| Abstract: | Normal rat kidney cells, infected with Moloney murine leukemia virus, were treated with 3-methylcholanthrene at passage 5 postinfection. Foci of transformed cells appeared after 9-11 passages following this treatment. Characterization of four different randomly isolated foci revealed a striking diversity with respect to various tested phenotypic parameters. Remarkable differences were observed among these transformed clones regarding their cell morphology, growth rate, saturation density, serum requirements, virus release and its response to rat and mouse fibroblast interferons. This study demonstrates that cell transformation by chemical-retroviral co-carcinogenesis may lead to the formation of phenotypically heterogeneous tumor cells. |
