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目的探讨榄香烯体外增强人脑胶质瘤U251细胞对γ射线敏感性的机制研究。方法人脑胶质瘤U251细胞分为4组:空白组、加药组(榄香烯治疗)、放射组(单独γ射线照射)和联合组(榄香烯联合γ射线照射),应用克隆形成计数法,绘制细胞放射生存曲线,计算增敏比,流式细胞仪(FCM)检测细胞周期,电镜观察不同方法处理的U251细胞超微结构的改变,逆转录-聚合酶链反应(RT-PCR)检测c-myc和bcl-2基因的表达。结果榄香烯增强γ射线对U251细胞株抑制率,呈剂量的依赖性,榄香烯增强U251细胞对γ射线敏感的比值为1.38,FCM检测榄香烯增强γ射线对U251细胞的阻滞作用,导致G_2/M期细胞比例明显升高,联合组细胞电镜下见细胞核分裂;RT-PCR证实榄香烯增强γ射线对U251细胞c-myc和bcl-2基因表达的抑制作用。结论榄香烯对U251细胞有放射增敏作用,其作用机制可能与下调bcl-2和c-myc基因表达有关,诱导U251细胞凋亡和对细胞G_2/M期阻滞有关。
Objective To investigate the mechanism of elemene enhancing γ-ray sensitivity of human glioma U251 cells in vitro. Methods Human glioma U251 cells were divided into four groups: blank group, dosing group (elemene treatment), radiotherapy group (single gamma irradiation) and combination group (elemene combined with gamma irradiation) The cell survival curve was plotted, the ratio of sensitization to radiation was calculated, the cell cycle was detected by flow cytometry (FCM), the ultrastructural changes of U251 cells treated by different methods were observed by electron microscopy, and the changes of the ultrastructure of U251 cells by reverse transcription polymerase chain reaction ) Were used to detect the expression of c-myc and bcl-2 genes. Results Elemene enhanced the inhibitory rate of γ-rays to U251 cells in a dose-dependent manner. The ratio of elemene enhanced U251 cells to γ-rays was 1.38. The inhibitory effect of elemene on γ-rays was enhanced by FCM in U251 cells , Resulting in a significant increase in the proportion of cells in G 2 / M phase. The nuclear cleavage was observed by electron microscopy in combination group. The inhibitory effect of elemene on the expression of c-myc and bcl-2 in U251 cells was confirmed by RT-PCR. Conclusion Elemene has a radiosensitizing effect on U251 cells, and its mechanism may be related to down-regulation of bcl-2 and c-myc gene expression, inducing apoptosis of U251 cells and arresting cell cycle of G 2 / M phase.