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Evidence supporting a dominant negative mechanism for DNMT3A hotspot mutation-mediated leukemic cell transformation

ABSTRACT: Mutation of DNA methyltransferase 3A at arginine 882 (DNMT3AR882mut) is prevalent in various hematological cancers. DNMT3AR882mut was recently shown to carry partially defective, dominant-negative or gain-of-function activities under different in vitro contexts. However, the causal roles for such a multifaceted effect of DNMT3AR882mut on leukemogenesis remain undefined. Here we report TF-1 leukemia cells as a robust system for modeling DNMT3AR882mut-dependent cell transformation phenotypes and for performing structure-function relationship studies of DNMT3AR882mut. We show that expression of DNMT3AR882mut and not its wildtype counterpart promotes TF-1 cell transformation and induces CpG hypomethylation predominantly at enhancers. Such effect by DNMT3AR882mut is dose-dependent, acts synergistically with that of IDH1 mutation, and resembles what was seen in human leukemia patients with DNMT3AR882mut. Both transformation- and hypomethylation-inducing capacities of DNMT3AR882mut rely on a motif involved in heterodimerization whereas its various chromatin-binding and enzymatic domains were dispensable. We also show bromodomain inhibition as a therapeutic means for treatment of murine leukemia carrying DNMT3AR882mut. Collectively, this study describes a useful model system for studying DNMT3AR882mut and supports a requirement for the dominant-negative effect of DNMT3AR882mut during leukemogenesis.

ORGANISM(S): Homo sapiens

PROVIDER: GSE130094 | GEO | 2019/06/12

REPOSITORIES: GEO

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