C-erbB-2 external domain: GP75

Abstract

Disclosed are methods and compositions for identifying malignant tumors that overexpress the c-erbB-2 oncogene. Assays useful for diagnosis and prognosis of neoplastic disease are provided which detect the external domain of c-erbB-2, the glycoprotein gp75 and quantitate the level of gp75 in the biological fluids of mammals carrying a tumor burden. Further disclosed are recombinant, synthetically and otherwise biologically produced novel proteins and polypeptides which are encoded by the external domain DNA sequence of the c-erbB-2 oncogene (the gp75 gene) or fragments thereof. Such gp75 proteins and polypeptides are useful as vaccines, therapeutically in the treatment of cancer either alone or in combination with chemotherapeutic agents. Also disclosed are antibodies to such gp75 proteins and polypeptides which are useful diagnostically and therapeutically. Still further disclosed are test kits embodying the assays of this invention.

1 - 64 . (canceled) 
     
     
         65 : A diagnostic method of detecting or detecting and quantitating antibodies in a sample of mammalian body fluid that are specific for soluble c-erbB-2 ectodomain, wherein said antibodies are not specific to intact c-erbB-2 ectodomain, comprising the use of a competition assay;
 wherein antibodies in said sample compete for binding to soluble c-erbB-2 ectodomain with antibodies known to bind specifically to soluble c-erbB-2 ectodomain but not to cross-react with antibodies that bind specifically to intact c-erbB-2 ectodomain; and   wherein inhibition of binding of the antibodies known to bind specifically to soluble c-erbB-2 ectodomain, by antibodies in said sample indicates the presence in said sample of antibodies specific for soluble but not intact c-erbB-2 ectodomain, and the extent of said binding inhibition is directly proportional to the quantity of antibodies in said body fluid sample that are specific to soluble but not intact c-erbB-2 ectodomain.   
     
     
         66 : The method according to claim  64  wherein said antibodies known to bind specifically to soluble c-erbB-2 ectodomain but not cross-react with antibodies that bind specifically to intact c-erbB-2 ectodomain are polyclonal and/or monoclonal. 
     
     
         67 : The method of  claim 66 , wherein said polyclonal and/or monoclonal antibodies are labeled. 
     
     
         68 : The method of  claim 67  wherein said labeled antibodies are monoclonal. 
     
     
         69 : The method of  claim 68 , wherein said monoclonal antibodies are incubated with the body fluid sample and soluble c-erbB-2 ectodomain under conditions and for a time sufficient to allow immunocomplexes to form. 
     
     
         70 : The method of  claim 65 , wherein said mammalian body fluids are human body fluids selected from the group consisting of serum, semen, plasma, breast exudate, urine, saliva, and cerebrospinal fluid. 
     
     
         71 : The method of  claim 65 , wherein said mammalian body fluid is serum or plasma. 
     
     
         72 : The method of  claim 68 , wherein binding of said monoclonal antibody in said sample to soluble c-erbB-2 ectodomain protein or polypeptide is detected or detected and quantitated by enzyme immunoassay or radioimmunoassay. 
     
     
         73 : A method of screening for the presence of a malignancy in a mammal wherein c-erbB-2 oncogene overexpression is associated with the malignancy, comprising the steps of:
 (a) contacting a sample of body fluid from said mammal, suspected of having a c-erbB-2 overexpressing malignancy, with a certain amount of soluble c-erbB-2 ectodomain protein/polypeptide and with a certain amount of antibodies that are specific for soluble c-erbB-2 ectodomain protein but that do not cross-react with antibodies specific for intact c-erbB-2 ectodomain;   (b) incubating the body fluid sample under conditions and for a time sufficient to allow immunocomplexes to form; and   (c) detecting the inhibition of immunocomplex formation between the soluble c-erbB-2 ectodomain protein/polypeptide and said antibodies specific for soluble c-erbB-2 ectodomain protein, and thereby determining the presence or absence of a c-erbB-2 expressing malignancy by detecting, or by detecting and quantitating antibodies in the body fluid sample that are specific for soluble c-erbB-2 ectodomain.   
     
     
         74 : The method of  claim 73  wherein said antibodies known to bind specifically to soluble c-erbB-2 ectodomain but not to cross-react with antibodies that bind specifically to intact c-erbB-2 ectodomain are polyclonal and/or monoclonal. 
     
     
         75 : The method of  claim 74  wherein said polyclonal and/or monoclonal antibodies are labeled. 
     
     
         76 : The method of  claim 75  wherein said labeled antibodies are monoclonal. 
     
     
         77 : The method of  claim 73  wherein said mammalian body fluid is a human body fluid selected from the group consisting of serum, semen, plasma, breast exudates, urine, saliva, and cerebrospinal fluid. 
     
     
         78 : The method of  claim 77  wherein said body fluid is serum, plasma, or semen. 
     
     
         79 : The method of  claim 78  wherein said body fluid is serum or plasma. 
     
     
         80 : The method of  claim 79  wherein said body fluid is serum. 
     
     
         81 : The method of  claim 73  wherein said malignancy associated with c-erbB-2 overexpression is selected from the group consisting of carcinomas, mesodermal tumors, sarcomas, leukemias, and lymphomas. 
     
     
         82 : The method of  claim 81  wherein said carcinomas are adenocarcinomas or melanomas; wherein said mesodermal tumors are neuroblastomas or retinoblastomas; and wherein said sarcomas are selected from the group consisting of osteosarcomas and Ewing's sarcoma. 
     
     
         83 : The method of  claim 73  wherein said malignancy associated with c-erbB-2 overexpression is selected from the group consisting of breast, ovarian, gastrointestinal, colon, stomach, liver, thyroid, brain, pancreatic, urinary tract, salivary gland and prostate tumors. 
     
     
         84 : The method of  claim 83  wherein said malignancy is selected from the group consisting of bladder, prostate, ovarian and breast tumors. 
     
     
         85 : The method of  claim 84  wherein said malignancy is selected from the group consisting of breast and ovarian carcinomas. 
     
     
         86 : The method of  claim 74  wherein said antibodies that are known to bind specifically to soluble c-erbB-2 ectodomain but not to cross-react with antibodies that bind specifically to intact c-erbB-2 ectodomain are monoclonal;
 wherein a reporter group is linked to each antibody of a second set of antibodies that are capable of binding specifically to said monoclonal antibodies; and   wherein the step of detecting the inhibition of said immunocomplex formation comprises (a) removing substantially any unbound antibody, (b) adding the second set of reporter-linked antibodies, and incubating for a time sufficient for immunocomplexes to form, (c) removing substantially any unbound reporter-linked antibodies, and (d) detecting either the absence of immunocomplexes formed with the reporter-linked antibodies, or detecting and quantitating immunocomplexes formed with the reporter-linked antibodies.   
     
     
         87 : The method of  claim 86  wherein the reporter group is selected from the group consisting of radioisotopes, fluorophores, enzymes, luminescers and dye particles.