转染PDCD5基因促进顺铂诱导前列腺癌细胞的凋亡作用

Transfection of PDCD5 Promotes Effects of Cisplatin on Apoptosis-inducing of Prostate Cancer Cells

目的探讨过表达细胞程序性死亡基因5(PDCD5)对顺铂诱导人前列腺癌DU145细胞凋亡以及细胞凋亡相关蛋白表达的影响。方法 CCK-8法检测顺铂处理DU145细胞后对细胞生长增殖的影响;构建稳定过表达PDCD5的DU145细胞系;Annexin V-FITC﹠PI双染法检测细胞的凋亡率、电子显微镜观察细胞凋亡的形态学变化;Western blot法检测细胞凋亡相关蛋白的表达。结果顺铂对DU145细胞的生长有抑制作用,且呈时间-剂量依赖性;成功构建稳定过表达PDCD5的DU145细胞;流式细胞术和电子显微镜都显示PDCD5联合顺铂(25μmol/L)促进细胞的凋亡作用比联合顺铂(10μmol/L)和单独使用顺铂明显,Western blot结果显示,顺铂联合PDCD5能明显降低Bcl-2的表达,而Bax的表达变化不明显。结论单独PDCD5过表达不引起DU145细胞的凋亡,但PDCD5能显著增强顺铂诱导DU145细胞凋亡的作用,其机制之一是通过降低Bcl-2/Bax的表达比率实现的。

Objective To investigate the effects of PDCD5 overexpression on apoptosis of human prostate cancer DU145 cells induced by eisplatin. Methods First, the proliferation of the DU145 ceils treated with cisplatin was assayed by CCK-8. Secondly,we established stably transfected DU145 cells overexpressing PDCD5. Then,apoptosis was determined by Annexin V-FITC PI double staining and electron microscopy,and the expression of apoptosirelated proteins was detected by western blot. Results Cisplatin inhibited cell proliferation of prostate cancer DU145 cells on a dose- and time-dependent manner. Stably transfeeted DUI45 cells with PDCD5 overexpression were successfully established. As shown in flow eytometric analysis and electron microscopy images the apoptosis of DU145 cells treated with PDCD5 and cisplatin （25 μmol/L） was increased markedly compared with the cells treated with PDCD5 and cisplatin（10 μmol/L） or the ceils treated with cisplatin alone. Western blot analysis suggested that the level of Bcl-2 expressed in the DU145 cells treated with PDCD5 and cisplatin was decreased obviously,while Bax protein level showed no significant difference. Conclusion Although PDCD5 overexpression alone does not cause apoptosis in DU145 cells,it can largely enhance the apoptosis-promoting effect of cisplatin on DU145 cells. The mechanism is involved in reducing the expression ratio of Bcl-2/Bax.