The UV-C Induced Cell Death in Human Malignant Melanoma and Normal Fibroblasts

Abstract

Differences in cellular death between melanoma (Me45) cells and fibroblasts (CCL-110) were investigated after irradiation with UV-C (1.5-15 J/m 2 ) and incubation for up to 48 h. The role of DNA double strand breaks in this process was assessed. Decrease of the Me45 cells viability began about 6 h after irradiation. The fibroblasts viability negatively correlated with the dose applied, since necrosis within this cell population began immediately after irradiation. The enhanced apoptosis of fibroblasts was observed between 6 and 24 h, while for melanoma cells, high level of apoptotic cells was still detected after 48 h. Statistically significant correlation between the percentage of apoptotic cells and DSBs was estimated for both cell lines. The melanoma cells responded differently to the UV-C radiation than did the fibroblasts. These differences were explained by deficiency of the necrotic processes as well as the delay of apoptotic melanoma response to UV-C damage.