紫杉醇体外诱导人胃癌细胞凋亡及对端粒酶活性的影响

Paclitaxel-induced apoptosis and the effect on telomerase activity in human gastric carcinoma cell line

目的研究紫杉醇对人胃癌细胞诱导凋亡作用及端粒酶活性变化.方法0.001～1μmol/L的紫杉醇处理SGC 7901细胞后,用MTT法测定胃癌细胞的生长抑制率,通过形态学观察及流式细胞术检测细胞凋亡率,半定量TRAP-银染法测定端粒酶活性变化.结果不同浓度的紫杉醇对胃癌细胞均有明显抑制作用,且呈时间依赖性及剂量依赖性,光镜及流式细胞术分析表明,0.01μmol/L的紫杉醇处理后24h,细胞即出现明显的凋亡形态特征及凋亡峰,对端粒酶活性的同步检测结果显示,紫杉醇在诱导细胞凋亡的同时伴随端粒酶活性下调,且随紫杉醇浓度增大,抑制作用逐渐增强,24h酶活性即显著受抑制,72h变为阴性.结论紫杉醇对胃癌细胞具有明显抑制作用,诱导细胞凋亡并抑制端粒酶活性可能是其发挥抗癌作用的机制之一,端粒酶可作为肿瘤化疗的敏感性指标.

Objective To study paclitaxel-induced apoptosis and the effect on telomerase activity in human gastric carcinoma cell.Methods Human gastric carcinoma cell line SGC 7901 was treated with paclitaxel( 0.001 ,0.01,0.1and 1μmol/L)for 1～4 days.MTT assay was used to determine the cell growth inhibition rate,cell morphology observation and flow cytometry were used to examine paclitaxel-induced apoptosis in gastric carcinoma cell line SGC 7901.Also telomerase activeity was detected by semi-quantity TRAP assay at the same time.Results Different concentration of paclitaxels were cytotoxic to human gastric carcinoma cell in time-dependent and dose-dependent manner.Analysis by optic microscopy and flow cytometry indicated that after treatment with 0.01μmol/L of paclitaxel for 24 h,cell underwent apoptosis with typical morphological feature and distinct apoptotic peak appeared.At the same time,decreased telomerase activity was detected in paclitaxel-induced apoptotic cell after 24 h,telomerase activity became negative after 72 h.Moreover,the inhibition effect on telomerase activity was enhanced in a dose-dependent and time-dependent pattern.Conclusion Paclitaxel is effective in growth inhibition on gastric carcinoma cell line in clinically attainable concentrations.Paclitaxel-induced apoptosis and inhibition on telomerase activity may be one of the anticancer machanisms.Telomerase could be another sensitive marker for chemotherapy of cancer.