Characterization and reactivity of a monoclonal antibody that recognizes a 76 kilodalton human colon tumor antigen.
A monoclonal antibody (MAb 76) was produced by immunizing mice with a soluble cytoplasmic protein fraction from a human adenocarcinoma of the colon. MAb 76 showed specific immunoreactivity against a 76 kDa protein in immunoblot studies using total colon tumor cytosol proteins. Immunoprecipitation of phosphorylated cytosolic protein products with MAb 76 and subsequent analysis on SDS containing polyacrylamide gels revealed a single 38 kDa band, indicating that the 76 kDa antigen is associated with a 38 kDa phosphoprotein species. Indirect immunofluorescence analysis of primary tumor specimens and human colon tumor cell lines showed positive immunoreactivity with 6/7 human colon adenocarcinoma tissues and 15/18 human colon tumor cell lines. MAb 76 was unreactive with normal colon, liver and lung specimens from human, mouse and hamster. The epitope-bearing monomer detected by MAb 76 is immunologically conserved in a high percentage of colon tumor cells and tissues and may represent a cellular product that is characteristic of the transformed colon cell phenotype.
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D000951:Antigens, Neoplasm / Q000032:analysis* / Q000276:immunology; D003110:Colonic Neoplasms / Q000276:immunology*; D005455:Fluorescent Antibody Technique; D006801:Humans; D007372:Interferons / Q000494:pharmacology; D051379:Mice; D008807:Mice, Inbred BALB C; D008970:Molecular Weight; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D000951:Antigens, Neoplasm; D007372:Interferons