The radiation response of human malignant melanoma cells grown in vitro.

Abstract

Summary The three malignant melanoma cell lines used are characterized by having high, intermediate , and low quantities of pigment production. The response of these malignant melanoma cells to X-ray in vitro does not correlate with a model of the classically radioresistant tumor cell that clinical experience might predict. The in vitro melanoma cells were only slightly more resistant to X-rays than the nontumor in vitro Chinese hamster ovary cell line tested. The responses to X-rays of all three melanoma lines were the same ( n = 40, D 0 = 100 rads). The response to ultraviolet light varied with the amount of pigment present in each cell line. The strain producing a high quantity of pigment was the most UV resistant ( n = 3, D 0 = 57 ergs/sq mm). The strain producing a low pigment quantity was the most UV sensitive ( n = 3, D 0 = 31 ergs/sq mm). All melanoma strains were more resistant to UV than the Chinese hamster ovary cell line ( n = 10, D 0 = 20 ergs/sq mm). Survival determinations made as a function of time between two fractionated UV doses of 100 + 100 ergs/sq mm indicated that these melanoma cells possessed ability to recover from sublethal UV damage.