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Nair PC, Piehler J, Tvorogov D, Ross DM, Lopez AF, Gotlib J, Thomas D. Next-Generation JAK2 Inhibitors for the Treatment of Myeloproliferative Neoplasms: Lessons from Structure-Based Drug Discovery Approaches. Blood Cancer Discov 2023; 4:352-364. [PMID: 37498362 PMCID: PMC10472187 DOI: 10.1158/2643-3230.bcd-22-0189] [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: 12/04/2022] [Revised: 04/20/2023] [Accepted: 06/07/2023] [Indexed: 07/28/2023] Open
Abstract
Selective inhibitors of Janus kinase (JAK) 2 have been in demand since the discovery of the JAK2 V617F mutation present in patients with myeloproliferative neoplasms (MPN); however, the structural basis of V617F oncogenicity has only recently been elucidated. New structural studies reveal a role for other JAK2 domains, beyond the kinase domain, that contribute to pathogenic signaling. Here we evaluate the structure-based approaches that led to recently-approved type I JAK2 inhibitors (fedratinib and pacritinib), as well as type II (BBT594 and CHZ868) and pseudokinase inhibitors under development (JNJ7706621). With full-length JAK homodimeric structures now available, superior selective and mutation-specific JAK2 inhibitors are foreseeable. SIGNIFICANCE The JAK inhibitors currently used for the treatment of MPNs are effective for symptom management but not for disease eradication, primarily because they are not strongly selective for the mutant clone. The rise of computational and structure-based drug discovery approaches together with the knowledge of full-length JAK dimer complexes provides a unique opportunity to develop better targeted therapies for a range of conditions driven by pathologic JAK2 signaling.
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Affiliation(s)
- Pramod C. Nair
- Cancer Program, South Australian Health and Medical Research Institute (SAHMRI), University of Adelaide, Adelaide, Australia
- Discipline of Medicine, Adelaide Medical School, The University of Adelaide, Adelaide, Australia
- Discipline of Clinical Pharmacology, Flinders Health and Medical Research Institute (FHMRI) Cancer Program, College of Medicine and Public Health, Flinders University, Adelaide, Australia
| | - Jacob Piehler
- Department of Biology and Center of Cellular Nanoanalytics, University of Osnabrück, Osnabrück, Germany
| | - Denis Tvorogov
- Centre for Cancer Biology, University of South Australia and SA Pathology, Adelaide, Australia
| | - David M. Ross
- Cancer Program, South Australian Health and Medical Research Institute (SAHMRI), University of Adelaide, Adelaide, Australia
- Discipline of Medicine, Adelaide Medical School, The University of Adelaide, Adelaide, Australia
- Centre for Cancer Biology, University of South Australia and SA Pathology, Adelaide, Australia
- Department of Hematology and Bone Marrow Transplantation, Royal Adelaide Hospital, Adelaide, South Australia, Australia
| | - Angel F. Lopez
- Centre for Cancer Biology, University of South Australia and SA Pathology, Adelaide, Australia
| | - Jason Gotlib
- Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California
| | - Daniel Thomas
- Cancer Program, South Australian Health and Medical Research Institute (SAHMRI), University of Adelaide, Adelaide, Australia
- Discipline of Medicine, Adelaide Medical School, The University of Adelaide, Adelaide, Australia
- Department of Hematology and Bone Marrow Transplantation, Royal Adelaide Hospital, Adelaide, South Australia, Australia
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Henry SP, Jorgensen WL. Progress on the Pharmacological Targeting of Janus Pseudokinases. J Med Chem 2023; 66:10959-10990. [PMID: 37578217 DOI: 10.1021/acs.jmedchem.3c00926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
The Janus kinases (JAKs) are key components of the JAK-STAT signaling pathway and are involved in myriad physiological processes. Though they are the molecular targets of many FDA-approved drugs, these drugs manifest adverse effects due in part to their inhibition of the requisite JAK kinase activity. However, the JAKs uniquely possess an integrated pseudokinase domain (JH2) that regulates the adjacent kinase domain (JH1). The therapeutic targeting of JH2 domains has been less thoroughly explored and may present an avenue to modulate the JAKs without the adverse effects associated with targeting the adjacent JH1 domain. The potential of this strategy was recently demonstrated with the FDA approval of the TYK2 JH2 ligand deucravacitinib for treating plaque psoriasis. In this light, the structure and targetability of the JAK pseudokinases are discussed, in conjunction with the state of development of ligands that bind to these domains.
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Affiliation(s)
- Sean P Henry
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - William L Jorgensen
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
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3
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Identification of Novel Small Molecule Ligands for JAK2 Pseudokinase Domain. Pharmaceuticals (Basel) 2023; 16:ph16010075. [PMID: 36678572 PMCID: PMC9865020 DOI: 10.3390/ph16010075] [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: 12/01/2022] [Revised: 12/22/2022] [Accepted: 12/29/2022] [Indexed: 01/05/2023] Open
Abstract
Hyperactive mutation V617F in the JAK2 regulatory pseudokinase domain (JH2) is prevalent in patients with myeloproliferative neoplasms. Here, we identified novel small molecules that target JH2 of JAK2 V617F and characterized binding via biochemical and structural approaches. Screening of 107,600 small molecules resulted in identification of 55 binders to the ATP-binding pocket of recombinant JAK2 JH2 V617F protein at a low hit rate of 0.05%, which indicates unique structural characteristics of the JAK2 JH2 ATP-binding pocket. Selected hits and structural analogs were further assessed for binding to JH2 and JH1 (kinase) domains of JAK family members (JAK1-3, TYK2) and for effects on MPN model cell viability. Crystal structures were determined with JAK2 JH2 wild-type and V617F. The JH2-selective binders were identified in diaminotriazole, diaminotriazine, and phenylpyrazolo-pyrimidone chemical entities, but they showed low-affinity, and no inhibition of MPN cells was detected, while compounds binding to both JAK2 JH1 and JH2 domains inhibited MPN cell viability. X-ray crystal structures of protein-ligand complexes indicated generally similar binding modes between the ligands and V617F or wild-type JAK2. Ligands of JAK2 JH2 V617F are applicable as probes in JAK-STAT research, and SAR optimization combined with structural insights may yield higher-affinity inhibitors with biological activity.
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Henry SP, Liosi ME, Ippolito JA, Menges F, Newton AS, Schlessinger J, Jorgensen WL. Covalent Modification of the JH2 Domain of Janus Kinase 2. ACS Med Chem Lett 2022; 13:1819-1826. [PMID: 36385940 PMCID: PMC9661697 DOI: 10.1021/acsmedchemlett.2c00414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 10/18/2022] [Indexed: 11/28/2022] Open
Abstract
Probe molecules that covalently modify the JAK2 pseudokinase domain (JH2) are reported. Selective targeting of JH2 domains over the kinase (JH1) domains is a necessary feature for ligands intended to evaluate JH2 domains as therapeutic targets. The JH2 domains of three Janus kinases (JAK1, JAK2, and TYK2) possess a cysteine residue in the catalytic loop that does not occur in their JH1 domains. Starting from a non-selective kinase binding molecule, computer-aided design directed attachment of substituents terminating in acrylamide warheads to modify Cys675 of JAK2 JH2. Successful covalent attachment was demonstrated first through observation of enhanced binding with increasing incubation time in fluorescence polarization experiments. Covalent binding also increased selectivity to as much as ca. 30-fold for binding the JAK2 JH2 domain over the JH1 domain after a 20-h incubation. Covalency was confirmed through HPLC electrospray quadrupole time-of-flight HRMS experiments, which revealed the expected mass shifts.
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Affiliation(s)
- Sean P. Henry
- Department
of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Maria-Elena Liosi
- Department
of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Joseph A. Ippolito
- Department
of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Fabian Menges
- Department
of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Ana S. Newton
- Department
of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Joseph Schlessinger
- Department
of Pharmacology, Yale University School
of Medicine, New Haven, Connecticut 06520-8066, United States
| | - William L. Jorgensen
- Department
of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
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5
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Patel LA, Chau P, Debesai S, Darwin L, Neale C. Drug Discovery by Automated Adaptation of Chemical Structure and Identity. J Chem Theory Comput 2022; 18:5006-5024. [PMID: 35834740 DOI: 10.1021/acs.jctc.1c01271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Computer-aided drug design offers the potential to dramatically reduce the cost and effort required for drug discovery. While screening-based methods are valuable in the early stages of hit identification, they are frequently succeeded by iterative, hypothesis-driven computations that require recurrent investment of human time and intuition. To increase automation, we introduce a computational method for lead refinement that combines concerted dynamics of the ligand/protein complex via molecular dynamics simulations with integrated Monte Carlo-based changes in the chemical formula of the ligand. This approach, which we refer to as ligand-exchange Monte Carlo molecular dynamics, accounts for solvent- and entropy-based contributions to competitive binding free energies by coupling the energetics of bound and unbound states during the ligand-exchange attempt. Quantitative comparison of relative binding free energies to reference values from free energy perturbation, conducted in vacuum, indicates that ligand-exchange Monte Carlo molecular dynamics simulations sample relevant conformational ensembles and are capable of identifying strongly binding compounds. Additional simulations demonstrate the use of an implicit solvent model. We speculate that the use of chemical graphs in which exchanges are only permitted between ligands with sufficient similarity may enable an automated search to capture some of the benefits provided by human intuition during hypothesis-guided lead refinement.
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Liosi ME, Ippolito JA, Henry SP, Krimmer SG, Newton AS, Cutrona KJ, Olivarez RA, Mohanty J, Schlessinger J, Jorgensen WL. Insights on JAK2 Modulation by Potent, Selective, and Cell-Permeable Pseudokinase-Domain Ligands. J Med Chem 2022; 65:8380-8400. [PMID: 35653642 PMCID: PMC9939005 DOI: 10.1021/acs.jmedchem.2c00283] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
JAK2 is a non-receptor tyrosine kinase that regulates hematopoiesis through the JAK-STAT pathway. The pseudokinase domain (JH2) is an important regulator of the activity of the kinase domain (JH1). V617F mutation in JH2 has been associated with the pathogenesis of various myeloproliferative neoplasms, but JAK2 JH2 has been poorly explored as a pharmacological target. In light of this, we aimed to develop JAK2 JH2 binders that could selectively target JH2 over JH1 and test their capacity to modulate JAK2 activity in cells. Toward this goal, we optimized a diaminotriazole lead compound into potent, selective, and cell-permeable JH2 binders leveraging computational design, synthesis, binding affinity measurements for the JH1, JH2 WT, and JH2 V617F domains, permeability measurements, crystallography, and cell assays. Optimized diaminotriazoles are capable of inhibiting STAT5 phosphorylation in both WT and V617F JAK2 in cells.
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Affiliation(s)
- Maria-Elena Liosi
- Department of Chemistry, Yale University, New Haven, CT 06520-8107, USA
| | | | - Sean P. Henry
- Department of Chemistry, Yale University, New Haven, CT 06520-8107, USA
| | - Stefan G. Krimmer
- Department of Chemistry, Yale University, New Haven, CT 06520-8107, USA,Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520-8066, USA
| | - Ana S. Newton
- Department of Chemistry, Yale University, New Haven, CT 06520-8107, USA
| | - Kara J. Cutrona
- Department of Chemistry, Yale University, New Haven, CT 06520-8107, USA
| | - Rene A. Olivarez
- Department of Chemistry, Yale University, New Haven, CT 06520-8107, USA
| | - Jyotidarsini Mohanty
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520-8066, USA
| | - Joseph Schlessinger
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520-8066, USA
| | - William L. Jorgensen
- Department of Chemistry, Yale University, New Haven, CT 06520-8107, USA,Corresponding author. William L. Jorgensen.
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Henry SP, Liosi ME, Ippolito JA, Cutrona KJ, Krimmer SG, Newton AS, Schlessinger J, Jorgensen WL. Conversion of a False Virtual Screen Hit into Selective JAK2 JH2 Domain Binders Using Convergent Design Strategies. ACS Med Chem Lett 2022; 13:819-826. [PMID: 35586418 PMCID: PMC9109162 DOI: 10.1021/acsmedchemlett.2c00051] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 04/19/2022] [Indexed: 12/12/2022] Open
Abstract
The Janus kinase 2 (JAK2) pseudokinase domain (JH2) is an ATP-binding domain that regulates the activity of the catalytic tyrosine kinase domain (JH1). Dysregulation of JAK2 JH1 signaling caused by the V617F mutation in JH2 is implicated in various myeloproliferative neoplasms. To explore if JAK2 activity can be modulated by a small molecule binding to the ATP site in JH2, we have developed several ligand series aimed at selectively targeting the JAK2 JH2 domain. We report here the evolution of a false virtual screen hit into a new JAK2 JH2 series. Optimization guided by computational modeling has yielded analogues with nanomolar affinity for the JAK2 JH2 domain and >100-fold selectivity for the JH2 domain over the JH1 domain. A crystal structure for one of the potent compounds bound to JAK2 JH2 clarifies the origins of the strong binding and selectivity. The compounds expand the platform for seeking molecules to regulate JAK2 signaling, including V617F JAK2 hyperactivation.
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Affiliation(s)
- Sean P. Henry
- Department
of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Maria-Elena Liosi
- Department
of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Joseph A. Ippolito
- Department
of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Kara J. Cutrona
- Department
of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Stefan G. Krimmer
- Department
of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States,Department
of Pharmacology, Yale University School
of Medicine, New Haven, Connecticut 06520-8066, United States
| | - Ana S. Newton
- Department
of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States
| | - Joseph Schlessinger
- Department
of Pharmacology, Yale University School
of Medicine, New Haven, Connecticut 06520-8066, United States
| | - William L. Jorgensen
- Department
of Chemistry, Yale University, New Haven, Connecticut 06520-8107, United States,
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