title: Improved transformation of C3H10T1/2CL8 cells by direct- and indirect-acting carcinogens.
abstract: Oncogenic transformation of C3H10T1/2CL8 cells was improved by treating the cells 5 days after seeding. Benzo[a]-pyrene-induced transformation was increased 3.5-fold by this method, compared with treating the cells 1 day after seeding. N-Methyl-N'-nitro-N-nitrosoguanidine, which does not transform asynchronous cultures of C3H10T1/2CL8 cells when administered 1 day after seeding, produced on average of 1 focus/dish, with 61% of the dishes exhibiting foci, when administered 5 days after seeding. Propane sultone and aflatoxin B1 also produced marked transformation responses when administered 5 days after seeding. However, 4-dimethylaminoazobenzene did not induce transformation when administered either 1 day or 5 days after seeding. With all chemicals examined, clonal cytotoxicity was reduced when they were administered 5 days after seeding. These results indicate the utility of this new procedure for the qualitative analysis of the transforming ability of chemicals.
mesh_terms: D016604:Aflatoxin B1; D000348:Aflatoxins / Q000494:pharmacology; D000818:Animals; D001564:Benzo(a)pyrene; D001580:Benzopyrenes / Q000494:pharmacology; D002273:Carcinogens / Q000494:pharmacology*; D002460:Cell Line; D002471:Cell Transformation, Neoplastic / Q000187:drug effects*; D008769:Methylnitronitrosoguanidine / Q000494:pharmacology; D051379:Mice; D011336:Probability
chemical_list: D000348:Aflatoxins; D001580:Benzopyrenes; D002273:Carcinogens; D008769:Methylnitronitrosoguanidine; D001564:Benzo(a)pyrene; D016604:Aflatoxin B1