Project description:We assessed lineage involvement by NUP98 translocations in myelodysplastic syndromes (MDS), acute myeloid leukemia (AML), and T-cell acute lymphoblastic leukemia (T-ALL). Single cell analysis by FICTION (Fluorescence Immunophenotype and Interphase Cytogenetics as a Tool for Investigation of Neoplasms) showed that NUP98-translocations with various partners, i.e. NSD1, DDX10, RAP1GDS1, and LNP1, always affected a CD34+/CD133+ hematopoietic precursor. Interestingly, in MDS/AML myelomonocytes, erythroid cells, B- and T- lymphocytes belonged to the abnormal clone, while in T-ALL only CD7+/CD3+ cells were involved. The partner did not appear to play a major role in determining the leukemia phenotype as shown in AML and T-ALL with the same NUP98-RAP1GDS1 fusion. Additional hits, namely mutations of FLT3 and CEBPA in MDS/AML and mutation of NOTCH1 plus MYB duplication in T-ALL, were identified in leukemias with, respectively, myeloid or T-lymphoid phenotype. Affymetrix SNP arrays were performed according to the manufacturer's directions on DNA extracted from cryopreserved diagnostic bone marrow or peripheral blood samples. Copy number and Copy neutral LOH analysis of with Affymetrix Cytogenetic 2.7 and Cytoscan HD SNP arrays was performed on 6 NUP98 rearranged leukemias.
Project description: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 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 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. SIGNIFICANCE STATEMENT MOZ is a member of NUP98 FO condensates with key roles in leukemia phenotypes. MOZ inhibition is effective in multiple preclinical models, including those non-responsive to Menin inhibition. MOZ and Menin inhibition are synergistic in some NUP98-rearranged models, supporting clinical translation to improve outcomes of NUP98 FO-driven leukemias.