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Osborne MJ, Sulekha A, Culjkovic-Kraljacic B, Gasiorek J, Ruediger E, Jolicouer E, Marinier A, Assouline S, Borden KLB. Medicinal Chemistry and NMR Driven Discovery of Novel UDP-glucuronosyltransferase 1A Inhibitors That Overcome Therapeutic Resistance in Cells. J Mol Biol 2024; 436:168378. [PMID: 38043731 PMCID: PMC10841659 DOI: 10.1016/j.jmb.2023.168378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 11/24/2023] [Accepted: 11/28/2023] [Indexed: 12/05/2023]
Abstract
The UDP glucuronosyltransferases (UGT) deactivate many therapeutics via glucuronidation while being required for clearance of normal metabolites and xenobiotics. There are 19 UGT enzymes categorized into UGT1A and UGT2B families based on sequence conservation. This presents a challenge in terms of targeting specific UGTs to overcome drug resistance without eliciting overt toxicity. Here, we identified for the first time that UGT1A4 is highly elevated in acute myeloid leukemia (AML) patients and its reduction corresponded to objective clinical responses. To develop inhibitors to UGT1A4, we leveraged previous NMR-based fragment screening data against the C-terminal domain of UGT1A (UGT1A-C). NMR and medicinal chemistry strategies identified novel chemical matter based on fragment compounds with the capacity to bind ∼20 fold more tightly to UGT1A-C (Kd ∼ 600 μM vs ∼30 μM). Some compounds differentially inhibited UGT1A4 versus UGT1A1 enzyme activity and restored drug sensitivity in resistant human cancer cells. NMR-based NOE experiments revealed these novel compounds recognised a region distal to the catalytic site suggestive of allosteric regulation. This binding region is poorly conserved between UGT1A and UGT2B C-terminal sequences, which otherwise exhibit high similarity. Consistently, these compounds did not bind to the C-terminal domain of UGT2B7 nor a triple mutant of UGT1A-C replaced with UGT2B7 residues in this region. Overall, we discovered a site on UGTs that can be leveraged to differentially target UGT1As and UGT2Bs, identified UGT1A4 as a therapeutic target, and found new chemical matter that binds the UGT1A C-terminus, inhibits glucuronidation and restores drug sensitivity.
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Affiliation(s)
- Michael J Osborne
- Institute for Research in Immunology and Cancer and Department of Pathology and Cell Biology, University of Montreal, Montreal, Quebec, Canada
| | - Anamika Sulekha
- Institute for Research in Immunology and Cancer and Department of Pathology and Cell Biology, University of Montreal, Montreal, Quebec, Canada
| | - Biljana Culjkovic-Kraljacic
- Institute for Research in Immunology and Cancer and Department of Pathology and Cell Biology, University of Montreal, Montreal, Quebec, Canada
| | - Jadwiga Gasiorek
- Institute for Research in Immunology and Cancer and Department of Pathology and Cell Biology, University of Montreal, Montreal, Quebec, Canada
| | - Edward Ruediger
- Drug Discovery Unit, Institute for Research in Immunology and Cancer, University of Montreal, Montreal, Quebec, Canada
| | - Eric Jolicouer
- Drug Discovery Unit, Institute for Research in Immunology and Cancer, University of Montreal, Montreal, Quebec, Canada
| | - Anne Marinier
- Drug Discovery Unit, Institute for Research in Immunology and Cancer, University of Montreal, Montreal, Quebec, Canada
| | - Sarit Assouline
- Jewish General Hospital and McGill University, 3755 Cote Ste Catherine, Montreal, Quebec H3T1E2, Canada
| | - Katherine L B Borden
- Institute for Research in Immunology and Cancer and Department of Pathology and Cell Biology, University of Montreal, Montreal, Quebec, Canada
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