Melanoma and prostate cancer specific antibodies for immunodetection and immunotherapy

Abstract

Methods and compositions are provided for detecting antigens having a specific epitope associated with melanoma and prostatic carcinoma. The epitope is present in melanoma cells and prostatic cancer cells but is essentially absent from melanocytes and normal prostatic tissue. The antibody can be used in diagnostic methods for histochemical detection of human melanoma and prostate carcinoma, of various progression stages and in treatment of melanoma and prostate carcinoma.

What is claimed is:  
     
         1 . A method for detecting the presence of melanoma or prostatic cancer in a human host, said method comprising: 
 combining a sample from said human host with antibodies or antibody fragments which bind specifically to a peptide having the amino acid sequence depicted in SEQ ID NO:1, and detecting formation of immune complexes as indicative of the presence of melanoma cells or prostatic cancer cells.    
     
     
         2 . The method according to  claim 1 , wherein said sample is a tissue sample.  
     
     
         3 . The method according to  claim 2 , wherein said tissue sample is paraffin-embedded or cryo-preserved.  
     
     
         4 . The method according to  claim 1 , wherein said antibodies are monoclonal antibodies.  
     
     
         5 . The method according to  claim 4 , wherein said monoclonal antibodies or second antibodies to said monoclonal antibodies are conjugated to a label which provides a detectable signal.  
     
     
         6 . The method according to  claim 5 , wherein said label is a radionuclide, an enzyme, a fluorescer, a radioopaque dye, or a chemiluminescer.  
     
     
         7 . The method according to  claim 6 , wherein said radionuclide is technetium 99.  
     
     
         8 . The method according to  claim 1 , wherein said sample is a body fluid.  
     
     
         9 . The method according to  claim 8 , wherein said body fluid is blood.  
     
     
         10 . The method according to  claim 1 , wherein said antibodies bind to a surface membrane antigen of melanoma cells or prostatic cancer cells.  
     
     
         11 . A method for detecting high grade prostate intraepithelial neoplasia in a human host, said method comprising: 
 combining a sample from said human host with antibodies or antibody fragments which bind specifically to a peptide having the amino acid sequence depicted in SEQ ID NO: 1, and detecting formation of immune complexes as indicative of the presence of high grade prostate intraepithelial neoplasia.    
     
     
         12 . A method for early detection of prostate carcinoma, said method comprising: 
 combining a sample from said human host with antibodies or antibody fragments which bind specifically to a peptide having the amino acid sequence depicted in SEQ ID NO: 1, and detecting formation of immune complexes as an early indication of the presence of prostate carcinoma    
     
     
         13 . A method for treating human melanoma or prostate cancer, said method comprising: 
 administering a therapeutic dose of a conjugate comprising a monoclonal antibody or monoclonal antibody fragment, which binds specifically to a peptide having the amino acid sequence depicted in SEQ ID NO: 1, and a cytotoxic agent.    
     
     
         14 . The method according to  claim 13 , wherein said monoclonal antibody is a humanized monoclonal antibody.  
     
     
         15 . A kit for screening a sample to detect melanoma or prostate cancer cells, said kit comprising: 
 (a) an antibody or an antibody fragment, which binds specifically to a peptide having the amino acid sequence depicted in SEQ ID NO: 1; and    (b) means for detecting the reaction of said antibody or said antibody fragment with said melanoma cells or said prostate cancer cells.    
     
     
         16 . A peptide comprising an amino acid sequence characterized as (1) present in the extracellular domain of a polypeptide encoded an the mrk gene of Xiphophorus, and (2) reactive with antibodies obtained from hybridoma cell line 12f3.2.  
     
     
         17 . A peptide according to  claim 16 , wherein said amino acid sequence is L-F-R-S-E-D-Q-S-I-E.  
     
     
         18 . A peptide according to  claim 17 , further comprising a C at either terminus of said peptide.  
     
     
         19 . An antigen which binds to antibodies obtained from hybridoma cell line 12f3.2.  
     
     
         20 . The antigen according to  claim 19 , wherein said antigen is derived from a human melanoma or a human prostate tumor.