Virus Production Induced by Various Chemical Carcinogens in a Virogenic Hamster Cell Carcinogens in a Line Transformed Virus

Summary Virus was produced by 2 chemical carcinogens and 4 mutagens in a hamster cell line transformed by the Schmidt-Ruppin strain of Rous sarcoma virus. This cell line does not produce infectious virus or any C-type particles. The chemical carcinogens were 3-methylcholanthrene and benzofajpyrene. The mutagens were 4-nitroquinoline-1-oxide, urethan, 5-azacytidine, and phytohemagglutinin. The transformed hamster cell line was treated with various concentrations of these agents administered at different frequencies. In subsequent passages of treated cells, virus production was investigated by the inoculation of cell-free medium into 1-day-old chickens. Virus was first seen in the tenth passage of the treated cells. Virus was induced in all treated cell lines except those treated with urethan and phytohemagglutinin. Tumors induced in chickens by virus obtained from treated cells were sarcomas, which produced fully infectious virus for chickens.