Fig. 7.

Effect of ERK1/2 inhibition on curcumin-mediated radiosensitization. A, HeLa cells were serum starved for 24 h, cotreated with 0.1 or 0.3 μM PD184352 and DMSO or 10 μM curcumin for 8 h, followed by irradiation at 6 Gy, and the cells were harvested 6 h after radiation. Cell lysates were analyzed by Western blot using antibodies against pERK1/2 and ERK1/2. B, HeLa cells treated with DMSO, 10 μM curcumin (8 h), 0.3 μM PD184352 (2 h), or PD184352 treatment during the last 2 h of curcumin treatment. The cells were mock-irradiated or irradiated at 6 Gy. The drugs were washed off 1 h after radiation. Survival was assessed by low-density clonogenic survival assay. Results represent the averages of three independent experiments (±S.E.). C, HeLa cells treated with DMSO, 10 μM curcumin (8 h), 1 μM U0126 (2 h), or U0126 treatment during the last 2 h of curcumin treatment. The cells were mock-irradiated or irradiated at 6 Gy. The drugs were washed off 1 h after radiation. Survival was assessed by low-density clonogenic survival assay. Results represent the averages of three independent experiments (±S.E.).