Browsing by Author "Zhou, Bo"

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    Discovery of first-in-class inhibitors of ASH1L histone methyltransferase with anti-leukemic activity
    (Springer Nature, 2021-05-14) Rogawski, David S.; Deng, Jing; Li, Hao; Miao, Hongzhi; Borkin, Dmitry; Purohit, Trupta; Song, Jiho; Chase, Jennifer; Li, Shuangjiang; Ndoj, Juliano; Klossowski, Szymon; Kim, EunGi; Mao, Fengbiao; Zhou, Bo; Ropa, James; Krotoska, Marta Z.; Jin, Zhuang; Ernst, Patricia; Feng, Xiaomin; Huang, Gang; Nishioka, Kenichi; Kelly, Samantha; He, Miao; Wen, Bo; Sun, Duxin; Muntean, Andrew; Dou, Yali; Maillard, Ivan; Cierpicki, Tomasz; Grembecka, Jolanta; Microbiology and Immunology, School of Medicine
    ASH1L histone methyltransferase plays a crucial role in the pathogenesis of different diseases, including acute leukemia. While ASH1L represents an attractive drug target, developing ASH1L inhibitors is challenging, as the catalytic SET domain adapts an inactive conformation with autoinhibitory loop blocking the access to the active site. Here, by applying fragment-based screening followed by medicinal chemistry and a structure-based design, we developed first-in-class small molecule inhibitors of the ASH1L SET domain. The crystal structures of ASH1L-inhibitor complexes reveal compound binding to the autoinhibitory loop region in the SET domain. When tested in MLL leukemia models, our lead compound, AS-99, blocks cell proliferation, induces apoptosis and differentiation, downregulates MLL fusion target genes, and reduces the leukemia burden in vivo. This work validates the ASH1L SET domain as a druggable target and provides a chemical probe to further study the biological functions of ASH1L as well as to develop therapeutic agents.
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    HOXA9 Reprograms the Enhancer Landscape to Promote Leukemogenesis
    (Elsevier, 2018-10-08) Sun, Yuqing; Zhou, Bo; Mao, Fengbiao; Xu, Jing; Miao, Hongzhi; Zou, Zhenhua; Khoa, Le Tran Phuc; Jang, Younghoon; Cai, Sheng; Witkin, Matthew; Koche, Richard; Ge, Kai; Dressler, Gregory; Levine, Ross L.; Armstrong, Scott A.; Dou, Yali; Hess, Jay L.; Pathology and Laboratory Medicine, School of Medicine
    Aberrant expression of HOXA9 is a prominent feature of acute leukemia driven by diverse oncogenes. Here we show that HOXA9 overexpression in myeloid and B progenitor cells leads to significant enhancer reorganizations with prominent emergence of leukemia-specific de novo enhancers. Alterations in the enhancer landscape lead to activation of an ectopic embryonic gene program. We show that HOXA9 functions as a pioneer factor at de novo enhancers and recruits CEBPα and the MLL3/MLL4 complex. Genetic deletion of MLL3/MLL4 blocks histone H3K4 methylation at de novo enhancers and inhibits HOXA9/MEIS1-mediated leukemogenesis in vivo. These results suggest that therapeutic targeting of HOXA9-dependent enhancer reorganization can be an effective therapeutic strategy in acute leukemia with HOXA9 overexpression