Comparison of iodinated antigens of metastatic and non-metastatic mammary adenocarcinoma cells.
The surface and detergent-soluble proteins of metastatic (TMT-081) and nonmetastatic (MT-100) mammary adenocarcinoma cells were labeled using [125I]-lactoperoxidase. The iodinated proteins were analyzed by SDS-gel electrophoresis and autoradiography. The results revealed seven iodinated surface polypeptides in metastatic cells with molecular weights of 150,000, 130,000, 110,000, 78,000, 67,000, 40,000 and 22,000. The nonmetastatic cell surface revealed eight iodinated polypeptides with molecular weights of 175,000, 150,000, 130,000, 120,000, 110,000, 67,000, 40,000, and 24,000. The small molecular weight polypeptides, 22,000-24,000, of both metastatic and nonmetastatic cells were the most intensely labeled and appeared as a major surface component. Iodination of the detergent-soluble proteins in tumor extracts results in the labeling of five polypeptides (175,000, 67,000, 44,000, 29,000, 22,000 MW) of metastatic tumor and six polypeptides (175,000, 78,000, 67,000, 40,000, 35,000, 22,000 MW) of nonmetastatic tumor. Immunoprecipitation analyses indicate that the iodinated tumor polypeptides are antigenic to a xenogenic host. The 175,000 MW surface polypeptide of nonmetastatic and the 40,000 MW polypeptide of metastatic cells were not detected in the immunoprecipitates. The results of immunoprecipitation suggest that the small molecular weight (22,000-24,000) polypeptides are the predominant antigens of both tumor cells.
D000230:Adenocarcinoma / Q000276:immunology*; D000818:Animals; D000951:Antigens, Neoplasm / Q000032:analysis*; D000954:Antigens, Surface / Q000032:analysis; D007457:Iodine Radioisotopes; D008970:Molecular Weight; D009362:Neoplasm Metastasis; D009374:Neoplasms, Experimental / Q000276:immunology*; D010455:Peptides / Q000032:analysis; D051381:Rats
D000951:Antigens, Neoplasm; D000954:Antigens, Surface; D007457:Iodine Radioisotopes; D010455:Peptides