AEG-1表达下调对脑胶质瘤U373细胞的放射增敏效应

Down- regulation of AEG- 1 enhances the radiosensitivity of U373 cells in vitro

目的:探讨AEG-1基因表达下调对人脑胶质瘤细胞U373放射敏感性的影响。方法:以人MTDH/AEG-1(NM-178812)为靶标设计shRNA序列,慢病毒介导将AEG-1 shRNA转染至胶质瘤U373细胞中。荧光定量PCR及Western blot测定转染前后AEG-1 mRNA及蛋白的表达;克隆形成实验评估AEG-1基因下调后U373细胞放射敏感性;流式细胞术检测AEG-1下调后U373细胞凋亡及细胞周期分布。结果:通过慢病毒介导的shRNA转染,构建了AEG-1表达稳定下调的U373-shAEG-1细胞系,有效抑制了胶质瘤U373细胞中AEG-1的表达(抑制率84%,P<0.05),增加了凋亡细胞的比例(13.07%±0.28%,P<0.05),并提高细胞周期中S期细胞比例(58.18%,P<0.01),且AEG-1基因表达下调后U373细胞的D0值(1.60Gy)和Dq值(1.06Gy)均明显低于空白对照组及阴性对照组细胞(P<0.05)。结论:下调AEG-1可以增强人脑胶质瘤U373细胞的放射敏感性,其机制与诱导细胞凋亡及干预细胞周期分布有关。

To study the effect of AEG - 1 down - regulation on the radiosensitivity of U373 cells in vitro. Methods：We designed the shRNA that targets MTDH/ AEG - 1（NM 178812）and then transfected it into U373 cells via lentivirus. The AEG - 1 mRNA expression was determined using real - time quantitative PCR,and the protein was determined by Western blot. The radiosensitivity of U373 was evaluated with colony formation assay. Flow cytome-try was used to analyze the apoptosis and cell cycle. Results：Down - regulation of AEG - 1 expression could enhance the radiosensitivity of U373 cells（inhibition ratio 84% ,P ﹤ 0. 05）. Colony formation assay showed an enhanced radio-sensitivity of transfected U373 cells. Flow cytometry assay showed that AEG - 1 down - regulation could promote ap-optosis in U373 cells（13. 07% ± 0. 28% ,P ﹤ 0. 05）,and accumulate S - phase cells（58. 18% ,P ﹤ 0. 01）. Conclu-sion：Down - regulation of AEG - 1 expression can enhance the radiosensitivity of U373 cells in vitro,which might re-sult from the promoting apoptosis and intervening cell cycle distribution.