p53依赖的X-连锁凋亡抑制蛋白调节与卵巢癌顺铂耐药的关系

目的本研究旨在探讨X-连锁凋亡抑制蛋白（XIAP）在卵巢癌顺铂耐药中的作用。方法应用RT—PCR、Western Blot、流式细胞仪等检测卵巢癌顺铂敏感细胞株0V2008、A2780s和耐药株C13＊、A2780cp中XIAP表达和卵巢癌细胞的凋亡率，并将反义XIAP寡核苷酸（XIAPAs—ODN）、正义XIAP寡核苷酸（XIAPs—ODN）和随机对照链导入顺铂耐药细胞C13＊（p53野生型）和A2780cp（p53突变型）中，比较转染前、后耐药细胞Caspase-3活性和顺铂耐药性的改变。结果卵巢癌顺铂敏感细胞和耐药细胞中XIAP在mRNA水平的表达无明显差异（P〉0．05）。顺铂可以引起OV2008和A2780s中XIAP蛋白表达明显下降（P〈0．05），而对C13＊和A2780cp的XIAP蛋白含量无明显影响（P〉0．05）。转染XIAPAs—ODN可降调p53野生型耐药细胞C13＊中XIAP的表达，并显著增加Caspase-3活性和对顺铂敏感性（P〈0．05），而XIAP As—ODN对p53突变型耐药细胞A2780cp无此作用。结论卵巢癌细胞对顺铂产生耐药可能与XIAP蛋白相对高表达有关，反义XIAP可在一定程度上逆转卵巢癌顺铂耐药，该作用与卵巢癌细胞的p53表型有关。

p53-dependent regulation of X-linked inhibitor of apoptosis protein in chemo-resistance in human ovarian cancer

Objective： To investigate the role of X -linked inhibitor of apoptosis protein （XIAP） in chemo -resistance in ovarian cancer. Methods ： XIAP mRNA and protein levels were determined by RT - PCR and Western Blot in chemo - sensitive and - resistant ovarian cancer cells, respectively. CDDP - induced apoptosis was measured by flowcytometry. Caspase - 3 activity and CDDP - induced apoptosis were determined after were transfection with antisense and sense XIAP oligonucleotides （ODNs） into wild type p53 and mutant type p53 chemo - resistant cells. Results ： CDDP had no effect on XIAP mRNA level in both chemo - sensitive and resistant cells. XIAP protein content was decreased in chemo - sensitive 0V2008 and A2780s cells and this change was associated with the CD- DP - induced apoptosis. However, CDDP failed to induce decreased XIAP content and apoptosis in C13 ＊ or A2780cp cells. Antisense XIAP ODNs sensitized p53 wild type C13 ＊ cells to CDDP treatment, but had no effect on p53 mutant type A2780cp cells. Conclusions ： XIAP protein was an important factor in chemo - resistance of ovarian cancer. Down - regulation XIAP increased caspase - 3 activity and sensitized chemoresistant cells to CDDP treatment and this effect was dependent upon p53 type in ovarian cancer cells.