title: Characterization of a tumor cell surface protein with heterologous antisera to a spontaneous BALB/c lung carcinoma.
abstract: Line 1, a spontaneous alveolar carcinoma from a BALB/c mouse, is highly metastatic and weakly antigenic in the syngeneic host. Sera and enriched antibody preparations were made specific for line 1 cells by in vitro and in vivo absorptions. By lactoperoxidase-catalyzed radioiodination of cell surface protein followed by precipitation with specific antibodies, a protein with a molecular weight of about 180,000 (designated TSP-180) was identified that was present on line 1 cells but not on normal lung cells or Moloney sarcoma tumor cells. Studies of competition for immune precipitation of TSP-180 by unlabeled protein preparations from various sources indicate that (a) TSP-180 is present in tumor cells of various culture passage levels, (b) tumor cells grown i.m. also contain TSP-180, and (c) normal lung proteins compete weakly, and only at very high protein concentrations. A protein similar to TSP-180 was detected on Madison 109 carcinoma and on three other lung carcinomas adapted to culture. Experiments with specific antisera show that TSP-180 is not lactoperoxidase, fetal bovine serum protein, large external transformation-sensitive protein, or an antigen related to murine leukemia virus proteins.
mesh_terms: D002282:Adenocarcinoma, Bronchiolo-Alveolar / Q000276:immunology*; D000818:Animals; D000912:Antibodies, Neoplasm; D000951:Antigens, Neoplasm / Q000302:isolation & purification*; D000954:Antigens, Surface / Q000302:isolation & purification*; D002460:Cell Line; D007124:Immunoenzyme Techniques; D008175:Lung Neoplasms / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008970:Molecular Weight; D009363:Neoplasm Proteins / Q000276:immunology*; D009374:Neoplasms, Experimental / Q000276:immunology
chemical_list: D000912:Antibodies, Neoplasm; D000951:Antigens, Neoplasm; D000954:Antigens, Surface; D009363:Neoplasm Proteins