丙戊酸钠对AML1-ETO转染细胞中CEBPA基因表达及表观遗传修饰的影响

目的:探讨丙戊酸钠(VPA)对AML1-ETO转染细胞中CCAAT/增强子结合蛋白α(CEBPA)基因表达的影响及诱导沉默基因重新表达的机制。方法:不同浓度VPA处理AML1-ETO转染的急性髓系白血病细胞U937后,CCK-8法和台盼蓝染色活细胞计数检测细胞增殖能力,流式细胞术检测细胞表面抗原,RT-qPCR检测CEBPA mRNA的表达,ChIP-qPCR检测组蛋白H3和H4的乙酰化状态。结果:VPA对U937及AML1-ETO转染细胞有明显的生长抑制作用,呈现浓度依赖性和时间依赖性,VPA诱导U937及AML1-ETO转染细胞CD11b和CD14表达升高,VPA明显上调CEBPA mRNA的表达水平,VPA处理组CEBPA基因启动子区核染色质的组蛋白H3和H4乙酰化水平升高(P0.05)。结论:VPA对U937及其AML1-ETO转染细胞均有生长抑制和促分化的作用。VPA可能通过特异性调节CEBPA基因组蛋白乙酰化水平,改变其表观遗传修饰特征,从而诱导CEBPA基因重新表达。

Effect of sodium valproate on expression and epigenetic modification of CEBPA in AML1-ETO transfected cells

AIM:To investigate the effect of sodium valproate (VPA) on the expression of CCAAT/enhancer-binding protein α (CEBPA) in AML1-ETO transfected cells and to explore the possible mechanism for inducing re-expression of the silent gene. METHODS:The cell viability was measured by CCK-8 assay, and the living cell counting was performed by the method of trypan blue exclusion. The expression of myeloid cell differentiation antigen was simultaneously detected by flow cytometry.RT-qPCR was used to assess the mRNA expression of CEBPA. The acetylation levels of histones H3 and H4 were detected by ChIP-qPCR. RESULTS:VPA significantly inhibited the growth of U937 and AML1-ETO transfected cells in a concentration-and time-dependent manner. VPA enhanced the expression of cell differentiation antigens CD11b and CD14. VPA increased the mRNA expression of CEBPA. The acetylation levels of H3 and H4 were increased by the treatment with VPA. CONCLUSION:VPA inhibits the proliferation and induces differentiation of U937 and AML1-ETO transfected cells.VPA causes the changes of epigenetic modification and induces the re-expression of CEBPA gene which is silenced probably through specifically regulating the acetylation levels of H3 and H4.