为探讨RNA干扰共济失调毛细血管扩张性突变(Ataxia-telangiectasia mutated, ATM)基因表达后对胃癌细胞AGS放射敏感性的影响，通过构建ATM基因RNA干扰质粒转染AGS细胞，获得干扰效率高的克隆细胞AGS-Ri-ATM，并采用RT-PCR和Western blot分别检测mRNA和蛋白表达水平，平板克隆形成实验观察细胞经放射后对细胞生长的影响，流式细胞术检测细胞周期和凋亡情况。检测结果显示其ATM基因表达被干扰下调。经X射线照射至不同吸收剂量，AGS-Ri-ATM平板克隆形成数量/率远低于AGS-Vector的平板克隆形成数量/率，差异显著(p<0.05)，具有统计学意义。流式细胞术检测显示当吸收剂量为4 Gy时，AGS-Ri-ATM被阻滞在G1期，同时在12 h后出现明显的凋亡想象。结果表明，ATM基因被干扰后可以诱导细胞周期的阻滞，以及凋亡的增加而增强AGS细胞的放射敏感性。%To investigate the interference effect of ataxia-telangiectasia mutated (ATM) gene expression on the radiosensitivity of human gastric cancer AGS cells, the plasmid of interfering RNA was used to transfect AGS cells. The mRNA and protein expression levels of ATM gene were measured by RT-PCR and Western blot, respectively. The effect on cell growth after irradiation was analyzed by using the colonies formation assay. Cell cycle and cell apoptosis were analyzed by flow cytometry. The RNA interference plasmid of ATM gene was transfected into AGS cells and AGS-Ri-ATM cells were obtained successfully. The RT-PCR and Western blot results demonstrated that the expression of ATM gene was down-regulated in the AGS-Ri-ATM cells. The colonies formation numbers/ratios of AGS-Ri-ATM cells were less than those of AGS-Vector. The flow cytometry demonstrated that G1 arrest was induced and apoptosis appeared in AGS-Ri-ATM cells after irradiation at 4 Gy for 12 h, which was not observed in AGS-Vector cells. Interference of ATM expression increased the radiosensitivity of human gastric cancer AGS cells.
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