【摘要】 目的探讨HRAD17在DNA辐射损伤修复及辐射诱导的凋亡中的作用。方法利用基因转染技术,对小鼠成纤维细胞NIH3T3和人宫颈癌HeLa细胞均分别转染pDOR-neo载体,pDOR-HRAD17s(正义)和pDOR-HRAD17a(反义)质粒,G418筛选获得阳性克隆。转染后各组细胞去血清培养48 h同步化后给予60Coγ射线10 Gy照射,吸收剂量率为2.54 Gy/min,加入完全培养基继续培养,并于0、61、2、14、36和48 h收集固定细胞,碘化丙啶(PI)避光染色后,流式细胞仪检测细胞DNA量。结果在辐射损伤后,转染正义HRAD17的成纤维细胞主要发生G1/S期阻滞,转染正义HRAD17的肿瘤细胞主要发生G2/M期阻滞;转染正义HRAD17的细胞凋亡比例降低,转染反义HRAD17的细胞凋亡比例升高。结论HRAD17同时参与细胞周期G1/S和G2/M期阻滞,并抑制辐射损伤诱导的细胞凋亡。更多还原

【Abstract】 Objective To study the role of HRAD17 in DNA damage and apoptosis induced by ionizing radiation. Methods Plasmids including pDOR-neo vector,pDORHRAD17s（sense） and pDOR-HRAD17a（anti-sense） were transfected into mouse fibroblasts（NIH3T3） and human uterine cervix cancer cells（HeLa）.Positive clones were screened by G418.After 48 h of serume-free culture,all kinds of transfected cells were exposed to 10 Gy γ-rays（at 2.54 Gy/min） and immediately cultured with serum.The cells were isolated and fixed by 70% ethanol,with were collected at 0,6,12,24,36 and 48 h post-irradiation,and stained by propedium iodide（PI） in the dark.Flow cytometry was performed to detect DNA in these cells. Results （Ionizing） radiation could induce G₁/S arrest in normal cells transfected with sense HRAD17,but G₂/M arrest in tumour cells.Interestingly,cells transfected with antisense HRAD17 showed an elevated apoptotic rate compared to the control group. Conclusion HRAD17 is able to function in both G₁/S and G₂/M arrest and inhibit apoptosis induced by radiation damage.更多还原