AEG -1表达下调对脑胶质瘤 U373细胞的放射增敏效应

摘要

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.%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。