TET2-driven activation of AGO2 links epigenetic remodeling to myeloid commitment and leukemia.

DNA methylation dynamics shape hematopoietic differentiation and leukemogenesis, yet how the dioxygenase TET2-frequently mutated in myeloid malignancies-directs lineage-specific regulatory programs remains unclear. Here, we integrated DNA methylation, chromatin accessibility, three-dimensional (3D) genome architecture, transcriptional profiling, and TET2 chromatin occupancy to define TET2-dependent control of human myeloid commitment. We found that TET2-bound regulatory regions gain short- and long-range chromatin interactions and that a distinct subset of distal, enhancer-enriched sites undergoes TET2-driven demethylation and activation. Among these, we identified and functionally validated an AGO2 myeloid-specific intragenic enhancer that is frequently hypermethylated in patients with TET2-mutant acute myeloid leukemia. AGO2 expression stratifies patient survival, and AGO2 depletion abrogates leukemic engraftment in vivo. These findings uncover a TET2-AGO2 regulatory axis that integrates epigenetic remodeling, 3D genome reorganization, and leukemic fitness, and they highlight AGO2 as a potential biomarker and therapeutic target in myeloid leukemia.