下调REV7基因对于人结肠癌HCT116细胞放射敏感性影响及机制研究

Effect and mechanism of down-regulating REV7 expression on the radiosensitivity of human colon cancer cell HCT116

目的研究下调REV7基因表达对人结肠癌HCT116细胞放射敏感性影响及其机制。方法对HCT116细胞进行培养并运用RNA干扰技术实现REV7基因下调,将细胞分为空白组、转染阴性RNA oligo片段阴性对照组、转染REV7 RNA oligo的REV7基因下调组。克隆形成实验反映细胞增殖水平,蛋白印迹法检测相关基因表达水平、细胞凋亡发生水平和非同源末端连接途径发生水平。结果6Gy照后REV7 siRNA组细胞克隆形成率降低(P<0.05)。REV7 siRNA组REV7基因下调效率>60%。REV7 siRNA组γH2AX、Caspase9表达升高(P<0.05),Ku80、XRCC4表达降低(P<0.05)。结论下调REV7基因能提高HCT116细胞放射敏感性,其机制可能与下调REV7后非同源末端连接的发生被削弱有关。

Objective To evaluate the effect and mechanism of down-regulating the expression of REV7 on the radiosensitivity of human colon cancer cell HCT116.Methods HCT116 cells were cultured and the expression of REV7 was down-regulated by RNA interference technique.HCT116 cells were divided into the blank group,negative control transfected with negative RNA oligo group and REV7 expression down-regulation transfected with REV7 RNA oligo group,respectively.The cell proliferation was determined by colony formation assay.The expression levels of the proteins of relevant genes were detected by Western blot.The level of cell apoptosis and non-homologous end joining was evaluated.Results The colony formation rate was significantly reduced in THE REV7 siRNA group after 6Gy irradiation(P<0.05).The down-regulating efficiency rate of REV7 gene was>60%in the REV7 siRNA group.The expression levels ofγH2AX and Caspase9 were significantly up-regulated,whereas those of KU80 and XRCC4 were remarkably down-regulated in the REV7 siRNA group(all P<0.05).Conclusions The radiosensitivity of human colon cancer cell HCT116 can be increased by down-regulating the expression of REV7.The underlying mechanism may be related to the lower incidence rate of non-homologous end joining.