Malignant transformation with ara C, FUdR, MTX, and bleomycin in 10T 1/2 CL8 cells

Several chemotherapeutic agents, namely cytosine arabinoside (ara C), 5 fluorodeoxyuridine (FUdR), methotrexate (MTX) and bleomycin have been studied for their ability to transform the mouse cell line C3H/10T1/2CL8 developed in the laboratory of Dr. Charles Heidelberger. A concentration of 0.3 μg/ml to 300 μg/ml of ara C, 0.25 μg/ml to 25 μg/ml of FUdR, 10 μg/ml and 100 μg/ml of MTX and 1 μg/ml and 10 μg/ml of bleomycin all produced transformed foci, whereas no transformed foci were found in control cultures. Several transformed foci were isolated and when 2 x 10⁶ cells were injected subcutaneously into antithymocyte serum treated syngeneic C3H mice, fibrosarcomas were produced. Transformation with ara C and FUdR was found to be cell cycle dependent. Using either confluent monolayers or isoleucine deprivation to synchronize the cells, 10^-3M ara C or 10^-4M FUdR was added for 2 hour periods throughout the cell cycle. A peak of transformed foci was found in the DNA synthetic phase S phase) rather than in the G₁ phase of the cell cycle. Transformation with ara C and FUdR was also found to be dose dependent.