The Study of Topotecan Induced Apoptosis in Cisplatin-resistant Human Ovarion Cancer Cell Lines COCl/DDP

Objective:To explore the molecular mechanism of topotecan-induced apoptosis in cisplatin-resistant human ovarian cancer cell line COC1/DDP. Methods:Transmission electron microscope(TEM) and TUNEL were employed to observe the apoptosis of COC1/DDP induced by topotecan. RT-PCR and Western blot were used to determine the expression of bcl-2,bax and caspase-3.Changes of the activity of caspase-3 were also recorded. Results:After incubated with topotecan, COC1/DDP cell demonstrated a typical apoptosis morphology The apoptotic rate increased from 8.54% to 19.31%(P0.05).Although the expression of bcl-2 was not affected, the expression of bax and caspase-3 were upregulated and the caspase-3 activity was promoted in the course of COC1/DDP apoptosis when treated with topotecan. Conclusion:The increased bax expression and the promoted caspase-3 activity may play a crucial role in the apoptosis process of COC1/DDP induced by topotecan.