长链非编码RNA MALAT1在肿瘤细胞中调控IRF3的表达

Long non-coding RNA MALAT1 regulated IRF3 expression by cancer cell

目的:验证长链非编码RNA(long non-codingRNA,lncRNA)肺腺癌转移相关转录本1(metastasis-associated lung adenocarcinoma transcript 1,MALAT1)与干扰素调节因子3(interferon regulation factor 3,IRF3)的靶向调控关系。方法:将人IRF3启动子荧光素酶报告基因重组质粒p GL3-56与敲降MALAT1的siRNA(si MALAT1-1、si MALAT1-2)或阴性对照物(si NC)瞬时共转染A549细胞,检测相对荧光素酶活性。同样使用si NC或si MALAT1-1、si MALAT1-2瞬时共转染A549细胞,反转录-实时荧光定量PCR检测IRF3 mRNA表达水平,Western blot检测IRF3蛋白表达水平。结果:与si NC组比较,si MALAT1-1组和siMALAT1-2组荧光素酶活性均有下降,差异均有统计学意义(P<0.05);与si NC组比较,si MALAT1-1组和si MALAT1-2组MALAT1 mRNA和IRF3 mRNA相对表达量均有下降,差异有统计学意义(P<0.05);与si NC组比较,si MALAT1-1组和siMALAT1-2组的IRF3蛋白表达水平均有下降,差异有统计学意义(P<0.05)。结论:IRF3是MALAT1的靶基因,MALAT1通过调控IRF3启动子区来影响IRF3的转录与表达。

Objective：To validate whether interferon regulation factor 3（IRF3）is regulated by long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1（MALAT1）. Methods：Luciferase report plasmid pGL3-56 inserted with IRF3 promoter and MALAT1 knockdown siRNAs（negative control,siMALAT1-1 and siMALAT1-2） were co-transfected to A549 cells,then relative luciferase activities were determined. MALAT1 knockdown siRNAs were transfected to A549 cells,then IRF3 mRNA and protein levels were detected by qPCR and Western blotting respectively. Results：Relative luciferase activities of the siMALAT1-1 and the siMALAT1-2 groups were lower than that of the siNC group respectively,which were statistically significant（P 〈 0.05）. Relative MALAT1 RNA levels of the siMALAT1-1 and the siMALAT1-2 groups were lower than that of the siNC group respectively,which were statistically significant（P 〈 0.05）;Relative IRF3 mRNA levels of the siMALAT1-1 and the siMALAT1-2 groups were lower than that of the siNC group respectively,which were statistically significant（P 〈 0.05）. Relative IRF3 protein levels of the siMALAT1-1 and the siMALAT1-2 groups were lower than that of the siNC group respectively,which were statistically significant（P 〈 0.05）. Conclusion：IRF3 is a target of MALAT1 and MALAT1 regulates the expression of IRF3 by targeting IRF3 promoter.