野黄芩苷对人脑胶质瘤U87细胞的增殖抑制作用及其机制

Inhibitory effect of scutellarin on proliferation of human glioma U87 cells and its mechanism

目的:探讨野黄芩苷(SCU)对人脑胶质瘤U87细胞的增殖抑制作用,并初步阐明其作用机制。方法:培养U87细胞,采用不同浓度(20、40和80mg·L(-1))SCU处理U87细胞(野黄芩苷组),同时设空白对照组。MTT法检测各组U87细胞存活率,倒置显微镜观察U87细胞的形态表现,AnnexinⅤ/PI双染检测各组U87细胞凋亡率,Western blotting法检测各组U87细胞中bax和bcl-2蛋白表达水平。结果:MTT法,与空白对照组比较,20、40和80mg·L(-1)SCU组细胞存活率均明显降低(P<0.01)。倒置显微镜观察,与空白对照组比较,80mg·L(-1)SCU组细胞数明显减少,细胞体积变小,细胞间距变大;细胞出现皱缩、脱落,贴壁细胞轮廓模糊。AnnexinⅤ/PI双染,与空白对照组比较,80mg·L(-1)SCU组细胞晚期凋亡率和总凋亡率均明显升高(P<0.01)。Western blotting法,与空白对照组比较,20、40和80mg·L(-1) SCU组U87细胞中bcl-2蛋白水平降低,80mg·L(-1)SCU组差异有统计学意义(P<0.01);与空白对照组比较,80mg·L(-1) SCU组U87细胞中bax/bcl-2比值升高(P<0.01)。结论:SCU通过上调U87细胞中bax/bcl-2比值诱导细胞凋亡从而抑制肿瘤细胞的生长。

Objective：To explore the inhibitory effect of scutellarin（SCU）on the proliferation of human glioma U87 cells,and to clarify its mechanism.Methods：The U87 cells were cultured and divided into blank control group and 20,40,80 mg·L（-1） SCU groups,the surival rates of U87 cells in various groups were examined by MTT assay;the morphology of U87 cells in various groups were observed by inverted microscope;the apoptotic rates of U87 cells were examined by AnnexinⅤ/PI staining;the expression levels of bax and bcl-2 proteins in the U87 cells in various groups were detected by Western blotting method.Results：The MTT results showed that compared with blank control group,the survival rates of U87 cells in 20,40,and 80 mg·L（-1） SCU groups were decreased（P〈0.01）.The inverted microscope observation results showed that compared with blank control group,the number of U87 cells in 80 mg·L（-1） SCU group was significantly decreased,and the cell volume was smaller;the U87 cells were shrinkage,shedding,and the outline of adherent cells was fuzzy.The results of AnnexinⅤ/PI staining showed that the late and total apoptotic rates of U87 cells in 80 mg·L（-1） SCU group were increased compared with blank control group（P〈0.01）.The Western blotting results showed that compared with blank control group,the expression levels of bcl-2 protein in the U87 cells in 20,40 and 80 mg·L（-1） SCU groups were decreased,especially in 80 mg·L（-1） SCU group（P〈0.01）.Compared with blank control group,the ratio of bax/bcl-2 in the U87 cells in 80 mg·L（-1） SCU group was significantly increased（P〈0.01）.Conclusion：SCU can induce the apoptosis and suppress the tumor growth by upregulating the bax/bcl-2 ratio in the U87 cells.