Effect of DNMT3A R882H mutation or WT on gene expression in hematopoietic stem/progenitor cells with NRAS G12D co-transduction (Microarray)

DNA Methyltransferase 3A (DNMT3A) is frequently mutated in various hematopoietic malignancies; however, the underlying oncogenic mechanisms remain elusive. Here, we report that DNMT3A mutational hotspot at Arg882 (i.e., DNMT3A-R882H) cooperates with constitutively activated RAS in transforming murine hematopoietic stem/progenitor cells (HSPCs) ex vivo and inducing acute leukemias in vivo. DNMT3A-R882H potentiates aberrant transactivation of stemness gene expression programs, notably transcription factors Meis1, Hox-A, Mn1 and Mycn. Mechanistically, R882-mutated DNMT3A directly binds to cis-regulatory elements of these genes and induces focal CpG hypomethylation reminiscent of what was seen in human leukemias bearing DNMT3A R882 mutation. Furthermore, DNMT3A-R882H induced DNA hypomethylation facilitates gene enhancer/promoter activation and recruitment of Dot1l-associated transcription elongation machineries. Inactivation of Dot1l represses DNMT3AR882H-mediated stem cell gene dysregulation and acute leukemogenicity.

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Lu R, Wang P, Parton T, Zhou Y, Chrysovergis K, Rockowitz S, Chen WY, Abdel-Wahab O, Wade PA, Zheng D, Wang GG