WO2011024114A1

WO2011024114A1 - Targeting extracellular matrix molecules for the treatment of cancer

Info

Publication number: WO2011024114A1
Application number: PCT/IB2010/053789
Authority: WO
Inventors: Joerg Huelsken; Ilaria Malanchi
Original assignee: Ecole Polytechnique Federale De Lausanne (Epfl)
Priority date: 2009-08-25
Filing date: 2010-08-23
Publication date: 2011-03-03

Abstract

The present invention relates to an agent able to block a cancer supportive function of a fasciclin protein family member and to pharmaceutical compositions containing the same.

Description

Targeting extracellular matrix molecules for the treatment of cancer

FIELD OF THE INVENTION The present invention relates to an agent able to block a cancer supportive function of a fasciclin protein family member and to pharmaceutical compositions containing said agent.

BACKGROUND OF THE INVENTION

Stem cells possess the ability to self-renew for the life span of an organ giving rise to cycling (transit-amplifying) cells which in turn generate terminally differentiated cells. This hierarchy of cells with differential potential for proliferation and specialization is at the root of tissue homeostasis and ensures life-long function of our tissues. Applicants and others have provided evidence that the tissue specific stem cells which are at the root of this process of homeostasis can be an ideal target for oncogenic transformation (Malanchi et al., Nature. Apr 3;452(7187):650-3 (2008)). In many cases, a single mutation can be sufficient to generate cancerous stem cells, also termed cancer stem cells, which maintain stem cell properties such as unlimited self-renewal and give rise to all other tumor cells. Since the majority of tumor cells is not able to initiate a new cancer upon transplantation this has introduced the concept of cellular hierarchies also to the tumor field and it has been postulated that this will change the way we will treat cancers in the future.

Tissue specific stem cells are associated with specialized niches which provide a defined cellular and extracellular microenvironment to control stem cell self-renewal and differentiation. In order to identify molecules involved in stem cell - niche interactions in vivo, Applicants have previously identified niche expressed genes using a combination of expression profiling of micro-dissected material and in situ hybridization. They identified genes which are expressed in the niche of normal, tissue specific stem cells, in the niche of cancer stem cells as well as in the metastatic niche at an early step of metastatic colonization.

One of these genes is Periostin (POSTN) also called OSF-2. Periostin is expressed from stromal cells in primary mammary cancers and is strongly induced in spontaneous lung metastasis of such tumors where it is again produced by stromal cells. Various reports have been issued on high level expression of periostin in highly metastatic cancers [Erkan M. et al. Gastroenterology, 132(4), 1447-64 (2007) (pancreatic cancer), Siriwardena B S. et al. Br J Cancer, 95(10), 1396-403 (2006) (oral cancer), Baril P. et al. Oncogene, 26(14), 2082-94 (2007) (pancreatic cancer), Grigoriadis A. et al. Breast Cancer Res, 8(5), R56 (2006) (breast cancer), Kudo Y. et al. Cancer Res, 66(14), 6928-35 (2006) (head and neck cancer), Bao S. et al. Cancer Cell. 5(4), 329-39 (2004) (colon cancer), Shao R. et al., MoI Cell Biol. (2004) 24, 3992-4003 (breast cancer), Sasaki H. et al., Breast Cancer Res Treat. (2003) 77, 245-52 (breast cancer), Sasaki H. et al. Cancer Lett, 72(1), 37-42 (2001) (thymic cancer), Sasaki H. et al. Cancer, 92(4), 843-8 (2001) (non-small cell lung cancer), Gonzalez H E. et al., Arch Otolaryngol Head Neck Surg. (2003) 129, 754-9 (head and neck squamous cell carcinoma)). It has also been reported that a rat homolog of mouse periostin was less expressed in various cancer cells, introduction of the periostin gene into bladder cancer cells inhibited invasion of the bladder cancer cells, and introduction of the periostin gene into mouse melanoma B16-F10 cells inhibited their metastasis to lung (Kim C J, et al. Int J Cancer, 117(1), 51-8 (2005)).

As to periostin antibodies, there are reports of an antibody related to the inhibition of chemotaxis induced by periostin (Lindner V. et al., Arterioscler Thromb Vase Biol. (2005) 25, 77-83), an antibody against periostin inducing apoptosis in colon cancer cells in vitro at concentrations above lmg/ml (Tai I T, et al., Carcinogenesis (2005) 26, 908-15), as well as an antibody having the ability to neutralize anti-cell adhesive properties (US 2009/0074788). However, none of these antibodies can block metastasis, cancer stem cell self-renewal or another cancer supportive function of a fasciclin protein family member such as periostin.

Despite the above-mentioned approaches, there is still a profound need to provide an agent that is able to block cancer by another approach than by blocking cancer cell adhesion or chemotaxis. SUMMARY OF THE INVENTION This object has been achieved by providing an isolated and/or purified antibody, antibody fragment or derivative thereof able to able to block a cancer supportive function of a fasciclin protein family member, characterized in that it recognizes a protein consisting essentially in SEQ ID No 1, a fragment thereof and/or a conservative variant thereof. A further object of the present invention is to provide a pharmaceutical composition comprising a pharmaceutically effective amount of an isolated and/or purified antibody, antibody fragment or derivative thereof of the invention, optionally in combination with pharmaceutically acceptable carriers, diluents and/or adjuvants. Still a further object of the present invention is to provide an isolated and purified nucleic acid sequence encoding said isolated and/or purified antibody, antibody fragment or derivative thereof of the invention, a vector comprising the isolated and purified nucleic acid sequence and a host cell comprising said vector. Still a further object of the present invention is to provide a hybridoma, secreting the monoclonal an isolated and/or purified antibody, antibody fragment or derivative thereof.

A further object of the invention is to provide a method for treating and/or preventing cancer, cancer metastasis, or tumorigenesis, in a patient in need thereof, comprising administering a pharmaceutically effective amount of an isolated and/or purified antibody, antibody fragment or derivative thereof.

Another object of the invention is to provide a method for treating and/or preventing cancer cell self-renewal, expansion, proliferation, activation, survival, anchorage, niche interaction or homing to the niche in a patient in need thereof, comprising administering a pharmaceutically effective amount of an isolated and/or purified antibody, antibody fragment or derivative thereof.

Still a further object of the present invention is to provide a method for treating and/or preventing cancer stem cell self-renewal, expansion, proliferation, activation, survival, anchorage, niche interaction or homing to the nichein a patient in need thereof, comprising administering a pharmaceutically effective amount of an isolated and/or purified antibody, antibody fragment or derivative thereof. The present invention also relates to a kit for treating and/or preventing cancer metastasis formation, tumorigenesis or cancer stem cell anchorage and survival comprising a pharmaceutically effective amount of an isolated and/or purified antibody, antibody fragment or derivative thereof of any one of the invention, optionally with reagents and'or instractions

BRIEF DESCRIPTION OF THE FIGURES

Fig. 1 shows POSTN expression in primary mammary cancer as assessed by in situ hybridization. Sections from POSTN wild type MMTV-PyMT tumors were processed for in situ hybridization using sense and anti-sense probes against POSTN messenger RNA. The sense probe was used as an internal negative control. POSTN is highly expressed in the tumor stroma.

Fig. 2 shows POSTN expression in pulmonary mammary cancer metastasis as assessed by in situ hybridization. Sections from POSTN wild type MMTV-PyMT lung metastasis was processed for in situ hybridization using sense and anti-sense probes against POSTN messenger RNA. The red dotted line defines the borders of the early or the late metastasis from the surrounding lung tissue. The expression of periostin is mainly observed within the metastasis stroma and not in the tumor cells themselves or in the distant, metastasis-free lung tissue, and POSTN expression increases in the macro-metastasis stage.

Fig. 3 is a picture showing examples of a lung harbouring macroscopic metastasis (from a control mouse) compared to a metastasis free lung (from a POSTN knock out mouse). While the absence of POSTN does not affect the growth of the tumor at the primary site, it efficiently prevents lung metastasis formation. The pictures show examples of a lung harboring macroscopic metastasis (from a control mouse) compared to a metastasis free lung (from a POSTN knock out mouse). Fig. 4 represents the size distribution of control and POSTN mutant primary tumors and incidence of lung metastases. The graphic shows the incidence of macroscopic lung metastasis (black bar, right scale) in 5 control mice of the MMTV-PyMT mammary tumor model and 5 mice of the same model genetically deprived of the POSTN gene. The lack of POSTN expression dramatically compromises the process of lung metastasis, while the overall growth of the primary tumor is not altered (line chart, left scale).

Fig. 5 is a graphic representing the size distribution of control and POSTN mutant pulmonary metastases. Histological sections of control and POSTN knock out mice were analysed for the presence of microscopic metastasis. Fig. 6 is a graphic of a metastasis time course showing that the lack of POSTN compromises the transition from early colonization to metastatic progression and macro-metastasis formation. Tumor cells from POST -/- mice were injected intgravenously into either wild type control or POSTN -/- mice. Both, tumor cell amount and frequency of CSCs was severely reduced after 5 weeks in POSTN -/- recipient mice compared to controls while no significant difference was detected in the early colonization phase. This result proves that the CSC of survival, proliferation and self renewal were compromised in the absence of POSTN at the metastatic site.

Fig. 7 is a picture showing that POSTN deficient tumor cells do not form mammospheres and loose their long-term growth potential. Cells from primary tumors from control and POSTN knock out mice were plated in 1 OO μl of serum- free sphere medium for mammosphere culture.

After about 10 days, spheres efficiently formed in the cultures of control tumor cells while sphere formation was severely compromised in the POSTN knock out tumor cell cultures.

After serial passaging of sphere cultures, the failure of POSTN cells to maintain their self- renewal became evident whereas control tumor cells efficiently reconstitutes secondary spheres. Fig. 8 is a picture showing that POSTN deficient tumor cells can be rescued to form mammospheres by addition of POSTN protein. Spheres were generated from tree independent POSTN deficient tumors. The sphere cultures were grown in presence of the indicated amount (100 ng/ml or 500 ng/ml) of purified human POSTN which was sufficient to rescue sphere formation.

Fig. 9 shows a FACS analysis of harvested tumor cells incubated with the indicated antibodies. Tumor cells grown in suspension for 10 days were harvested, trypsinized and incubated with the indicated antibodies. The FACS analysis shows that the number of cancer stem cells(CD24+/CD90+) is reduced in the culture of POSTN deficient tumor cells (numbers show percentage of total tumor cells).

Fig. 10 shows the results of comparative test between antibodies of the invention and commercial antibodies. Sphere cultures of wild type mammary cancer stem cells can be inhibited by monoclonal antibodies of the invention (d-f) however not by commercial antibodies against POSTN (b-c).

The indicated antibodies were added in equal amounts to the sphere culture media at the time of plating of control tumor cells into low adherent 96-well plates.

DETAILED DESCRIPTION OF THE INVENTION The present invention concerns an isolated and/or purified antibody, antibody fragment or derivative thereof able to block a cancer supportive function of a fasciclin protein family member, characterized in that said and/or purified antibody, antibody fragment or derivative thereof recognizes a protein consisting essentially in SEQ ID No 1, a fragment thereof and/or a conservative variant thereof .

Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described below. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. The publications and applications discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present invention is not entitled to antedate such publication by virtue of prior invention. In addition, the materials, methods, and examples are illustrative only and are not intended to be limiting.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in art to which the subject matter herein belongs. As used herein, the following definitions are supplied in order to facilitate the understanding of the present invention.

The phrase "consisting essentially in" when referring to a particular amino acid means a sequence having the properties of a given SEQ ID NO. For example, when used in reference to an amino acid sequence, the phrase includes the sequence per sc and molecular modifications that would not affect the essential characteristics of the sequence.

The term "comprise" or "comprising" is generally used in the sense of

include/including, that is to say permitting the presence of one or more features or components.

As used in the specification and claims, the singular form "a", "an" and "the" include plural references unless the context clearly dictates otherwise.

As used herein, "at least one" means "one or more."

As used herein the term "patient" is well-recognized in the art, and, is used herein to refer to a mammal, including dog, cat, rat, mouse, monkey, cow, horse, goat, sheep, pig, camel, and, most preferably, a human. The term does not denote a particular age or sex. Thus, adult and newborn subjects, whether male or female, are intended to be covered.

"A cancer supportive function of a fasciclin protein family member" refers to a function or effect mediated/caused by a fasciclin family member such as POSTN which is necessary/essential for cancer progression or metastasis. This function or effect is characterized in that in the absence of said protein or after block of said protein by an an isolated and/or purified antibody, antibody fragment or derivative thereof defined in this patent application, tumor growth is deteriorated and tumor metastasis declines. Preferably, the isolated and/or purified antibody, antibody fragment or derivative thereof of the invention is able to block a cancer supportive function of a fasciclin protein family member. Members of the fasciclin family of proteins occur in a wide range of vertebrates, invertebrates and microorganisms. They are generally cell-surface and membrane- anchored proteins involved in homophilic cell adhesion or symbiotic processes.

Preferably the member of the fasciclin family is a periostin protein. This protein is expressed from stromal cells in primary mammary cancers and is strongly induced in spontaneous lung metastasis of such tumors where it is again produced by stromal cells. Various reports have been issued on high level expression of periostin in highly metastatic cancers. It has also been reported that a rat homo log of mouse periostin was less expressed in various cancer cells, introduction of the periostin gene into bladder cancer cells inhibited invasion of the bladder cancer cells, and introduction of the periostin gene into mouse melanoma Bl 6-F 10 cells inhibited their metastasis to lung (Kim C J, et al. Int J Cancer, 117(1), 51-8 (2005)).

To test the function of periostin in mammary cancer metastasis, inventors' combined the MMTV-PymT transgene with the periostin knock out allele in mice. Surprisingly, while formation of primary tumors is not affected by the knock out, the formation of lung metastasis is dependent on its expression (Figures 3-4). Furthermore, orthotopic transplantation of wild type tumor cells into knock out recipients failed to form metastasis. Similarly, inventors found that wild type tumor cells injected into knock out recipient animals showed a dramatically reduced metastasis formation when compared to injections into wild type recipients.

In wild type control recipients, inventors observed expression of this extracellular matrix (ECM) molecule to be initiated already in very tiny micro-metastasis (<50 cells) from the surrounding, fibroblastoid stroma (Figure 2). To inventors' knowledge, this is the first example describing an essential role of an ECM molecule in metastasis formation. These results show an essential function of specific components of the extracellular matrix, such as POSTN, in cancer stem cell maintenance, initial phase of metastatic colonization and a function as cancer support. Preferably, the amino acid sequence recognized by the isolated and/or purified antibody, antibody fragment or derivative thereof of the invention is a protein consisting essentially in SEQ ID No 1, a fragment thereof and/or a conservative variant thereof as described below:

SEQ ID NoI MIPFLPMFSLLLLLIVNPINANNHYDKILAHSRIRGRDQGPNVCALQQIL

GTKKKYFSTCKNWYKKSICGQKTTVLYECCPGYMRMEGMKGCPAVLPIDH

VYGTLGIVGATTTQRYSDASKLREEIEGKGSFTYFAPSNEA WDNLDSDIR

RGLESNVNVELLNALHSHMINKRMLTKDLKNGMIIPSMYNNLGLFINHYP

NGWTVNCARIIHGNQIATNGWHVIDRVLTQIGTSIQDFIEAEDDLSSF

RAAAITSDILEALGRDGHFTLFAPTNEAFEKLPRGVLERIMGDKVASEAL

MKYHILNTLQCSESIMGGAVFETLEGNTIEIGCDGDSITWGIKMVNKKD

IVTNNGVIHLIDQVLIPDSAKQVIELAGKQQTTFTDLVAQLGLASALRPD

GEYTLLAPVNNAFSDDTLSMDQRLLKLILQNHILKVKVGLNELYNGQILE

TIGGKQLRVFVYRTAVCIENSCMEKGSKQGRNGAIHIFREIIKPAEKSLH

EKLKQDKRFSTFLSLLEAADLKELLTQPGDWTLFVPTNDAFKGMTSEEKE

ILIRDKNALQNIILYHLTPGVFIGKGFEPGVTNILKTTQGSKIFLKEVND

TLLVNELKSKESDIMTTNGVIHWDKLLYPADTPVGNDQLLEILNKLIKY

IQIKFVRGSTFKEIPVTVYKPIIKKYTKIIDGVPVEITEKETREERIITG

PEIKYTRISTGGGETEETLKKLLQEEVTKVTKFIEGGDGHLFEDEEIKRL

LQGDTPVRKLQANKKVQGSRRRLREGRSQ

This sequence corresponds to a full size human POSTN protein lacking exon 17.

The present invention also refers to a fragment of the SEQ ID No 1 disclosed above. This refers to a sequence containing less amino acids in length than the SEQ ID No 1 sequence of the periostin protein. This fragment sequence is a biologically active fragment that can be used as long as it exhibits the same properties as the sequence from which it derives. Preferably this sequence contains less than 90%, preferably less than 60%, in particular less than 30% amino acids in length than the respective sequence of the periostin protein.

The present invention further refers to a conservative variant of the SEQ ID No 1 disclosed above. This conservative variant refers to polypeptides having amino acid sequences that differ to some extent from the native sequence polypeptide, that is amino acid sequences that vary from the native 3D sequence whereby one or more amino acids are substituted by another one. The variants can occur naturally (e.g. polymorphism) or can be synthesized. Variants possess substitutions, deletions, and/or insertions at certain positions within the amino acid sequence of the native amino acid sequence. Amino acid substitutions are herein defined as exchanges within one of the following five groups:

I. Small aliphatic, nonpolar or slightly polar residues: Ala, Ser, Thr, Pro, GIy

II. Polar, positively charged residues: His, Arg, Lys

III. Polar, negatively charged residues: and their amides: Asp, Asn, GIu, GIn

IV. Large, aromatic residues: Phe, Tyr, Trp

V. Large, aliphatic, nonpolar residues: Met, Leu, He, VaI, Cys.

Preferably the amino acid substitutions are conservative, i.e. occur within one of the above- identified group.

Usually, the blocking activity of the agent of the invention concerns a cancer cell or a cancer stem cell. As used herein, "a cancer stem cell" refers to a cell which is able to initiate tumor formation at the primary or secondary site and is responsible for long-term tumor growth.

As used herein, an "antibody" is a protein molecule that reacts with a specific antigenic determinant or epitope and belongs to one or five distinct classes based on structural properties: IgA, IgD, IgE, IgG and IgM. The antibody may be a polyclonal (e.g. a polyclonal serum) or a monoclonal antibody, including but not limited to fully assembled antibody, single chain antibody, antibody fragment, and chimeric antibody, humanized antibody as long as these molecules are still biologically active and still bind to at least one peptide of the invention. Preferably the antibody is a monoclonal antibody. Preferably also the monoclonal antibody will be selected from the group comprising the IgGl, IgG2, IgG2a, IgG2b, IgG3 and IgG4. A typical antibody is composed of two immunoglobulin (Ig) heavy chains and two Ig light chains. Several different types of heavy chain exist that define the class or isotype of an antibody. These heavy chain types vary between different animals. All heavy chains contain a series of immunoglobulin domains, usually with one variable (VH) domain that is important for binding antigen and several constant (CH) domains. Each light chain is composed of two tandem immunoglobulin domains: one constant (CL) domain and one variable domain (VL) that is important for binding antigen.

The term "isolated," when used as a modifier of an antibody of the invention means that the antibody is made by the hand of man or is separated, completely or at least in part, from their naturally occurring in vivo environment Generally, isolated antibodies are substantially free of one or more materials with which they normally associate with in nature, for example, one or more protein. The term "isolated" does not exclude alternative physical forms of the antibodies, such as multimers/oligomers, modifications (e g , phosphorylation, glycosylation, lipidation) or derivatized forms, or forms expressed in host cells produced by the hand of man

An "isolated" antibody can also be "substantially pure" or "purified" when free of most or all of the materials with which it typically associates with in nature Thus, an isolated antibody that also is substantially pure or purified does not include polypeptides or polynucleotides present among millions of other sequences, such as antibodies of an antibody library or nucleic acids in a genomic or cDNA library.

The term "complementary determining region" or "CDR" is well-defined in the art (see, for example, Harlow and Lane, "Antibodies, a laboratory manual", CSH Press, Cold Spring Harbour, 1988) and refers to the stretches of amino acids within the variable region of an antibody that primarily makes contact with the antigen.

Usually, the isolated and/or purified antibody, antibody fragment or derivative thereof of the invention comprises i) at least one complementary determining region (CDR) of the VH, a biologically active fragment thereof and/or a variant thereof, and/or ii) at least one complementary determining region (CDR) of the VL region, a biologically active fragment thereof and/or a variant thereof.

Preferably, the amino acid sequence determining the least one CDR of the VH consists essentially in SEQ ID No 2, a biologically active fragment thereof and/or a variant thereof. Preferably also, the amino acid sequence determining the at least one CDR of the VL region consists essentially in SEQ ID No 3, a biologically active fragment thereof and/or a variant thereof. In the present case, the sequences define an IgGl isotype:

SEO ID No 2

MOVKLQESGPELKKPGETVKISCKASGYTFTNYPMHWLKQAPGKGLKWMGWINTYSGAPT YADDFKGRFAFSLETSANTAYLQLNNLKNDDMATYFCARGELLRWWYYFDYWGQGTSLTV SSAKTTPPSVYPLAPGSAAQTNSMVTLGCLVKGYFPEPVTVTWNSGSLSSGVHTFPAVLQSDL YTLSSSVTVPSSTWPSETVTCNVAHPASSTKVDKKI

The three CDR hypervariable regions are underlined and correspond to Hl= GYTFTNYPMH, H2= TYSGAPTYADDFKG and H3= GELLRWWYYFDY. The constant region starts with TTPPSV.

SEO ID No 3:

MDIVMTQSPASLSVSVGETVTITCRASEX¹X²X³X⁴X⁵X⁶X⁷X⁸X⁹X¹⁰X¹¹WYQQKQGKSPQLLVY X¹²A X¹³N X¹⁴X¹⁵X¹⁶GVPSRFSGSGSGTQFSLKINSLQSEDFGSYYCQ X¹⁷ X¹⁸ X¹⁹ X²⁰ X²¹PYTFG GGTKLEIKRADAAPTVSIFPPSSEQLTSGGASWCFLNNFYPKDINVKWKIDGSERQNGVLNS

wherein, independently from one each other,

X¹ is N or S, X² is V or Y, X³ is D or Y, X⁴ is S or N, X⁵ is H or Y, X⁶ is G or L, X⁷ is F or A, X is S or absent, X is F or absent, X is M or absent, X is N or absent, X is A or S, X is S or T, X¹⁴ is L or Q, X¹⁵ is Q or A, X¹⁶ is S or D, X¹⁷ is Q or H, X¹⁸ is F or S, X¹⁹ is W or K, X²⁰ is E or G and X²¹ is T or V.

The three CDR hypervariable regions correspond to Ll= RASENVYSHLA, L2= SATNLAD and L3= QHFWGTPYT. The constant region starts with DAAPTV.

The present invention also refers to a biologically active fragment of the SEQ ID No 2 disclosed above. This refers to a sequence containing less amino acids in length than the SEQ ID No 2 sequence of the periostin protein. This biologically active fragment can be used as long as it exhibits the same properties as the sequence from which it derives. Preferably this sequence contains less than 90%, preferably less than 60%, in particular less than 30% amino acids in length than the respective sequence of CDR of the VH. Preferably, the biologically active fragment will be selected from the group comprising SEQ ID N° 4 (GYTFTNYPMH), SEQ ID N° 5 (TYSGAPTYADDFKG) and SEQ ID N° 6

(GELLRWWYYFDY) .

A variant of the SEQ ID No 2 disclosed above is a conservative variant and refers to polypeptides having amino acid sequences that differ to some extent from the native sequence polypeptide, i.e. amino acid sequences that vary from the native 3D sequence whereby one or more amino acids are substituted by another one. The variants can occur naturally (e.g.

polymorphism) or can be synthesized. Variants possess substitutions, deletions, and/or insertions at certain positions within the amino acid sequence of the native amino acid sequence as disclosed supra.

The present invention also refers to a biologically active fragment of the SEQ ID No 3 disclosed above. This refers to a sequence containing less amino acids in length than the SEQ ID No 3 sequence of the periostin protein. This fragment sequence can be used as long as it exhibits the same properties as the sequence from which it derives. Preferably this sequence contains less than 90%, preferably less than 60%, in particular less than 30% amino acids in length than the respective sequence of CDR of the VL.

Preferably, the biologically active fragment will be selected from the group comprising SEQ ID N° 10 (RASEX¹X²X³X⁴X⁵X⁶X⁷X⁸X⁹X¹⁰X¹¹), SEQ ID N° 11 (X¹²A X¹³N X¹⁴X¹⁵X¹⁶) and SEQ ID N° 12 (X¹⁷X¹⁸X¹⁹ X²⁰ X²¹PYT), wherein, independently from one each other, X¹ is N or S, X² is V or Y, X³ is D or Y, X⁴ is S or N, X⁵ is H or Y, X⁶ is G or L, X⁷ is F or A, X⁸ is S or absent, X⁹ is F or absent, X¹⁰ is M or absent, X¹¹ is N or absent, X¹² is A or S, X¹³ is S or T, X¹⁴ is L or Q, X¹⁵ is Q or A, X¹⁶ is S or D, X¹⁷ is Q or H, X¹⁸ is F or S, X¹⁹ is W or K, X²⁰ is E or G and X²¹ is T or V.

Most preferably, the biologically active fragment is selected from the group comprising SEQ ID N° 7 (RASENVYSHLA), SEQ ID N° 8 (SATNLAD) and SEQ ID N° 9 (QHFWGTPYT). A variant of the SEQ ID No 3 disclosed above is a conservative variant and refers to polypeptides having amino acid sequences that differ to some extent from the native sequence polypeptide, i.e. amino acid sequences that vary from the native 3D sequence whereby one or more amino acids are substituted by another one. The variants can occur naturally (e.g.

Preferably, the isolated and/or purified antibody, antibody fragment or derivative thereof of the invention recognizes a protein consisting essentially in SEQ ID No 1, a fragment thereof and/or a conservative variant thereof. By "bind", or "recognize", used interchangeably herein, it is generally meant that a binding molecule, e g , an antibody binds to an epitope via its antigen- binding domain, and that the binding entails some

complementarity between the antigen- binding domain and the epitope.

The isolated and/or purified antibody may be a polyclonal (e.g. a polyclonal serum) or a monoclonal antibody. Preferably, the isolated and/or purified antibody is a monoclonal antibody.

Antibodies used in the present invention are not limited to whole antibody molecules and may be antibody fragments or derivatives as long as they can block the cancer supportive function of a fasciclin protein family member such as periostin and that they recognize or bind to a protein consisting essentially in SEQ ID No 1, a fragment thereof and/or a conservative variant thereof.

Examples of isolated and/or purified antibody fragment or derivative thereof are selected amongst the group comprising a Fab-fragment, a F(ab2)'-fragment, a single-chain antibody, a chimeric antibody, a CDR-grafted antibody, a bivalent antibody-construct, a humanized antibody, a synthetic antibody, a chemically modified derivative thereof, a multispecific antibody, a diabody, a scFv- fragment; a dsFv-fragment, a labeled antibody, or another type of recombinant antibody. Specifically, an antibody fragment is synthesized by treating the antibody with an enzyme such as papain or pepsin, or genes encoding these antibody fragments are constructed, and expressed by appropriate host cells as known to the skilled artisan. Fragments or derivatives of the above antibodies which are able to block a cancer supportive function of a fasciclin protein family member can be obtained by using methods which are described, e.g., in Harlow and Lane "Antibodies, A Laboratory Manual", CSH Press, Cold Spring Harbor, 1988. When derivatives of said antibodies are obtained by the phage display technique, surface plasmon resonance as employed in the BIAcore system can be used to increase the efficiency of phage antibodies which bind to an epitope of EAGl

(Schier, Human Antibodies Hybridomas 7 (1996), 97-105; Malmborg, J. Immunol. Methods 183 (1995), 7-13).

The term "CDR-grafted antibody" refers to an antibody in which the CDR from one antibody, or a biologically active fragment of said CDR, is inserted into the framework of another antibody. In certain embodiments, the antibody from which the CDR is derived and the antibody from which the framework is derived are of different species. In certain embodiments, the antibody from which the CDR is derived and the antibody from which the framework is derived are of different isotypes.

Hie term ^''humanized antibody^'' refers to an antibody in which all or part of an antibody frame woik region is derived fiom a human, but all oi part of one or rnoie CDR regions is derived from another species, for example, including, but not limiieJ to, a mυuse.

The term "humanized antibody" rctets to antibodies in which the framework or

"complementarity determining regions^" (CDR) have been modified to comprise the CDR of an immunoglobulin oi different specificity as cumpaied tu that of the parent immunoglobulin. rl hc term "bi valent or bispceific antibody" as used herein refers to an antibody in which each of the two pairs of heavy chain and light chain (HC /LC) is specifically binding to a different antigen, Lc. the first heavy and the first iighi chain (^'originating from an aniibody against a first antigen) arc specifically binding together to a first antigen, and . the second heavy and the second light chain (originating from an antibody against a second antigen ) are specifically binding together to a second antigen; such bivalent, bispecific antibodies aie capable of specifically binding to two different antigens at the same rime, and not to more than two antigens, in contrary to, on the one hand a monospecific antibody capable of binding only UJ one antigen, and on the oilier hand a.g, a tetravalcnL tctraspcciflc antibody which can bind to four antigen

at the same time,

Among the antibody fragments of the present invention, Fab, F(ab')2 and the like can be obtained by treating an antibody inhibiting the anti-cell adhesive activity of periostin with a proteolytic enzyme such as papain or pepsin, or alternatively, can be prepared by constructing a gene encoding the resulting antibody fragment and introducing this construct into an expression vector, followed by expression in an appropriate host cell.

The term "recombinant antibody", as used herein, is intended to include all antibodies that are prepared, expressed, created or isolated by recombinant means, such as antibodies isolated from a host cell (such as a NSO or CHO cell) or from an animal (e.g. a mouse) that is transgenic for, for example, human immunoglobulin genes or antibodies expressed using a recombinant expression vector transfected into a host cell. Such recombinant antibodies have variable and constant regions in a rearranged form.

The "diabody" refers to an antibody produced in accordance with the technology described by Hollinger et al., Proc. Natl. Acad. Sci. USA, 90:6444-6448 (1993). These authors have provided an alternative mechanism for making bispecifte antibody fragments. The fragments comprise a heavy-chain variable domain (VH) connected to a light-chain variable domain (VL) by a linker which is too short to allow pairing between the two domains on the same chain. Accordingly, the VH and VL domains of one fragment are forced to pair with the complementary VL and VH domains of another fragment, thereby forming two antigen-binding sites. Another strategy for making bispecifte antibody fragments by the use of single-chain Fv (sFv) dimers has also been reported. See Gruber et al., J. Immunol., 152:5368 (1994).

Antibodies with more than two valencies are also contemplated. For example, multispecifϊc antibodies such as trispecific antibodies can be prepared as known to the skilled artisan.

Among the antibody fragments of the present invention, single chain Fv (scFv) can be prepared by linking together an H chain V region and an L chain V region from an antibody blocking a cancer supportive function of a fasciclin protein family member by using an appropriate peptide linker or the like. Alternatively, scFv can be prepared by constructing a DNA segment encoding the entire sequences or desired amino acid sequences of a gene encoding an H chain or H chain V region from the above antibody and a gene encoding an L chain or L chain V region from the antibody, and introducing this construct into an expression vector, followed by expression in an appropriate host cell.

Among the antibody fragments of the present invention, disulfide-stabilized antibody (dsFv) is an antibody fragment in which polypeptides modified to replace one amino acid residue by a cysteine residue in both H and L chain V regions from an antibody blocking a cancer supportive function of a fasciclin protein family member are linked together between these cysteine residues via a disulfide linkage. An amino acid residue to be replaced by a cysteine residue can be selected by stereostructural estimation of the antibody. dsFv can be prepared by constructing a DNA segment encoding the entire sequence or a desired amino acid sequence of a gene encoding the antibody fragment, and introducing this construct into an expression vector, followed by expression in an appropriate host cell.

Among the antibody fragments of the present invention, a CDR-containing peptide comprises at least one or more CDR regions selected from CDR regions in H or L chains of an antibody inhibiting the anti-cell adhesive activity of periostin. Also, multiple CDR regions may be linked together by techniques using an appropriate peptide linker or the like. The CDR-containing peptide may also be prepared by constructing a DNA segment encoding the entire sequence or a desired amino acid sequence of a gene encoding the peptide, and introducing this construct into an expression vector, followed by expression in an appropriate host cell. Alternatively, the CDR-containing peptide can also be prepared by chemical synthesis such as Fmoc or tBoc method.

The production of chimeric antibodies is described, for example, in W089/09622. Methods for the production of humanized antibodies are described in, e.g., EP-Al 0 239 400 and W090/07861. A further source of antibodies to be utilized in accordance with the present invention are so-called xenogenic antibodies. The general principle for the production of xenogenic antibodies such as human antibodies in mice is described in, e.g., WO 91/10741, WO 94/02602, WO 96/34096 and WO 96/33735. As discussed above, the antibody of the invention may exist in a variety of forms besides complete antibodies; including, for example, Fv, Fab and F(ab)2, as well as in single chains; see e.g. W088/09344.

One additional aspect of the present invention is to provide a pharmaceutical composition comprising a pharmaceutically effective amount of an isolated and/or purified antibody, antibody fragment or derivative thereof able to block a cancer supportive function of a fasciclin protein family member as disclosed. The pharmaceutical agent can be in a variety of well known formulations and administered using any of a variety of well known methods of administration such as intra-nasal, oral, subcutaneous, intravenous, intraarterial, intraperitoneal and/or intramuscular are also contemplated.or the like.

Pharmaceutical compositions adapted for nasal administration wherein the pharmaceutically acceptable carrier is a solid include a coarse powder having a particle size for example in the range 20 to 500 microns which is administered in the manner in which snuff is taken, e.g, by rapid inhalation through the nasal passage from a container of the powder held close up to the nose. Suitable compositions wherein the carrier is a liquid, for administration as a nasal spray or as nasal drops, include aqueous or oil solutions of the active ingredient.

Pharmaceutical compositions adapted for administration by inhalation include fine particle dusts or mists which may be generated by means of various types of metered dose pressurized aerosols, nebulizers or insufflators.

In cases where the agent of the invention is included in a suspension, the formulation may contain suspending agents, as for example, ethoxylated isostearyl alcohols,

polyoxyethylene sorbitol and sorbitan esters, microcrystalline cellulose, aluminum metahydroxide, bentonite, agar-agar and tragacanth, or mixtures of these substances, among others.

Useful intranasal formulations of an alarm pheromone may contain at least one stabilizer and surfactant. Among the pharmaceutically acceptable surfactants are

polyoxyethylene castor oil derivatives, such as polyoxyethylene-glycerol-triricinoleate, also known as polyoxyl 35 caster oil (CREMOPHOR EL), or poloxyl 40 hydrogenated castor oil (CREMOPHOR RH40) both available from BASF Corp.; mono-fatty acid esters of polyoxyethylene (20) sorbitan, such as polyoxyethylene (20) sorbitan monolaurate (TWEEN 80), polyoxyethylene monostearate (TWEEN 60), polyoxyethylene (20) sorbitan

monopalmitate (TWEEN 40), or polyoxyethylene 20 sorbitan monolaurate (TWEEN 20) (all available from ICI Surfactants of Wilmington, Del.); polyglyceryl esters, such as polyglyceryl oleate; and polyoxyethylated kernel oil (LABRAFIL, available from Gattefosse Corp.).

Preferably, the surfactant will be between about 0.01% and 10% by weight of the

pharmaceutical composition. Among the pharmaceutically useful stabilizers are antioxidants such as sodium sulfite, sodium metabisulfite, sodium thiosulfate, sodium formaldehyde sulfoxylate, sulfur dioxide, ascorbic acid, isoascorbic acid, thioglycerol, thioglycolic acid, cysteine hydrochloride, acetyl cysteine, ascorbyl palmitate, hydroquinone, propyl gallate, nordihydroguaiaretic acid, butylated hydroxytoluene, butylated hydroxyanisole, alpha- tocopherol and lecithin. Preferably, the stabilizer will be between about 0.01% and 5% by weight of the pharmaceutical composition.

Suspensions may also include chelating agents such as ethylene diamine tetraacetic acid, its derivatives and salts thereof, dihydroxyethyl glycine, citric acid and tartaric acid among others. Additionally, proper fluidity of a suspension can be maintained, for example, by the use of coating materials such as lecithin, by the maintenance of the required particle size in the case of dispersions and by the use of surfactants, such as those previously mentioned.

Solid dosage forms for oral administration include capsules, tablets, pills, powders and granules. In such solid dosage forms, the pharmaceutically effective amount of an agent of the invention may be 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

carboxymethylcellulose, alginates, gelatin, polyvinylpyrrolidone, 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 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, capsules, pills and granules can be prepared with coatings and shells such as enteric coating and other coatings well-known in the

pharmaceutical formulating art. They may optionally contain opacifying agents and may also be of a composition such that they release the active ingredient(s) only, or preferentially, in a certain part of the intestinal tract, optionally, in a delayed manner. Examples of embedding compositions which can be used include polymeric substances and waxes.

Liquid dosage forms for oral administration or for spray formulation include pharmaceutically acceptable emulsions, solutions, suspensions, syrups and elixirs. In addition to the pharmaceutically effective amount o an agent of the invention , 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, dimethyl formamide, oils (in particular, cottonseed, groundnut, corn, germ, olive, castor and sesame oils), glycerol, tetrahydrofurfuryl alcohol, polyethylene glycols and fatty acid esters of sorbitan and mixtures thereof.

This invention also envisages the use of an isolated and/or purified antibody, antibody fragment or derivative thereof of the invention in a pharmaceutically acceptable salt form. Examples of such salts may include sodium, potassium, calcium, aluminum, gold and silver salts. Also contemplated are salts formed with pharmaceutically acceptable amines such as ammonia, alkyl amines, hydroxyalkylamines, N-methylglucamine and the like. Certain basic compounds also form pharmaceutically acceptable salts, e.g., acid addition salts. For example, pyrido-nitrogen atoms may form salts with strong acid, while compounds having basic substituents such as amino groups also form salts with weaker acids. Examples of suitable acids for salt formation are hydrochloric, sulfuric, phosphoric, acetic, citric, oxalic, malonic, salicylic, malic, fumaric, succinic, ascorbic, maleic, pamoic, methanesulfonic and other mineral and carboxylic acids well known to those skilled in the art.

The salts are prepared by contacting the free base form with a sufficient amount of the desired acid to produce a salt in the conventional manner. The free base forms may be regenerated by treating the salt with a suitable dilute aqueous base solution such as dilute aqueous NaOH, potassium carbonate, ammonia and sodium bicarbonate. The free base forms differ from their respective salt forms somewhat in certain physical properties, such as solubility in polar solvents, but the acid and base salts are otherwise equivalent to their respective free base forms for purposes of the invention.

All such acid and base salts are intended to be pharmaceutically acceptable salts within the scope of the invention and all acid and base salts are considered equivalent to the free forms of the corresponding compounds for purposes of the invention.

The pharmaceutical composition comprising an isolated and/or purified antibody, antibody fragment or derivative thereof of the invention, as described herein, as an active ingredient may also be incorporated or impregnated into a bioabsorbable matrix, with the matrix being administered in the form of a suspension of matrix, a gel or a solid support. In addition the matrix may be comprised of a biopolymer.

Sustained-release preparations may be prepared. Suitable examples of sustained- release preparations include semi permeable matrices of solid hydrophobic polymers containing a pharmaceutically effective amount of an agent of the invention, which matrices are in the form of shaped articles, e.g. films, or microcapsules. Examples of sustained-release matrices include polyesters, hydrogels (for example, poly(2-hydroxyethyl-methacrylate), or poly(vinylalcohol)), polylactides (U.S. Pat. No. 3,773,919), copolymers of L-glutamic acid and [gamma] ethyl-L-glutamate, non-degradable ethylene -vinyl acetate, degradable lactic acid-glycolic acid copolymers such as the LUPRON DEPOT(TM) (injectable microspheres composed of lactic acid-glycolic acid copolymer and leuprolide acetate), and poly-D-(-)-3- hydroxybutyric acid.

The formulations to be used for in vivo administration must be sterile. This is readily accomplished for example by filtration through sterile filtration membranes.

It is understood that the suitable dosage of a pharmaceutically effective amount of an isolated and/or purified antibody, antibody fragment or derivative thereof of the present invention will be dependent upon the age, sex, health, and weight of the recipient, kind of concurrent treatment, if any and the nature of the effect desired.

The appropriate dosage form will depend on the disease, the isolated and/or purified antibody, antibody fragment or derivative thereof of the invention, and the mode of administration. Usually, the pharmaceutically effective amount of an isolated and/or purified antibody, antibody fragment or derivative thereof of the invention is present in an amount between about 0.001% and 20% by weight of the pharmaceutical composition.

While a preferred pharmaceutical composition of the present invention comprises a pharmaceutically effective amount of an isolated and/or purified antibody, antibody fragment or derivative thereof able to block a cancer supportive function of a fasciclin protein family member as an active ingredient, an alternative pharmaceutical composition may contain an isolated and/or purified nucleic acid sequence encoding said isolated and/or purified antibody, antibody fragment or derivative thereof, as described herein, as an active ingredient. This pharmaceutical composition may include either the sole isolated and/or purified DNA sequence, an expression vector comprising said isolated and/or purified DNA sequence or a host cell previously transfected or transformed with an expression vector described herein.

In this latter example, host cell will preferably be isolated from the patient to be treated in order to avoid any antigenicity problem. These gene and cell therapy approaches are especially well suited for patients requiring repeated administration of the pharmaceutical composition, since the said purified and/or isolated DNA sequence, expression vector or host cell previously transfected or transformed with an expression vector can be incorporated into the patient's cell which will then produce the protein endogenously.

The pharmaceutical compositions of the invention are preferably for the treatment or prevention of cancer, tumorigenesis or metastasis formation. "Cancer" is an unregulated proliferation of cells due to loss of normal controls, resulting in unregulated growth, lack of differentiation, local tissue invasion, and, often, metastasis. Cancer can develop in any tissue or organ at any age. There is often evidence of an immune response to tumors, but the role of the immune system in preventing and treating cancer is still uncertain.

Preferably, the cancer is selected from the group consisting of carcinoma, lymphoma, blastoma, sarcoma, liposarcoma, neuroendocrine tumor, mesothelioma, schwanoma, meningioma, adenocarcinoma, melanoma, leukemia, lymphoid malignancy, squamous cell cancer, epithelial squamous cell cancer, lung cancer, small-cell lung cancer, non-small cell lung cancer, adenocarcinoma of the lung, squamous carcinoma of the lung, cancer of the peritoneum, hepatocellular cancer, gastric or stomach cancer, gastrointestinal cancer, pancreatic cancer, glioblastoma, cervical cancer, ovarian cancer, liver cancer, bladder cancer, hepatoma, breast cancer, colon cancer, rectal cancer, colorectal cancer, endometrial or uterine carcinoma, salivary gland carcinoma, kidney or renal cancer, prostate cancer, vulval cancer, thyroid cancer, hepatic carcinoma, anal carcinoma, penile carcinoma, testicular cancer, esophageal cancer, a tumor of the biliary tract, and head and neck cancer. "Tumorigenesis", as used herein, is the process involved in the production of a new tumor or tumors.

"Metastasis" is the spread of a malignant tumor cells from one organ or part to another non-adjacent organ or part. Cancer cells can "break away", "leak", or "spill" from a primary tumor, enter lymphatic and blood vessels, circulate through the bloodstream, and settle down to grow within normal tissues elsewhere in the body. Metastasis is one of three hallmarks of malignancy (contrast benign tumors). Most tumors and cancers, in particular those listed above and other neoplasms can metastasize, although in varying degrees (e.g., glioma and basal cell carcinoma rarely metastasize). When tumor cells metastasize, the new tumor is called a secondary or metastatic tumor.

The present invention further contemplates an isolated and/or purified nucleic acid sequence comprising

i) a nucleotide sequence encoding an isolated and/or purified antibody, an antibody fragment or derivative of said antibody of the invention,

ii) a nucleic acid sequence having substantial sequence identity or homology to a nucleic acid sequence encoding an isolated and/or purified antibody, an antibody fragment of or derivative of said antibody of the invention,

iii) a nucleic acid sequence complementary to i) or ii),

iv) a degenerated nucleic acid sequence of i), ii) or iii), or

v) a nucleic acid sequence capable of hybridizing under stringent conditions to i), ii), iii) or iv). "An isolated and/or purified nucleic acid sequence" refers to nucleic acid free or substantially free of material with which it is naturally associated such as other polypeptides or nucleic acids with which it is found in its natural environment, or the environment in which it is prepared (e. g. cell culture) when such preparation is by recombinant nucleic acid technology practised in vitro or in vivo.

The term "nucleic acid" is intended to refer either to DNA or to RNA.

In case the nucleic acid is DNA, then DNA which can be used herein is any polydeoxynuclotide sequence, including, e.g. double-stranded DNA, single-stranded DNA, double-stranded DNA wherein one or both strands are composed of two or more fragments, double-stranded DNA wherein one or both strands have an uninterrupted phosphodiester backbone, DNA containing one or more single-stranded portion(s) and one or more double- stranded portion(s), double-stranded DNA wherein the DNA strands are fully complementary, double-stranded DNA wherein the DNA strands are only partially complementary, circular DNA, covalently- closed DNA, linear DNA, covalently cross-linked DNA, cDNA, chemically- synthesized DNA, semi-synthetic DNA, biosynthetic DNA, naturally-isolated DNA, enzyme-digested DNA, sheared DNA, labeled DNA, such as radiolabeled DNA and fluorochrome-labeled DNA, DNA containing one or more non-naturally occurring species of nucleic acid.

DNA sequences that encode the isolated and/or purified antibody, an antibody fragment of or derivative of said antibody of the invention, or a biologically active fragment thereof, can be synthesized by standard chemical techniques, for example, the phosphotriester method or via automated synthesis methods and PCR methods.

The purified and/or isolated DNA sequence encoding an isolated and/or purified antibody, an antibody fragment of or derivative of said antibody of the invention according to the invention may also be produced by enzymatic techniques. Thus, restriction enzymes, which cleave nucleic acid molecules at predefined recognition sequences can be used to isolate nucleic acid sequences from larger nucleic acid molecules containing the nucleic acid sequence, such as DNA (or RNA) that codes for the isolated and/or purified antibody, an antibody fragment of or derivative of said antibody of the invention or for a fragment thereof.

Encompassed by the present invention is also a nucleic acid in the form of a polyribonucleotide (RNA), including, e.g., single- stranded RNA, double- stranded RNA, double-stranded RNA wherein one or both strands are composed of two or more fragments, double-stranded RNA wherein one or both strands have an uninterrupted phosphodiester backbone, RNA containing one or more single-stranded portion(s) and one or more double- stranded portion(s), double- stranded RNA wherein the RNA strands are fully complementary, double-stranded RNA wherein the RNA strands are only partially complementary, covalently crosslmked RNA, enzyme-digested RNA, sheared RNA, mRNA, chemically-synthesized

RNA, semi-synthetic RNA, biosynthetic RNA, naturally-isolated RNA, labeled RNA, such as radiolabeled RNA and fluorochrome-labeled RNA, RNA containing one or more non- naturally- occurring species of nucleic acid. The isolated and purified nucleic acid sequence, DNA or RNA, also comprises an isolated and/or purified nucleic acid sequence having substantial sequence identity or homology to a nucleic acid sequence encoding an isolated and/or purified antibody, an antibody fragment of or derivative of said antibody of the invention. Preferably, the nucleic acid will have substantial sequence identity for example at least 50%, 55%, 60%, 65%, 70%, 75%, 80%, or 85% nucleic acid identity; more preferably 90% nucleic acid identity; and most preferably at least 95%, 96%, 97%, 98%, or 99% sequence identity.

Identity as known in the art and used herein, is a relationship between two or more amino acid sequences or two or more nucleic acid sequences, as determined by comparing the sequences. It also refers to the degree of sequence relatedness between amino acid or nucleic acid sequences, as the case may be, as determined by the match between strings of such sequences. Identity and similarity are well known terms to skilled artisans and they can be calculated by conventional methods (for example see Computational Molecular Biology, Lesk, A. M. ed., Oxford University Press, New York, 1988; Biocomputing: Informatics and Genome Projects, Smith, D. W. ed., Academic Press, New York, 1993; Computer Analysis of Sequence Data, Part I, Griffin, A. M. and Griffin, H. G. eds., Humana Press, New Jersey, 1994; Sequence Analysis in Molecular Biology, von Heinje, G. Academic Press, 1987; and Sequence Analysis Primer, Gribskov, M. and Devereux, J. eds. M. Stockton Press, New York, 1991, Carillo, H. and Lipman, D., SIAM J. Applied Math. 48: 1073, 1988).

Methods which are designed to give the largest match between the sequences are generally preferred. Methods to determine identity and similarity are codified in publicly available computer programs including the GCG program package (Devereux J. et al., Nucleic Acids Research 12(1): 387, 1984); BLASTP, BLASTN, and FASTA (Atschul, S. F. et al. J. Molec. Biol. 215: 403-410, 1990). The BLAST X program is publicly available from NCBI and other sources (BLAST Manual, Altschul, S. et al. NCBI NLM NIH Bethesda, Md. 20894; Altschul, S. et al. J. MoI. Biol. 215: 403-410, 1990).

Also encompassed by the present invention is a nucleic acid sequence complementary to the isolated and purified nucleic acid sequence encoding an isolated and/or purified antibody, an antibody fragment of or derivative of said antibody of the invention. Also within the scope of the invention is a degenerated nucleic acid sequence having a sequence which differs from a nucleic acid sequence encoding the isolated and/or purified antibody, an antibody fragment or derivative of said antibody of the invention, or a derivative or complementary sequence thereof, due to degeneracy in the genetic code. Such nucleic acid encodes functionally equivalent isolated and/or purified antibody, antibody fragment or derivative of said antibody of the invention but differs in sequence from the sequence due to degeneracy in the genetic code. This may result in silent mutations which do not affect the amino acid sequence. Any and all such nucleic acid variations are within the scope of the invention. In addition, also considered is a nucleic acid sequence capable of hybridizing under stringent conditions, preferably high stringency conditions, to a nucleic acid sequence encoding an isolated and/or purified antibody, an antibody fragment of or derivative of said antibody of the invention, a nucleic acid sequence complementary thereof or a degenerated nucleic acid sequence thereof. Appropriate stringency conditions which promote DNA hybridization are known to those skilled in the art, or can be found in Current Protocols in Molecular Biology, John Wiley & Sons, N.Y. (1989), 6.3.1-6.3.6. For example, 6.0X sodium chloride/sodium citrate (SSC) at about 45°C, followed by a wash of 2.0XSSC at 50⁰C may be employed. The stringency may be selected based on the conditions used in the wash step. By way of example, the salt concentration in the wash step can be selected from a high stringency of about 0.2XSSC at 50⁰C. In addition, the temperature in the wash step can be at high stringency conditions, at about 65° C. The present invention also includes an isolated and/or purified nucleic acid encoding an antibody, an antibody fragment or derivative of said antibody of the invention comprising a nucleic acid sequence encoding a truncation or an analog of the antibody, antibody fragment or derivative of said antibody of the invention. The term "truncation" refers to a sequence encoding a peptide containing less amino acid than the native but exhibiting the same properties.

The invention also encompasses allelic variants of the disclosed isolated and/or purified nucleic sequence; that is, naturally-occurring alternative forms of the isolated and/or purified nucleic acid that also encode peptides that are identical, homologous or related to that encoded by the isolated and/or purified nucleic sequences. Alternatively, non-naturally occurring variants may be produced by mutagenesis techniques or by direct synthesis.

A biologically active fragment of the disclosed isolated and/or purified nucleic sequence is also considered and refers to a sequence containing less nucleotides in length than the nucleic acid sequence encoding an isolated and/or purified antibody, an antibody fragment of or derivative of said antibody of the invention, a nucleic acid sequence complementary thereof or a degenerated nucleic acid sequence thereof. This sequence can be used as long as it exhibits the same properties as the native sequence from which it derives. Preferably this sequence contains less than 90%, preferably less than 60%, in particular less than 30% amino acids in length than the respective isolated and/or purified nucleic sequence of the antibody, antibody fragment or derivative of said antibody of the invention.

Yet another concern of the present invention is to provide an expression vector comprising the isolated and/or purified nucleic acid sequence encoding an isolated and/or purified antibody, an antibody fragment or derivative of said antibody of the invention. The choice of an expression vector depends directly, as it is well known in the art, on the functional properties desired, e.g., an isolated and/or purified antibody, an antibody fragment of or derivative of said antibody of the invention expression and the host cell to be transformed or transfected.

A further concerned of the present invention is to provide a host cell comprising the expression vector of the invention. Generally, the host cell is a bacterium, a fungal, a plant, or an animal cell. Preferably, the animal cell is a mammalian cell and most preferably a human cell or a human cell line.

The present invention also provides one or more hybridoma secreting the monoclonal antibody of the invention. These hybridomas termed ID8, IVB2, IF6, IIIH9, IC12, IIB4 produce IgGl antibodies which bind to human and murine periostin and block its tumor supportive function.

However, monoclonal antibodies can be prepared using a wide variety of techniques known in the ail including ihe use of hybridoma, recombinant, and phage display technologies, or a combination thereof, for example, monoclonal antibodies can be produced

hybridoma techniques including those known in the an and taught, for example, in Harlow ct ai., Λndbodies: Λ Laboratory Manual. (Cold Spring Harbor Laboratory Press, 2nd ed.. 1988); Hammer -ling, et ai, in: Monoclonal Antibodies and T-CeII Hybrido-mas 563- 681 (Elsevier, N. Y., J 981 ) (said references incorporated by reference in their entireties). The terra

''monoclonal antibody" as used herein is not limited to antibodies produced through hybridoma technology. The term "monoclonal antibody" refers to an antibody that is derived from a single clone, including any eukaryoiic. prukaryutic, or phage done, and not the method by which it is produced. Methods for producing and screening for specific antibodies using hybridoma technology are routine and well known in the art.

Also encompassed in the present invention is a method for treating and/or preventing cancer, cancer metastasis, or tumorigenesis, in a patient in need thereof, comprising administering a pharmaceutically effective amount of an isolated and/or purified antibody, antibody fragment or derivative thereof of the invention.

Further encompassed in the present invention is a method for treating and/or preventing cancer cell self-renewal, expansion, proliferation, activation, survival, anchorage, niche interaction or homing to the niche in a patient in need thereof, comprising administering a pharmaceutically effective amount of an isolated and/or purified antibody, antibody fragment or derivative thereof of the invention. Also encompassed in the present invention is a method for treating and/or preventing cancer stem cell self-renewal, expansion, proliferation, activation, survival, anchorage, niche interaction or homing to the niche in a patient in need thereof, comprising administering a pharmaceutically effective amount of an isolated and/or purified antibody, antibody fragment or derivative thereof of the invention.

The isolated and/or purified antibody, antibody fragment or derivative thereof of the invention to be used in the above-mentioned methods for treating and/or or preventing the claimed diseases or conditions, can be in a variety of well known formulations, as described infra, and administered using any of a variety of well known methods of administration such as intra-nasal, oral, subcutaneous, intravenous, intraarterial, intraperitoneal and/or intramuscular are also contemplated or the like.

Preferably, the isolated and/or purified antibody, antibody fragment or derivative thereof of the invention is in the form of a pharmaceutical composition as described herein.

"Administering" or "administered", as it applies in the present invention means "giving" or "contacting" and refers to contact of a pharmaceutical composition or a therapeutical composition to a patient in need thereof, preferably a human.

The appropriate dosage form will depend on the disease, the isolated and/or purified antibody, antibody fragment or derivative thereof of the invention, and the mode of administration. Usually, the pharmaceutically effective amount of an agent of the invention is present in an amount between about 0.001% and 20% by weight of the pharmaceutical composition. In one embodiment, the isolated and/or purified antibody, antibody fragment or derivative thereof blocking the cancer supportive function binds or targets a fasciclin protein family.

Alternatively, the isolated and/or purified antibody, antibody fragment or derivative thereof of the invention binds or targets at least one protein interacting with a fasciclin protein family.

Alternatively also, the isolated and/or purified antibody, antibody fragment or derivative thereof blocking the cancer supportive function alters the structure, distribution or concentration of said fasciclin protein or of said at least one protein interacting with said fasciclin protein.

Generally, the cancer is selected from the group consisting of carcinoma, lymphoma, blastoma, sarcoma, liposarcoma, neuroendocrine tumor, mesothelioma, schwanoma, meningioma, adenocarcinoma, melanoma, leukemia, lymphoid malignancy, squamous cell cancer, epithelial squamous cell cancer, lung cancer, small-cell lung cancer, non-small cell lung cancer, adenocarcinoma of the lung, squamous carcinoma of the lung, cancer of the peritoneum, hepatocellular cancer, gastric or stomach cancer, gastrointestinal cancer, pancreatic cancer, glioblastoma, cervical cancer, ovarian cancer, liver cancer, bladder cancer, hepatoma, breast cancer, colon cancer, rectal cancer, colorectal cancer, endometrial or uterine carcinoma, salivary gland carcinoma, kidney or renal cancer, prostate cancer, vulval cancer, thyroid cancer, hepatic carcinoma, anal carcinoma, penile carcinoma, testicular cancer, esophageal cancer, a tumor of the biliary tract, and head and neck cancer.

The present invention further relates to a kit useful for treating and/or preventing cancer metastasis formation, tumorigenesis or cancer stem cell anchorage and survival comprising a pharmaceutically effective amount of an isolated and/or purified antibody, antibody fragment or derivative thereof blocking the cancer supportive function of the invention, optionally with reagents ancl'oϊ instructions for use.

Also encompassed is a kit for treating and/or preventing cancer metastasis formation, tumorigenesis or cancer stem cell anchorage and survival comprising a pharmaceutically effective amount of an isolated and/or purified antibody, antibody fragment or derivative thereof of the invention, optionally with reagents aiκl/θ3 instructions ibi use. EXAMPLES

Example 1

Material and Methods

Mice

The POSTN knock out was generated by homologous recombination in 12901a ES cells inserting a neo cassette to disrupt the coding sequence and mice were produced by blastocyst injection. Afterwards the line was back-crossed onto a FVB background.

The murine tumor model used for this study expresses oncogenic human Polyoma Middle T- (PyMT) antigen under the control of the Mouse Mammary Tumor Virus (MMTV) promoter to allow the specific expression of the oncogene in the mammary gland. Mice develop mammary gland tumors starting from the 6^th week of life. The tumors are metastasising to the lung after about 2-3 month.

For transplantation experiments, the POSTN knock out was bred into immuno-compromized backgrounds (Nude^"Λ or Rag-1^"Λ).

Analysis of metastasis formation in wild type and POSTN knock out mice.

Transgenic mice of the genotype MMTV-PyMT and POSTN wild type or knock out were sacrificed when the primary tumor exceeded a defined size. Primary tumors were harvested and weighted. The lung was dissected and analysed for the presence of visible metastasis and visible metastases termed "macroscopic" were counted.

Harvested lungs were then fixed in 4% paraformaldehyde, paraffin embedded and micro- dissected. Every 4^th section of consecutive 5μm sections was collected and stained with haematoxylin/eosin. They were then analysed for the presence of "microscopic" metastasis which were measured by computerized imaging (in pixels) and counted. Tumor cell transplantation

OOrrtthhoottooppiicc ttrraannssppllaannttaattiioonnss were performed by injecting 10⁶ tumor cells from MMTV-PyMT and POSTN wild type or knock out tumors in serum reduced Matrigel into the mammary fat pad of immuno-compromized mice. For tail vein injections, 10⁶ tumor cells from GFP+, MMTV-PyMT and POSTN wild type or knock out tumors in lOOμl PBS were used.

Tumor cell isolation and analysis from lungs

Lungs where harvested and dissociated using collagenase treatment. After isolation, cells were stained with the different antibody (CD90, CD24) and with 7AAD for dead cells exclusion. FACS analysis was performed using FACS "CIAN" machine. The total amount of tumor cells in the lungs was estimated as GFP positive, 7AAD negative fraction. The Cancer stem cell (CSC) fraction was estimated as CD90 and CD24 positive subpopulation of the GFP positive, 7AAD negative tumor cells present in the lung.

In situ hybridization.

Tumors and lungs were harvested, fixed in Bouin's (picric acid, formaldehyde, acetic acid) and paraffin embedded. Micro-dissection was performed and the sections were processed and hybridized using a labelled anti-sense probe to detect POSTN messenger RNA. A sense probe was used as an internal negative control. The probes used the complete murine mRNA sequence (l-2373nt) of clone BC031449.1.

Tumor mammosphere culture.

Primary tumors from control and POSTN knock out mice were dissected and, after collagenase treatment, single cell suspensions were produced. The cells were plated on collagen for 24h in order to eliminate all immune cells present in the tumor cell preparation. The cells were then trypsinized, washed and counted. 10⁴ cells were plated in 100 μl of serum- free sphere medium (DMEM/F12 with B27 supplement, 20ng/ml EGF, 20ng/ml FGF, 1 μM Hepes) into 96-well low attachment plates. After about 10 days, mammospheres are usually formed in the culture.

To achieve sphere culture propagation, the cells grown as spheres were collected and trypsinized in order to produce a single cell suspension. 10⁴ cells were then seeded into 96-well low attachment plate.

Production of human POSTN protein.

A histidine tag (His) and a streptavidin binding protein tag (SBP) were fused to the human POSTN gene (SEQ ID N°l) lacking exon 17. A TEV cleavage site was added between the two tags and the protein coding sequence. The protein was expressed in CHO cells.

Supernatant was harvested and the protein was first purified on a Streptavidin column. Upon biotin elution the protein was loaded on a Ni-column. TEV protease was use to elute the purified protein from the column which at the same time removed the purification tags. For the ELISA, the Ni-column was instead eluted by imidazole so that the SBP tag could be used for binding to streptavidin-coated plates.

POSTN sphere formation rescue experiment.

The purified hPOSTN protein was added to the tumor cells prepared from MMTV-PyMT POSTN knock out tumors when seeded in low attachment 96-well plates for sphere culture. FACS analysis.

Tumor cells derived from MMTV-PyMT POSTN wild type or knock out tumors were grown in suspension for 10 days. Cells were then trypsinized and the single cell preparation was incubated with CD90 and CD24 antibodies. After washing, cells were analysed by

Fluorescent Activated Cell Sorter (FACS) analyser. Monoclonal antibody production and testing.

The purified hPOSTN protein was injected 3 times into POSTN knock out mice. Spleens were harvested and hybrodoma cells were produced by fusion to a murine myeloma cell line. 400 clones were isolated and propagated to collect antibody-containing supernatants. All supernatants were tested positive by ELISA against recombinant human POSTN protein. The blocking activity of all supernatants was tested by seeding the MMTV-PyMT derived tumor cells in low attachment 96-well plates.

Metastasis time course experiment

Ragl knock-out mice of two groups Control and POSTN knock-out were injected

intravenously with one million of OSF knock-out tumor cells to induce lung metastasis. To facilitate tumor cell isolation from the lungs, the injected tumor cells expressed the fluorescent marker GFP. The mice were sacrificed at 2 time points: after 1 week, when the tumor cells had extravasated into the lung and formed 1 -5 cell clusters or colonies; and after 5 weeks, when the cancer stem cells (CSCs) in the colonies, upon an active process of proliferation, survival and self renewal, had given rise to metastatic progression. The lungs of the two groups of mice at the two time points were digested and single cell preparation was analyzed by FACS to determine the amount of tumor cells present in the lungs. Furthermore, staining with the cancer stem cells markers CD90 and CD24 was performed to identify the frequency of CSCs among the tumor cells present in the different lung samples.

Example 2

Results

We ablated the periostin/OSF2/POSTN gene from the mouse genome using ES cell technology. Homozygous mutant mice display no overt phenotype and are viable and fertile. We next wanted to test POSTN function in a murine cancer model. We used the MMTV- PymT transgene which induces highly penetrant development of mammary adenocarcinomas with extensive, spontaneous pulmonary metastases. To test the function of POSTN in mammary cancer metastasis, we combined the MMTV-PymT transgene with the POSTN knock out allele. While formation of primary tumors is not affected by the knock out, the formation of lung metastasis is dependent on its expression (Figures 3-4). In the absence of the POSTN gene, hardly any lung metastasis are found even when primary mutant tumors exceed the size or age of littermate control tumors, which typically give rise to more than 30 pulmonary metastasis per mouse, whereas the mutants display only 1 metastasis on average. Furthermore, orthotopic transplantation of wild type tumor cells into knock out recipients failed to form metastasis (on average 13 metastases in transplants of wild type tumor cells into wild type recipients vs. no metastasis in transplants of wild type tumor cells into POSTN deficient recipients). Similarly, even if we dramatically increase the amount of tumor cells in the circulation by tail vein injections, we find that wild type tumor cells injected into knock out recipient animals show a dramatically reduced metastasis formation when compared to injections into wild type recipients (on average 16 metastases in transplants of wild type tumor cells into wild type recipients vs. 6 metastases in transplants of wild type tumor cells into POSTN deficient recipients).

In wild type control recipients we observed expression of this ECM molecule to be initiated already in very tiny micro -metastasis (<50 cells) from the surrounding, fibroblastoid stroma (Figure 2). To Inventors' knowledge, this is the first example describing an essential role of an ECM molecule in metastasis formation. If one takes into account that metastasis formation may too be cancer stem cell dependant, the experiments together hint at an essential function of specific components of the extracellular matrix in cancer stem cell maintenance. This tumor supportive niche most likely involves receptor-ECM interactions which mediate cancer stem cell anchorage and survival. In line with this concept, we find a strong decrease of early, micro-metastasis in POSTN mutant mice (Figure 5), which points to an essential function of POSTN in the initial phase of metastatic colonization. These results pointed to an effect of periostin on early metastatic colonization which may interfere with the survival or self- renewal of cancer stem cells (CSC). These CSC are essential at this early step of metastasis. We analyzed such an effect of periostin on CSC by monitoring the relative amount of such CSC during early and late phase of metastasis. For this we freshly isolated tumor cells from a GFP+/MMTV-PyMT mouse and injected this cell preparation into the tail vein of several recipient mice, either into wild type control or into POSTN -/-. The initial frequency of CSC (as positive for the markers CD24 and CD90) in this preparation was 2%. This frequency increased to about 10% within 1 week in the control and was only 8% in the mutant recipients. After macro-metastasis had established at 5 weeks, these frequencies dropped to 1.2% in the control and only 0.4% in the mutants (Figure 6). This demonstrated a clear detrimental effect of the absence of periostin for the maintenance of CSC in vivo.

One assay to analyze stem cell properties is the growth under non-adherent conditions in vitro. In this experimental setting, cancer cells are selected to grow as "mammospheres", i.e. hollow, ball- like aggregates of one or two cell layers which contain a high amount of cancer stem cells. Importantly, these sphere-cultures are not possible from knock out tumor cells. From wild type tumors we have established sphere cultures in 7 out of 11 cases whereas none of the 9 tested POST deficient tumors produced spheres (Figure 7). This dependency of cancer stem cells for POSTN is further manifested in the failure of such knock out cells to maintain long-term self-renewal potential as mutant tumor cells can not be sustained under sphere culture conditions. This phenotype can be rescued by addition of recombinant POSTN protein (Figure 8). In line with these results, we also observed a reduced number of mammary cancer stem cells in POSTN deficient primary tumors compared to controls (Figure 9). Inventors reasoned that this essential function of POSTN presents a novel target to block cancer stem cell maintenance. They therefore decided to develop monoclonal antibodies which could target this function of POSTN. They produced full size human POSTN protein lacking exon 17 (SEQ ID N°l) in vitro and used this sequence to immunize POSTN knock- out mice in order to obtain highly specific and affine antibodies.

400 clones which showed binding to POSTN in ELISA assays have been isolated and then further selected blocking antibodies in our sphere culture assay of wild type mammary cancer cells. This allowed identifying six clones with blocking activity. Importantly, other, commercial available antibodies against POSTN do not show this blocking activity.

Antibodies

The following IgG 1 isotype monoclonal antibody has been isolated and sequenced: SEO ID No 2

MQVKLQESGPELKKPGETVKISCKASGYTFTNYPMHWLKQAPGKGLKWMGWINTYSGAPTYADDFKGRFA FSLETSANTAYLQLNNLKNDDMATYFCARGELLRWWYYFDYWGQGTSLTVSSAKTTPPSVYPLAPGSAAQT NSMVTLGCL VKGYFPEPVTVTWNSGSLSSGVHTFP AVLQSDLYTLSSSVTVPSSTWPSETVTCNVAHPASSTK VDKKI

The three CDR hypervariable regions correspond to Hl= GYTFTNYPMH, H2=

TYSGAPTYADDFKG and H3= GELLRWWYYFDY. The constant region starts with TTPPSV.

SEO ID No 3:

MDIVMTQSPASLSVSVGETVTITCRASENVYSHLAWYQQKQGKSPQLLVYSATNLADGVPSRFSGSGSGTQF SLKINSLQSEDFGSYYCQHFWGTPYTFGGGTKLEIKRADAAPTVSIFPPSSEQLTSGGASWCFLNNFYPKDIN VKWKIDGSERQNGVLNS

Claims

1. An isolated and/or purified antibody, antibody fragment or derivative thereof able to block a cancer supportive function of a fasciclin protein family member characterized in that it recognizes a protein consisting essentially in SEQ ID No 1 , a fragment thereof and/or a conservative variant thereof , said isolated and/or purified antibody, antibody fragment or derivative thereof comprising

i) at least one complementary determining region (CDR) of the VH region , wherein the amino acid sequence determining said CDR consists essentially in the amino acid sequence set forth in SEQ ID No 2:

MQVKLQESGPELKKPGETVKISCKASGYTFTNYPMHWLKQAPGKGLKWMGWINTYSGAPT YADDFKGRFAFSLETSANTAYLQLNNLKNDDMATYFCARGELLRWWYYFDYWGQGTSLTV SSAKTTPPSVYPLAPGSAAQTNSMVTLGCLVKGYFPEPVTVTWNSGSLSSGVHTFPAVLQSDL YTLSSSVTVPSSTWPSETVTCNVAHPASSTKVDKKI, a biologically active fragment thereof and/or a variant thereof, and/or

ii) at least one complementary determining region (CDR) of the VL region, wherein the amino acid sequence determining said CDR consists essentially in the amino acid sequence set forth in SEQ ID No 3:

MDIVMTQSPASLSVSVGETVTITCRASEX¹X²X³X⁴X⁵X⁶X⁷X⁸X⁹X¹⁰X¹¹WYQQKQGKSPQLLVY X¹²A X¹³N X¹⁴X¹⁵X¹⁶GVPSRFSGSGSGTQFSLKINSLQSEDFGSYYCQ X¹⁷ X¹⁸ X¹⁹ X²⁰ X²¹PYTFG GGTKLEIKRADAAPTVSIFPPSSEQLTSGGASWCFLNNF YPKDINVKWKIDGSERQNGVLNS

wherein, independently from one each other,

X¹ is N or S, X² is V or Y, X³ is D or Y, X⁴ is S or N, X⁵ is H or Y, X⁶ is G or L, X⁷ is

F or A, X⁸ is S or absent, X⁹ is F or absent, X¹⁰ is M or absent, X¹¹ is N or absent, X¹² is A or S, X¹³ is S or T, X¹⁴ is L or Q, X¹⁵ is Q or A, X¹⁶ is S or D, X¹⁷ is Q or H, X¹⁸ is F or S, X¹⁹ is W or K, X²⁰ is E or G and X²¹ is T or V, a biologically active fragment thereof and/or a variant thereof.

2. The isolated and/or purified antibody, antibody fragment or derivative thereof of claim 1 , characterized in that the biologically active fragment of i) and/or ii) contains less than 90%, preferably less than 60%, in particular less than 30% amino acids in length than the respective sequence of CDR of the VH and/or CDR of the VL regions.

3. The isolated and/or purified antibody, antibody fragment or derivative thereof of any of the preceding claims, characterized in that the biologically active fragment for SEQ ID No

2 is selected from the group comprising SEQ ID N° 4 (GYTFTNYPMH), SEQ ID N° 5

(TYSGAPTYADDFKG) and SEQ ID N° 6 (GELLRWWYYFDY).

4. The isolated and/or purified antibody, antibody fragment or derivative thereof of any one of the preceding claims, characterized in that the biologically active fragment for SEQ ID

No 3 is selected from the group comprising

SEQ ID N° 10 (RASEX¹X²X³X⁴X⁵X⁶X⁷X⁸X⁹X¹⁰X¹¹), SEQ ID N° 11 (X¹²AX¹³NX¹⁴X¹⁵X¹⁶) and SEQ ID N° 12 (X¹⁷ X¹⁸ X¹⁹ X²⁰ X²¹PYT), wherein, independently from one each other, X¹ is N or S, X² is V or Y, X³ is D or Y, X⁴ is S or N, X⁵ is H or Y, X⁶ is G or L, X⁷ is F or A, X⁸ is S or absent, X⁹ is F or absent, X¹⁰ is M or absent, X¹¹ is N or absent, X¹² is A or S, X¹³ is S or T, X¹⁴ is L or Q, X¹⁵ is Q or A, X¹⁶ is S or D, X¹⁷ is Q or H, X¹⁸ is F or S, X¹⁹ is W or K, X²⁰ is E or G and X²¹ is T or V.

5. The isolated and/or purified antibody, antibody fragment or derivative thereof of any one of the preceding claims, characterized in that the biologically active fragment for SEQ ID

No 3 is selected from the group comprising SEQ ID N° 7 (RASENVYSHLA), SEQ ID N° 8 (SATNLAD) and SEQ ID N° 9 (QHFWGTPYT).

6. The isolated and/or purified antibody, antibody fragment or derivative thereof of claim 1 , characterized in that the blocking activity concerns a cancer cell or a cancer stem cell.

7. The isolated and/or purified antibody, antibody fragment or derivative thereof of any of the preceding claims, characterized in it is a monoclonal antibody.

8. The isolated and/or purified antibody, antibody fragment or derivative thereof of any one of the preceding claims, characterized in that said isolated and/or purified antibody fragment or derivative thereof is a Fab-fragment, a F(ab2)'-fragment, a single-chain antibody, a chimeric antibody, a CDR-grafted antibody, a CDR-containing peptide, a bivalent antibody- construct, a humanized antibody, a synthetic antibody, a chemically modified derivative thereof, a multispecific antibody, a diabody, a Fv-fragment, a labeled antibody or another type of recombinant antibody.

9. A pharmaceutical composition comprising a pharmaceutically effective amount of an isolated and/or purified antibody, antibody fragment or derivative thereof of any one of claims 1 to 8, optionally in combination with pharmaceutically acceptable carriers, diluents and/or adjuvants.

10. The pharmaceutical composition of claim 9 for the treatment or prevention of cancer, tumorigenesis or metastasis formation.

11. The pharmaceutical composition of claim 10, characterized in that the cancer is selected from the group consisting of carcinoma, lymphoma, blastoma, sarcoma, liposarcoma, neuroendocrine tumor, mesothelioma, schwanoma, meningioma, adenocarcinoma, melanoma, leukemia, lymphoid malignancy, squamous cell cancer, epithelial squamous cell cancer, lung cancer, small-cell lung cancer, non-small cell lung cancer, adenocarcinoma of the lung, squamous carcinoma of the lung, cancer of the peritoneum, hepatocellular cancer, gastric or stomach cancer, gastrointestinal cancer, pancreatic cancer, glioblastoma, cervical cancer, ovarian cancer, liver cancer, bladder cancer, hepatoma, breast cancer, colon cancer, rectal cancer, colorectal cancer, endometrial or uterine carcinoma, salivary gland carcinoma, kidney or renal cancer, prostate cancer, vulval cancer, thyroid cancer, hepatic carcinoma, anal carcinoma, penile carcinoma, testicular cancer, esophageal cancer, a tumor of the biliary tract, and head and neck cancer.

12. Use of an isolated and/or purified antibody, antibody fragment or derivative thereof of claims 1 to 8, for the preparation of a medicament.

13. An isolated and/or purified nucleic acid sequence comprising

i) a nucleotide sequence encoding an isolated antibody, antibody fragment or derivative thereof of claims 1 to 8,

ii) a nucleic acid sequence having substantial sequence identity or homology to i), iii) a nucleic acid sequence complementary to i) or ii)), iv) a degenerated nucleic acid sequence of i), ii) or iii), or

v) a nucleic acid sequence capable of hybridizing under stringent conditions to i), ii), iii) or iv).

14. A vector comprising the isolated and/or purified nucleic acid sequence of claim 13.

15. A host cell comprising the vector of claim 14.

16. The host cell of claim 15, characterized in that it is a bacterium, a fungal, a plant, or an animal cell.

17. The host cell of claim 16, characterized in that the animal cell is a mammalian cell.

18. The host cell of claim 17, characterized in that the mammalian cell is a human cell or a human cell line.

19. A hybridoma, secreting the monoclonal antibody of claim 7.

20. A method for treating and/or preventing cancer, cancer metastasis, or tumorigenesis, in a patient in need thereof, comprising administering a pharmaceutically effective amount of an isolated and/or purified antibody, antibody fragment or derivative thereof of claims 1 to 8.

21. A method for treating and/or preventing cancer cell self-renewal, expansion, proliferation, activation, survival, anchorage, niche interaction or homing to the niche in a patient in need thereof, comprising administering a pharmaceutically effective amount of an isolated and/or purified antibody, antibody fragment or derivative thereof of claims 1 to 8.

22. A method for treating and/or preventing cancer stem cell self-renewal, expansion, proliferation, activation, survival, anchorage, niche interaction or homing to the niche in a patient in need thereof, comprising administering a pharmaceutically effective amount of an isolated and/or purified antibody, antibody fragment or derivative thereof of claims 1 to 8.

23. The method of any one of claims 20 to 22, characterized in that the isolated and/or purified antibody, antibody fragment or derivative thereof of claims 1 to 8 binds targets a fasciclin protein family.

24. The method of any one of claims 20 to 22, characterized in that the isolated and/or purified antibody, antibody fragment or derivative thereof of claims 1 to 8 binds targets at least one protein interacting with a fasciclin protein family.

25. The method of any one of claims 22 to 24, characterized in that the isolated and/or purified antibody, antibody fragment or derivative thereof of claims 1 to 8 alters the structure, distribution or concentration of said fasciclin protein or of said at least one protein interacting with said fasciclin protein.

26. The method of any one of claims 22 to 25, characterized in that the cancer is selected from the group consisting of carcinoma, lymphoma, blastoma, sarcoma, liposarcoma, neuroendocrine tumor, mesothelioma, schwanoma, meningioma, adenocarcinoma, melanoma, leukemia, lymphoid malignancy, squamous cell cancer, epithelial squamous cell cancer, lung cancer, small-cell lung cancer, non-small cell lung cancer, adenocarcinoma of the lung, squamous carcinoma of the lung, cancer of the peritoneum, hepatocellular cancer, gastric or stomach cancer, gastrointestinal cancer, pancreatic cancer, glioblastoma, cervical cancer, ovarian cancer, liver cancer, bladder cancer, hepatoma, breast cancer, colon cancer, rectal cancer, colorectal cancer, endometrial or uterine carcinoma, salivary gland carcinoma, kidney or renal cancer, prostate cancer, vulval cancer, thyroid cancer, hepatic carcinoma, anal carcinoma, penile carcinoma, testicular cancer, esophageal cancer, a tumor of the biliary tract, and head and neck cancer.

27. A kit for treating and/or preventing cancer metastasis formation, tumorigenesis or cancer stem cell anchorage and survival comprising a pharmaceutically effective amount of an isolated and/or purified antibody, antibody fragment or derivative thereof of any one of claims 1 to 8, optionally with reagents and Or instructioriN for use.