沉默JMJD2B通过诱导DNA损伤抑制人胃癌细胞的恶性表型

Silencing JMJD2B inhibits human gastric cancer cell malignant phenotype via inducing DNA damage response

目的:探讨人胃癌细胞中含Jumonji结构域的蛋白2B(JMJD2B)与DNA损伤反应之间的关系,及其在肿瘤恶性表型中的作用。方法:应用JMJD2B siRNA特异性抑制人胃癌细胞MGC803和SGC7901中JMJD2B的表达,采用Western blotting检测经处理后DNA损伤特异性标志物磷酸化H2AX(γH2AX)的表达,通过DNA损伤检测方法彗星实验测定DNA拖尾的情况,并分别采用CCK-8和流式细胞仪分析细胞增殖、细胞周期分布及细胞凋亡情况。结果:人胃癌细胞MGC803和SGC7901中,JMJD2B siRNA特异性抑制了JMJD2B的表达,γH2AX表达上调,同时彗星实验提示DNA拖尾百分比明显增加,肿瘤细胞发生了G_( 2)/M或G _(0)/G _(1)期阻滞,细胞凋亡比例增加,细胞增殖显著受抑(P<0.05)。结论:沉默JMJD2B可诱导人胃癌细胞发生DNA损伤,进而抑制了癌细胞的恶性表型。

Objective:To explore the relationship between JMJD2B and DNA damage response in human gastric cancer cells,and their role in tumor malignant phenotype.Methods:JMJD2B siRNAs were transiently transfected into human gastric cancer cells MGC803 and SGC7901 for silencing JMJD2B expression.The expression of DNA damage specific marker-phosphorylation expression of H2AX(γH2AX)was assessed by Western blotting,and Comet assay was used to investigate DNA damage.Cell proliferation was detected using CCK-8 assay,while flow cytometry was performed to detect cell cycle distribution and apoptosis.Results:JMJD2B siRNA specifically inhibited the expression of JMJD2B in human gastric cancer cells,which up-regulated theγH2AX,at the same time,Comet assay revealed the percentage of DNA in tail increased sharply thus led to cell cycle arrest in G_( 2)/M or G _(0)/G _(1) phase,increased proportion of cell apoptosis and significantly inhibited cell proliferation(P<0.05).Conclusion:Silencing JMJD2B induces DNA damage response in human gastric cancer cells,which in turn inhibits the malignant phenotype of cancer cells.