Effects of Cisplatin and hyperthermia on apoptosis and drug resistance of ovarian cancer cell line COC1,COC1/DDP

OBJECTIVE To investigate effect of hyperthermia,hyperthermia combined with chemotherapy on proliferation,apoptosis and platinum resistance of ovarian cancer cell lines COC1,COC1/DDP and try to explore their possible mechanisms.METHODS MTT method was performed to test growth inhibition ratios of hyperthermia and of cisplatin(1.25,2.5,5,10,20 μg·mL-1) at certain temperature of hyperthermia on cell COC1,COC1/DDP.RT-PCR was adopted to detect expression level of Survivin mRNA and ERCC1 mRNA of the two cell lines.RESULTS Apoptosis rate of COC1/DDP increased significantly when treated with cisplatin at the temperature of 42 ℃.The cell median lethal dose decreased from 4.98 μg·mL-1(37 ℃)to 1.82 μg·mL-1(42 ℃),which was decreased by 2.78-fold compared with the former(P0.01).Howerver,the median lethal dose of COC1 did not significantly changed although its apoptosis rate increased(P0.05).Both expression level of survivin mRNA and ERCC1 mRNA of cell lines at 42 ℃ were significantly lower than that at 37 ℃(P0.05).CONCLUSION Hyperthermia itself might kill tumor cells.Hyperthermia combined with chemotherapy might reserve platinum resistance of COC1/DDP and enhance its sensitivity to cisplatin to some extent.The mechanism may be related to down expression of the survivin mRNA and ERCC1 mRNA.