Effects of bleomycin on progression through the cell cycle of mouse L-cells.

Abstract

Summary The effect of bleomycin on progression of mouse L-cells through the cell cycle was studied. In the presence of bleomycin, the beginning of DNA-synthetic (S) phase occurred at the same rate as that of the untreated control, but the duration was prolonged. In cells treated pulse-wise with bleomycin at the G 1 phase, the prolongation of S phase was slight, whereas the G 2 phase showed a considerable delay. Bleomycin also affected the entry of asynchronous cells into mitosis by arresting them at the early half of the G 2 phase. Interference did not occur with transition of mitosis to the G 1 phase. The observed prolongation of DNA-synthetic phase in the presence of bleomycin might be due to the inhibition of DNA synthesis or the damage to DNA molecules by the drug.