中文摘要：

目的 探讨神经上皮细胞转化基因1（Net1）对细胞辐射敏感性的影响及相关的分子作用机制.方法 运用实时荧光定量PCR检测辐射后细胞中Net1基因表达水平的变化;采用RNAi干扰技术抑制细胞中Net1的表达,用克隆形成率分析细胞的辐射敏感性;利用免疫共沉淀技术发现Net1的结合蛋白.结果 电离辐射损伤后,细胞中的Net1 mRNA水平显著上升（t=-10.52,P＜0.05）;与对照组相比,siRNA沉默细胞中的Net1表达后明显增加了细胞的辐射敏感性（t=15.31、11.65,P＜0.05）;无论在正常状态下还是在细胞受到辐照后,Net1都能与非同源末端连接修复蛋白Ku70、Ku80和DNA-PKcs结合.结论 Net1对细胞的辐射防护作用可能是通过与非同源末端连接修复蛋白相互作用来调控辐射损伤修复实现的.

英文摘要：

Objective To study the effect of neuroepithelial cell transforming gene 1 （Net1） on the cellular radiosensitivity and underlying mechanism.Methods Real-time quantitative PCR was used to measure the variations in Net1 expression level upon irradiation.Radiosensitivity was analyzed by colonyforming assay after Net1-siRNAs.Net1-associated proteins were identified by co-immunoprecipitation.Results The Net1 mRNA level in the cells was increased significantly （t =-10.52,P 〈 0.05） after irradiation.Compared to the control group,siRNA-mediated silencing of Net1 enhanced cell radiosensitivity （t =15.31,11.65,P 〈0.05）.Net1 was found to interact with Ku70,Ku80 and DNA-PKcs under either normal conditions or after irradiation.Conclusions Net1 could protect cells from irradiation by interaction with DNA repair proteins in non-homologous end joining pathway.