Enhancement of UV-A-induced cytotoxicity to cancer cell lines by camptothecin.

The exposure of cultured mouse melanoma (B-16) cells, to camptothecin (CAM) after irradiation of the cells with UV-A synergistically enhanced cytotoxicity. CAM treatment prior to irradiation had the same effect. Similar results were also obtained with the combination of γ-ray irradiation and CAM in this model. Thus, the sensitivity of the cells to UV-A and γ-ray, irradiation was significantly elevated by CAM. These findings have potential clinical utility.