转bak基因促膀胱癌多药耐药细胞凋亡的研究

Acceleration of apoptosis by transfection of bak gene in multi-drug resistant (MDR) bladder cancer cells

目的 观察转入bak基因对膀胱癌多药耐药 (MDR)细胞的杀伤效果 ,探讨其可能的机制。 方法 用脂质体将bak基因导入MDR细胞 ,通过原位杂交法检测bakmRNA的表达 ,SABC免疫组化法分析bak和bcl 2的表达。采用细胞计数法检测细胞生长抑制率 ,流式细胞仪检测细胞周期的变化。荧光染色观察细胞形态。 结果 bak基因可成功转入MDR细胞 ,转染第 3天bakmR NA阳性率 64 % ,bak表达阳性率 60 % ,明显高于对照组 ;转染后细胞中bcl 2表达显著减少 ,P <0 .0 5。转染第 4天EJ/bak细胞抑制率 32 % ,显著高于对照组 ,P <0 .0 5。细胞周期分析可见凋亡峰 ,凋亡率 35 %。凋亡细胞在荧光显微镜下形成凋亡小体。 结论 转入bak基因可显著促进MDR细胞的凋亡 ,其作用机制与下调bcl

Objective To observe the effects of bak gene on killing MDR bladder cancer cells and to study its mechanisms. Methods Bak gene was transfected into MDR bladder cancer cells by liposome.The mRNA of bak and bcl 2 were detected by in situ hybridization.The protein of bak and bcl 2 were detected by SABC immunohistochemistry. The growth rate of human bladder cancer cells was studied by constructing the growth curve,cell apoptosis being observed by flow cytometry,and the outline of cells observed by fluorescence stain. Results The expression of bak mRNA was positive in EJ/bak cells (64%, P < 0.05 ).Bak protein expression of EJ/bak cells was positive(60%) and bcl 2 protein expression was decreased ( P < 0.05 ).The growth of MDR bladder cancer cells was significantly inhibited by 32% after bak gene was transfected ( P < 0.05 ). Apoptosis cells increased significantly. The apoptosis rate was 35%.Apoptotic bodies can be found in these cells on fluorescence stain. Conclusions Bak gene could inhibit the growth of MDR bladder cancer cells effectively. Inducing cell apoptosis by down regulating the expression of bcl 2 gene might be one of its mechanisms.