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Thomas AM, Serafini M, Grant EK, Coombs EAJ, Bluck JP, Schiedel M, McDonough MA, Reynolds JK, Lee B, Platt M, Sharlandjieva V, Biggin PC, Duarte F, Milne TA, Bush JT, Conway SJ. Mutate and Conjugate: A Method to Enable Rapid In-Cell Target Validation. ACS Chem Biol 2023; 18:2405-2417. [PMID: 37874862 PMCID: PMC10660337 DOI: 10.1021/acschembio.3c00437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 09/22/2023] [Accepted: 10/05/2023] [Indexed: 10/26/2023]
Abstract
Target validation remains a challenge in drug discovery, which leads to a high attrition rate in the drug discovery process, particularly in Phase II clinical trials. Consequently, new approaches to enhance target validation are valuable tools to improve the drug discovery process. Here, we report the combination of site-directed mutagenesis and electrophilic fragments to enable the rapid identification of small molecules that selectively inhibit the mutant protein. Using the bromodomain-containing protein BRD4 as an example, we employed a structure-based approach to identify the L94C mutation in the first bromodomain of BRD4 [BRD4(1)] as having a minimal effect on BRD4(1) function. We then screened a focused, KAc mimic-containing fragment set and a diverse fragment library against the mutant and wild-type proteins and identified a series of fragments that showed high selectivity for the mutant protein. These compounds were elaborated to include an alkyne click tag to enable the attachment of a fluorescent dye. These clickable compounds were then assessed in HEK293T cells, transiently expressing BRD4(1)WT or BRD4(1)L94C, to determine their selectivity for BRD4(1)L94C over other possible cellular targets. One compound was identified that shows very high selectivity for BRD4(1)L94C over all other proteins. This work provides a proof-of-concept that the combination of site-directed mutagenesis and electrophilic fragments, in a mutate and conjugate approach, can enable rapid identification of small molecule inhibitors for an appropriately mutated protein of interest. This technology can be used to assess the cellular phenotype of inhibiting the protein of interest, and the electrophilic ligand provides a starting point for noncovalent ligand development.
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Affiliation(s)
- Adam M. Thomas
- Department
of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Marta Serafini
- Department
of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Emma K. Grant
- Department
of Chemical Biology, GSK, Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, United Kingdom
| | - Edward A. J. Coombs
- Department
of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Joseph P. Bluck
- Department
of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
- Department
of Biochemistry, South Parks Road, Oxford OX1 3QU, United Kingdom
| | - Matthias Schiedel
- Department
of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Michael A. McDonough
- Department
of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Jessica K. Reynolds
- Department
of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Bernadette Lee
- Department
of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Michael Platt
- Department
of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Vassilena Sharlandjieva
- MRC
Molecular Haematology Unit, MRC Weatherall Institute of Molecular
Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DS, United
Kingdom
| | - Philip C. Biggin
- Department
of Biochemistry, South Parks Road, Oxford OX1 3QU, United Kingdom
| | - Fernanda Duarte
- Department
of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
| | - Thomas A. Milne
- MRC
Molecular Haematology Unit, MRC Weatherall Institute of Molecular
Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DS, United
Kingdom
| | - Jacob T. Bush
- Department
of Chemical Biology, GSK, Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, United Kingdom
| | - Stuart J. Conway
- Department
of Chemistry, Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, United Kingdom
- Department
of Chemistry & Biochemistry, University
of California Los Angeles, 607 Charles E. Young Drive East, P.O. Box 951569, Los Angeles, California 90095-1569, United States
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Jake Shortt, Galettis P, Cheah CY, Davis J, Ludford-Menting M, Link EK, Martin JH, Koldej R, Ritchie D. A phase 1 clinical trial of the repurposable acetyllysine mimetic, n-methyl-2-pyrrolidone (NMP), in relapsed or refractory multiple myeloma. Clin Epigenetics 2023; 15:15. [PMID: 36709310 PMCID: PMC9884426 DOI: 10.1186/s13148-023-01427-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Accepted: 01/13/2023] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND N-methyl-2-pyrrolidone (NMP) is an epigenetically active chemical fragment and organic solvent with numerous applications including use as a drug-delivery vehicle. Previously considered biologically inert, NMP demonstrates immunomodulatory and anti-myeloma properties that are partly explained by acetyllysine mimetic properties and non-specific bromodomain inhibition. We therefore evaluated orally administered NMP in a phase 1 dose-escalation trial to establish its maximum tolerated dose (MTD) in patients with relapsed/refractory multiple myeloma (RR-MM). Secondary endpoints were safety, pharmacokinetics (PK), overall response rate and immunological biomarkers of activity. RESULTS Thirteen patients received NMP at starting doses between 50 and 400 mg daily. Intra-patient dose escalation occurred in five patients, with one attaining the ceiling protocolised dose of 1 g daily. Median number of monthly cycles commenced was three (range 1-20). Grade 3-4 adverse events (AEs) were reported in seven (54%; 95% CI 25-81%) patients. Most common AEs (> 30% of patients) of any grade were nausea and musculoskeletal pain. The only dose limiting toxicity (DLT) was diarrhoea in a patient receiving 200 mg NMP (overall DLT rate 8%; 95% CI 0-36%). Hence, the MTD was not defined. Median progression-free and overall survival were 57 (range 29-539) days and 33 (95% CI 9.7- > 44) months, respectively. The best response of stable disease (SD) was achieved in nine patients (69%; 95% CI 39-91%). PK analysis demonstrated proportional dose-concentrations up to 400 mg daily, with a more linear relationship above 500 mg. Maximum plasma concentrations (Cmax) of 16.7 mg/L at the 800 mg dose were below those predicted to inhibit BET-bromodomains. Peripheral blood immune-profiling demonstrated maintenance of natural killer (NK) cells, and a gene expression signature suggestive of enhanced T, B and NK cell functions; a subject with prolonged exposure manifested sustained recovery of B and NK cells at 12 months. CONCLUSIONS NMP demonstrated potential disease stabilising and immunomodulatory activity at sub-BET inhibitory plasma concentrations and was well tolerated in RR-MM; an MTD was not determined up to a maximum dose of 1 g daily. Further dose-finding studies are required to optimise NMP dosing strategies for therapeutic intervention.
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Affiliation(s)
- Jake Shortt
- grid.1002.30000 0004 1936 7857Blood Cancer Therapeutics Laboratory, Department of Medicine, School of Clinical Sciences at Monash Health, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, VIC Australia ,grid.419789.a0000 0000 9295 3933Monash Haematology, Monash Health, Clayton, VIC Australia ,grid.1008.90000 0001 2179 088XSir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC Australia
| | - Peter Galettis
- grid.266842.c0000 0000 8831 109XCentre for Drug Repurposing and Medicines Research, University of Newcastle, Callaghan, NSW Australia ,grid.413648.cHunter Medical Research Institute, Kookaburra Circuit, New Lambton Heights, NSW Australia
| | - Chan Y. Cheah
- grid.3521.50000 0004 0437 5942Department of Haematology, Sir Charles Gairdner Hospital, Perth, WA Australia ,grid.1012.20000 0004 1936 7910Division of Internal Medicine, Medical School, University of Western Australia, Perth, WA Australia
| | - Joanne Davis
- grid.416153.40000 0004 0624 1200ACRF Translational Research Laboratory, Royal Melbourne Hospital, Melbourne, VIC Australia ,grid.1008.90000 0001 2179 088XDepartment of Medicine, University of Melbourne, Melbourne, VIC Australia
| | - Mandy Ludford-Menting
- grid.416153.40000 0004 0624 1200ACRF Translational Research Laboratory, Royal Melbourne Hospital, Melbourne, VIC Australia ,grid.1008.90000 0001 2179 088XDepartment of Medicine, University of Melbourne, Melbourne, VIC Australia
| | - Emma K. Link
- grid.1008.90000 0001 2179 088XSir Peter MacCallum Department of Oncology, University of Melbourne, Parkville, VIC Australia ,grid.1055.10000000403978434Centre for Biostatistics and Clinical Trials, Peter MacCallum Cancer Centre, Melbourne, VIC Australia
| | - Jennifer H. Martin
- grid.266842.c0000 0000 8831 109XCentre for Drug Repurposing and Medicines Research, University of Newcastle, Callaghan, NSW Australia ,grid.413648.cHunter Medical Research Institute, Kookaburra Circuit, New Lambton Heights, NSW Australia
| | - Rachel Koldej
- grid.416153.40000 0004 0624 1200ACRF Translational Research Laboratory, Royal Melbourne Hospital, Melbourne, VIC Australia ,grid.1008.90000 0001 2179 088XDepartment of Medicine, University of Melbourne, Melbourne, VIC Australia
| | - David Ritchie
- grid.416153.40000 0004 0624 1200ACRF Translational Research Laboratory, Royal Melbourne Hospital, Melbourne, VIC Australia ,grid.1008.90000 0001 2179 088XDepartment of Medicine, University of Melbourne, Melbourne, VIC Australia ,grid.1055.10000000403978434Clinical Haematology, Peter MacCallum Cancer Centre and Royal Melbourne Hospital, Melbourne, VIC Australia
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Vaidergorn MM, da Silva Emery F, Ganesan A. From Hit Seeking to Magic Bullets: The Successful Union of Epigenetic and Fragment Based Drug Discovery (EPIDD + FBDD). J Med Chem 2021; 64:13980-14010. [PMID: 34591474 DOI: 10.1021/acs.jmedchem.1c00787] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
We review progress in the application of fragment-based drug discovery (FBDD) to epigenetic drug discovery (EPIDD) targeted at epigenetic writer and eraser enzymes as well as reader domains over the last 15 years. The greatest successes to date are in prospecting for bromodomain binding ligands. From a diverse array of fragment hits, multiple potent and selective compounds ensued, including the oncology clinical candidates mivebresib, ABBV-744, pelabresib, and PLX51107.
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Affiliation(s)
- Miguel M Vaidergorn
- School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo 14040-903, Brazil
| | - Flavio da Silva Emery
- School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo 14040-903, Brazil
| | - A Ganesan
- School of Pharmacy, University of East Anglia, Norwich NR4 7TJ, United Kingdom
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Guest EE, Pickett SD, Hirst JD. Structural variation of protein-ligand complexes of the first bromodomain of BRD4. Org Biomol Chem 2021; 19:5632-5641. [PMID: 34105560 DOI: 10.1039/d1ob00658d] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The bromodomain-containing protein 4 (BRD4), a member of the bromodomain and extra-terminal domain (BET) family, plays a key role in several diseases, especially cancers. With increased interest in BRD4 as a therapeutic target, many X-ray crystal structures of the protein in complex with small molecule inhibitors are publicly available over the recent decade. In this study, we use this structural information to investigate the conformations of the first bromodomain (BD1) of BRD4. Structural alignment of 297 BRD4-BD1 complexes shows a high level of similarity between the structures of BRD4-BD1, regardless of the bound ligand. We employ WONKA, a tool for detailed analyses of protein binding sites, to compare the active site of over 100 of these crystal structures. The positions of key binding site residues show a high level of conformational similarity, with the exception of Trp81. A focused analysis on the highly conserved water network in the binding site of BRD4-BD1 is performed to identify the positions of these water molecules across the crystal structures. The importance of the water network is illustrated using molecular docking and absolute free energy perturbation simulations. 82% of the ligand poses were better predicted when including water molecules as part of the receptor. Our analysis provides guidance for the design of new BRD4-BD1 inhibitors and the selection of the best structure of BRD4-BD1 to use in structure-based drug design, an important approach for faster and more cost-efficient lead discovery.
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Affiliation(s)
- Ellen E Guest
- School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, UK.
| | - Stephen D Pickett
- GlaxoSmithKline R&D Pharmaceuticals, Computational Chemistry, Stevenage, UK
| | - Jonathan D Hirst
- School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, UK.
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5
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Yang Y, Chen P, Zhao L, Zhang B, Xu C, Zhang H, Zhou J. Design, synthesis and biological evaluation of imidazolopyridone derivatives as novel BRD4 inhibitors. Bioorg Med Chem 2020; 29:115857. [PMID: 33191086 DOI: 10.1016/j.bmc.2020.115857] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Revised: 10/27/2020] [Accepted: 11/01/2020] [Indexed: 11/17/2022]
Abstract
Bromodomain containing protein 4 (BRD4) has been demonstrated to play critical roles in cellular proliferation and cell cycle progression. In this study, using the BRD4 inhibitor Fragment 9 as a lead compound, a series of imidazolopyridone derivatives were designed and tested for their inhibitory activity against BRD4 protein in vitro. Among them, HB100-A7 showed excellent BRD4(1) inhibitory activities with an IC50 value of 0.035 μM in amplified luminescent proximity homogeneous assay (Alphascreen). The result of MTT assay showed that HB100-A7 could suppress the proliferation of pancreatic cancer cells. In addition, flow cytometry further illustrated that HB100-A7 treatment resulted in G0/G1 phase arrest and promoted apoptosis of BxPc3 cells. Furthermore, the in vivo study found that HB100-A7 displayed significant tumor growth inhibition in a pancreatic mouse tumor model (Panc-02). Moreover, IHC staining suggested that HB100-A7 induce cell apoptosis in pancreatic cancer tumor tissue. Together, this study revealed, for the first time, HB100-A7 is a promising lead compound for further development as a new generation of small molecule inhibitors targeting the BRD4 protein.
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Affiliation(s)
- Yifei Yang
- Department of Medicinal Chemistry, China Pharmaceutical University, Nanjing 210009, PR China
| | - Pan Chen
- Department of Medicinal Chemistry, China Pharmaceutical University, Nanjing 210009, PR China
| | - Leilei Zhao
- Center of Drug Discovery, Jiangsu Key Laboratory of Drug Discovery for Metabolic Disease, China Pharmaceutical University, Nanjing 210009, PR China
| | - Bing Zhang
- Center of Drug Discovery, Jiangsu Key Laboratory of Drug Discovery for Metabolic Disease, China Pharmaceutical University, Nanjing 210009, PR China
| | - Changliang Xu
- Jiangsu Collaborative Innovation Center of Traditional Chinese Medicine Prevention and Treatment of Tumor, Nanjing University of Chinese Medicine, Nanjing, Jiangsu 210023, PR China.
| | - Huibin Zhang
- Center of Drug Discovery, Jiangsu Key Laboratory of Drug Discovery for Metabolic Disease, China Pharmaceutical University, Nanjing 210009, PR China.
| | - Jinpei Zhou
- Department of Medicinal Chemistry, China Pharmaceutical University, Nanjing 210009, PR China.
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Prieto-Martínez FD, Medina-Franco JL. Current advances on the development of BET inhibitors: insights from computational methods. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2020; 122:127-180. [PMID: 32951810 DOI: 10.1016/bs.apcsb.2020.06.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Epigenetics was coined almost 70 years ago for the description of heritable phenotype without altering DNA sequences. Research on the field has uncovered significant roles of such mechanisms, that account for the biogenesis of several diseases. Further studies have led the way for drug development which targets epi-enzymes, mainly for cancer treatment. Of the numerous epi-targets involved with histone acetylation, bromodomains have captured the spotlight of drug discovery focused on novel therapies. However, due to high sequence identity, the development of potent and selective inhibitors poses a significant challenge. Herein, we discuss recent computational developments on BET inhibitors and other methods that may be applied for drug discovery in general. As a proof-of-concept, we discuss a virtual screening to identify novel BET inhibitors based on coumarin derivatives. From public data, we identified putative structure-activity relationships of coumarin scaffold and propose R-group modifications for BET selectivity. Results showed that the optimization and design of novel coumarins could be further explored.
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Affiliation(s)
- Fernando D Prieto-Martínez
- Department of Pharmacy, School of Chemistry, National Autonomous University of Mexico, Mexico City, Mexico
| | - José L Medina-Franco
- Department of Pharmacy, School of Chemistry, National Autonomous University of Mexico, Mexico City, Mexico
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7
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Substituted 1-methyl-4-phenylpyrrolidin-2-ones – Fragment-based design of N-methylpyrrolidone-derived bromodomain inhibitors. Eur J Med Chem 2020; 191:112120. [DOI: 10.1016/j.ejmech.2020.112120] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 01/16/2020] [Accepted: 02/03/2020] [Indexed: 01/12/2023]
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