Inhibitors of proteins specific for the secretome of a chondrocyte for use in the treatment of breast cancer metastasis

Abstract

The present invention relates to a method for identifying inhibitors of breast cancer metastasis based on a screening with proteins that are specific for the secretome of a chondrocyte, preferably cytokines and/or chemokines. The ligands as identified lead to a decrease of the migration and/or a re-differentiation of a breast cancer cell and/or a reduction of the number and/or size of breast cancer metastases. The present invention further relates to a method for detecting breast cancer metastasis, comprising the step of detecting at least one protein that is specific for the secretome of a chondrocyte, and for methods for treating and/or preventing breast cancer metastasis in a patient in need thereof, comprising the step of administering an effective amount of at least one ligand for one protein that is specific for the secretome of a chondrocyte to said patient in need thereof.

1 . A method for identifying inhibitors of breast cancer metastasis, comprising the steps of:
 a) providing at least one protein that is specific for the secretome of a chondrocyte;   b) contacting said at least one protein with at least one putative ligand of said at least one said protein of the secretome, and   c) detecting a binding between said at least one putative ligand and said at least one said protein of the secretome.   
     
     
         2 . The method according to  claim 1 , wherein said at least one protein that is specific for the secretome of a chondrocyte is selected from the group consisting of cytokines, chemokines, CXCL5, GCP-2, MIP-3a, NAP-2, IL-6, IL-7, IL-8, IL-10, and GRO-a. 
     
     
         3 . The method according to  claim 1 , further comprising the steps of:
 d) in case of a binding of said ligand to said at least one protein, detecting whether said binding between said ligand to said at least one protein leads to a decrease of the migration and/or a re-differentiation of a breast cancer cell and/or a reduction of the number and/or size of breast cancer metastases.   
     
     
         4 . The method according to  claim 1 , wherein said ligand is an inhibitor of the expression, stability and/or biological function of said at least one protein. 
     
     
         5 . A ligand for at least one protein that is specific for the secretome of a chondrocyte, wherein said ligand is an inhibitor of the expression, stability and/or biological function of said at least one protein, and is a peptide library molecule, an aptamer, a combinatory library molecule, a cell extract derived molecule, a small molecular drug, a bacterial metabolite, a phage display molecule, an antibody or fragment thereof, a protein, a protein fragment an aptamer, or an antibody or fragment thereof. 
     
     
         6 . The ligand according to  claim 5 , wherein said at least one protein is selected from the group consisting of cytokines, chemokines, CXCL5, GCP-2, MIP-3a, NAP-2, IL-6, IL-7, IL-8, IL-10, GRO, and GRO-a. 
     
     
         7 . The ligand according to  claim 5 , wherein said ligand is part of a fusion protein; is part of a carrier molecule that optionally comprises at least one anticancer agent that is conjugated to said ligand; is covalently bound to bisphosphonate or other bone-tissue homing moieties; and/or is part of a diagnostic agent that optionally comprises at least one detectable moiety. 
     
     
         8 . A method for producing a pharmaceutical composition, comprising formulating at least one ligand of  claim 5  with at least one pharmaceutically acceptable excipient. 
     
     
         9 . A pharmaceutical composition, produced according to  claim 8 , wherein said ligand is formulated with other ligands, and/or chemotherapeutically active substances. 
     
     
         10 . The pharmaceutical composition according to  claim 9 , wherein said ligand is part of a fusion protein; is part of a carrier molecule that optionally comprises at least one anticancer agent that is conjugated to said ligand; and/or is part of a diagnostic agent that optionally comprises at least one detectable moiety. 
     
     
         11 . A method for detecting breast cancer metastasis, comprising the step of detecting at least one protein that is specific for the secretome of a chondrocyte selected from the group consisting of chemokines, cytokines, CXCL5, GCP-2, MIP-3a, NAP-2, IL-6, IL-7, IL-8, IL-10, GRO, and GRO-a in a biological sample obtained from a subject having primary breast cancer; wherein the presence of said at least one protein that is specific for the secretome of a chondrocyte is indicative for breast cancer metastasis and/or an increased risk for breast cancer metastasis. 
     
     
         12 . The method according to  claim 11 , wherein said detecting comprises detecting a binding of a ligand for at least one protein that is specific for the secretome of a chondrocyte, wherein said ligand is an inhibitor of the expression, stability and/or biological function of said at least one protein, and is a peptide library molecule, an aptamer, a combinatory library molecule, a cell extract derived molecule, a small molecular drug, a bacterial metabolite, a phage display molecule, an antibody or fragment thereof, a protein, or a protein fragment. 
     
     
         13 . The method according to  claim 11 , wherein said sample is selected from blood, plasma, urine, a sample comprising chondrocytes, and tissue samples. 
     
     
         14 . The method, according to  claim 3 , wherein said breast cancer metastases are bone and/or lung metastases. 
     
     
         15 . The method, according to  claim 4 , wherein said ligand is a peptide comprising an amino acid sequence selected from ALWPPNLHAWVP (SEQ ID NO: 1) and AHSVSNSDVLGI (SEQ ID NO: 2), or is a ligand that binds to CXCL5 in a similar or the same manner as the peptide comprising ALWPPNLHAWVP (SEQ ID NO: 1) or AHSVSNSDVLGI (SEQ ID NO: 2). 
     
     
         16 . The ligand, according to  claim 5 , wherein said ligand is a peptide comprising an amino acid sequence selected from ALWPPNLHAWVP (SEQ ID NO: 1) and AHSVSNSDVLGI (SEQ ID NO: 2), or is a ligand that binds to CXCL5 in a similar or the same manner as the peptide comprising ALWPPNLHAWVP (SEQ ID NO: 1) or AHSVSNSDVLGI (SEQ ID NO: 2). 
     
     
         17 . A method for inhibiting breast cancer metastasis wherein said method comprises administering, to a subject in need of such inhibition, a ligand of  claim 5 .