1
|
Tashkandi H, Younes IE. Advances in Molecular Understanding of Polycythemia Vera, Essential Thrombocythemia, and Primary Myelofibrosis: Towards Precision Medicine. Cancers (Basel) 2024; 16:1679. [PMID: 38730632 PMCID: PMC11083661 DOI: 10.3390/cancers16091679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Revised: 04/22/2024] [Accepted: 04/23/2024] [Indexed: 05/13/2024] Open
Abstract
Myeloproliferative neoplasms (MPNs), including Polycythemia Vera (PV), Essential Thrombocythemia (ET), and Primary Myelofibrosis (PMF), are characterized by the clonal proliferation of hematopoietic stem cells leading to an overproduction of hematopoietic cells. The last two decades have seen significant advances in our understanding of the molecular pathogenesis of these diseases, with the discovery of key mutations in the JAK2, CALR, and MPL genes being pivotal. This review provides a comprehensive update on the molecular landscape of PV, ET, and PMF, highlighting the diagnostic, prognostic, and therapeutic implications of these genetic findings. We delve into the challenges of diagnosing and treating patients with prognostic mutations, clonal evolution, and the impact of emerging technologies like next-generation sequencing and single-cell genomics on the field. The future of MPN management lies in leveraging these molecular insights to develop personalized treatment strategies, aiming for precision medicine that optimizes outcomes for patients. This article synthesizes current knowledge on molecular diagnostics in MPNs, underscoring the critical role of genetic profiling in enhancing patient care and pointing towards future research directions that promise to further refine our approach to these complex disorders.
Collapse
Affiliation(s)
- Hammad Tashkandi
- Department of Pathology and Laboratory Medicine, Moffitt Cancer Center, Tampa, FL 33612, USA
| | - Ismail Elbaz Younes
- Department of Laboratory Medicine and Pathology, Division of Hematopathology, University of Minnesota, Minneapolis, MN 55455, USA;
| |
Collapse
|
2
|
Targeting Pim kinases in hematological cancers: molecular and clinical review. Mol Cancer 2023; 22:18. [PMID: 36694243 PMCID: PMC9875428 DOI: 10.1186/s12943-023-01721-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 01/13/2023] [Indexed: 01/26/2023] Open
Abstract
Decades of research has recognized a solid role for Pim kinases in lymphoproliferative disorders. Often up-regulated following JAK/STAT and tyrosine kinase receptor signaling, Pim kinases regulate cell proliferation, survival, metabolism, cellular trafficking and signaling. Targeting Pim kinases represents an interesting approach since knock-down of Pim kinases leads to non-fatal phenotypes in vivo suggesting clinical inhibition of Pim may have less side effects. In addition, the ATP binding site offers unique characteristics that can be used for the development of small inhibitors targeting one or all Pim isoforms. This review takes a closer look at Pim kinase expression and involvement in hematopoietic cancers. Current and past clinical trials and in vitro characterization of Pim kinase inhibitors are examined and future directions are discussed. Current studies suggest that Pim kinase inhibition may be most valuable when accompanied by multi-drug targeting therapy.
Collapse
|
3
|
Downes CEJ, McClure BJ, McDougal DP, Heatley SL, Bruning JB, Thomas D, Yeung DT, White DL. JAK2 Alterations in Acute Lymphoblastic Leukemia: Molecular Insights for Superior Precision Medicine Strategies. Front Cell Dev Biol 2022; 10:942053. [PMID: 35903543 PMCID: PMC9315936 DOI: 10.3389/fcell.2022.942053] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 06/16/2022] [Indexed: 11/13/2022] Open
Abstract
Acute lymphoblastic leukemia (ALL) is the most common pediatric cancer, arising from immature lymphocytes that show uncontrolled proliferation and arrested differentiation. Genomic alterations affecting Janus kinase 2 (JAK2) correlate with some of the poorest outcomes within the Philadelphia-like subtype of ALL. Given the success of kinase inhibitors in the treatment of chronic myeloid leukemia, the discovery of activating JAK2 point mutations and JAK2 fusion genes in ALL, was a breakthrough for potential targeted therapies. However, the molecular mechanisms by which these alterations activate JAK2 and promote downstream signaling is poorly understood. Furthermore, as clinical data regarding the limitations of approved JAK inhibitors in myeloproliferative disorders matures, there is a growing awareness of the need for alternative precision medicine approaches for specific JAK2 lesions. This review focuses on the molecular mechanisms behind ALL-associated JAK2 mutations and JAK2 fusion genes, known and potential causes of JAK-inhibitor resistance, and how JAK2 alterations could be targeted using alternative and novel rationally designed therapies to guide precision medicine approaches for these high-risk subtypes of ALL.
Collapse
Affiliation(s)
- Charlotte EJ. Downes
- Blood Cancer Program, Precision Cancer Medicine Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
- School of Biological Sciences, Faculty of Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Barbara J. McClure
- Blood Cancer Program, Precision Cancer Medicine Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
- Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Daniel P. McDougal
- School of Biological Sciences, Faculty of Sciences, University of Adelaide, Adelaide, SA, Australia
- Institute for Photonics and Advanced Sensing (IPAS), University of Adelaide, Adelaide, SA, Australia
| | - Susan L. Heatley
- Blood Cancer Program, Precision Cancer Medicine Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
- Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA, Australia
- Australian and New Zealand Children’s Oncology Group (ANZCHOG), Clayton, VIC, Australia
| | - John B. Bruning
- School of Biological Sciences, Faculty of Sciences, University of Adelaide, Adelaide, SA, Australia
- Institute for Photonics and Advanced Sensing (IPAS), University of Adelaide, Adelaide, SA, Australia
| | - Daniel Thomas
- Blood Cancer Program, Precision Cancer Medicine Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
- Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA, Australia
| | - David T. Yeung
- Blood Cancer Program, Precision Cancer Medicine Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
- Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA, Australia
- Department of Haematology, Royal Adelaide Hospital and SA Pathology, Adelaide, SA, Australia
| | - Deborah L. White
- Blood Cancer Program, Precision Cancer Medicine Theme, South Australian Health and Medical Research Institute (SAHMRI), Adelaide, SA, Australia
- School of Biological Sciences, Faculty of Sciences, University of Adelaide, Adelaide, SA, Australia
- Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA, Australia
- Australian and New Zealand Children’s Oncology Group (ANZCHOG), Clayton, VIC, Australia
| |
Collapse
|
4
|
Bochicchio MT, Di Battista V, Poggio P, Carrà G, Morotti A, Brancaccio M, Lucchesi A. Understanding Aberrant Signaling to Elude Therapy Escape Mechanisms in Myeloproliferative Neoplasms. Cancers (Basel) 2022; 14:cancers14040972. [PMID: 35205715 PMCID: PMC8870427 DOI: 10.3390/cancers14040972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 02/08/2022] [Accepted: 02/10/2022] [Indexed: 02/01/2023] Open
Abstract
Aberrant signaling in myeloproliferative neoplasms may arise from alterations in genes coding for signal transduction proteins or epigenetic regulators. Both mutated and normal cells cooperate, altering fragile balances in bone marrow niches and fueling persistent inflammation through paracrine or systemic signals. Despite the hopes placed in targeted therapies, myeloid proliferative neoplasms remain incurable diseases in patients not eligible for stem cell transplantation. Due to the emergence of drug resistance, patient management is often very difficult in the long term. Unexpected connections among signal transduction pathways highlighted in neoplastic cells suggest new strategies to overcome neoplastic cell adaptation.
Collapse
Affiliation(s)
- Maria Teresa Bochicchio
- Biosciences Laboratory, IRCCS Istituto Scientifico Romagnolo per lo Studio dei Tumori (IRST) “Dino Amadori”, 47014 Meldola, Italy;
| | - Valeria Di Battista
- Hematology Unit, IRCCS Istituto Scientifico Romagnolo per lo Studio dei Tumori (IRST) “Dino Amadori”, 47014 Meldola, Italy;
| | - Pietro Poggio
- Department of Molecular Biotechnology and Health Sciences, University of Torino, 10126 Torino, Italy;
| | - Giovanna Carrà
- Department of Clinical and Biological Sciences, University of Torino, 10043 Orbassano, Italy;
| | - Alessandro Morotti
- Department of Clinical and Biological Sciences, University of Torino, 10043 Orbassano, Italy;
- Correspondence: (A.M.); (M.B.); (A.L.)
| | - Mara Brancaccio
- Department of Molecular Biotechnology and Health Sciences, University of Torino, 10126 Torino, Italy;
- Correspondence: (A.M.); (M.B.); (A.L.)
| | - Alessandro Lucchesi
- Hematology Unit, IRCCS Istituto Scientifico Romagnolo per lo Studio dei Tumori (IRST) “Dino Amadori”, 47014 Meldola, Italy;
- Correspondence: (A.M.); (M.B.); (A.L.)
| |
Collapse
|
5
|
Defining the landscape of ATP-competitive inhibitor resistance residues in protein kinases. Nat Struct Mol Biol 2020; 27:92-104. [PMID: 31925410 DOI: 10.1038/s41594-019-0358-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 11/27/2019] [Indexed: 02/07/2023]
Abstract
Kinases are involved in disease development and modulation of their activity can be therapeutically beneficial. Drug-resistant mutant kinases are valuable tools in drug discovery efforts, but the prediction of mutants across the kinome is challenging. Here, we generate deep mutational scanning data to identify mutant mammalian kinases that drive resistance to clinically relevant inhibitors. We aggregate these data with subsaturation mutagenesis data and use it to develop, test and validate a framework to prospectively identify residues that mediate kinase activity and drug resistance across the kinome. We validate predicted resistance mutations in CDK4, CDK6, ERK2, EGFR and HER2. Capitalizing on a highly predictable residue, we generate resistance mutations in TBK1, CSNK2A1 and BRAF. Unexpectedly, we uncover a potentially generalizable activation site that mediates drug resistance and confirm its impact in BRAF, EGFR, HER2 and MEK1. We anticipate that the identification of these residues will enable the broad interrogation of the kinome and its inhibitors.
Collapse
|
6
|
SOHO State of the Art Updates and Next Questions: Myelofibrosis. CLINICAL LYMPHOMA MYELOMA & LEUKEMIA 2019; 19:191-199. [PMID: 30987952 DOI: 10.1016/j.clml.2019.03.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 03/12/2019] [Indexed: 01/09/2023]
Abstract
The discovery of a mutation in the Janus Kinase 2 gene in 2005 spurred significant progress in the field of myeloproliferative neoplasms. A comprehensive description of genomic factors at play in the malignant clone in myeloproliferative neoplasms, particularly myelofibrosis (MF), have recently led to more precise, personalized prognostic tools. Despite this, understanding of the disease pathogenesis remains relatively limited. We continue to lack a detailed description of the interaction between the hematopoietic stem cell clone, abnormal bone marrow niche cells, and circulating signaling molecules and an understanding of how they cooperate to promote cell proliferation, fibrogenesis, and extramedullary hematopoiesis. Despite our knowledge gaps, recent research in MF has led to promising clinical translation. In this article, we summarize recent insights into MF pathophysiology, progress in the development of novel therapeutics, and opportunities for further advancement of the field.
Collapse
|
7
|
Abstract
PURPOSE OF REVIEW The purpose of the review was to provide a contemporary update of novel agents and targets under investigation in myelofibrosis in the Janus kinase (JAK) inhibitor era. RECENT FINDINGS Myelofibrosis (MF) is a clonal stem cell disease characterized by marrow fibrosis and a heterogeneous disease phenotype with a variable degree of splenomegaly, cytopenias, and constitutional symptoms that significantly impact quality of life and survival. Overactive JAK/STAT signaling is a hallmark of MF. The only approved therapy for MF, JAK1/2 inhibitor ruxolitinib, can ameliorate splenomegaly, improve symptoms, and prolong survival in some patients. Therapeutic challenges remain, however. Myelosuppression limits the use of ruxolitinib in some patients, eventual drug resistance is common, and the underlying malignant clone persists despite therapy. A deeper understanding of the pathogenesis of MF has informed the development of additional agents. Promising targets under investigation include JAK1 and JAK2 and downstream intermediates in related signaling pathways, epigenetic modifiers, pro-inflammatory cytokines, and immune regulators.
Collapse
Affiliation(s)
- Kristen Pettit
- Section of Hematology/Oncology, Department of Medicine, The University of Chicago, 5841 S. Maryland Ave, MC2115, Chicago, IL, 60637, USA
| | - Olatoyosi Odenike
- Section of Hematology/Oncology, Department of Medicine, The University of Chicago, 5841 S. Maryland Ave, MC2115, Chicago, IL, 60637, USA.
| |
Collapse
|
8
|
Beauverd Y, McLornan DP, Harrison CN. Pacritinib: a new agent for the management of myelofibrosis? Expert Opin Pharmacother 2016; 16:2381-90. [PMID: 26389774 DOI: 10.1517/14656566.2015.1088831] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
INTRODUCTION Myelofibrosis (MF) is a clonal haematological disease associated with recurrent somatic gene mutations (JAK2V617F, MPL, CALR) and constitutive activation of the Janus kinase (JAK)/Signal Transducer and Activator of Transcription pathway. MF is often characterised by debilitating symptoms and JAK inhibitors (JAKIs) have revolutionised available therapeutic options. Ruxolitinib, a JAK1 and 2 inhibitor, is the only currently approved agent. Several other JAKIs are undergoing evaluation in the clinical trial setting and Pacritinib , a novel JAK2 and FLT3 inhibitor, is at an advanced stage of investigation with recent completion of a Phase III trial and another ongoing. AREAS COVERED Within this article we focus on pacritinib, summarising the development, preclinical and up-to-date results from the Phase I - III trials. We present the most recent data on efficacy and safety and indirectly compare this novel JAKI with ruxolitinib. EXPERT OPINION The kinome array data for pacritinib suggests that it has a range of targets differing to those for ruxolitinib. Pacritinib appears to be an effective agent for the control of MF-related symptoms and splenomegaly with potentially fewer haematological side-effects when compared with ruxolitinib and seems a particularly promising agent for anaemic and thrombocytopenic patients. It is also an attractive drug for potential combination studies due to its good tolerability.
Collapse
Affiliation(s)
- Yan Beauverd
- a 1 Guy's and St. Thomas' NHS Foundation Trust, Department of Haematology , London, UK
| | - Donal P McLornan
- a 1 Guy's and St. Thomas' NHS Foundation Trust, Department of Haematology , London, UK.,b 2 King's College Hospital NHS Foundation Trust, Department of Haematological Medicine , London, UK
| | - Claire N Harrison
- c 3 Guy's and St. Thomas' NHS Foundation Trust, Department of Haematology , London, UK
| |
Collapse
|
9
|
Springuel L, Renauld JC, Knoops L. JAK kinase targeting in hematologic malignancies: a sinuous pathway from identification of genetic alterations towards clinical indications. Haematologica 2015; 100:1240-53. [PMID: 26432382 PMCID: PMC4591756 DOI: 10.3324/haematol.2015.132142] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 07/17/2015] [Indexed: 12/16/2022] Open
Abstract
Constitutive JAK-STAT pathway activation occurs in most myeloproliferative neoplasms as well as in a significant proportion of other hematologic malignancies, and is frequently a marker of poor prognosis. The underlying molecular alterations are heterogeneous as they include activating mutations in distinct components (cytokine receptor, JAK, STAT), overexpression (cytokine receptor, JAK) or rare JAK2 fusion proteins. In some cases, concomitant loss of negative regulators contributes to pathogenesis by further boosting the activation of the cascade. Exploiting the signaling bottleneck provided by the limited number of JAK kinases is an attractive therapeutic strategy for hematologic neoplasms driven by constitutive JAK-STAT pathway activation. However, given the conserved nature of the kinase domain among family members and the interrelated roles of JAK kinases in many physiological processes, including hematopoiesis and immunity, broad usage of JAK inhibitors in hematology is challenged by their narrow therapeutic window. Novel therapies are, therefore, needed. The development of more selective inhibitors is a questionable strategy as such inhibitors might abrogate the beneficial contribution of alleviating the cancer-related pro-inflammatory microenvironment and raise selective pressure to a threshold that allows the emergence of malignant subclones harboring drug-resistant mutations. In contrast, synergistic combinations of JAK inhibitors with drugs targeting cascades that work in concert with JAK-STAT pathway appear to be promising therapeutic alternatives to JAK inhibitors as monotherapies.
Collapse
Affiliation(s)
- Lorraine Springuel
- de Duve Institute, Université Catholique de Louvain, Brussels, Belgium Ludwig Institute for Cancer Research, Brussels, Belgium
| | - Jean-Christophe Renauld
- de Duve Institute, Université Catholique de Louvain, Brussels, Belgium Ludwig Institute for Cancer Research, Brussels, Belgium
| | - Laurent Knoops
- de Duve Institute, Université Catholique de Louvain, Brussels, Belgium Ludwig Institute for Cancer Research, Brussels, Belgium Hematology Unit, Cliniques Universitaires Saint-Luc, Brussels, Belgium
| |
Collapse
|
10
|
Kesarwani M, Huber E, Kincaid Z, Evelyn CR, Biesiada J, Rance M, Thapa MB, Shah NP, Meller J, Zheng Y, Azam M. Targeting substrate-site in Jak2 kinase prevents emergence of genetic resistance. Sci Rep 2015; 5:14538. [PMID: 26419724 PMCID: PMC4588578 DOI: 10.1038/srep14538] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 08/18/2015] [Indexed: 12/13/2022] Open
Abstract
Emergence of genetic resistance against kinase inhibitors poses a great challenge for durable therapeutic response. Here, we report a novel mechanism of JAK2 kinase inhibition by fedratinib (TG101348) that prevents emergence of genetic resistance. Using in vitro drug screening, we identified 211 amino-acid substitutions conferring resistance to ruxolitinib (INCB018424) and cross-resistance to the JAK2 inhibitors AZD1480, CYT-387 and lestaurtinib. In contrast, these resistant variants were fully sensitive to fedratinib. Structural modeling, coupled with mutagenesis and biochemical studies, revealed dual binding sites for fedratinib. In vitro binding assays using purified proteins showed strong affinity for the substrate-binding site (Kd = 20 nM) while affinity for the ATP site was poor (Kd = ~8 μM). Our studies demonstrate that mutations affecting the substrate-binding pocket encode a catalytically incompetent kinase, thereby preventing emergence of resistant variants. Most importantly, our data suggest that in order to develop resistance-free kinase inhibitors, the next-generation drug design should target the substrate-binding site.
Collapse
Affiliation(s)
- Meenu Kesarwani
- Cincinnati Children's Hospital Medical Center, Cancer Blood Disease Institute, Divisions of Experimental Hematology and Cancer Pathology, Cincinnati, Ohio, 45229 USA
| | - Erika Huber
- Cincinnati Children's Hospital Medical Center, Cancer Blood Disease Institute, Divisions of Experimental Hematology and Cancer Pathology, Cincinnati, Ohio, 45229 USA
| | - Zachary Kincaid
- Cincinnati Children's Hospital Medical Center, Cancer Blood Disease Institute, Divisions of Experimental Hematology and Cancer Pathology, Cincinnati, Ohio, 45229 USA
| | - Chris R Evelyn
- Cincinnati Children's Hospital Medical Center, Cancer Blood Disease Institute, Divisions of Experimental Hematology and Cancer Pathology, Cincinnati, Ohio, 45229 USA
| | - Jacek Biesiada
- Cincinnati Children's Hospital Medical Center, Cancer Blood Disease Institute, Divisions of Experimental Hematology and Cancer Pathology, Cincinnati, Ohio, 45229 USA
| | - Mark Rance
- Department of Molecular Genetics, Biochemistry and Microbiology University of Cincinnati College of Medicine, University of Cincinnati, Ohio 45229 USA
| | - Mahendra B Thapa
- Department of Molecular Genetics, Biochemistry and Microbiology University of Cincinnati College of Medicine, University of Cincinnati, Ohio 45229 USA
| | - Neil P Shah
- Division of Hematology-Oncology UCSF School of Medicine, San Francisco, California, 94143 USA
| | - Jarek Meller
- Cincinnati Children's Hospital Medical Center, Cancer Blood Disease Institute, Divisions of Experimental Hematology and Cancer Pathology, Cincinnati, Ohio, 45229 USA
| | - Yi Zheng
- Cincinnati Children's Hospital Medical Center, Cancer Blood Disease Institute, Divisions of Experimental Hematology and Cancer Pathology, Cincinnati, Ohio, 45229 USA
| | - Mohammad Azam
- Cincinnati Children's Hospital Medical Center, Cancer Blood Disease Institute, Divisions of Experimental Hematology and Cancer Pathology, Cincinnati, Ohio, 45229 USA.,Department of Molecular Genetics, Biochemistry and Microbiology University of Cincinnati College of Medicine, University of Cincinnati, Ohio 45229 USA
| |
Collapse
|
11
|
Targeting JAK kinase in solid tumors: emerging opportunities and challenges. Oncogene 2015; 35:939-51. [DOI: 10.1038/onc.2015.150] [Citation(s) in RCA: 153] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2014] [Revised: 03/24/2015] [Accepted: 03/24/2015] [Indexed: 02/07/2023]
|
12
|
Huang SMA, Wang A, Greco R, Li Z, Barberis C, Tabart M, Patel V, Schio L, Hurley R, Chen B, Cheng H, Lengauer C, Pollard J, Watters J, Garcia-Echeverria C, Wiederschain D, Adrian F, Zhang J. Combination of PIM and JAK2 inhibitors synergistically suppresses MPN cell proliferation and overcomes drug resistance. Oncotarget 2015; 5:3362-74. [PMID: 24830942 PMCID: PMC4102815 DOI: 10.18632/oncotarget.1951] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Inhibitors of JAK2 kinase are emerging as an important treatment modality for myeloproliferative neoplasms (MPN). However, similar to other kinase inhibitors, resistance to JAK2 inhibitors may eventually emerge through a variety of mechanisms. Effective drug combination is one way to enhance therapeutic efficacy and combat resistance against JAK2 inhibitors. To identify potential combination partners for JAK2 compounds in MPN cell lines, we performed pooled shRNA screen targeting 5,000 genes in the presence or absence of JAK2 blockade. One of the top hits identified was MYC, an oncogenic transcription factor that is difficult to inhibit directly, but could be targeted by modulation of upstream regulatory elements such as kinases. We demonstrate herein that PIM kinase inhibitors efficiently suppress MYC protein levels in MPN cell lines. Overexpression of MYC restores the viability of PIM inhibitor-treated cells, revealing causal relationship between MYC down-regulation and cell growth inhibition by PIM compounds. Combination of various PIM inhibitors with a JAK2 inhibitor results in significant synergistic growth inhibition of multiple MPN cancer cell lines and induction of apoptosis. Mechanistic studies revealed strong downregulation of phosphorylated forms of S6 and 4EBP1 by JAK2/PIM inhibitor combination treatment. Finally, such combination was effective in eradicating in vitro JAK2 inhibitor-resistant MPN clones, where MYC is consistently up-regulated. These findings demonstrate that simultaneous suppression of JAK2 and PIM kinase activity by small molecule inhibitors is more effective than either agent alone in suppressing MPN cell growth. Our data suggest that JAK2 and PIM combination might warrant further investigation for the treatment of JAK2-driven hematologic malignancies.
Collapse
|
13
|
Kesarwani M, Huber E, Kincaid Z, Azam M. A method for screening and validation of resistant mutations against kinase inhibitors. J Vis Exp 2014:51984. [PMID: 25549138 PMCID: PMC4362691 DOI: 10.3791/51984] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
The discovery of BCR/ABL as a driver oncogene in chronic myeloid leukemia (CML) resulted in the development of Imatinib, which, in fact, demonstrated the potential of targeting the kinase in cancers by effectively treating the CML patients. This observation revolutionized drug development to target the oncogenic kinases implicated in various other malignancies, such as, EGFR, B-RAF, KIT and PDGFRs. However, one major drawback of anti-kinase therapies is the emergence of drug resistance mutations rendering the target to have reduced or lost affinity for the drug. Understanding the mechanisms employed by resistant variants not only helps in developing the next generation inhibitors but also gives impetus to clinical management using personalized medicine. We reported a retroviral vector based screening strategy to identify the spectrum of resistance conferring mutations in BCR/ABL, which has helped in developing the next generation BCR/ABL inhibitors. Using Ruxolitinib and JAK2 as a drug target pair, here we describe in vitro screening methods that utilizes the mouse BAF3 cells expressing the random mutation library of JAK2 kinase.
Collapse
Affiliation(s)
- Meenu Kesarwani
- Divisions of Experimental Hematology and Cancer Pathology, Cancer Blood Disease Institute, Cincinnati Children's Hospital Medical Center
| | - Erika Huber
- Divisions of Experimental Hematology and Cancer Pathology, Cancer Blood Disease Institute, Cincinnati Children's Hospital Medical Center
| | - Zachary Kincaid
- Divisions of Experimental Hematology and Cancer Pathology, Cancer Blood Disease Institute, Cincinnati Children's Hospital Medical Center
| | - Mohammad Azam
- Divisions of Experimental Hematology and Cancer Pathology, Cancer Blood Disease Institute, Cincinnati Children's Hospital Medical Center;
| |
Collapse
|
14
|
Improved targeting of JAK2 leads to increased therapeutic efficacy in myeloproliferative neoplasms. Blood 2014; 123:2075-83. [PMID: 24470592 DOI: 10.1182/blood-2014-01-547760] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
The discovery of JAK2/MPL mutations in patients with myeloproliferative neoplasms (MPN) led to clinical development of Janus kinase (JAK) inhibitors for treatment of MPN. These inhibitors improve constitutional symptoms and splenomegaly but do not significantly reduce mutant allele burden in patients. We recently showed that chronic exposure to JAK inhibitors results in inhibitor persistence via JAK2 transactivation and persistent JAK-signal transducer and activator of transcription signaling. We performed genetic and pharmacologic studies to determine whether improved JAK2 inhibition would show increased efficacy in MPN models and primary samples. Jak2 deletion in vivo led to profound reduction in disease burden not seen with JAK inhibitors, and deletion of Jak2 following chronic ruxolitinib therapy markedly reduced mutant allele burden. This demonstrates that JAK2 remains an essential target in MPN cells that survive in the setting of chronic JAK inhibition. Combination therapy with the heat shock protein 90 (HSP90) inhibitor PU-H71 and ruxolitinib reduced total and phospho-JAK2 and achieved more potent inhibition of downstream signaling than ruxolitinib monotherapy. Combination treatment improved blood counts, spleen weights, and reduced bone marrow fibrosis compared with ruxolitinib alone. These data suggest alternate approaches that increase JAK2 targeting, including combination JAK/HSP90 inhibitor therapy, are warranted in the clinical setting.
Collapse
|
15
|
The resistance tetrad: amino acid hotspots for kinome-wide exploitation of drug-resistant protein kinase alleles. Methods Enzymol 2014; 548:117-46. [PMID: 25399644 DOI: 10.1016/b978-0-12-397918-6.00005-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Acquired resistance to targeted kinase inhibitors is a well-documented clinical problem that is potentially fatal for patients to whom a suitable back-up is not available. However, protein kinase alleles that promote resistance to inhibitors can be exploited experimentally as gold-standards for "on"- and "off"-target validation strategies and constitute a powerful resource for assessing the ability of new or combined therapies to override resistance. Clinical resistance to kinase inhibitors is an evident in all tyrosine kinase-driven malignancies, where high rates of mutation drive tumor evolution toward the insidious drug-resistant (DR) state through a variety of mechanisms. Unfortunately, this problem is likely to intensify in the future as the number of target kinases, approved inhibitors, and clinical indications increase. To empower the analysis of resistance in kinases, we have validated a bioinformatic, structural, and cellular workflow for designing and evaluating resistance at key mutational hotspots among kinome members. In this chapter, we discuss how mutation of amino acids in the gatekeeper and hinge-loop regions (collectively termed the "resistance tetrad") and the DFG motif represent an effective approach for generating panels of DR kinase alleles for chemical genetics and biological target validation.
Collapse
|
16
|
Anderson NM, Javadi M, Berndl E, Berberovic Z, Bailey ML, Huang K, Flenniken AM, Osborne LR, Adamson SL, Rossant J, Carter-Su C, Wang C, McNagny KM, Paulson RF, Minden MD, Stanford WL, Barber DL. Enu mutagenesis identifies a novel platelet phenotype in a loss-of-function Jak2 allele. PLoS One 2013; 8:e75472. [PMID: 24086539 PMCID: PMC3783367 DOI: 10.1371/journal.pone.0075472] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Accepted: 08/14/2013] [Indexed: 01/17/2023] Open
Abstract
Utilizing ENU mutagenesis, we identified a mutant mouse with elevated platelets. Genetic mapping localized the mutation to an interval on chromosome 19 that encodes the Jak2 tyrosine kinase. We identified a A3056T mutation resulting in a premature stop codon within exon 19 of Jak2 (Jak2(K915X)), resulting in a protein truncation and functionally inactive enzyme. This novel platelet phenotype was also observed in mice bearing a hemizygous targeted disruption of the Jak2 locus (Jak2(+/-)). Timed pregnancy experiments revealed that Jak2(K915X/K915X) and Jak2(-/-) displayed embryonic lethality; however, Jak2(K915X/K915X) embryos were viable an additional two days compared to Jak2(-/-) embryos. Our data suggest that perturbing JAK2 activation may have unexpected consequences in elevation of platelet number and correspondingly, important implications for treatment of hematological disorders with constitutive Jak2 activity.
Collapse
Affiliation(s)
- Nicole M. Anderson
- Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Mojib Javadi
- Department of Medical Biophysics, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Elizabeth Berndl
- Institute of Biomaterials and Biomedical Engineering, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | | | - Monica L. Bailey
- Department of Veterinary and Biomedical Sciences, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Kai Huang
- Department of Veterinary and Biomedical Sciences, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | | | - Lucy R. Osborne
- Department of Medicine, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
- Department of Molecular Genetics, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - S. Lee Adamson
- Department of Obstetrics and Gynecology, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
- Samuel Lunenfeld Research Institute, Toronto, Ontario, Canada
| | - Janet Rossant
- Department of Molecular Genetics, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
- Hospital for Sick Children, Toronto, Ontario, Canada
| | - Christin Carter-Su
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Chen Wang
- Mount Sinai Hospital, Toronto, Ontario, Canada
| | - Kelly M. McNagny
- The Biomedical Research Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Robert F. Paulson
- Department of Veterinary and Biomedical Sciences, Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Mark D. Minden
- Department of Medical Biophysics, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
- Ontario Cancer Institute, Toronto, Ontario, Canada
| | - William L. Stanford
- Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
- Institute of Biomaterials and Biomedical Engineering, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
- Sprott Centre for Stem Cell Research, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Dwayne L. Barber
- Department of Medical Biophysics, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
- Ontario Cancer Institute, Toronto, Ontario, Canada
- * E-mail:
| |
Collapse
|
17
|
Abstract
A recent article by Weigert et al. published in The Journal of Experimental Medicine described the in vitro generation of synthetic mutations in Janus kinase 2 (JAK 2) that decreased the potency of JAK2 (or JAK1/JAK2) inhibitors in artificial systems. The authors found that heat shock protein 90 (HSP90) inhibitors circumvented the potency shift and suggested that HSP90 inhibition may abrogate JAK inhibitor resistance in these experimental systems. However, the clinical relevance of these laboratory-generated JAK2 mutations, which have not been identified to-date in patients treated with JAK inhibitors, and the therapeutic potential of HSP90 inhibitors in diseases involving aberrant JAK-STAT signaling remain to be determined.
Collapse
|
18
|
Duhé RJ. Redox regulation of Janus kinase: The elephant in the room. JAKSTAT 2013; 2:e26141. [PMID: 24416654 PMCID: PMC3876428 DOI: 10.4161/jkst.26141] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Revised: 08/12/2013] [Accepted: 08/13/2013] [Indexed: 12/21/2022] Open
Abstract
The redox regulation of Janus kinases (JAKs) is a complex subject. Due to other redox-sensitive kinases in the kinome, redox-sensitive phosphatases, and cellular antioxidant systems and reactive oxygen species (ROS) production systems, the net biological outcomes of oxidative stress on JAK-dependent signal transduction vary according to the specific biological system examined. This review begins with a discussion of the biochemical evidence for a cysteine-based redox switch in the catalytic domain of JAKs, proceeds to consider direct and indirect regulatory mechanisms involved in biological experiments, and ends with a discussion of the role(s) of redox regulation of JAKs in various diseases.
Collapse
Affiliation(s)
- Roy J Duhé
- Department of Pharmacology and Toxicology and Department of Radiation Oncology; University of Mississippi Medical Center; Jackson, MS USA
| |
Collapse
|
19
|
Gäbler K, Behrmann I, Haan C. JAK2 mutants (e.g., JAK2V617F) and their importance as drug targets in myeloproliferative neoplasms. JAKSTAT 2013; 2:e25025. [PMID: 24069563 PMCID: PMC3772115 DOI: 10.4161/jkst.25025] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Revised: 05/13/2013] [Accepted: 05/13/2013] [Indexed: 12/25/2022] Open
Abstract
The Janus kinase 2 (JAK2) mutant V617F and other JAK mutants are found in patients with myeloproliferative neoplasms and leukemias. Due to their involvement in neoplasia and inflammatory disorders, Janus kinases are promising targets for kinase inhibitor therapy. Several small-molecule compounds are evaluated in clinical trials for myelofibrosis, and ruxolitinib (INCB018424, Jakafi®) was the first Janus kinase inhibitor to receive clinical approval. In this review we provide an overview of JAK2V617F signaling and its inhibition by small-molecule kinase inhibitors. In addition, myeloproliferative neoplasms are discussed regarding the role of JAK2V617F and other mutant proteins of possible relevance. We further give an overview about treatment options with special emphasis on possible combination therapies.
Collapse
Affiliation(s)
- Karoline Gäbler
- Signal Transduction Laboratory; Life Sciences Research Unit; University of Luxembourg; Luxembourg
| | - Iris Behrmann
- Signal Transduction Laboratory; Life Sciences Research Unit; University of Luxembourg; Luxembourg
| | - Claude Haan
- Signal Transduction Laboratory; Life Sciences Research Unit; University of Luxembourg; Luxembourg
| |
Collapse
|
20
|
Sensitivity and resistance of JAK2 inhibitors to myeloproliferative neoplasms. Int J Hematol 2013; 97:695-702. [DOI: 10.1007/s12185-013-1353-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Accepted: 04/30/2013] [Indexed: 12/28/2022]
|
21
|
Dymock BW, See CS. Inhibitors of JAK2 and JAK3: an update on the patent literature 2010 – 2012. Expert Opin Ther Pat 2013; 23:449-501. [DOI: 10.1517/13543776.2013.765862] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
|