Conditional knockin of Dnmt3a R878H initiates acute myeloid leukemia with mTOR pathway involvement

Significance DNMT3A is a critical epigenetic modifier and tumor suppressor in the hematopoietic system. This gene is frequently mutated in hematopoietic malignancies, including acute myeloid leukemia (AML), with Dnmt3a R878H being the most common mutant. By using a conditional knockin approach, this study shows that Dnmt3a R878H is sufficient to initiate AML and recapitulate human leukemic features in mice. The leukemia-initiating cells are enriched in hematopoietic stem/progenitor cells. Through gene expression profiling, DNA methylation and histone modification analysis, and functional tests on important regulators for cell proliferation and differentiation in an animal model, this study has not only discovered mTOR pathway activation as a key player in the disease mechanism but also revealed the potential therapeutic effects of mTOR inhibition on DNMT3A mutation-related leukemia.