The histone acetyltransferase MOZ is a molecular dependency and therapeutic target in NUP98-rearranged acute myeloid leukemia [WGS, ATACseq, CUT&RUN, scRNAseq]

NUP98 fusion oncoproteins (FOs) are a hallmark of childhood acute myeloid leukemia (AML), and drive leukemogenesis through liquid-liquid phase separation-mediated nuclear condensate formation. However, the composition and consequences of NUP98 FO-associated condensates are incompletely understood. Here we show that histone acetyltransferase (HAT) complex proteins including MOZ associate with NUP98 FOs, and that BRPF1, an epigenetic writer that associates with MOZ, is a molecular dependency in NUP98::KDM5A AML. Inactivation of Brpf1 as well as HAT complex member Moz, Hbo1, Brd1 or Meaf6 in Nup98::Kdm5a;Vav-Cre cells impaired fitness of NUP98-rearranged cells. MOZ acetyltransferase inhibition decreased global H3K23ac levels, displaced FO from chromatin at the Meis1 locus, and led to myeloid cell differentiation. Additionally, MOZ inhibition decreased leukemic burden in multiple NUP98-rearranged leukemia xenograft mouse models, synergized with Menin inhibitor treatment, and was efficacious in Menin inhibitor-resistant cells. In summary, we show that MOZ is a potentially targetable dependency in NUP98-rearranged AMLs. IgG, NUP98, MOZ, Menin, and KMT2A chromatin binding sites were identified in CHRF-288-11 cells [CUT&RUN]. MSKG5191 (NUP98::NSD1) PDX-bearing mice were treated with vehicle, MOZ inhibitor PF9363, Menin inhibitor SNDX-5613, or combination, and spleen samples were analyzed to identify drug-induced changes in gene expression [scRNAseq]. For scRNAseq, spleens from three mice were pooled for each individual sample.