雷公藤红素对结肠癌细胞株HCT-116生长的影响及其作用机制

Effects and Mechanisms of Celastrol (CSL) on Human Colon Cancer Cell Line HCT-116 in vitro

目的探讨雷公藤红素(CSL)对人结肠癌细胞株HCT-116生长的影响及可能的作用机制。方法采用不同浓度的CSL处理HCT-116细胞,MTT法检测细胞生长的抑制率;流式细胞术(FCM)检测细胞周期;透射电镜观察细胞凋亡形态变化;荧光底物法检测细胞蛋白酶体活性;Westernblot检测p27、Bax的表达变化。结果CSL明显抑制HCT-116细胞生长,呈现时间、剂量依赖性;流式细胞术显示CSL可阻止细胞周期于G0/G1期;电镜下观察部分细胞具有典型的凋亡细胞形态特征;CSL对HCT-116细胞糜蛋白酶活性具有明显的抑制作用,其效应呈现浓度依赖性;CSL干预后细胞内p27、Bax蛋白表达明显增加。结论CSL具有抑制结肠癌HCT-116细胞的生长、阻滞细胞周期、诱导凋亡的作用,其分子机制可能与其抑制细胞内蛋白酶体活性,导致p27、Bax蛋白降解受阻有关。

Objective To study the inhibiting effects and mechanisms of Celastrol （CSL） on human colon cancer cell line HCT-116 in vitro. Methods In vitro,human colon cancer cell line HCT-116 was treated by CSL with various concentrations,and then the inhibiting effects of cell growth was assayed by MTT method; cell cycles and apoptosis were analyzed by flow cytometry（FCM）; electron microscope was used to observe the presence of apoptosis. The proteasome activity of HCT-116 cells was measured by detecting the fluorescence units given out by substrate,and the expression of p27,Bax were analyzed by Western blot. Results CSL showed inhibitory effects on the proliferation of HCT-116 cell in dose-and-time dependent manner. Flow cytometric analysis displayed that CSL induced cell apoptosis and Gl phase arrest. Typic ultrastructure of apoptosis cells was found under electron microscope after the cells were treated with CSL. CSL had inhibitory effect on chymotrypsin-like activity in a dose-dependent manner. Exposure to CSL lead to an accumulation of p27 and Bax protein in HCT-116 cells. Conclusion CSL can inhibit the proliferation of HCT-116 cells,arrest cell cycle and induce apoptosis. The mechanisms may be inhibiting proteasomal activity which decreased the degradation of p27 and Bax protein levels.