二氢青蒿素对人脑胶质瘤SHG44细胞辐射增敏作用及其机制的研究

Investigation of radiation sensitivity and mechanism on SHG44 cells of human glioma induced by dihydrodihydroartemisinin

为研究二氢青蒿素(Dihydroartemisinin)对人脑胶质瘤SHG44细胞辐射增敏作用及其机制,采用MTT法(Methyl thiazolyl tetrazolium)检测增殖抑制作用;应用克隆形成法检测放射增敏作用;运用流式细胞术检测二氢青蒿素及^(60)Coγ射线作用后细胞周期的变化;应用Western Blot技术观察细胞周期调控蛋白CyclinB1、Cdc2表达的改变。结果表明:二氢青蒿素对人脑胶质瘤SHG44细胞有增殖抑制作用,具有时间依赖性和浓度依赖性;二氢青蒿素(5μmol/L)能提高人脑胶质瘤SHG44细胞对γ射线的辐射敏感性,辐射增敏比(SER)为1.42;单纯照射组较对照组G_2/M期的细胞比例升高,二氢青蒿素+照射组较单纯照射组G_2/M期的细胞比例降低;二氢青蒿素+照射相对于单纯照射组,CyclinB1蛋白表达水平增加,Cdc2蛋白表达水平无明显变化。由此得出,二氢青蒿素对人脑胶质瘤SHG44细胞具有明显放射增敏作用,其机制可能是提高CyclinB1蛋白表达减弱G_2关卡作用,从而解除了照射引起的G_2期阻滞。

The subject is to investigate the radiation sensitivity and it＇s mechanism on SHG44 cells of human glioma induced by dihydroartemisinin. MTT assay was used to measure the inhibition effect, cloning survival assay was used to study the radiation sensitized effect and flow cytometry was adopted to detect the changes of cell cycle distribution meanwhile western blot was used to examine the expression of CyclinB 1, Cdc2. The results showed that dihydroartemisinin inhibited the proliferation of SHG44 cells in dose-dependent and time-dependent manner. DHA（5gmol/L） had obvious radiation sensitivity effect on SHG44 cells and the sensitized enhancement rat（SER） was 1.42. Compared with the radiation group, the G2/M ratio decreased and the expression of CyclinB 1 increased while the expression of Cdc2 didn＇t change in the radiation plus drug group. It can be concluded that dihydroartemisinin has radiation sensitivity effect on SHG44 cell, which may be related to weakening of the function of G2 checkpoint by increasing the expression of CyclinB 1 and relieve from the cycle blockage of G2/M stage.