Figure 3

(A) Effects of cisplatin and/or UV-C on PARP cleavage and DNA fragmentation in human colorectal cancer cells. SW480, DLD-1, HT29 and HCT116 cells were first exposed to the indicated doses of UV-C (0 J/m² or 10 J/m²), and then treated with/without 10 μM of cisplatin for the indicated periods. Protein extracts were then harvested and examine by Western blotting using anti-PARP and anti-GAPDH antibodies. (B) SW480 and HT29 cells were first exposed to the indicated doses of UV-C (0 J/m² or 10 J/m²), and then treated with/without 10 μM of cisplatin for the indicated periods. They were then treated with Hoechst 33258 and were examined by fluorescence microscopy. The numbers of Hoechst33258-positive cells (apoptotic nuclei) from 5 randomly chosen fields (x 40) were counted, respectively. Bars designate SD of triplicate assay. The asterisks (*) indicate significant increase (p < 0.05) as compared to the corresponding controls, respectively.