/step for 48 hr. Some of these estrogen deprived cells were then given 10^"9 M β- 17-estradiol (Sigma) for 4 hr, 8 hr and 24 hr. For the tamoxifen treated samples, 70% confluent cultures of MCF-7 cells in RPMI + 10% FCS + pen/strep media containing phenol red, were treated with either 1 μm or 10 μm tamoxifen (Sigma) for 48 hr. mRNA was prepared from each sample using a FastTrack 2.0 mRNA Kit

(Invitrogen) and compared on 23,000 clone, or 44,000 clone cDNA microarrays prepared as described in Example 1 and in Perou, C. M., et al. Proc Natl Acad Sci USA 96(16), 9212-9217, 1999. In the case ofthe tamoxifen treated samples, the control untreated cells were labeled with Cy3 and were compared to the tamoxifen treated samples that were labeled with Cy5; for the estrogen add back experiments, the 48 hr estrogen deprived samples were labeled with Cy3 and were compared to the estrogen treated samples (Cy5).

Results

The location of Rerg within a gene expression cluster that includes the ER, the high expression of Rerg in ER-positive breast cell lines, and the presence of two potential ER binding sites within the promoter region suggested that Rerg might be an estrogen- responsive gene. To evaluate this possibility, cDNA microarray analysis was used to examine Rerg expression in response to β-estradiol stimulation in the estrogen responsive MCF-7 cell line (see http://genome-www4.stanford.edu/MicroArray/SMD/ for all microarray primary data files). MCF-7 cells grown in estrogen-free media for 2 days were supplemented with β-estradiol (1 X 10^"8 M) for 4, 8, or 24 hr before harvesting mRNA and were compared to 48 hr estrogen deprived MCF-7 cultures. As shown in Figure 5, Rerg was rapidly expressed in response to β-estradiol treatment (1.9-fold stimulation after 4 hr and 3-fold after 24 hr), suggesting that it is a direct target of activated ER. Tamoxifen, an ER antagonist in the breast, acts as an inhibitor of estrogen-induced responses including the regulation ofER-responsive genes. Thus, the effect of tamoxifen (1 X IO^"6 M) in the presence of estrogen was examined on global gene expression patterns. As expected for an ER-regulated gene, Rerg expression was completely repressed by tamoxifen and induced by estrogen, although not as dramatically as other known estrogen regulated genes (see cathepsin D and protein kinase HI 1 for examples of how known ER-responsive genes behaved in these experiments) (Fig. 5).

Example 11 Subcellular Distribution of Rerg in Living Cells

Materials and Methods Plasmids

The Rerg coding sequence was amplified from I.M.A.G.E. EST clone 28777 using primers that contain EcoRI-Ndel and BamHI restriction sites and was subcloned into the corresponding sites ofthe yeast expression vector pWHA, which contains a hemagglutanin (HA) epitope tag, to create pWHA-i?erg. Next, HA-i?erg was subcloned into the EcoRI-BamHI sites ofthe human expression vector pCDNA3 (Invitrogen) resulting in pCDNA3-HA-i?erg. For localization studies in live cells, Rerg in pKH3 (an expression plasmid used to generate fusions with the HAl epitope as described in Mol. Cell. Biol, 14, 7943, 1994) was used as a PCR template to generate open reading frame cassettes for subcloning into the enhanced GFP expression vector pEGFP-C3 (Clontech). The cassettes contained 5' EcoRI and 3' BamHI restriction enzyme recognition sites and were directionally cloned downstream of and in frame with the green fluorescent protein (GFP) tag ofthe vector (generating plasmid pEGFP-iterg) to express GFP-Rerg fusion protein.

Cell Culture for Transfections NIH 3T3 mouse fibroblasts were maintained in Dulbecco's Modified Eagle Medium (DMEM) supplemented with 10% calf serum. MCF-7 human breast carcinoma cells used for Rerg overexpression studies were maintained in αMEM supplemented with 10%> FCS. MCF-7 cells overexpressing HA-tagged wild type Rerg (designated MCF-7-Rerg), or vector alone (designated MCF-7-pCDNA3), were generated by transfecting cells with either pCDNA3-HA-i?erg or pCDNA3 respectively. Stable MCF-7 transformants were selected for resistance to 0.5 mg/ml of G418 and individual clones were isolated using cloning discs. All transfections were performed using LipoFectamine Plus Reagent (GibcoBRL) according to the directions ofthe manufacturer.

Localization of GFP-Rerg in Cultured Cells

NIH 3T3, MCF-7, or MDA-MB-231 cells maintained as described above were transiently transfected with 1 μg pEGFP or pEGFP-iϊerg using the LipofectAMINE PLUS Reagent (GibcoBRL) in serum-free medium according to manufacturer's protocol. Three hours post-transfection cells were then switched to normal growth medium, and 20 hr post-transfection cells were viewed in a Zeiss Axiophot fluorescence microscope (63X Plan-APOCHROMAT objective) equipped with a cooled charge-coupled device (CCD) camera and digitized images were captured using MetaMoφh™ 4.1.4 digital imaging software (Universal Imaging Coφ.). GFP expression was detected from 20 μg of cell lysate by immunoblotting with anti-GFP monoclonal antibody (Clontech) followed by anti-mouse HRP-conjugated antibody and visualized by enhanced chemiluminescence reagent (Pierce).

Results

To determine the subcellular localization of Rerg, a green fluorescent protein (GFP) tagged Rerg fusion protein was transiently expressed in the human breast tumor-derived cell lines MCF-7 and MDA-MB-231 and in NIH 3T3 mouse fibroblasts. As shown in Figure 7A, transient transfection with the GFP-Rerg vector (pEGFP-iϊerg) led to the production of an intact GFP-Rerg fusion protein as determined by anti-GFP western blotting (lane 2 in each panel). Epifluorescence microscopy of live cells transiently expressing GFP-Rerg revealed a uniform distribution throughout the cell, including signal localized in the nucleus (Figure 7B, lower panels). A similar expression and distribution was detected in MCF-7 cells stably expressing HA-epitope tagged Rerg, and in a series of additional cell lines transiently expressing GFP-Rerg. No cells were found that exhibited a plasma membrane localization of Rerg, which is consistent with the lack of a COOH-terminal prenylation signal sequence. This distribution is similar to that seen in cells expressing GFP alone (Figure 7B, upper panels).

The distribution of HA-epitope-tagged Rerg was also examined using biochemical fractionation and Western blot analysis and showed that HA-Rerg was present predominantly in the cytosolic fraction of MCF-7 cell lysates, with a small amount in the nuclear fraction.

Example 12 Growth Inhibition by Rerg Protein

This example demonstrates the ability of Rerg to inhibit both anchorage- dependent growth (i.e., cell growth on the bottom tissue culture dishes in liquid medium) and anchorage-independent growth (i.e., cell growth in soft agar).

Materials and Methods

Western Blot Analysis of HA-Rerg

Total cell lysates were prepared by first growing cells to 80% confluence on 100 mm plates. Next, the cells were washed one time with IX PBS and incubated on ice with 1 ml of RIPA buffer (150 mM NaCl, 1% NP-40, 0.5% DOC, 0.1% SDS, and 50 mM Tris, pH 7.5) for 30 min with occasional shaking. Cells were then spun for 10 min at 10,000 X g, and the protein concentration ofthe lysate determined by the Bradford Assay (BioRad). 40 μg of cell lysate was resolved on al2% SDS- polyacrylamide gel and HA-Rerg expression analyzed by Western blotting using the anti-HA.11 monoclonal antibody (BAbCo). Anchorage-dependent and anchorage-independent growth assays

MCF-7 cells stably expressing empty vector pCDNA3 (control) or overexpressing HA-Rerg (clones 1C4, 1C2, or 2B6) were generated as described in Example 11. Growth curves were generated for MCF-7 cells stably expressing HA- Rerg protein or vector controls as described in Clark, G. J., Cox, A. D., Graham, S. M., and Der, C. J., Methods Enzymol 255, 395-412, 1995. In brief, stable transfectants (MCF-7 cells stably expressing empty vector (control) or Rerg overexpressing clones 1C4, 1C2, or 2B6 generated as described in Example 11) were seeded at 2 x IO⁴ cells per well in tissue culture medium in 6 well plates, then trypsinized and counted from triplicate wells at 1, 2, 3, 4, 5, 6, and 7 days after seeding.

Soft agar growth analyses were performed as described previously (Clark, G. J., Cox, A. D., Graham, S. M., and Der, C. J., Methods Enzymol 255, 395-412, 1995). Briefly, IO⁴ MCF-7 cells stably expressing empty vector pCDNA (control) or HA- Rerg overexpressing clones 1C4, 1C2, or 2B6, were seeded in duplicate into 0.3% bacto-agar (Difco) over a 0.6% agar bottom layer, with colonies quantitated after -20 days.

Results

The level ofexpression of HA-Rerg in clonal cell lines generated by tranfecting MCF-7 cells with empty vector (pCDNA3) or HA-Rerg expression vector (pCDNA-HA-i?erg) was evaluated by Western blot analysis. As shown in Figure 8A, Western blot analysis with anti-HA antibodies verified expression of HA-Rerg in three clonal Rerg overexpressing isolates, with the highest expression detected in clone 2B6, medium expression detected in clone 1C4, and lowest expression detected in clone 1C2.

The consequences of constitutively high Rerg expression on the rate of cell proliferation was first assessed in cell cultures maintained on plastic. All three clonal cell lines expressing HA-Rerg showed reduced rates of cell proliferation when compared to the vector-transfected control cell line (Figure 8B). A similar growth inhibition was observed with MCF-7 cells when Rerg expression was transient, i.e., induced under the control of an inducible promoter. Second, the effect of Rerg overexpression on anchorage-independent growth potential of MCF-7 cells was determined. As shown in Figure 8C, MCF-7 cells expressing HA-Rerg showed greatly reduced colony forming efficiency (50-80%> reduction) in soft agar when compared to the control vector only MCF-7 cells. These results indicate that elevated Rerg expression causes a growth-inhibitory effect, suggesting that loss of Rerg expression or inhibition of Rerg function or activity may facilitate tumor development and/or growth.

Example 13

Effect of Rerg Overexpression on Tumor Formation in Immunocompromised Mice

Materials and Methods

Tumorigenicity in Immunocompromised Mice Tumorigenicity analyses were performed as described previously (Clark, G. J.,

Cox, A. D., Graham, S. M., and Der, C. J., Methods Enzymol 255, 395-412, 1995), except that 0.72mg/60-day time-release 17-β estradiol pellets (Innovative Research of America) were implanted subcutaneously ~24 hr prior to injection of cells. MCF-7 cells stably expressing empty vector (pCDNA) or clones overexpressing Rerg at medium or high levels (clones 1C4 and 2B6, respectively) were injected subcutaneously into 6-8 week athymic nude (BALB/c nu/nu) female mice at IO⁶ cells per site, at two sites per animal (dorsal flanks). Tumor formation was monitored at least twice a week and measured using calipers over the skin ofthe animal from 9-70 days post-injection.

Results

As shown in Table 1, tumors grew at each site injected with empty vector control MCF-7 cells with a latency of approximately 52 days. Tumors were also found in mice injected with cells from clone 1C4 (low HA-Rerg-expressing clone) with a similar latency. In contrast, mice injected with cells from the high HA-Rerg- expressing 2B6 clone remained tumor-free for an additional month (remaining tumor- free through the end ofthe observation period). Thus elevated Rerg expression inhibited tumor formation in nude mice, suggesting that loss of Rerg expression or inhibition of Rerg function or activity may facilitate tumor development and/or growth. Table I. Suppression of MCF-7 cell tumor formation in nude mice by Rerg expression

post-injection

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Claims

We claim: 1. A substantially purified polypeptide whose sequence comprises the polypeptide sequence of SEQ ID NO: 1.

la. A fragment ofthe polypeptide of claim 1, wherein the fragment is at least 50 amino acids in length.

lb. A fragment ofthe polypeptide of claim 1, wherein the fragment is at least 100 amino acids in length.

lc. A fragment ofthe polypeptide of claim 1 , wherein the fragment is at least 150 amino acids in length.

Id. A variant ofthe polypeptide of claim 1, wherein the variant includes between 1 and 10 amino acid substitutions, inclusive.

le. A variant ofthe polypeptide of claim 1, wherein the variant includes between 11 and 25 amino acid substitutions, inclusive.

If. A variant ofthe polypeptide of claim 1, wherein the variant includes between 26 and 50 amino acid substitutions, inclusive.

lg. A variant ofthe polypeptide of claim 1, wherein the variant includes an addition or substitution of between 1 and 10 amino acids, inclusive.

lh. A variant ofthe polypeptide of claim 1, wherein the variant includes an addition or substitution of between 11 and 25 amino acids, inclusive.

1 i. A substantially purified polypeptide having significant similarity to a polypeptide whose sequence is set forth in SEQ ID NO: 1, wherein a polypeptide is considered significantly similar if, when the amino acid sequence ofthe polypeptide is compared with the amino acid sequence ofthe polypeptide of SEQ ID NO: 1 using the BLAST algorithm and the BLOSUM substitution matrix with default parameters, the result is a % identity greater than 60 or a % positive greater than 70 encompassing at least 25% ofthe length of SEQ ID NO: 1, or both.

lj. A substantially purified polypeptide having significant similarity to a polypeptide whose sequence is set forth in SEQ ID NO: 1, wherein a polypeptide is considered significantly similar if, when the amino acid sequence ofthe polypeptide is compared with the amino acid sequence ofthe polypeptide of SEQ ID NO: 1 using the BLAST algorithm and the BLOSUM substitution matrix with default parameters, the result is a % identity greater than 60 or a % positive greater than 70 encompassing at least 50% ofthe length of SEQ ID NO:l, or both.

1 jj . A substantially purified polypeptide having significant similarity to a polypeptide whose sequence is set forth in SEQ ID NO: 1, wherein a polypeptide is considered significantly similar if, when the amino acid sequence ofthe polypeptide is compared with the amino acid sequence of the polypeptide of SEQ ID NO: 1 using the BLAST algorithm and the BLOSUM substitution matrix with default parameters, the result is a % identity greater than 60 or a % positive greater than 70 encompassing at least 75% ofthe length of SEQ ID NO:l, or both.

Ik. A substantially purified polypeptide having significant similarity to a polypeptide whose sequence is set forth in SEQ ID NO: 1, wherein a polypeptide is considered significantly similar if, when the amino acid sequence ofthe polypeptide is compared with the amino acid sequence ofthe polypeptide of SEQ ID NO: 1 using the BLAST algorithm and the BLOSUM substitution matrix with default parameters, the result is a % identity greater than 70 or a % positive greater than 80 encompassing at least 25% ofthe length of SEQ. ID NO: 1 , or both.

11. A substantially purified polypeptide having significant similarity to a polypeptide whose sequence is set forth in SEQ ID NO: 1, wherein a polypeptide is considered significantly similar if, when the amino acid sequence ofthe polypeptide is compared with the amino acid sequence ofthe polypeptide of SEQ ID NO:l using the BLAST algorithm and the BLOSUM substitution matrix with default parameters, the result is a %> identity greater than 70 or a % positive greater than 80 encompassing at least 50% ofthe length of SEQ ID NO:l, or both. .

111. A substantially purified polypeptide having significant similarity to a polypeptide whose sequence is set forth in SEQ ID NO: 1, wherein a polypeptide is considered significantly similar if, when the amino acid sequence ofthe polypeptide is compared with the amino acid sequence ofthe polypeptide of SEQ ID NO: 1 using the BLAST algorithm and the BLOSUM substitution matrix with default parameters, the result is a % identity greater than 70 or a % positive greater than 80 encompassing at least 75% of the length of SEQ ID NO: 1 , or both.

lm. A substantially purified polypeptide having significant similarity to a polypeptide whose sequence is set forth in SEQ ID NO: 1, wherein a polypeptide is considered significantly similar if, when the amino acid sequence ofthe polypeptide is compared with the amino acid sequence ofthe polypeptide of SEQ ID NO: 1 using the BLAST algorithm and the BLOSUM substitution matrix with default parameters, the result is a % identity greater than 80 or a % positive greater than 90 encompassing at least 25% of the length of SEQ ID NO: 1 , or both.

In. A substantially purified polypeptide having significant similarity to a polypeptide whose sequence is set forth in SEQ ID NO: 1, wherein a polypeptide is considered significantly similar if, when the amino acid sequence ofthe polypeptide is compared with the amino acid sequence ofthe polypeptide of SEQ ID NO:l using the BLAST algorithm and the BLOSUM substitution matrix with default parameters, the result is a %> identity greater than 80 or a %> positive greater than 90 encompassing at least 50%> ofthe length of SEQ ID NO: 1 , or both. Inn. A substantially purified polypeptide having significant similarity to a polypeptide whose sequence is set forth in SEQ ID NO: 1, wherein a polypeptide is considered significantly similar if, when the amino acid sequence ofthe polypeptide is compared with the amino acid sequence ofthe polypeptide of SEQ ID NO: 1 using the BLAST algorithm and the BLOSUM substitution matrix with default parameters, the result is a % identity greater than 80 or a % positive greater than 90 encompassing at least 75% ofthe length of SEQ ID NO: 1 , or both.

2. A purified and isolated polynucleotide comprising the polynucleotide sequence of SEQ ID NO: 2.

3. A purified and isolated polynucleotide comprising the polynucleotide sequence of SEQ ID NO: 3.

4. A purified and isolated polynucleotide comprising the polynucleotide sequence of SEQ ID NO: 3.

5. A purified and isolated polynucleotide having a sequence that is complementary to the polynucleotide sequence of any of claims 2, 3, or 4.

6. An isolated and purified polynucleotide encoding a polypeptide whose amino acid sequence comprises the amino acid sequence of SEQ ID NO: 1.

6a. An isolated and purified polynucleotide encoding a polypeptide having significant similarity to the polypeptide having a sequence set forth in SEQ ID NO: 1 , wherein a polypeptide having significant similarity the polypeptide having a sequence set forth in SEQ ID NO:l is defined as in claim li, lj, Ik, 11, lm, or In.

7. An isolated and purified polynucleotide that hybridizes to the polynucleotide of SEQ ID NO: 2 under stringent conditions. 7a. An isolated and purified polynucleotide that hybridizes to the polynucleotide of SEQ ID NO:3 under stringent conditions.

7b. An isolated and purified polynucleotide that hybridizes to the polynucleotide of SEQ ID NO:4 under stringent conditions.

7c. An isolated and purified polynucleotide that hybridizes to the polynucleotide of SEQ ID NO:4 under stringent conditions.

7d. An isolated and purified polynucleotide that hybridizes to the polynucleotide of SEQ ID NO:5 under stringent conditions.

7e. An isolated and purified polynucleotide that hybridizes to the polynucleotide of SEQ ID NO: 2 under moderately stringent conditions.

7f. An isolated and purified polynucleotide that hybridizes to the polynucleotide of SEQ ID NO:3 under moderately stringent conditions.

7g. An isolated and purified polynucleotide that hybridizes to the polynucleotide of SEQ ID NO:4 under moderately stringent conditions.

7h. An isolated and purified polynucleotide that hybridizes to the polynucleotide of SEQ ID NO:4 under moderately stringent conditions.

7i. An isolated and purified polynucleotide that hybridizes to the polynucleotide of SEQ ID NO:5 under moderately stringent conditions.

7j. An isolated and purified polynucleotide that hybridizes to the polynucleotide of claim 6 under stringent conditions.

7k. An isolated and purified polynucleotide that hybridizes to the polynucleotide of claim 6a under stringent conditions.

71. An isolated and purified polynucleotide that hybridizes to the polynucleotide of claim 6 under moderately stringent conditions.

7m. An isolated and purified polynucleotide that hybridizes to the polynucleotide of claim 6a under moderately stringent conditions.

10. An expression vector comprising the polynucleotide of claim 6.

10a. An expression vector comprising the polynucleotide of claim 6a.

11. An expression vector comprising a polynucleotide that encodes the fragment of any of claims la, lb, or lc.

12. An expression vector comprising a polynucleotide that encodes the variant of any of claims Id, le, If, lg, or lh.

20. A host cell comprising the expression vector of claim 10. 20a. A host cell comprising the expression vector of claim 10a.

30. A method of producing a polypeptide comprising an amino acid sequence selected from the group consisting of SEQ ID NO: 1 and a polypeptide whose sequence has significant similarity to the amino acid sequence of SEQ ID NO: 1 , the method comprising the steps of: culturing the host cell of claim 20 under conditions wherein the polypeptide is expressed; and recovering the polypeptide from the host cell culture.

50. A pharmaceutical composition comprising: the polypeptide of claim 1, or a polypeptide whose sequence has significant similarity to the amino acid sequence of SEQ ID NO: 1 ; and a pharmaceutically acceptable carrier.

55. A pharmaceutical composition comprising: • the polynucleotide of claim 6; and a pharmaceutically acceptable carrier.

60. A purified antibody that specifically binds to the polypeptide of claim 1.

65. A purified antibody that specifically binds to the polypeptide of SEQ ID NO: 1.

65a. A purified antibody that specifically binds to a polypeptide having significant similarity to the polypeptide having a sequence set forth in SEQ ID NO: 1, wherein a polypeptide having significant similarity the polypeptide having a sequence set forth in SEQ ID NO:l is defined as in claim li, lj, Ik, 11, lm, or In.

66. The antibody of claim 60 or claim 65, wherein the antibody is a polyclonal antibody.

67. The antibody of claim 60 or claim 65, wherein the antibody is a monoclonal antibody.

70. A pharmaceutical composition comprising: the antibody of claim 60 or claim 65; and a pharmaceutically acceptable carrier.

80. A method for detecting a polynucleotide that encodes a polypeptide comprising an amino acid sequence set forth in SEQ ID NO:l in a biological sample, the method comprising steps of: (a) hybridizing a nucleic acid complementary to the polynucleotide that encodes a polypeptide comprising an amino acid sequence set forth in SEQ ID NO:l, or that encodes a fragment or variant ofthe polypeptide, to at least one nucleic acid in the biological sample, thereby forming a hybridization complex; and (b) detecting the hybridization complex, wherein the presence ofthe hybridization complex indicates the presence of a polynucleotide encoding the polypeptide in the biological sample.

81. The method of claim 80, wherein the biological sample comprises breast cancer tissue or cells.

82. The method of claim 80, wherein the biological sample comprises normal breast tissue or cells.

85. A method for detecting a polynucleotide that encodes a polypeptide comprising an amino acid sequence set forth in SEQ ID NO:l comprising steps of: (a) hybridizing a nucleic acid that encodes a polypeptide comprising an amino acid sequence set forth in SEQ ID NO:l to at least one nucleic acid complementary to a nucleic acid in the biological sample, thereby forming a hybridization complex; and (b) detecting the hybridization complex, wherein the presence ofthe hybridization complex indicates the presence ofthe polynucleotide in the biological sample.

86. The method of claim 85, wherein the biological sample comprises breast cancer tissue or cells.

87. The method of claim 85, wherein the biological sample comprises normal breast tissue or cells.

90. A method for detecting a polypeptide whose sequence comprises the amino acid sequence set forth in SEQ ID NO:l in a biological sample comprising steps of: (a) contacting the biological sample with the antibody of claim 60 or claim 65; and (b) determining whether the antibody specifically binds to the sample, the binding being an indication that the sample contains the polypeptide.

91. The method of claim 90, wherein the biological sample comprises breast cancer tissue or cells.

92. The method of claim 90, wherein the biological sample comprises a cell, tissue, blood, urine, serum, ascites, saliva, or another body fluid, secretion, or excretion.

93. The method of claim 90, wherein the determining step comprises performing an enzyme-linked immunosorbent assay.

94. The method of claim 90, wherein the determining step comprises performing immunohistochemistry.

95. The method of claim 90, wherein the determining step comprises contacting an antibody array with the sample.

90a. A method for detecting a polypeptide having significant similarity to the polypeptide whose sequence is set forth in SEQ ID NO:l in a biological sample comprising steps of: (a) contacting the biological sample with the antibody of claim 60 or claim 65; and (b) determining whether the antibody specifically binds to the sample, the binding being an indication that the sample contains the polypeptide.

91a. The method of claim 90a, wherein the biological sample comprises breast cancer tissue or cells.

92a. The method of claim 90a, wherein the biological sample comprises a cell, tissue, blood, urine, serum, ascites, saliva, or another body fluid, secretion, or excretion.

93a. The method of claim 90a, wherein the determining step comprises performing an enzyme-linked immunosorbent assay. 94a. The method of claim 90a, wherein the determining step comprises performing immunohistochemistry.

95a. The method of claim 90a, wherein the determining step comprises contacting an antibody array with the sample.

100. A method for treating or preventing a disorder of cell proliferation, the method comprising administering to a subject in need of such treatment an effective amount ofthe pharmaceutical composition of any of claims 50, 55, or 70.

150. A method for classifying a disease comprising the steps of: (a) providing a sample from a subject; (b) detecting the presence of a polynucleotide that encodes a polypeptide having the sequence of SEQ ID NO:l within the sample; and (c) assigning the disease to one of a set of predetermined categories based on detection of the polynucleotide.

151. The method of claim 150, wherein the disease is cancer.

152. The method of claim 150, wherein the disease is breast cancer.

153. The method of claim 150, wherein the detecting step comprises a nucleic acid amplification step.

154. The method of claim 150, wherein the sample comprises a cell, tissue, blood, urine, saliva, ascites, other body fluid, secretion, or excretion.

150a. A method for classifying a disease comprising the steps of: (a) providing a sample from a subject; (b) detecting the presence of a polynucleotide that encodes a polypeptide having significant similarity to a polypeptide whose sequence comprises the sequence of SEQ ID NO: 1 within the sample; and (c) assigning the disease to one of a set of predetermined categories based on detection ofthe polynucleotide.

151a. The method of claim 150a, wherein the disease is cancer.

152a. The method of claim 150a, wherein the disease is breast cancer.

153a. The method of claim 150a, wherein the detecting step comprises a nucleic acid amplification step.

154a. The method of claim 150a, wherein the sample comprises a cell, tissue, blood, urine, saliva, ascites, other body fluid, secretion, or excretion.

155. The method of claim 150, further comprising the step of: providing diagnostic, prognostic, or predictive information based on the predetermined category assigned in the assigning step.

155a. The method of claim 150a, further comprising the step of: providing diagnostic, prognostic, or predictive information based on the predetermined category assigned in the assigning step.

156. The method of claim 155 or claim 155a, wherein the disease is breast cancer.

160. A method for classifying a disease comprising the steps of: (a) providing a sample from a subject; (b) detecting the presence of a polypeptide comprising the sequence of SEQ ID NO: 1 within the sample; and (c) assigning the disease to one of a set of predetermined categories based on detection ofthe polynucleotide.

161. The method of claim 160, wherein the disease is cancer.

162. The method of claim 160, wherein the disease is breast cancer.

164. The method of claim 160, wherein the sample comprises a cell, tissue, blood, urine, saliva, ascites, other body fluid, secretion, or excretion.

165. The method of claim 160, further comprising the step of providing diagnostic, prognostic, or predictive information based on the category assigned in the assigning step.

166. The method of claim 160, wherein the detecting step is performed using an antibody that specifically binds to the polypeptide of SEQ ID NO: 1.

166a. The method of claim 166, wherein the determining step comprises performing an enzyme-linked immunosorbent assay.

166b. The method of claim 166, wherein the determining step comprises performing immunohistochemistry.

166c. The method of claim 166, wherein the determining step comprises contacting an antibody array with the sample.

170. A method for classifying a disease comprising the steps of: (a) providing a sample from a subject; (b) detecting the presence of a polypeptide having significant similarity to a polypeptide comprising the sequence of SEQ ID NO: 1 within the sample; and (c) assigning the disease to one of a set of predetermined categories based on detection ofthe polynucleotide.

171. The method of claim 170, wherein the disease is cancer.

172. The method of claim 170, wherein the disease is breast cancer.

174. The method of claim 170, wherein the sample comprises a cell, tissue, blood, urine, saliva, ascites, other body fluid, secretion, or excretion.

175. The method of claim 170, further comprising the step of providing diagnostic, prognostic, or predictive information based on the category assigned in the assigning step.

176. The method of claim 170, wherein the detecting step is performed using an antibody that specifically binds to the polypeptide.

176a. The method of claim 176, wherein the determining step comprises performing an enzyme-linked immunosorbent assay.

176b. The method of claim 176, wherein the determining step comprises performing immunohistochemistry.

176c. The method of claim 176, wherein the determining step comprises contacting an antibody array with the sample.

180. A method for obtaining prognostic, diagnostic, or therapeutic information comprising steps of: (i) obtaining a sample containing cells or tissue from a subject; and (ii) detecting, within the sample, a mutation in a regulatory or coding region of a gene that encodes the BSTP-Ras/Rerg polypeptide of SEQ ID NO: 1.

181. The method of claim 180, wherein the mutation is in an estrogen receptor binding site.

182. The method of claim 180, wherein the mutation is in a site encoding a GTPase domain.

183. The method of claim 180, wherein the mutation is in an ER binding site.

200. A method of identifying a compound that enhances the expression or activity of a polypeptide comprising the amino acid sequence of SEQ ID NO: 1 comprising steps of: (i) contacting a polypeptide comprising the amino acid sequence of SEQ ID NO:l, a polypeptide having significant similarity to the polypeptide whose amino acid sequence is set forth in SEQ ID NO: 1, or a fragment of any of these polypeptides with a test compound; (ii) measuring GTP-binding and/or GTPase activity ofthe polypeptide; and (iii) identifying the test compound as an activator ofthe polypeptide if the polypeptide or fragment exhibits enhanced GTP-binding activity and/or reduced GTPase activity in the presence ofthe test compound relative to the level of GTP- binding activity and/or GTPase activity in the absence ofthe test compound.

210. The method of claim 200, wherein the polypeptide or fragment includes a GTP- binding domain.

220. A method of inhibiting the growth of a cell comprising enhancing the level or activity of a polypeptide comprising the amino acid sequence of SEQ ID NO:l or a polypeptide having significant similarity to the polypeptide of SEQ ID NO: 1 in the cell.

225. A method of inhibiting the growth of a cell comprising treating the cell, or treating an organism containing the cell, with a compound identified according to the method of claim 200.

226. The method of claim 220 or claim 225, wherein the cell is a tumor cell.

250. A method of treating or preventing a tumor comprising steps of: (i) providing an individual in need of treatment or prevention of a tumor; (ii) administering a compound that enhances the level or activity of a polypeptide whose sequence comprises the amino acid sequence of SEQ ID NO: 1.

300. A method of identifying a compound that reduces or inhibits the expression or activity of a polypeptide whose sequence comprises the amino acid comprising steps of steps of: (i) contacting a polypeptide comprising the amino acid sequence of SEQ ID NO: 1, a polypeptide having significant similarity to the polypeptide whose amino acid sequence is set forth in SEQ ID NO: 1, or a fragment of any of these polypeptides with a test compound; (ii) measuring GTP-binding and/or GTPase activity ofthe polypeptide or fragment; and (iii) identifying the test compound as an inhibitor ofthe polypeptide if the polypeptide or fragment exhibits decreased GTP-binding activity and/or increased GTPase activity in the presence ofthe test compound relative to the level of GTP- binding activity and/or GTPase activity in the absence ofthe test compound.

305. The method of claim 300, wherein the polypeptide or fragment comprises a GTP-binding domain.

310. A method of inhibiting the growth of a cell comprising reducing the level or activity of a polypeptide comprising the amino acid sequence of SEQ ID NO: 1 in the cell.

320. A method of increasing the rate of growth or division of a cell comprising treating the cell, or treating an organism containing the cell, with a compound identified according to the method of claim 300.

400. A diagnostic kit comprising: an antibody that specifically binds to the polypeptide of SEQ ID NO: 1 ; instructions for use ofthe antibody; and a control sample, wherein the antibody specifically binds to a polypeptide in the control sample.

601. A method of classifying a tumor comprising the steps of: providing a tumor sample; detecting expression or activity of a gene encoding the polypeptide of SEQ ID NO:l in the sample; and classifying the tumor as belonging to a tumor subclass based on the results of the detecting step.

605. The method of claim 601, wherein the detecting step comprises detecting the polypeptide.

606. The method of claim 605, wherein the polypeptide is detected by performing immunohistochemical analysis on the sample using an antibody that specifically binds to the polypeptide.

606a. The method of claim 605, wherein the polypeptide is detected by performing an ELISA assay using an antibody that specifically binds to the polypeptide.

606b. The method of claim 605, wherein the polypeptide is detected using an antibody array comprising an antibody that specifically binds to the polypeptide.

606c. The method of claim 605, wherein the detecting step comprises: detecting modification of a substrate by the polypeptide.

607. The method of claim 601 , wherein classifying a tumor comprises: stratifying a subject having the tumor for a clinical trial.

608. The method of claim 607, wherein the tumor is a breast tumor.

609. The method of claim 601 , wherein the tumor is a breast tumor and the tumor subclass is a luminal tumor subclass.

601 a. The method of claim 601 , further comprising: providing diagnostic, prognostic, or predictive information based on the classifying step.

605a. The method of claim 605, further comprising: providing diagnostic, prognostic, or predictive information based on the classifying step.

606aa. The method of claim 605a, wherein the polypeptide is detected by performing immunohistochemical analysis on the sample using an antibody that specifically binds to the polypeptide.

606ab. The method of claim 605a, wherein the polypeptide is detected by performing an ELISA assay using an antibody that specifically binds to the polypeptide.

606ac. The method of claim 605a, wherein the polypeptide is detected using an antibody array comprising an antibody that specifically binds to the polypeptide.

606ad. The method of claim 605a, wherein the detecting step comprises: detecting modification of a substrate by the polypeptide.

609a. The method of claim 601 a, wherein the tumor is a breast tumor and the tumor subclass is a luminal tumor subclass.

601 g. The method of claim 601 , further comprising: selecting a treatment based on the classifying step.

605g. The method of claim 605, further comprising: selecting a treatment based on the classifying step.

606ag. The method of claim 605g, wherein the polypeptide is detected by performing immunohistochemical analysis on the sample using an antibody that specifically binds to the polypeptide. 606bg. The method of claim 605g, wherein the polypeptide is detected by performing an ELISA assay using an antibody that specifically binds to the polypeptide.

606cg. The method of claim 605g, wherein the polypeptide is detected using an antibody array comprising an antibody that specifically binds to the polypeptide.

606dg. The method of claim 605g, wherein the detecting step comprises: detecting modification of a substrate by the polypeptide.

609g. The method of claim 601 g, wherein the tumor is a breast tumor and the tumor subclass is a luminal tumor subclass.

601m. A method of testing a subject comprising the steps of: providing a sample isolated from a subject; detecting expression or activity of a gene encoding the polypeptide of SEQ ID NO: 1 in the sample; and providing diagnostic, prognostic, or predictive information based on the detecting step.

605m. The method of claim 601m, wherein the detecting step comprises detecting the polypeptide.

606m. The method of claim 605m, wherein the polypeptide is detected by performing immunohistochemical analysis on the sample using an antibody that specifically binds to the polypeptide.

606ma. The method of claim 605m, wherein the polypeptide is detected by performing an ELISA assay using an antibody that specifically binds to the polypeptide. 606mb. The method of claim 605m, wherein the polypeptide is detected using an antibody array comprising an antibody that specifically binds to the polypeptide.

606mc. The method of claim 605m, wherein the detecting step comprises: detecting modification of a substrate by the polypeptide.

609m. The method of any of claim 601m, wherein the sample is selected from the group consisting of: a blood sample, a urine sample, a serum sample, an ascites sample, a saliva sample, a cell, and a portion of tissue.

610m. The method of claim 601m, wherein the sample is a tumor sample.

61 lm. The method of claim 610m, wherein the tumor sample is a breast tumor sample.

601 r. A method of testing a subj ect comprising the steps of: providing a sample isolated from a subject; detecting expression or activity of a gene encoding the polypeptide of SEQ ID NO:l in the sample; and stratifying the subject for a clinical trial based on the detecting step.

605r. The method of claim 60 lr, wherein the detecting step comprises detecting the polypeptide.

606r. The method of claim 605r, wherein the polypeptide is detected by performing immunohistochemical analysis on the sample using an antibody that specifically binds to the polypeptide.

606ra. The method of claim 605r, wherein the polypeptide is detected by performing an ELISA assay using an antibody that specifically binds to the polypeptide. 606rb. The method of claim 605r, wherein the polypeptide is detected using an antibody array comprising an antibody that specifically binds to the polypeptide.

606rc. The method of claim 605r, wherein the detecting step comprises: detecting modification of a substrate by the polypeptide.

609r. The method of claim 60 lr, wherein the sample is selected from the group consisting of: a blood sample, a urine sample, a serum sample, an ascites sample, a saliva sample, a cell, and a portion of tissue.

610r. The method of claim 601r, wherein the sample is a tumor sample.

61 lr. The method of claim 61 Or, wherein the tumor sample is a breast tumor sample.

60 lq. A method of testing a subject comprising the steps of: providing a sample isolated from a subject; detecting expression or activity of a gene encoding the polypeptide of SEQ ID NO:l in the sample; and selecting a treatment based on the detecting step.

605q. The method of claim 60 lq, wherein the detecting step comprises detecting the polypeptide.

606q. The method of claim 605q, wherein the polypeptide is detected by performing immunohistochemical analysis on the sample using an antibody that specifically binds to the polypeptide.

606qa. The method of claim 605q, wherein the polypeptide is detected by performing an ELISA assay using an antibody that specifically binds to the polypeptide. 606qb. The method of claim 605q, wherein the polypeptide is detected using an antibody array comprising an antibody that specifically binds to the polypeptide.

606qc. The method of claim 605q, wherein the detecting step comprises: detecting modification of a substrate by the polypeptide.

609q. The method of claim 60 lq, wherein the sample is selected from the group consisting of: a blood sample, a urine sample, a serum sample, an ascites sample, a saliva sample, a cell, and a portion of tissue.

610q. The method of claim 601q, wherein the sample is a tumor sample.

611 q. The method of claim 61 Oq, wherein the tumor sample is a breast tumor sample.