【摘要】 研究12C6+离子辐照对体外培养人肝癌细胞SMMC-7721细胞周期和P53、MDM2及P21表达的影响。采用0、1.0、2.0、4.0、6.0Gy12C6+离子束辐照细胞,用克隆形成法观察细胞存活情况;同时在辐照24h后用流式细胞仪检测细胞周期的变化,Western-blot检测细胞中P53、MDM2及P21蛋白表达情况。结果发现,重离子辐照后细胞存活率显著下降;1.0Gy、4.0Gy和6.0Gy照射组发生G0/G1期阻滞,而2.0Gy照射组出现G2/M期阻滞;Western-blot结果显示细胞辐照后MDM2的57kD蛋白表达水平无明显变化,而76kD蛋白表达水平随辐照剂量逐渐上升;P53和P21蛋白表达水平随辐照剂量增高。以上结果提示不同剂量的12C6+离子束照射可激活SMMC-7721细胞不同的细胞周期检测点,其中G0/G1期阻滞与P53和P21蛋白以及MDM2截短体76kD蛋白的表达水平升高有关。更多还原

【Abstract】 To investigate the effect of 12C6+ ions radiation on the cell cycle and the expression of P53, MDM2 and P21 of SMMC-7721 cells. SMMC-7721 cells were irradiated with 12C6+ ions with the doses of 0Gy, 1.0Gy, 2.0Gy, 4.0Gy or 6.0Gy, then dose-survival curve of SMMC-7721 cells was figured by colony-forming assay. At 24h after ir- radiation cell cycle was analyzed by FACS and the expressions of P53, MDM2 and P21 were detected by West- ern-blot Assay. Results showed that the percentage of survival SMMC-7721 cells decreased with irradiation doses. The percentage of cells in G0/G1 phase increased after 1.0Gy, 4.0Gy, 6.0Gy 12C6+ ions irradiation compared with that of the control group. However, 2.0Gy 12C6+ ions irradiation increased the percentage of cells in G2/M phase. Com- pared to control, there were no changes in the expression of 57kD MDM2 in irradiated groups, but the expression levels of 76kD MDM2, P53 and P21 increased with irradiation doses. Therefore, the different doses of 12C6+ ions ir- radiation can activate different cell cycle checkpoints. The increased percentages of cells in G0/G1 phase were associ- ated with the high expression levels of P53, P21 and 76kD MDM2 proteins.更多还原