重楼皂苷Ⅰ对膀胱癌细胞凋亡的影响

Polyphyllin Ⅰ Affected Apoptosis of Human Urothelial Carcinoma of Bladder

目的:研究重楼提取物单体重楼皂苷Ⅰ对膀胱癌细胞增殖和凋亡的影响。方法:体外培养膀胱尿路上皮细胞癌BIU-87细胞株,采用MTT法检测重楼皂苷Ⅰ对BIU-87细胞增殖的影响,计算半抑制率(IC50);采用流式细胞术检测重楼皂苷Ⅰ干预后BIU-87细胞凋亡的情况,透射电镜观察细胞超微结构的变化;采用实时定量PCR分析凋亡相关基因Bcl-2的变化,采用Western blot检测蛋白的表达变化。结果:重楼皂苷Ⅰ对BIU-87细胞的增殖有明显的抑制作用,24,48,72 h的IC50为9.71,5.91,4.68μmol·L-1。重楼皂苷Ⅰ对BIU-87细胞生长的抑制作用表现出时间和浓度依赖性。此外重楼皂苷Ⅰ干预以后,BIU-87细胞的凋亡率与对照组相比有显著性差异。实时定量PCR及Western blot的检测可见到凋亡相关基因Bcl-2的表达显著降低。结论:这些体外实验结果表明,重楼皂苷Ⅰ对膀胱癌有潜在的抗癌作用,下调Bcl-2基因的表达是其诱导膀胱癌细胞凋亡的作用机制之一。

Objective：To investigate the potential antitumour effects of polyphyllin Ⅰ （PP Ⅰ） on urothelial carcinoma of the bladder.Method：Urothelial carcinoma of bladder cell lines BIU-87 were cultured with or without PP Ⅰ.Cell proliferation were measured by MTT assay.Cell apoptosis and cell cycle were measured by flow cytometry.The changes of cell morphology were observed by transmission electron microscopy.The expression of Bcl-2 was detected by real-time PCR and western blot.Result：The results showed that the proliferation of BIU87 cells were significantly inhibited by PP Ⅰ.The 50％ inhibitory concentrations （IC50） of PP Ⅰ were 9.71,5.91,4.68 μmol · L-1 at 24,48,72 h.The inhibition rate of PP Ⅰ was in a manner of dose-and timedependent.The treatment of PP Ⅰ led to activation of apoptosis.After being treated with PP Ⅰ,the apoptotic rate of BIU-87 cells was remarkably higher than that of the control.The results of real-time PCR and western blot showed that the expression of Bcl-2 was decreased in the group of PP Ⅰ treated.Conclusion：These results suggest that PP Ⅰ potentially has anticancer effects on urothelial carcinoma of the bladder cells in vitro.To deregulate the expression of Bcl-2 is one of the potential mechanisms.