Browsing by Author "Sun, Duxin"

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    Development of 2,5-dihydro-4H-pyrazolo[3,4-d]pyrimidin-4-one inhibitors of Aldehyde Dehydrogenase 1A (ALDH1A) as potential adjuncts to ovarian cancer chemotherapy
    (Elsevier, 2021-02) Huddle, Brandt C.; Grimley, Edward; Chtcherbinine, Mikhail; Buchman, Cameron D.; Takahashi, Cyrus; Debnath, Bikash; McGonigal, Stacy C.; Mao, Shuai; Li, Siwei; Felton, Jeremy; Pan, Shu; Wen, Bo; Sun, Duxin; Neamati, Nouri; Buckanovich, Ronald J.; Hurley, Thomas D.; Larsen, Scott D.; Biochemistry and Molecular Biology, School of Medicine
    There is strong evidence that inhibition of one or more Aldehyde Dehydrogenase 1A (ALDH1A) isoforms may be beneficial in chemotherapy-resistant ovarian cancer and other tumor types. While many previous efforts have focused on development of ALDH1A1 selective inhibitors, the most deadly ovarian cancer subtype, high-grade serous (HGSOC), exhibits elevated expression of ALDH1A3. Herein, we report continued development of pan-ALDH1A inhibitors to assess whether broad spectrum ALDH1A inhibition is an effective adjunct to chemotherapy in this critical tumor subtype. Optimization of the CM39 scaffold, aided by metabolite ID and several new ALDH1A1 crystal structures, led to improved biochemical potencies, improved cellular ALDH inhibition in HGSOC cell lines, and substantial improvements in microsomal stability culminating in orally bioavailable compounds. We demonstrate that two compounds 68 and 69 are able to synergize with chemotherapy in a resistant cell line and patient-derived HGSOC tumor spheroids, indicating their suitability for future in vivo proof of concept experiments.
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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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    Pharmacologic inhibition of the Menin-MLL interaction blocks progression of MLL leukemia in vivo
    (Elsevier, 2015-04-13) Borkin, Dmitry; He, Shihan; Miao, Hongzhi; Kempinska, Katarzyna; Pollock, Jonathan; Chase, Jennifer; Purohit, Trupta; Malik, Bhavna; Zhao, Ting; Wang, Jingya; Wen, Bo; Zong, Hongliang; Jones, Morgan; Danet-Desnoyers, Gwenn; Guzman, Monica L.; Talpaz, Moshe; Bixby, Dale L.; Sun, Duxin; Hess, Jay L.; Muntean, Andrew G.; Maillard, Ivan; Cierpicki, Tomasz; Grembecka, Jolanta; Dean, IU School of Medicine
    Chromosomal translocations affecting mixed lineage leukemia gene (MLL) result in acute leukemias resistant to therapy. The leukemogenic activity of MLL fusion proteins is dependent on their interaction with menin, providing basis for therapeutic intervention. Here we report the development of highly potent and orally bioavailable small-molecule inhibitors of the menin-MLL interaction, MI-463 and MI-503, and show their profound effects in MLL leukemia cells and substantial survival benefit in mouse models of MLL leukemia. Finally, we demonstrate the efficacy of these compounds in primary samples derived from MLL leukemia patients. Overall, we demonstrate that pharmacologic inhibition of the menin-MLL interaction represents an effective treatment for MLL leukemias in vivo and provide advanced molecular scaffold for clinical lead identification.
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    Structure-Based Optimization of a Novel Class of Aldehyde Dehydrogenase 1A (ALDH1A) Subfamily-Selective Inhibitors as Potential Adjuncts to Ovarian Cancer Chemotherapy
    (American Chemical Society, 2018-10-11) Huddle, Brandt C.; Grimley, Edward; Buchman, Cameron D.; Chtcherbinine, Mikhail; Debnath, Bikash; Mehta, Pooja; Yang, Kun; Morgan, Cynthia A.; Li, Siwei; Felton, Jeremy; Sun, Duxin; Mehta, Geeta; Neamati, Nouri; Buckanovich, Ronald J.; Hurley, Thomas D.; Larsen, Scott D.; Biochemistry and Molecular Biology, School of Medicine
    Aldehyde dehydrogenase (ALDH) activity is commonly used as a marker to identify cancer stem-like cells. The three ALDH1A isoforms have all been individually implicated in cancer stem-like cells and in chemoresistance; however, which isoform is preferentially expressed varies between cell lines. We sought to explore the structural determinants of ALDH1A isoform selectivity in a series of small-molecule inhibitors in support of research into the role of ALDH1A in cancer stem cells. An SAR campaign guided by a cocrystal structure of the HTS hit CM39 (7) with ALDH1A1 afforded first-in-class inhibitors of the ALDH1A subfamily with excellent selectivity over the homologous ALDH2 isoform. We also discovered the first reported modestly selective single isoform 1A2 and 1A3 inhibitors. Two compounds, 13g and 13h, depleted the CD133+ putative cancer stem cell pool, synergized with cisplatin, and achieved efficacious concentrations in vivo following IP administration. Compound 13h additionally synergized with cisplatin in a patient-derived ovarian cancer spheroid model.
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    Structure-Based Optimization of a Novel Class of Aldehyde Dehydrogenase 1A (ALDH1A) Subfamily-Selective Inhibitors as Potential Adjuncts to Ovarian Cancer Chemotherapy
    (ACS, 2018-09) Huddle, Brandt C.; Grimley, Edward; Buchman, Cameron D.; Chtcherbinine, Mikhail; Debnath, Bikash; Mehta, Pooja; Yang, Kun; Morgan, Cynthia A.; Li, Siwei; Felton, Jeremy; Sun, Duxin; Mehta, Geeta; Neamati, Nouri; Buckanovich, Ronald J.; Hurley, Thomas D.; Larsen, Scott D.; Biochemistry and Molecular Biology, School of Medicine
    Aldehyde dehydrogenase (ALDH) activity is commonly used as a marker to identify cancer stem-like cells. The three ALDH1A isoforms have all been individually implicated in cancer stem-like cells and in chemoresistance; however, which isoform is preferentially expressed varies between cell lines. We sought to explore the structural determinants of ALDH1A isoform selectivity in a series of small-molecule inhibitors in support of research into the role of ALDH1A in cancer stem cells. An SAR campaign guided by a cocrystal structure of the HTS hit CM39 (7) with ALDH1A1 afforded first-in-class inhibitors of the ALDH1A subfamily with excellent selectivity over the homologous ALDH2 isoform. We also discovered the first reported modestly selective single isoform 1A2 and 1A3 inhibitors. Two compounds, 13g and 13h, depleted the CD133+ putative cancer stem cell pool, synergized with cisplatin, and achieved efficacious concentrations in vivo following IP administration. Compound 13h additionally synergized with cisplatin in a patient-derived ovarian cancer spheroid model.