Inhibition 01 Recovery From Bleomycin-Induced Potentially Lethai Damage 1,2

ABSTRACT-Mammalian cells are able to recover from bleomy-cin (Bleo)-induced potentially lethai damage. We examined the influences of inhibitors of DNA, RNA, or protein synthesis on that recovery. Cytosine arabinoside and cycloheximide did not inhibit recovery from Bleo-induced damage; however, actinomy-cin 0 (Act 0) did inhibit it. At a dose that produced minimal cell killing and inhibited only RNA synthesis, inhibition of recovery by Act 0 was immediate and complete.-J Natl Cancer Inst 59: 1685-1689, 1977. Recovery from PLD is measured by the increase in survival when cells are exposed to various incubation conditions after single-drug or irradiation treatments (1-5). Factors such as inhibition of protein synthesis, incubation in nutritionally deficient medium, or low temperatures favored recovery from PLD (2-4). Hyper