RNF20对紫外线诱导的胃癌细胞DNA损伤修复的影响

Effect of RNF20 on DNA damage repair in ultraviolet ray-induced gastric cancer cells

目的探究在紫外线暴露下环指蛋白20(ring finger protein 20,RNF20)低表达对胃癌细胞DNA损伤修复的影响及其相关作用机制。方法实验采用慢病毒载体构建稳定低表达胃癌细胞系,分为对照组和RNF20敲低组,用CCK-8法检测两组细胞的增殖情况,用总共照射剂量为20 J/m^(2)紫外线照射胃癌MGC803细胞,采用Western blotting及免疫荧光技术检测两组细胞γ-H2AX、RAD51和p21的情况。结果荧光显微镜观察两组细胞均有绿色荧光蛋白表达;CCK-8显示RNF20表达降低会促进胃癌细胞增殖;敲低组细胞中RNF20蛋白较对照组表达降低。与对照组相比,经20 J/m^(2)紫外线照射细胞后,敲低组γ-H2AX消失更加迟缓,RAD51蛋白表达降低,p21蛋白表达下降趋势更慢。结论RNF20敲低会抑制紫外线诱导的胃癌细胞DNA损伤修复过程。

Objective To investigate the effect of ring finger protein 20(RNF20)deficiency on DNA damage and repair in gastric cancer cells exposure to ultraviolet ray and its underlying mechanism.Methods MGC803 gastric cancer cell lines with stable low expression of RNF20 were constructed by lentivirus vector,and they were divided into control group and RNF20 deficient group.The cell proliferation was detected by CCK-8 method.The total irradiation dose of 20 J/m^(2)ultraviolet radiation was used to irradiate MGC803 gastric cancer cells.The levels ofγ-H2AX,RAD51 and p21 proteins in the two groups were detected by Western blotting and immunofluorescence techniques.Results The expression of green fluorescent protein was observed by fluorescence microscope in both groups.CCK-8 showed that decreased expression of RNF20 promoted the proliferation of gastric cancer cells.Western blooting results showed that the expression of RNF20 protein in knockdown group was lower than that in control group.Compared with the control group,after 20 J/m^(2)ultraviolet irradiation,γ-H2AX disappeared more slowly,the expression of RAD51 protein decreased,and the expression of p21 protein decreased more slowly in the knockdown group.Conclusion RNF20 deficiency can inhibit the repair process of DNA damage induced by ultraviolet rays in gastric cancer cells.