[The effect of actinomycin D on the survival and recoverability of irradiated human melanoma cells].

The presence of actinomycin D during gamma-irradiation of human melanoma cells leads to an increased radiosensitivity under aerobic and hypoxic conditions. This interaction of both treatment modalities depends upon the drug dose. Incubation of cells prior or after irradiation with essentially non-cytotoxic amounts of actinomycin D under normal conditions has only little effect on the shape of the radiation dose-response-curve, irrespectively of the time interval between drug treatment and irradiation. However, high doses of actinomycin D given immediately after irradiation increase the radiosensitivity of human cells. The drug does not effect recovery from sublethal or potentially lethal radiation damage.