GSE186129
Dissection of the MEF2D-IRF8 transcriptional circuit dependency in acute myeloid leukemia [ChIP-seq]
Transcriptional dysregulation is a prominent feature in leukemia. Here, we systematically surveyed the transcription factor (TF) vulnerabilities in leukemia, and uncovered TF clusters that exhibit context-specific addictions within and between different subtypes of leukemia. We focused on and  validated MEF2D as a requirement exclusively in AML with high IRF8 expression. Transcriptomic and chromatin-binding profiling revealed a key TF circuit composed of MEF2D-IRF8 vital for AML maintenance. AML can acquire dependence on this circuit through various mechanisms, including enhancer activation of the circuit via MLL-rearrangement. IRF8 cooperates with PU.1 to control PU.1/MEIS1 co-regulated transcriptional outputs, meanwhile coordinating with MEF2D to directly regulate genes in a non-redundant manner. Collectively, our study nominates a TF circuit in support of the pathogenesis of AML. Overall design: PU.1 binding profiles upon IRF8 targeted degradation in human AML cells