PTEN及Caspase-3可能参与卵巢癌铂类耐药的机制

PTEN and Caspase-3 May Be Involved in Cisplatin Drug Resistance in Ovarian Cancer Cells

目的探讨(phosphatase and tensin homologue deleted on chromosometen,PTEN)PTEN(第10号染色体缺失的磷酸酶及张力蛋白同源的基因)及(半胱氨酸蛋白酶-3)Caspase-3在卵巢癌细胞系A2780,A2780CP(顺铂耐药卵巢癌细胞系)中在顺铂诱导的细胞凋亡过程中的调控作用.方法细胞用10mol/L的顺铂处理24 h,通过Western印迹对PTEN的蛋白水平进行定量分析,观察顺铂处理过的A2780细胞及A2780-CP细胞中PTEN蛋白水平的变化.用Caspase-3抑制剂处理A2780细胞,观察Caspase-3抑制剂是否可恢复PTEN蛋白的水平,来研究PTEN的降解机制.结果 PTEN蛋白水平在A2780细胞显著下降;在顺铂处理过的A2780-CP细胞中PTEN蛋白水平没有变化。相对于于载体处理的细胞(P<0.05).在A2780细胞中,伴随着PTEN蛋白水平的降低,有AKT(分子蛋白激酶B)磷酸化水平(p AKT)水平升高.在A2780细胞,使用caspase-3抑制剂可恢复PTEN蛋白的水平.结论在顺铂处理的卵巢癌A2780细胞中,促凋亡基因PTEN的蛋白的水平的降低和存活因子PAKT水平的升高,能进一步增加A2780细胞的的耐药性.

Objective To investigate the regulation of PTEN and Caspase-3 during cisplatin induced apoptosis in A2780, A270-CP （cisplatin resistant） , ovarian cancer cell lines. Methods Cells were treated with 10mol/L of cisplatin for 24 h to observe the change of PTEN protein levels in A2780, A2780-CP ceils with cisplatin treatment. Protein levels were analysed by western blotting, caspase-3 inhibitor were used to observe whether the PTEN protein level could be restored in A2780 cells. And to find the mechanism of PTEN degradation Similar results were observed. Results PTEN protein levels were found to be decreased significantly in A2780 cells; however, there was no change in PTEN protein levels in A2780-CP cells with cisplatin treatment （P〈0.05） . The decrease in PTEN protein was accompanied with an increase in the levels of AKT phosphorylation （pAKT） in A2780 cells. Cisplatin treatment induced the activation/cleavage of caspase-3 in A2780 cells, but there was no change in A2780-CP ceils. In A2780 cells, restoration of PTEN levels was achieved upon pre-treatment with caspases inhibitor. Conclusion The decrease in pro-apoptotic PTEN protein levels and increase in survival factor pAKT in A2780 ovarian cancer ceils suggest that cisplatin treatment could further exacerbate drug resistance in A2780 ovarian cancer cells.