DNMT3A在IDH1致急性髓系白血病基因组高甲基化中的作用

Role of DNMT3A in IDH1 Mutation Induced Acute Myeloidleukemia Genome Methylation

目的 探讨DNMT3A水平高低对IDH1致急性髓系白血病基因组高甲基化的影响。方法 利用人AML细胞株HL60和THP-1,通过转染IDH1、DNMT3A突变表达质粒,研究DNMT3A表达水平高低对IDH1致基因组高甲基化的影响。结果(1)在IDH1突变的原代AML细胞以及转染IDH1突变表达质粒的人AML细胞株HL60或THP-1中,2-HG和5-甲基胞嘧啶(5-mC)的含量增高;与此同时,DNMT3A的mRNA水平及其蛋白质酶活性也发生了增加(P < 0.05);(2)在转染IDH1突变表达质粒的人AML细胞株HL60或THP-1中,抑制DNMT3A的表达水平可以降低5-mC的含量(P < 0.05),但并不影响2-HG的表达水平(P = 0.989);(3)与单独转染IDH1突变(IDH1 R132H)表达质粒的HL60细胞相比,同时转染IDH1突变(IDH1 R132H)和DNMT3A突变(DNMT3A R882H)表达质粒会使其细胞内5-mC的含量降低(P < 0.05);但并不影响2-HG的表达水平(p=1.294)。结论 DNMT3A参与介导IDH1/2突变所致的基因组高甲基化。

Objective To investigate the role of DNMT3A in IDH1 mutation induced acute myeloidleukemia genome methylation . Methods To study the effect of DNMT3A expression level on IDH1 induced genomic hypermethylation, human AML cell lines HL60 and THP-1 were transfected with IDH1,DNMT3A mutant expression plasmid. Results (1) The levels of 2-HG and 5-methylcytosine (5-mC) were increased in the primary AML cells with IDH1 mutation and the human AML cell lines HL60 or THP-1 transfected with IDH1 mutant expression plasmid was increased,while the level of DNMT3A mRNA and its protease activity also increased(P < 0.05).(2) Inhibiting the expression of DN MT3Ain HL60 or THP-1 cells transfected with IDH1 mutant expression plasmid could reduce the content of 5-mC(P < 0.05),but the expression level of 2-HG was not affected(P = 0.989).(3)Compared with HL60 cells transfected with IDH1 mutation (IDH1 R132H)expression plasmids alone, the expression plasmids transfected IDH1 mutation (IDH1 R132H) and DNMT3A mutation (DNMT3A R882H) decreased the content of 5-mC in cells(P < 0.05), but the expression of 2-HG wasn't affected(p=1.294). Conclusion DNMT3A participates in the genomic hypermethylation induced by IDH1 mutation.