青蒿素对脑胶质瘤U251细胞的辐射增敏作用

Effects of artemisinin on the radio-sensitivity of U251 glioma cells

为探讨青蒿素(Artemisinin)对脑胶质瘤细胞辐射敏感性的影响及其机制,采用甲基四唑蓝(MTT)法检测青蒿素对胶质瘤U251细胞增殖的抑制作用;Hoechst 33258荧光染色观察凋亡小体;单丹磺酞尸胺(MDC)染色和Western blotting检测U251细胞的自噬活性的改变;用克隆形成实验测定自噬抑制剂3-MA对U251细胞的增殖抑制作用。结果显示:青蒿素对U251细胞增殖有抑制作用;青蒿素和X射线联合处理组细胞凋亡增加,并出现大量自噬泡且LC3-Ⅱ表达量值增大(p<0.01);3-MA、青蒿素和X射线三联处理组细胞克隆形成率较联合处理组显著降低(p<0.01)。研究表明,青蒿素可能主要通过诱导细胞凋亡来增强U251细胞对X射线的辐射敏感性,同时青青蒿素也能增强辐射诱导U251细胞的自噬活性,但自噬机制在此过程中可能起到细胞保护作用。

To investigate the radio-sensitizing effect of artemisinin on U251 glioma cells in vitro, MTT assay, hoechst fluorescent staining, MDC staining, Western blot assay and cloning survival assay were used. The results show that artemisinin can inhibit the proliferation of U251 cells confirmed by MTT assay. The combined treatment with artemisinin and X-rays can significantly increase the apoptosis level in U251 cells studied by hoechst fluorescent staining and induce autophagy confirmed by MDC staining and Western blot assay. Cells previously treated with autophagy inhibitors 3-MA, artemisinin and X-rays can decrease number of colonies as compared with combination therapy group （artemisinin ＋ IR）. The results suggest that artemisinin can increase the radiation sensitivity of glioma U251 cells by inducing apoptosis. Autophagy can also be induced by treatment with artemisinin and X-rays, and it may play a protective role in the regulation of radio-sensitization of U251 cells.