Abstract: Objective To determine whether annexin A3 could regulate cisplatin sensitivity through apoptosis induced by cisplatin or not. Methods Retroviral vector constuction and cell infection technology were used to obtain high-level annexin A3 and low-level annexin A3 ovarian cancer cells. Then Annexin V/propidium iodide analysis and western blot were used to determine the cell apoptosis rate and caspase cleavage. Results After annexin A3 level was up-regualted, the average apoptosis rate induced by 60μg/ml cisplatin in sensitive cells was changed from 68.72%±1.01% to 29.13%±2.61% (P<0.05), cleavages of caspase and PARP were induced by high level cisplatin. Conversely, in cisplatin resistant cells with low-level annexin A3, the average apoptosis rate was up-reguated from 35.05%±3.06% to 76.73%±6.42% (P<0.05), low level cisplatin stimulated cleavages of caspase and PARP. Besides, annexin A3 could delay phosphorylation of p38 MAPK in ovarian cancer cells. Conclusion All these results showed that apoptosis inhibition might be a potential mechanism of annexin A3 regulating platinum resistance in ovarian cancer cells.

Key words: ovarian cancer, annexin A3, apoptosis, cisplatin, drug resistance