肺癌mdig基因对H3k9me3的去甲基化作用

Methylation effects of lung cancer-associated mdig gene on the trimethylation of histone H3 lysine9

目的:观察肺癌mdig基因对组蛋白H3及H4部分位点赖氨酸残基的甲基化状态的作用。方法:用过表达和沉默mdig质粒转染人类肺腺癌细胞系A549细胞建立稳定转染细胞系,通过免疫蛋白印迹法和免疫荧光法检测mdig对H3k4me3、H3k4me2、H3k4me1,H3k9me3、H3k9me2、H3k9me1,H3k27me3、H3k27me2、H3k27me1,H3k36me3、H3k36me2、H3k36me1及H4k20me3的甲基化状态的影响。结果:免疫蛋白印迹法显示过表达mdig引起H3k9me3的表达减弱,沉默mdig引起H3k9me3的表达增强,组蛋白H3上的4、27、36和组蛋白H4上的20位点上的赖氨酸残基甲基化状态未见明显变化。免疫荧光法显示沉默mdig引起H3k9me3的荧光表达增强,与免疫蛋白印迹法结果一致。结论:肺癌mdig基因对H3k9me3有去甲基化的作用,未见其对其他赖氨酸位点的去甲基化作用。

Objective： To observe the effect of lung cancer - associated mdig gene on the methylation status of par tial lysine residues on histone H3 and H4. Methods：The mdig - GFP and shRNA - RFP was transfected to human lung adenocarcinoma epithelial cell line A549 to establish overexpressing and silencing mdig stable cell lines. Western blot and Immunofluorescent method was used to show the effect of mdig gene on the methylation status of H3k4me3, H3k4me2, H3k4mel, H3k9me3, H3k9me2, H3k9mel, H3 k27me3, H3k27me2, H3k27mel, H3k36me3, H3k36me2, H3k36mel and H4k20me3. Results：Western blot results showed overexpressing mdig induced decrease in the level of H3K9me3 and silencing mdig induced increase of H3K9me3. No notable effect of mdig on the methylation states of H3k4, H3K27,H3k36 and H4k20 was observed. Immunofluoreseent staining also indicated increase of H3K9me3 in the silencing mdig stable cell. Conclusion： Lung cancer - associated mdig gene has demethylation effect on H3k9me3 ,not on other lysine residues of histone H3 and H4.