ASXL2 is essential for haematopoiesis and acts as a haploinsufficient tumour suppressor in leukemia
نویسندگان
چکیده
Additional sex combs-like (ASXL) proteins are mammalian homologues of additional sex combs (Asx), a regulator of trithorax and polycomb function in Drosophila. While there has been great interest in ASXL1 due to its frequent mutation in leukemia, little is known about its paralog ASXL2, which is frequently mutated in acute myeloid leukemia patients bearing the RUNX1-RUNX1T1 (AML1-ETO) fusion. Here we report that ASXL2 is required for normal haematopoiesis with distinct, non-overlapping effects from ASXL1 and acts as a haploinsufficient tumour suppressor. While Asxl2 was required for normal haematopoietic stem cell self-renewal, Asxl2 loss promoted AML1-ETO leukemogenesis. Moreover, ASXL2 target genes strongly overlapped with those of RUNX1 and AML1-ETO and ASXL2 loss was associated with increased chromatin accessibility at putative enhancers of key leukemogenic loci. These data reveal that Asxl2 is a critical regulator of haematopoiesis and mediates transcriptional effects that promote leukemogenesis driven by AML1-ETO.
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Loss of Asxl2 leads to myeloid malignancies in mice
ASXL2 is frequently mutated in acute myeloid leukaemia patients with t(8;21). However, the roles of ASXL2 in normal haematopoiesis and the pathogenesis of myeloid malignancies remain unknown. Here we show that deletion of Asxl2 in mice leads to the development of myelodysplastic syndrome (MDS)-like disease. Asxl2-/- mice have an increased bone marrow (BM) long-term haematopoietic stem cells (HS...
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