1
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Sarson-Lawrence KTG, Hardy JM, Iaria J, Stockwell D, Behrens K, Saiyed T, Tan C, Jebeli L, Scott NE, Dite TA, Nicola NA, Leis AP, Babon JJ, Kershaw NJ. Cryo-EM structure of the extracellular domain of murine Thrombopoietin Receptor in complex with Thrombopoietin. Nat Commun 2024; 15:1135. [PMID: 38326297 PMCID: PMC10850085 DOI: 10.1038/s41467-024-45356-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 01/19/2024] [Indexed: 02/09/2024] Open
Abstract
Thrombopoietin (Tpo) is the primary regulator of megakaryocyte and platelet numbers and is required for haematopoetic stem cell maintenance. Tpo functions by binding its receptor (TpoR, a homodimeric Class I cytokine receptor) and initiating cell proliferation or differentiation. Here we characterise the murine Tpo:TpoR signalling complex biochemically and structurally, using cryo-electron microscopy. Tpo uses opposing surfaces to recruit two copies of receptor, forming a 1:2 complex. Although it binds to the same, membrane-distal site on both receptor chains, it does so with significantly different affinities and its highly glycosylated C-terminal domain is not required. In one receptor chain, a large insertion, unique to TpoR, forms a partially structured loop that contacts cytokine. Tpo binding induces the juxtaposition of the two receptor chains adjacent to the cell membrane. The therapeutic agent romiplostim also targets the cytokine-binding site and the characterisation presented here supports the future development of improved TpoR agonists.
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Affiliation(s)
- Kaiseal T G Sarson-Lawrence
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, 3052, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Royal Parade, Parkville, 3052, Victoria, Australia
| | - Joshua M Hardy
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, 3052, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Royal Parade, Parkville, 3052, Victoria, Australia
- ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, 3052, Victoria, Australia
| | - Josephine Iaria
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, 3052, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Royal Parade, Parkville, 3052, Victoria, Australia
| | - Dina Stockwell
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, 3052, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Royal Parade, Parkville, 3052, Victoria, Australia
| | - Kira Behrens
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, 3052, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Royal Parade, Parkville, 3052, Victoria, Australia
| | - Tamanna Saiyed
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, 3052, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Royal Parade, Parkville, 3052, Victoria, Australia
| | - Cyrus Tan
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, 3052, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Royal Parade, Parkville, 3052, Victoria, Australia
| | - Leila Jebeli
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, 3000, Victoria, Australia
| | - Nichollas E Scott
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, 3000, Victoria, Australia
| | - Toby A Dite
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, 3052, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Royal Parade, Parkville, 3052, Victoria, Australia
| | - Nicos A Nicola
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, 3052, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Royal Parade, Parkville, 3052, Victoria, Australia
| | - Andrew P Leis
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, 3052, Victoria, Australia
- Department of Medical Biology, The University of Melbourne, Royal Parade, Parkville, 3052, Victoria, Australia
- ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, 3052, Victoria, Australia
| | - Jeffrey J Babon
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, 3052, Victoria, Australia.
- Department of Medical Biology, The University of Melbourne, Royal Parade, Parkville, 3052, Victoria, Australia.
| | - Nadia J Kershaw
- Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, 3052, Victoria, Australia.
- Department of Medical Biology, The University of Melbourne, Royal Parade, Parkville, 3052, Victoria, Australia.
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2
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Borsani O, Pietra D, Casetti IC, Vanni D, Riccaboni G, Catricalà S, Grazia B, Boveri E, Arcaini L, Rumi E. Germline MPL mutations may be a rare cause of "triple-negative" thrombocytosis. Exp Hematol 2024; 129:104127. [PMID: 37939832 DOI: 10.1016/j.exphem.2023.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Revised: 10/17/2023] [Accepted: 10/31/2023] [Indexed: 11/10/2023]
Abstract
Hereditary thrombocytosis (HT) is a rare inherited disorder with clinical features resembling those of sporadic essential thrombocythemia. This study included 933 patients with persistent isolated thrombocytosis for whom secondary reactive causes were excluded. Of 933 patients screened, 567 were JAK2-mutated, 255 CALR-mutated, 41 MPL-mutated, 2 double-mutated, and 68 were triple-negative. Two patients carried germline non-canonical mutations in exon 10: MPL W515* and MPL V501A. One triple-negative patient carried another germline non-canonical MPL mutation outside exon 10: MPL R102P. As germline MPL mutations may be underlying causes of HT, we recommend screening patients with triple-negative isolated thrombocytosis for non-canonical MPL mutations. Although clear evidence concerning HT treatment is still lacking, individuals with HT should probably be excluded from cytoreductive treatment. Thus, an accurate diagnosis is pivotal in avoiding unnecessary treatments.
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Affiliation(s)
- Oscar Borsani
- Department of Molecular Medicine, University of Pavia, Pavia, Italy; Division of Hematology, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Daniela Pietra
- Division of Hematology, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | | | - Daniele Vanni
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | | | - Silvia Catricalà
- Division of Hematology, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy; Department of Biology and Biotechnology, University of Pavia, Pavia, Italy
| | - Bossi Grazia
- Department of Pediatrics, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Emanuela Boveri
- Department of Pathology, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Luca Arcaini
- Department of Molecular Medicine, University of Pavia, Pavia, Italy; Division of Hematology, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy
| | - Elisa Rumi
- Department of Molecular Medicine, University of Pavia, Pavia, Italy; Division of Hematology, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy.
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3
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Papadopoulos N, Pristavec A, Nédélec A, Levy G, Staerk J, Constantinescu SN. Modulation of human thrombopoietin receptor conformations uncouples JAK2 V617F-driven activation from cytokine-induced stimulation. Blood 2023; 142:1818-1830. [PMID: 37616564 DOI: 10.1182/blood.2022019580] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 07/25/2023] [Accepted: 07/27/2023] [Indexed: 08/26/2023] Open
Abstract
The thrombopoietin receptor (TpoR) plays a central role in myeloproliferative neoplasms (MPNs). Mutations in JAK2, calreticulin, or TpoR itself drive the constitutive activation of TpoR and uncontrolled proliferation and differentiation of hematopoietic stem cells and progenitors. The JAK2 V617F mutation is responsible for most MPNs, and all driver mutants induce pathologic TpoR activation. Existing therapeutic strategies have focused on JAK2 kinase inhibitors that are unable to differentiate between the mutated MPN clone and healthy cells. Surprisingly, the targeting of TpoR itself has remained poorly explored despite its central role in pathology. Here, we performed a comprehensive characterization of human TpoR activation under physiological and pathological conditions, focusing on the JAK2 V617F mutant. Using a system of controlled dimerization of the transmembrane and cytosolic domains of TpoR, we discovered that human TpoR (hTpoR) adopts different dimeric conformations upon Tpo-induced vs JAK2 V617F-mediated activation. We identified the amino acids and specific dimeric conformation of hTpoR responsible for activation in complex with JAK2 V617F and confirmed our findings in the full-length receptor context in hematopoietic cell lines and primary bone marrow cells. Remarkably, we found that the modulation of hTpoR conformations by point mutations allowed for specific inhibition of JAK2 V617F-driven activation without affecting Tpo-induced signaling. Our results demonstrate that modulation of the hTpoR conformation is a viable therapeutic strategy for JAK2 V617F-positive MPNs and set the path for novel drug development by identifying precise residues of hTpoR involved in JAK2 V617F-specific activation.
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Affiliation(s)
- Nicolas Papadopoulos
- de Duve Institute, Université Catholique de Louvain, Brussels, Belgium
- Ludwig Institute for Cancer Research, Brussels, Belgium
- Walloon Excellence in Life Sciences and Biotechnology Department, Walloon Excellence Research Institute, Wavre, Belgium
| | - Ajda Pristavec
- de Duve Institute, Université Catholique de Louvain, Brussels, Belgium
| | - Audrey Nédélec
- de Duve Institute, Université Catholique de Louvain, Brussels, Belgium
- Ludwig Institute for Cancer Research, Brussels, Belgium
- Walloon Excellence in Life Sciences and Biotechnology Department, Walloon Excellence Research Institute, Wavre, Belgium
| | - Gabriel Levy
- de Duve Institute, Université Catholique de Louvain, Brussels, Belgium
- Ludwig Institute for Cancer Research, Brussels, Belgium
- Walloon Excellence in Life Sciences and Biotechnology Department, Walloon Excellence Research Institute, Wavre, Belgium
| | - Judith Staerk
- de Duve Institute, Université Catholique de Louvain, Brussels, Belgium
- Ludwig Institute for Cancer Research, Brussels, Belgium
- Centre for Molecular Medicine Norway, Nordic European Molecular Biology Laboratory Partnership, University of Oslo, Oslo, Norway
| | - Stefan N Constantinescu
- de Duve Institute, Université Catholique de Louvain, Brussels, Belgium
- Ludwig Institute for Cancer Research, Brussels, Belgium
- Walloon Excellence in Life Sciences and Biotechnology Department, Walloon Excellence Research Institute, Wavre, Belgium
- Nuffield Department of Medicine, Ludwig Institute for Cancer Research, Oxford University, Oxford, United Kingdom
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4
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Havelange V, Constantinescu SN. Molecular pathogenesis of myeloproliferative neoplasms: Where do we stand in 2023? Am J Hematol 2023; 98:1512-1516. [PMID: 37635451 DOI: 10.1002/ajh.27062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 08/02/2023] [Indexed: 08/29/2023]
Affiliation(s)
- Violaine Havelange
- Université catholique de Louvain and de Duve Institute, Brussels, Belgium
- Department of Hematology, Cliniques universitaires Saint-Luc, Brussels, Belgium
| | - Stefan N Constantinescu
- Université catholique de Louvain and de Duve Institute, Brussels, Belgium
- Department of Hematology, Cliniques universitaires Saint-Luc, Brussels, Belgium
- Ludwig Institute for Cancer Research Brussels, Brussels, Belgium
- WelBio Department, Wel Research Institute, Wavre, Belgium
- Ludwig Institute for Cancer Research, Nuffield Department of Medicine, Oxford University, Oxford, UK
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5
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Sato T, Shinohara A. Characterizing interaction between the juxtamembrane region of the single transmembrane protein and membrane using chemically synthesized peptides. STAR Protoc 2023; 4:102454. [PMID: 37515758 PMCID: PMC10400950 DOI: 10.1016/j.xpro.2023.102454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 05/03/2023] [Accepted: 06/21/2023] [Indexed: 07/31/2023] Open
Abstract
In membrane proteins, a transmembrane region and a juxtamembrane region play important roles in its function. Here, we present a protocol for characterizing membrane protein dynamics between the juxtamembrane region of the single transmembrane protein and acidic membrane. We describe steps for solid-phase peptide synthesis, peptide purification, and labeling. We then detail reconstitution of the transmembrane peptide into lipid bilayers and its evaluation and structural analysis. For complete details on the use and execution of this protocol, please refer to Prasada Rao et al.1.
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Affiliation(s)
- Takeshi Sato
- Kyoto Pharmaceutical University, Kyoto City, Kyoto Prefecture 607-8414, Japan.
| | - Akira Shinohara
- Institute for Protein Research, Osaka University, Suita City, Osaka Prefecture 565-0871, Japan.
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6
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Desikan H, Kaur A, Pogozheva ID, Raghavan M. Effects of calreticulin mutations on cell transformation and immunity. J Cell Mol Med 2023; 27:1032-1044. [PMID: 36916035 PMCID: PMC10098294 DOI: 10.1111/jcmm.17713] [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: 11/04/2022] [Revised: 02/22/2023] [Accepted: 02/24/2023] [Indexed: 03/16/2023] Open
Abstract
Myeloproliferative neoplasms (MPNs) are cancers involving dysregulated production and function of myeloid lineage hematopoietic cells. Among MPNs, Essential thrombocythemia (ET), Polycythemia Vera (PV) and Myelofibrosis (MF), are driven by mutations that activate the JAK-STAT signalling pathway. Somatic mutations of calreticulin (CRT), an endoplasmic reticulum (ER)-localized lectin chaperone, are driver mutations in approximately 25% of ET and 35% of MF patients. The MPN-linked mutant CRT proteins have novel frameshifted carboxy-domain sequences and lack an ER retention motif, resulting in their secretion. Wild type CRT is a regulator of ER calcium homeostasis and plays a key role in the assembly of major histocompatibility complex (MHC) class I molecules, which are the ligands for antigen receptors of CD8+ T cells. Mutant CRT-linked oncogenesis results from the dysregulation of calcium signalling in cells and the formation of stable complexes of mutant CRT with myeloproliferative leukemia (MPL) protein, followed by downstream activation of the JAK-STAT signalling pathway. The intricate participation of CRT in ER protein folding, calcium homeostasis and immunity suggests the involvement of multiple mechanisms of mutant CRT-linked oncogenesis. In this review, we highlight recent findings related to the role of MPN-linked CRT mutations in the dysregulation of calcium homeostasis, MPL activation and immunity.
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Affiliation(s)
- Harini Desikan
- Department of Microbiology and ImmunologyUniversity of Michigan Medical SchoolAnn ArborMichiganUSA
| | - Amanpreet Kaur
- Department of Microbiology and ImmunologyUniversity of Michigan Medical SchoolAnn ArborMichiganUSA
| | - Irina D. Pogozheva
- Department of Medicinal ChemistryCollege of Pharmacy, University of MichiganAnn ArborMichiganUSA
| | - Malini Raghavan
- Department of Microbiology and ImmunologyUniversity of Michigan Medical SchoolAnn ArborMichiganUSA
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7
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Lewandowski K, Kanduła Z, Gniot M, Paczkowska E, Nawrocka PM, Wojtaszewska M, Janowski M, Mariak M, Handschuh L, Kozlowski P. Essential thrombocythaemia progression to the fibrotic phase is associated with a decrease in JAK2 and PDL1 levels. Ann Hematol 2022; 101:2665-2677. [PMID: 36266510 DOI: 10.1007/s00277-022-05001-8] [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: 07/16/2022] [Accepted: 10/01/2022] [Indexed: 11/01/2022]
Abstract
It has been postulated that the changes in the molecular characteristics of the malignant clone(s) and the abnormal activation of JAK-STAT signaling are responsible for myeloproliferative neoplasm progression to more advanced disease phases and the immune escape of the malignant clone. The continuous JAK-STAT pathway activation leads to enhanced activity of the promoter of CD274 coding programmed death-1 receptor ligand (PD-L1), increased PD-L1 level, and the immune escape of MPN cells. The aim of study was to evaluate the PDL1 mRNA and JAK2 mRNA level in molecularly defined essential thrombocythaemia (ET) patients (pts) during disease progression to post-ET- myelofibrosis (post-ET-MF). The study group consisted of 162 ET pts, including 30 pts diagnosed with post-ET-MF. The JAK2V617F, CALR, and MPL mutations were found in 59.3%, 19.1%, and 1.2% of pts, respectively. No copy-number alternations of the JAK2, PDL1, and PDCDL1G2 (PDL2) genes were found. The level of PD-L1 was significantly higher in the JAK2V617F than in the JAK2WT, CALR mutation-positive, and triple-negative pts. The PD-L1 mRNA level was weakly correlated with both the JAK2V617F variant allele frequency (VAF), and with the JAK2V617F allele mRNA level. The total JAK2 level in post-ET-MF pts was lower than in ET pts, despite the lack of differences in the JAK2V617F VAF. In addition, the PD-L1 level was lower in post-ET-MF. A detailed analysis has shown that the decrease in JAK2 and PDL1 mRNA levels depended on the bone marrow fibrosis grade. The PDL1 expression showed no differences in relation to the genotype of the JAK2 haplotypeGGCC_46/1, hemoglobin concentration, hematocrit value, leukocyte, and platelet counts. The observed drop of the total JAK2 and PDL1 levels during the ET progression to the post-ET-MF may reflect the changes in the JAK2V617F positive clone proliferative potential and the PD-L1 level-related immunosuppressive effect. The above-mentioned hypothesis is supported by The Cancer Genome Atlas (TCGA) data, confirming a strong positive association between CD274 (encoding PD-L1), CXCR3 (encoding CXCR3), and CSF1 (encoding M-CSF) expression levels, and recently published results documenting a drop in the CXCR3 level and circulating M-CSF in patients with post-ET-MF.
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Affiliation(s)
- Krzysztof Lewandowski
- Department of Hematology and Bone Marrow Transplantation, Poznan University of Medical Sciences, Poznan, Poland.
| | - Zuzanna Kanduła
- Department of Hematology and Bone Marrow Transplantation, Poznan University of Medical Sciences, Poznan, Poland
| | - Michał Gniot
- Department of Hematology and Bone Marrow Transplantation, Poznan University of Medical Sciences, Poznan, Poland
| | - Edyta Paczkowska
- Department of General Pathology, Pomeranian Medical University, Szczecin, Poland
| | - Paulina Maria Nawrocka
- Laboratory of Genomics, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland
| | - Marzena Wojtaszewska
- Department of Hematology and Bone Marrow Transplantation, Poznan University of Medical Sciences, Poznan, Poland
| | - Michał Janowski
- Department of General Pathology, Pomeranian Medical University, Szczecin, Poland
| | - Magdalena Mariak
- Department of Hematology and Bone Marrow Transplantation, Poznan University of Medical Sciences, Poznan, Poland
| | - Luiza Handschuh
- Institute of Computing Science, Poznan University of Technology, 60-965, Poznan, Poland.,Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland
| | - Piotr Kozlowski
- Laboratory of Genomics, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland
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8
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Levy G, Guglielmelli P, Langmuir P, Constantinescu S. JAK inhibitors and COVID-19. J Immunother Cancer 2022; 10:jitc-2021-002838. [PMID: 35459733 PMCID: PMC9035837 DOI: 10.1136/jitc-2021-002838] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/28/2022] [Indexed: 12/11/2022] Open
Abstract
During SARS-CoV-2 infection, the innate immune response can be inhibited or delayed, and the subsequent persistent viral replication can induce emergency signals that may culminate in a cytokine storm contributing to the severe evolution of COVID-19. Cytokines are key regulators of the immune response and virus clearance, and, as such, are linked to the—possibly altered—response to the SARS-CoV-2. They act via a family of more than 40 transmembrane receptors that are coupled to one or several of the 4 Janus kinases (JAKs) coded by the human genome, namely JAK1, JAK2, JAK3, and TYK2. Once activated, JAKs act on pathways for either survival, proliferation, differentiation, immune regulation or, in the case of type I interferons, antiviral and antiproliferative effects. Studies of graft-versus-host and systemic rheumatic diseases indicated that JAK inhibitors (JAKi) exert immunosuppressive effects that are non-redundant with those of corticotherapy. Therefore, they hold the potential to cut-off pathological reactions in COVID-19. Significant clinical experience already exists with several JAKi in COVID-19, such as baricitinib, ruxolitinib, tofacitinib, and nezulcitinib, which were suggested by a meta-analysis (Patoulias et al.) to exert a benefit in terms of risk reduction concerning major outcomes when added to standard of care in patients with COVID-19. Yet, only baricitinib is recommended in first line for severe COVID-19 treatment by the WHO, as it is the only JAKi that has proven efficient to reduce mortality in individual randomized clinical trials (RCT), especially the Adaptive COVID-19 Treatment Trial (ACTT-2) and COV-BARRIER phase 3 trials. As for secondary effects of JAKi treatment, the main caution with baricitinib consists in the induced immunosuppression as long-term side effects should not be an issue in patients treated for COVID-19. We discuss whether a class effect of JAKi may be emerging in COVID-19 treatment, although at the moment the convincing data are for baricitinib only. Given the key role of JAK1 in both type I IFN action and signaling by cytokines involved in pathogenic effects, establishing the precise timing of treatment will be very important in future trials, along with the control of viral replication by associating antiviral molecules.
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Affiliation(s)
- Gabriel Levy
- Signal Transduction and Molecular Hematology, Ludwig Institute for Cancer Research, Brussels, Belgium.,Signal Transduction on Molecular Hematology, de Duve Institute, Université Catholique de Louvain, Bruxelles, Belgium.,WELBIO, Walloon Excellence in Life Sciences and Biotechnology, Brussels, Belgium
| | - Paola Guglielmelli
- Department of Clinical and Experimental Medicine, University of Florence, Firenze, Italy.,Center of Research and Innovation for Myeloproliferative Neoplasms (CRIMM), Azienda Ospedaliero Universitaria Careggi, Firenze, Italy
| | - Peter Langmuir
- Oncology Targeted Therapeutics, Incyte Corp, Wilmington, Delaware, USA
| | - Stefan Constantinescu
- Signal Transduction and Molecular Hematology, Ludwig Institute for Cancer Research, Brussels, Belgium .,Signal Transduction on Molecular Hematology, de Duve Institute, Université Catholique de Louvain, Bruxelles, Belgium.,WELBIO, Walloon Excellence in Life Sciences and Biotechnology, Brussels, Belgium.,Nuffield Department of Medicine, Oxford University, Ludwig Institute for Cancer Research, Oxford, UK
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9
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Varghese LN, Carreño-Tarragona G, Levy G, Gutiérrez-López de Ocáriz X, Rapado I, Martínez-López J, Ayala R, Constantinescu SN. MPL S505C enhances driver mutations at W515 in essential thrombocythemia. Blood Cancer J 2021; 11:188. [PMID: 34845187 PMCID: PMC8630145 DOI: 10.1038/s41408-021-00583-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 09/24/2021] [Accepted: 11/18/2021] [Indexed: 11/22/2022] Open
Affiliation(s)
- Leila N Varghese
- Université Catholique de Louvain and de Duve Institute, Brussels, Belgium.,Ludwig Institute for Cancer Research, Brussels, Belgium.,WELBIO (Walloon Excellence in Life Sciences and Biotechnology), Brussels, Belgium
| | - Gonzalo Carreño-Tarragona
- Haematology and Haemotherapy Department, Hospital Universitario 12 de Octubre, I+12, CNIO, Complutense University, CIBERONC, Madrid, Spain
| | - Gabriel Levy
- Université Catholique de Louvain and de Duve Institute, Brussels, Belgium.,Ludwig Institute for Cancer Research, Brussels, Belgium.,WELBIO (Walloon Excellence in Life Sciences and Biotechnology), Brussels, Belgium
| | - Xabier Gutiérrez-López de Ocáriz
- Haematology and Haemotherapy Department, Hospital Universitario 12 de Octubre, I+12, CNIO, Complutense University, CIBERONC, Madrid, Spain
| | - Inmaculada Rapado
- Haematology and Haemotherapy Department, Hospital Universitario 12 de Octubre, I+12, CNIO, Complutense University, CIBERONC, Madrid, Spain
| | - Joaquín Martínez-López
- Haematology and Haemotherapy Department, Hospital Universitario 12 de Octubre, I+12, CNIO, Complutense University, CIBERONC, Madrid, Spain
| | - Rosa Ayala
- Haematology and Haemotherapy Department, Hospital Universitario 12 de Octubre, I+12, CNIO, Complutense University, CIBERONC, Madrid, Spain.
| | - Stefan N Constantinescu
- Université Catholique de Louvain and de Duve Institute, Brussels, Belgium. .,Ludwig Institute for Cancer Research, Brussels, Belgium. .,WELBIO (Walloon Excellence in Life Sciences and Biotechnology), Brussels, Belgium. .,Ludwig Institute for Cancer Research, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
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10
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Guglielmelli P, Calabresi L. The MPL mutation. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2021; 365:163-178. [PMID: 34756243 DOI: 10.1016/bs.ircmb.2021.09.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
Abstract
Myeloproliferative neoplasms (MPN) patients share driver mutations in JAK2, MPL or CALR genes leading to the activation of the thrombopoietin receptor (TPOR) and downstream signaling pathways. JAK2 mutation drives all the three major entities of MPN (Polycythemia Vera, Essential Thrombocythemia and Primary Myelofibrosis) through the constitutive activation of TPOR, erythropoietin (EPOR) and colony stimulating factor 3 receptor (CSF3R) signaling. MPL is a proto-oncogene encoding for TPOR, the hematopoietic growth factor receptor of myeloid stem cells. MPL mutants induce the stable dimerization of TPOR that in turn activate JAK2 and the thrombopoietin pathway. The thrombopoietin pathway plays an important role in the development of megakaryocytes and platelets as well as the self-renewal of hematopoietic stem cells. Little wonder therefore that mutations of MPL result in thrombocytosis, leading to an abnormal MPL trafficking or receptor activation. Finally, some extremely rare germline genetic variants in MPL can induce MPN-like hereditary disease. Against this molecular background, TPOR is a key actor in the MPN development and MPL mutations are of major relevance to fully elucidate the molecular mechanisms underlying the clinical manifestations of MPN and to arrange novel therapeutic strategies aiming to disrupt the dysegulated signaling cascade. This chapter will focus on the role MPL in the pathogenesis of MPN and in familial thrombocytosis and will review these different subtypes of somatic and germline genetic variants by dissecting how they impact clinical phenotype.
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Affiliation(s)
- Paola Guglielmelli
- Department of Experimental and Clinical Medicine, Center for Research and Innovation of Myeloproliferative Neoplasms (CRIMM), AOU Careggi, University of Florence, Florence, Italy.
| | - Laura Calabresi
- Department of Experimental and Clinical Medicine, Center for Research and Innovation of Myeloproliferative Neoplasms (CRIMM), AOU Careggi, University of Florence, Florence, Italy
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Roy A, Shrivastva S, Naseer S. In and out: Traffic and dynamics of thrombopoietin receptor. J Cell Mol Med 2021; 25:9073-9083. [PMID: 34448528 PMCID: PMC8500957 DOI: 10.1111/jcmm.16878] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 07/27/2021] [Accepted: 08/04/2021] [Indexed: 12/17/2022] Open
Abstract
Thrombopoiesis had long been a challenging area of study due to the rarity of megakaryocyte precursors in the bone marrow and the incomplete understanding of its regulatory cytokines. A breakthrough was achieved in the early 1990s with the discovery of the thrombopoietin receptor (TpoR) and its ligand thrombopoietin (TPO). This accelerated research in thrombopoiesis, including the uncovering of the molecular basis of myeloproliferative neoplasms (MPN) and the advent of drugs to treat thrombocytopenic purpura. TpoR mutations affecting its membrane dynamics or transport were increasingly associated with pathologies such as MPN and thrombocytosis. It also became apparent that TpoR affected hematopoietic stem cell (HSC) quiescence while priming hematopoietic stem cells (HSCs) towards the megakaryocyte lineage. Thorough knowledge of TpoR surface localization, dimerization, dynamics and stability is therefore crucial to understanding thrombopoiesis and related pathologies. In this review, we will discuss the mechanisms of TpoR traffic. We will focus on the recent progress in TpoR membrane dynamics and highlight the areas that remain unexplored.
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Affiliation(s)
- Anita Roy
- Kusuma School of Biological Sciences, Indian Institute of Technology, New Delhi, India
| | - Saurabh Shrivastva
- Kusuma School of Biological Sciences, Indian Institute of Technology, New Delhi, India
| | - Saadia Naseer
- Kusuma School of Biological Sciences, Indian Institute of Technology, New Delhi, India
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12
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Integration of Molecular Information in Risk Assessment of Patients with Myeloproliferative Neoplasms. Cells 2021; 10:cells10081962. [PMID: 34440731 PMCID: PMC8391705 DOI: 10.3390/cells10081962] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 07/27/2021] [Accepted: 07/30/2021] [Indexed: 12/30/2022] Open
Abstract
Philadelphia chromosome-negative myeloproliferative neoplasms (MPN) are clonal disorders of a hematopoietic stem cell, characterized by an abnormal proliferation of largely mature cells driven by mutations in JAK2, CALR, and MPL. All these mutations lead to a constitutive activation of the JAK-STAT signaling, which represents a target for therapy. Beyond driver ones, most patients, especially with myelofibrosis, harbor mutations in an array of "myeloid neoplasm-associated" genes that encode for proteins involved in chromatin modification and DNA methylation, RNA splicing, transcription regulation, and oncogenes. These additional mutations often arise in the context of clonal hematopoiesis of indeterminate potential (CHIP). The extensive characterization of the pathologic genome associated with MPN highlighted selected driver and non-driver mutations for their clinical informativeness. First, driver mutations are enlisted in the WHO classification as major diagnostic criteria and may be used for monitoring of residual disease after transplantation and response to treatment. Second, mutation profile can be used, eventually in combination with cytogenetic, histopathologic, hematologic, and clinical variables, to risk stratify patients regarding thrombosis, overall survival, and rate of transformation to secondary leukemia. This review outlines the molecular landscape of MPN and critically interprets current information for their potential impact on patient management.
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Nann D, Fend F. Synoptic Diagnostics of Myeloproliferative Neoplasms: Morphology and Molecular Genetics. Cancers (Basel) 2021; 13:cancers13143528. [PMID: 34298741 PMCID: PMC8303289 DOI: 10.3390/cancers13143528] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 07/06/2021] [Accepted: 07/09/2021] [Indexed: 02/02/2023] Open
Abstract
Simple Summary The diagnosis of myeloproliferative neoplasms requires assessment of a combination of clinical, morphological, immunophenotypic and genetic features, and this integrated, multimodal approach forms the basis for precise classification. Evaluation includes cell counts and morphology in the peripheral blood, bone marrow aspiration and trephine biopsy, and may encompass flow cytometry for specific questions. Diagnosis nowadays is completed by targeted molecular analysis for the detection of recurrent driver and, optionally, disease-modifying mutations. According to the current World Health Organization classification, all myeloproliferative disorders require assessment of molecular features to support the diagnosis or confirm a molecularly defined entity. This requires a structured molecular analysis workflow tailored for a rapid and cost-effective diagnosis. The review focuses on the morphological and molecular features of Ph-negative myeloproliferative neoplasms and their differential diagnoses, addresses open questions of classification, and emphasizes the enduring role of histopathological assessment in the molecular era. Abstract The diagnosis of a myeloid neoplasm relies on a combination of clinical, morphological, immunophenotypic and genetic features, and an integrated, multimodality approach is needed for precise classification. The basic diagnostics of myeloid neoplasms still rely on cell counts and morphology of peripheral blood and bone marrow aspirate, flow cytometry, cytogenetics and bone marrow trephine biopsy, but particularly in the setting of Ph− myeloproliferative neoplasms (MPN), the trephine biopsy has a crucial role. Nowadays, molecular studies are of great importance in confirming or refining a diagnosis and providing prognostic information. All myeloid neoplasms of chronic evolution included in this review, nowadays feature the presence or absence of specific genetic markers in their diagnostic criteria according to the current WHO classification, underlining the importance of molecular studies. Crucial differential diagnoses of Ph− MPN are the category of myeloid/lymphoid neoplasms with eosinophilia and gene rearrangement of PDGFRA, PDGFRB or FGFR1, or with PCM1-JAK2, and myelodysplastic/myeloproliferative neoplasms (MDS/MPN). This review focuses on morphological, immunophenotypical and molecular features of BCR-ABL1-negative MPN and their differential diagnoses. Furthermore, areas of difficulties and open questions in their classification are addressed, and the persistent role of morphology in the area of molecular medicine is discussed.
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Affiliation(s)
- Dominik Nann
- Institute of Pathology and Neuropathology, University Hospital Tübingen, 72076 Tübingen, Germany;
- Comprehensive Cancer Center, University Hospital Tübingen, 72076 Tübingen, Germany
| | - Falko Fend
- Institute of Pathology and Neuropathology, University Hospital Tübingen, 72076 Tübingen, Germany;
- Comprehensive Cancer Center, University Hospital Tübingen, 72076 Tübingen, Germany
- Correspondence: ; Tel.: +49-7071-2980207
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14
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Functional Consequences of Mutations in Myeloproliferative Neoplasms. Hemasphere 2021; 5:e578. [PMID: 34095761 PMCID: PMC8171364 DOI: 10.1097/hs9.0000000000000578] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 04/13/2021] [Indexed: 01/14/2023] Open
Abstract
Driver mutations occur in Janus kinase 2 (JAK2), thrombopoietin receptor (MPL), and calreticulin (CALR) in BCR-ABL1 negative myeloproliferative neoplasms (MPNs). From mutations leading to one amino acid substitution in JAK2 or MPL, to frameshift mutations in CALR resulting in a protein with a different C-terminus, all the mutated proteins lead to pathologic and persistent JAK2-STAT5 activation. The most prevalent mutation, JAK2 V617F, is associated with the 3 entities polycythemia vera (PV), essential thrombocythemia (ET), and myelofibrosis (MF), while CALR and MPL mutations are associated only with ET and MF. Triple negative ET and MF patients may harbor noncanonical mutations in JAK2 or MPL. One major fundamental question is whether the conformations of JAK2 V617F, MPL W515K/L/A, or CALR mutants differ from those of their wild type counterparts so that a specific treatment could target the clone carrying the mutated driver and spare physiological hematopoiesis. Of great interest, a set of epigenetic mutations can co-exist with the phenotypic driver mutations in 35%–40% of MPNs. These epigenetic mutations, such as TET2, EZH2, ASXL1, or DNMT3A mutations, promote clonal hematopoiesis and increased fitness of aged hematopoietic stem cells in both clonal hematopoiesis of indeterminate potential (CHIP) and MPNs. Importantly, the main MPN driver mutation JAK2 V617F is also associated with CHIP. Accumulation of several epigenetic and splicing mutations favors progression of MPNs to secondary acute myeloid leukemia. Another major fundamental question is how epigenetic rewiring due to these mutations interacts with persistent JAK2-STAT5 signaling. Answers to these questions are required for better therapeutic interventions aimed at preventing progression of ET and PV to MF, and transformation of these MPNs in secondary acute myeloid leukemia.
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15
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Lee SE. Disease modifying agents of myeloproliferative neoplasms: a review. Blood Res 2021; 56:S26-S33. [PMID: 33935032 PMCID: PMC8093995 DOI: 10.5045/br.2021.2020325] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 03/25/2021] [Accepted: 03/30/2021] [Indexed: 01/14/2023] Open
Abstract
The identification of driver mutations in Janus kinase (JAK) 2, calreticulin (CALR), and myeloproliferative leukemia (MPL) has contributed to a better understanding of disease pathogenesis by highlighting the importance of JAK signal transducer and activator of transcription (STAT) signaling in classical myeloproliferative neoplasms (MPNs). This has led to the therapeutic use of novel targeted treatments, such as JAK2 inhibitors. More recently, with the development of next-generation sequencing, additional somatic mutations, which are not restricted to MPNs, have been elucidated. Treatment decisions for MPN patients are influenced by the MPN subtype, symptom burden, and risk classification. Although prevention of vascular events is the main objective of therapy for essential thrombocythemia (ET) and polycythemia vera (PV) patients, disease-modifying drugs are needed to eradicate clonal hematopoiesis and prevent progression to more aggressive myeloid neoplasms. JAK inhibitors are a valuable therapeutic strategy for patients with myelofibrosis (MF) who have splenomegaly and/or disease-related symptoms, but intolerance, refractory, resistance, and disease progression still present challenges. Currently, allogeneic stem cell transplantation remains the only curative treatment for MF, but it is typically limited by age-related comorbidities and high treatment-related mortality. Therefore, a better understanding of the molecular pathogenesis and potential new therapies with the aim of modifying the natural history of the disease is important. In this article, I review the current understanding of the molecular basis of MPNs and clinical studies on potential disease-modifying agents.
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Affiliation(s)
- Sung-Eun Lee
- Department of Hematology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea
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16
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Makarik TV, Abdullaev AO, Nikulina EE, Treglazova SA, Stepanova EE, Subortseva IN, Kovrigina AM, Melikyan AL, Kulikov SM, Sudarikov AB. Low JAK2 V617F Allele Burden in Ph-Negative Chronic Myeloproliferative Neoplasms Is Associated with Additional CALR or MPL Gene Mutations. Genes (Basel) 2021; 12:genes12040559. [PMID: 33921387 PMCID: PMC8069892 DOI: 10.3390/genes12040559] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 04/07/2021] [Accepted: 04/08/2021] [Indexed: 01/08/2023] Open
Abstract
JAK2 (Janus kinase 2) V617F, CALR (Calreticulin) exon 9, and MPL (receptor for thrombopoietin) exon 10 mutations are associated with the vast majority of Ph-negative chronic myeloproliferative neoplasms (MPNs). These mutations affect sequential stages of proliferative signal transduction and therefore, after the emergence of one type of mutation, other types should not have any selective advantages for clonal expansion. However, simultaneous findings of these mutations have been reported by different investigators in up to 10% of MPN cases. Our study includes DNA samples from 1958 patients with clinical evidence of MPN, admitted to the National Research Center for Hematology for genetic analysis between 2016 and 2019. In 315 of 1402 cases (22.6%), CALR mutations were detected. In 23 of these 315 cases (7.3%), the JAK2 V617F mutation was found in addition to the CALR mutation. In 16 from 24 (69.6%) cases, with combined CALR and JAK2 mutations, V617F allele burden was lower than 1%. A combination of JAK2 V617F with MPL W515L/K was also observed in 1 out of 1348 cases, only. JAK2 allele burden in this case was also lower than 1%. Additional mutations may coexist over the low background of JAK2 V617F allele. Therefore, in cases of detecting MPNs with a low allelic load JAK2 V617F, it may be advisable to search for other molecular markers, primarily mutations in exon 9 of CALR. The load of the combined mutations measured at different time points may indicate that, at least in some cases, these mutations could be represented by different clones of malignant cells.
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17
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Loscocco GG, Guglielmelli P, Vannucchi AM. Impact of Mutational Profile on the Management of Myeloproliferative Neoplasms: A Short Review of the Emerging Data. Onco Targets Ther 2020; 13:12367-12382. [PMID: 33293830 PMCID: PMC7718985 DOI: 10.2147/ott.s287944] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 11/18/2020] [Indexed: 12/16/2022] Open
Abstract
Philadelphia-chromosome negative myeloproliferative neoplasms (MPN) are a heterogeneous group of clonal hematopoietic stem cell disorders characterized by an increased risk of thrombosis and progression to acute myeloid leukemia. MPN are associated with driver mutations in JAK2, CALR and MPL which are crucial for the diagnosis and lead to a constitutive activation of the JAK-STAT signaling, independent of cytokine regulation. Moreover, most patients have concomitant mutations in genes involved in DNA methylation, chromatin modification, messenger RNA splicing, transcription regulation and signal transduction. These additional mutations may arise before, in the context of clonal hematopoiesis of indeterminate potential (CHIP), or after the acquisition of the driver mutation. The clinical phenotype of MPN results from complex interactions between mutations and host factors. The increased application of next-generation sequencing (NGS) techniques to a large series of patients with MPN has expanded the knowledge of mutational landscape and contributed to define the clinical significance of mutations. This molecular information is being increasingly used to refine diagnosis, risk stratification, monitoring of residual disease and response to treatment. ASXL1, SRSF2, EZH2, IDH1/IDH2 and U2AF1 mutations are associated with a more advanced disease and reduced overall survival in primary myelofibrosis (PMF), whereas spliceosome mutations in Polycythemia vera (PV) and essential thrombocythemia (ET) adversely affect both overall (SF3B1, SRSF2 in ET and SRSF2 in PV) and myelofibrosis-free (U2AF1, SF3B1 in ET) survival. This review discusses current knowledge of the molecular landscape of MPN, and how the availability of those molecular information may impact patient management.
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Affiliation(s)
- Giuseppe G Loscocco
- CRIMM, Centro di Ricerca e Innovazione per le Malattie Mieloproliferative, Azienda Ospedaliero-Universitaria Careggi, Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Paola Guglielmelli
- CRIMM, Centro di Ricerca e Innovazione per le Malattie Mieloproliferative, Azienda Ospedaliero-Universitaria Careggi, Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Alessandro M Vannucchi
- CRIMM, Centro di Ricerca e Innovazione per le Malattie Mieloproliferative, Azienda Ospedaliero-Universitaria Careggi, Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
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18
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Ramesh S, Park S, Call MJ, Im W, Call ME. Experimentally Guided Computational Methods Yield Highly Accurate Insights into Transmembrane Interactions within the T Cell Receptor Complex. J Phys Chem B 2020; 124:10303-10310. [PMID: 33030343 DOI: 10.1021/acs.jpcb.0c06403] [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
Understanding how molecular interactions within the plasma membrane govern assembly, clustering, and conformational changes in single-pass transmembrane (TM) receptors has long presented substantial experimental challenges. Our previous work on activating immune receptors has combined direct biochemical and biophysical characterizations with both independent and experimentally restrained computational methods to provide novel insights into the key TM interactions underpinning assembly and stability of complex, multisubunit receptor systems. The recently published cryo-EM structure of the intact T cell receptor (TCR)-CD3 complex provides a unique opportunity to test the models and predictions arising from these studies, and we find that they are accurate, which we attribute to robust simulation environments and careful consideration of limitations related to studying TM interactions in isolation from additional receptor domains. With this in mind, we revisit results in other immune receptors and look forward to how similar methods may be applied to understand receptors for which little or no structural information is currently available.
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Affiliation(s)
- Samyuktha Ramesh
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia.,Department of Medical Biology, University of Melbourne, Parkville, Victoria 3052, Australia
| | - Soohyung Park
- Departments of Biological Sciences, Chemistry, Bioengineering, and Computer Science and Engineering, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Melissa J Call
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia.,Department of Medical Biology, University of Melbourne, Parkville, Victoria 3052, Australia
| | - Wonpil Im
- Departments of Biological Sciences, Chemistry, Bioengineering, and Computer Science and Engineering, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Matthew E Call
- The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria 3052, Australia.,Department of Medical Biology, University of Melbourne, Parkville, Victoria 3052, Australia
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19
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MPL mutations in essential thrombocythemia uncover a common path of activation with eltrombopag dependent on W491. Blood 2020; 135:948-953. [PMID: 31978223 DOI: 10.1182/blood.2019003240] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 01/10/2020] [Indexed: 12/26/2022] Open
Abstract
Mutations in the MPL gene encoding the human thrombopoietin receptor (TpoR) drive sporadic and familial essential thrombocythemias (ETs). We identified 2 ET patients harboring double mutations in cis in MPL, namely, L498W-H499C and H499Y-S505N. Using biochemical and signaling assays along with partial saturation mutagenesis, we showed that L498W is an activating mutation potentiated by H499C and that H499C and H499Y enhance the activity of the canonical S505N mutation. L498W and H499C can activate a truncated TpoR mutant, which lacks the extracellular domain, indicating these mutations act on the transmembrane (TM) cytosolic domain. Using a protein complementation assay, we showed that L498W and H499C strongly drive dimerization of TpoR. Activation by tryptophan substitution is exquisitely specific for position 498. Using structure-guided mutagenesis, we identified upstream amino acid W491 as a key residue required for activation by L498W or canonical activating mutations such as S505N and W515K, as well as by eltrombopag. Structural data point to a common dimerization and activation path for TpoR via its TM domain that is shared between the small-molecule agonist eltrombopag and canonical and novel activating TpoR mutations that all depend on W491, a potentially accessible extracellular residue that could become a target for therapeutic intervention.
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20
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Novel drivers and modifiers of MPL-dependent oncogenic transformation identified by deep mutational scanning. Blood 2020; 135:287-292. [PMID: 31697803 DOI: 10.1182/blood.2019002561] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 09/20/2019] [Indexed: 12/15/2022] Open
Abstract
The single transmembrane domain (TMD) of the human thrombopoietin receptor (TpoR/myeloproliferative leukemia [MPL] protein), encoded by exon 10 of the MPL gene, is a hotspot for somatic mutations associated with myeloproliferative neoplasms (MPNs). Approximately 6% and 14% of JAK2 V617F- essential thrombocythemia and primary myelofibrosis patients, respectively, have "canonical" MPL exon 10 driver mutations W515L/K/R/A or S505N, which generate constitutively active receptors and consequent loss of Tpo dependence. Other "noncanonical" MPL exon 10 mutations have also been identified in patients, both alone and in combination with canonical mutations, but, in almost all cases, their functional consequences and relevance to disease are unknown. Here, we used a deep mutational scanning approach to evaluate all possible single amino acid substitutions in the human TpoR TMD for their ability to confer cytokine-independent growth in Ba/F3 cells. We identified all currently recognized driver mutations and 7 novel mutations that cause constitutive TpoR activation, and a much larger number of second-site mutations that enhance S505N-driven activation. We found examples of both of these categories in published and previously unpublished MPL exon 10 sequencing data from MPN patients, demonstrating that some, if not all, of the new mutations reported here represent likely drivers or modifiers of myeloproliferative disease.
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21
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Wilmes S, Hafer M, Vuorio J, Tucker JA, Winkelmann H, Löchte S, Stanly TA, Pulgar Prieto KD, Poojari C, Sharma V, Richter CP, Kurre R, Hubbard SR, Garcia KC, Moraga I, Vattulainen I, Hitchcock IS, Piehler J. Mechanism of homodimeric cytokine receptor activation and dysregulation by oncogenic mutations. Science 2020; 367:643-652. [PMID: 32029621 PMCID: PMC8117407 DOI: 10.1126/science.aaw3242] [Citation(s) in RCA: 94] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 10/08/2019] [Accepted: 12/20/2019] [Indexed: 12/11/2022]
Abstract
Homodimeric class I cytokine receptors are assumed to exist as preformed dimers that are activated by ligand-induced conformational changes. We quantified the dimerization of three prototypic class I cytokine receptors in the plasma membrane of living cells by single-molecule fluorescence microscopy. Spatial and spatiotemporal correlation of individual receptor subunits showed ligand-induced dimerization and revealed that the associated Janus kinase 2 (JAK2) dimerizes through its pseudokinase domain. Oncogenic receptor and hyperactive JAK2 mutants promoted ligand-independent dimerization, highlighting the formation of receptor dimers as the switch responsible for signal activation. Atomistic modeling and molecular dynamics simulations based on a detailed energetic analysis of the interactions involved in dimerization yielded a mechanistic blueprint for homodimeric class I cytokine receptor activation and its dysregulation by individual mutations.
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Affiliation(s)
- Stephan Wilmes
- Department of Biology and Center of Cellular Nanoanalytics, University of Osnabrück, 49076 Osnabrück, Germany
- Division of Cell Signalling and Immunology, School of Life Sciences, University of Dundee, Dundee, UK
| | - Maximillian Hafer
- Department of Biology and Center of Cellular Nanoanalytics, University of Osnabrück, 49076 Osnabrück, Germany
| | - Joni Vuorio
- Department of Physics, University of Helsinki, Helsinki, Finland
- Computational Physics Laboratory, Tampere University, Tampere, Finland
| | - Julie A Tucker
- York Biomedical Research Institute and Department of Biology, University of York, Heslington, York YO10 5DD, UK
| | - Hauke Winkelmann
- Department of Biology and Center of Cellular Nanoanalytics, University of Osnabrück, 49076 Osnabrück, Germany
| | - Sara Löchte
- Department of Biology and Center of Cellular Nanoanalytics, University of Osnabrück, 49076 Osnabrück, Germany
| | - Tess A Stanly
- York Biomedical Research Institute and Department of Biology, University of York, Heslington, York YO10 5DD, UK
| | - Katiuska D Pulgar Prieto
- York Biomedical Research Institute and Department of Biology, University of York, Heslington, York YO10 5DD, UK
| | - Chetan Poojari
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - Vivek Sharma
- Department of Physics, University of Helsinki, Helsinki, Finland
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Christian P Richter
- Department of Biology and Center of Cellular Nanoanalytics, University of Osnabrück, 49076 Osnabrück, Germany
| | - Rainer Kurre
- Department of Biology and Center of Cellular Nanoanalytics, University of Osnabrück, 49076 Osnabrück, Germany
| | - Stevan R Hubbard
- Skirball Institute and Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
| | - K Christopher Garcia
- Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA, USA
- Department of Molecular and Cellular Physiology and Department of Structural Biology, Stanford University School of Medicine, Stanford, CA, USA
| | - Ignacio Moraga
- Division of Cell Signalling and Immunology, School of Life Sciences, University of Dundee, Dundee, UK
| | - Ilpo Vattulainen
- Department of Physics, University of Helsinki, Helsinki, Finland.
- Computational Physics Laboratory, Tampere University, Tampere, Finland
| | - Ian S Hitchcock
- York Biomedical Research Institute and Department of Biology, University of York, Heslington, York YO10 5DD, UK.
| | - Jacob Piehler
- Department of Biology and Center of Cellular Nanoanalytics, University of Osnabrück, 49076 Osnabrück, Germany.
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22
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MPL membrane domain sequencing goes deep. Blood 2020; 135:236-237. [PMID: 31972012 DOI: 10.1182/blood.2019003482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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23
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C. Diaconu C, Gurban P, Mambet C, Chivu-Economescu M, G. Necula L, Matei L, Dragu D, Nedeianu S, I. Neagu A, Tatic A, Cristodor D, Bleotu C. Programmed Cell Death Deregulation in BCR-ABL1-Negative Myeloproliferative Neoplasms. PROGRAMMED CELL DEATH 2020. [DOI: 10.5772/intechopen.86062] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/26/2024]
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24
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Jang MA, Choi CW. Recent insights regarding the molecular basis of myeloproliferative neoplasms. Korean J Intern Med 2020; 35:1-11. [PMID: 31778606 PMCID: PMC6960053 DOI: 10.3904/kjim.2019.317] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 11/11/2019] [Indexed: 12/14/2022] Open
Abstract
Myeloproliferative neoplasms (MPNs) are a heterogeneous group of clonal disorders characterized by the overproduction of mature blood cells that have an increased risk of thrombosis and progression to acute myeloid leukemia. Next-generation sequencing studies have provided key insights regarding the molecular mechanisms of MPNs. MPN driver mutations in genes associated with the JAK-STAT pathway include JAK2 V617F, JAK2 exon 12 mutations and mutations in MPL, CALR, and CSF3R. Cooperating driver genes are also frequently detected and also mutated in other myeloid neoplasms; these driver genes are involved in epigenetic methylation, messenger RNA splicing, transcription regulation, and signal transduction. In addition, other genetic factors such as germline predisposition, order of mutation acquisition, and variant allele frequency also influence disease initiation and progression. This review summarizes the current understanding of the genetic basis of MPN, and demonstrates how molecular pathophysiology can improve both our understanding of MPN heterogeneity and clinical practice.
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Affiliation(s)
- Mi-Ae Jang
- Department of Laboratory Medicine and Genetics, Soonchunhyang University Bucheon Hospital, Bucheon, Korea
| | - Chul Won Choi
- Division of Oncology and Hematology, Department of Internal Medicine, Korea University Guro Hospital, Seoul, Korea
- Correspondence to Chul Won Choi, M.D. Division of Oncology and Hematology, Department of Internal Medicine, Korea University Guro Hospital, 148 Gurodong-ro, Guro-gu, Seoul 08308, Korea Tel: +82-2-2626-3058 Fax: +82-2-862-6453 E-mail:
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25
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Wang B, Mehta H. Cytokine receptor splice variants in hematologic diseases. Cytokine 2019; 127:154919. [PMID: 31816579 DOI: 10.1016/j.cyto.2019.154919] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 10/08/2019] [Accepted: 11/04/2019] [Indexed: 12/13/2022]
Abstract
Cytokine and cytokine receptors are important regulators of hematopoiesis. Hematopoietic stem cells (HSCs) and progenitors differentiate into the myeloid or lymphoid lineage in response to specific cytokines. Cell-type specific receptors are expressed on committed progenitors that bind to other late-acting cytokines that are involved in terminal differentiation of hematopoietic cells. In normal hematopoiesis, these receptors undergo alternative splicing and are developmentally regulated. Splicing changes can significantly affect the structure and function of the receptors resulting in alterations of either the extracellular ligand binding domain or the cytoplasmic signaling domain responsible for cellular growth and differentiation. Most alternatively spliced isoforms generally lose the ability to promote differentiation. Evidently, overexpression of naturally occurring cytokine receptor alternate isoforms are observed in multiple myeloid diseases such as myelodysplastic syndromes (MDS), acute myeloid leukemia (AML), and polycythemia vera (PV). The purpose of this review is to introduce the various isoforms of key cytokine receptors that play a crucial role in myeloid development and their potential role in myeloid diseases.
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Affiliation(s)
- Borwyn Wang
- Center for Clinical and Translational Research, Virginia Commonwealth University, Richmond, VA, United States; Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Hrishikesh Mehta
- Department of Cancer Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States.
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26
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Labuhn M, Perkins K, Matzk S, Varghese L, Garnett C, Papaemmanuil E, Metzner M, Kennedy A, Amstislavskiy V, Risch T, Bhayadia R, Samulowski D, Hernandez DC, Stoilova B, Iotchkova V, Oppermann U, Scheer C, Yoshida K, Schwarzer A, Taub JW, Crispino JD, Weiss MJ, Hayashi Y, Taga T, Ito E, Ogawa S, Reinhardt D, Yaspo ML, Campbell PJ, Roberts I, Constantinescu SN, Vyas P, Heckl D, Klusmann JH. Mechanisms of Progression of Myeloid Preleukemia to Transformed Myeloid Leukemia in Children with Down Syndrome. Cancer Cell 2019; 36:123-138.e10. [PMID: 31303423 PMCID: PMC6863161 DOI: 10.1016/j.ccell.2019.06.007] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 04/07/2019] [Accepted: 06/11/2019] [Indexed: 12/22/2022]
Abstract
Myeloid leukemia in Down syndrome (ML-DS) clonally evolves from transient abnormal myelopoiesis (TAM), a preleukemic condition in DS newborns. To define mechanisms of leukemic transformation, we combined exome and targeted resequencing of 111 TAM and 141 ML-DS samples with functional analyses. TAM requires trisomy 21 and truncating mutations in GATA1; additional TAM variants are usually not pathogenic. By contrast, in ML-DS, clonal and subclonal variants are functionally required. We identified a recurrent and oncogenic hotspot gain-of-function mutation in myeloid cytokine receptor CSF2RB. By a multiplex CRISPR/Cas9 screen in an in vivo murine TAM model, we tested loss-of-function of 22 recurrently mutated ML-DS genes. Loss of 18 different genes produced leukemias that phenotypically, genetically, and transcriptionally mirrored ML-DS.
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MESH Headings
- Animals
- Biomarkers, Tumor/genetics
- Cell Transformation, Neoplastic/genetics
- Chromosomes, Human, Pair 21
- Cytokine Receptor Common beta Subunit/genetics
- Disease Models, Animal
- Disease Progression
- Down Syndrome/diagnosis
- Down Syndrome/genetics
- GATA1 Transcription Factor/genetics
- GATA1 Transcription Factor/metabolism
- Gene Expression Regulation, Leukemic
- Genetic Predisposition to Disease
- HEK293 Cells
- Humans
- Leukemia, Myeloid/diagnosis
- Leukemia, Myeloid/genetics
- Leukemia, Myeloid/pathology
- Leukemoid Reaction/diagnosis
- Leukemoid Reaction/genetics
- Mice, Inbred C57BL
- Mice, Inbred NOD
- Mice, Transgenic
- Mutation
- Phenotype
- Transcription, Genetic
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Affiliation(s)
- Maurice Labuhn
- Pediatric Hematology and Oncology, Hannover Medical School, 30625 Hannover, Germany
| | - Kelly Perkins
- MRC MHU, BRC Hematology Theme, Oxford Biomedical Research Centre, Oxford Centre for Haematology, WIMM, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK
| | - Sören Matzk
- Pediatric Hematology and Oncology, Martin-Luther-University Halle-Wittenberg, 06120 Halle, Germany; Max Planck Institute for Molecular Genetics, 14195 Berlin, Germany
| | - Leila Varghese
- Ludwig Institute for Cancer Research Brussels Branch, 1200 Brussels, Belgium
| | - Catherine Garnett
- MRC MHU, BRC Hematology Theme, Oxford Biomedical Research Centre, Oxford Centre for Haematology, WIMM, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK
| | - Elli Papaemmanuil
- Departments of Epidemiology and Biostatistics and Cancer Biology, MSKCC, New York, NY 10065, USA
| | - Marlen Metzner
- MRC MHU, BRC Hematology Theme, Oxford Biomedical Research Centre, Oxford Centre for Haematology, WIMM, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK
| | - Alison Kennedy
- MRC MHU, BRC Hematology Theme, Oxford Biomedical Research Centre, Oxford Centre for Haematology, WIMM, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK
| | | | - Thomas Risch
- Max Planck Institute for Molecular Genetics, 14195 Berlin, Germany
| | - Raj Bhayadia
- Pediatric Hematology and Oncology, Martin-Luther-University Halle-Wittenberg, 06120 Halle, Germany
| | - David Samulowski
- Pediatric Hematology and Oncology, Martin-Luther-University Halle-Wittenberg, 06120 Halle, Germany
| | - David Cruz Hernandez
- MRC MHU, BRC Hematology Theme, Oxford Biomedical Research Centre, Oxford Centre for Haematology, WIMM, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK
| | - Bilyana Stoilova
- MRC MHU, BRC Hematology Theme, Oxford Biomedical Research Centre, Oxford Centre for Haematology, WIMM, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK
| | - Valentina Iotchkova
- MRC MHU, BRC Hematology Theme, Oxford Biomedical Research Centre, Oxford Centre for Haematology, WIMM, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK
| | - Udo Oppermann
- Botnar Research Centre, NDORMS, Oxford NIHR BRC and Structural Genomics Consortium, UK University of Oxford, Oxford OX3 7LD, UK
| | - Carina Scheer
- Pediatric Hematology and Oncology, Hannover Medical School, 30625 Hannover, Germany
| | - Kenichi Yoshida
- Department of Pathology and Tumor Biology, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto 606-8315 Japan
| | - Adrian Schwarzer
- Pediatric Hematology and Oncology, Hannover Medical School, 30625 Hannover, Germany
| | - Jeffrey W Taub
- Division of Pediatric Hematology/Oncology, Children's Hospital of Michigan, Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - John D Crispino
- Division of Hematology/Oncology, Northwestern University, Chicago, IL 60611, USA
| | - Mitchell J Weiss
- Hematology Department, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Yasuhide Hayashi
- Institute of Physiology and Medicine, Jobu University, Takasaki-shi, Gunma 370-0033, Japan
| | - Takashi Taga
- Department of Pediatrics, Shiga University of Medical Science, Shiga 520-2192, Japan
| | - Etsuro Ito
- Department of Pediatrics, Hirosaki University Graduate School of Medicine, Hirosaki 036-8562, Japan
| | - Seishi Ogawa
- Department of Pathology and Tumor Biology, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto 606-8315 Japan; Center for Hematology and Regenerative Medicine, Karolinska Institute, 171 77 Stockholm, Sweden
| | - Dirk Reinhardt
- Pediatric Hematology and Oncology, Pediatrics III, University Hospital Essen, 45122 Essen, Germany
| | | | - Peter J Campbell
- Cancer Genome Project, Wellcome Trust Sanger Institute, Hinxton CB10 1SA, UK
| | - Irene Roberts
- MRC MHU, BRC Hematology Theme, Oxford Biomedical Research Centre, Oxford Centre for Haematology, WIMM, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK; Department of Paediatrics, University of Oxford, Oxford OX3 9DS, UK
| | | | - Paresh Vyas
- MRC MHU, BRC Hematology Theme, Oxford Biomedical Research Centre, Oxford Centre for Haematology, WIMM, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 9DU, UK; Department of Haematology, Oxford University Hospitals NHS Trust, Oxford OX3 7LE, UK.
| | - Dirk Heckl
- Pediatric Hematology and Oncology, Hannover Medical School, 30625 Hannover, Germany; Pediatric Hematology and Oncology, Martin-Luther-University Halle-Wittenberg, 06120 Halle, Germany.
| | - Jan-Henning Klusmann
- Pediatric Hematology and Oncology, Martin-Luther-University Halle-Wittenberg, 06120 Halle, Germany.
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27
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Schulze S, Stengel R, Jaekel N, Wang SY, Franke GN, Roskos M, Schneider M, Niederwieser D, Al-Ali HK. Concomitant and noncanonical JAK2 and MPL mutations in JAK2V617F- and MPLW515 L-positive myelofibrosis. Genes Chromosomes Cancer 2019; 58:747-755. [PMID: 31135094 DOI: 10.1002/gcc.22781] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 04/29/2019] [Accepted: 05/23/2019] [Indexed: 11/10/2022] Open
Abstract
Sequential genotyping for phenotype-driver mutations in JAK2 (exon 14), CALR (exon 9), and MPL (exon 10) is recommended in patients with myeloproliferative neoplasms. Yet, atypical JAK2- and MPL-mutations were described in some triple-negative patients. Whether noncanonical and/or concomitant JAK2- and MPL-mutations exist in myelofibrosis (MF) regardless of phenotype-driver mutations is not yet elucidated. For this, next-generation sequencing (NGS) was performed using blood genomic DNA from 128 MF patients (primary MF, n = 93; post-ET-MF, n = 18; post-PV-MF, n = 17). While no atypical JAK2- or MPL-mutations were seen in 24 CALR-positive samples, two JAK2-mutations [c.3323A > G, p.N1108S; c.3188G > A, p.R1063H] were detected in two of the 21 (9.5%) triple-negative patients. Twelve of the 82 (14.6%) JAK2V617F-positive cases had coexisting germline JAK2-mutations [JAK2R1063H, n = 6; JAK2R893T, n = 1; JAK2T525A, n = 1] or at least one somatic MPL-mutation [MPLY591D, n = 3; MPLW515 L, n = 2; MPLE335K, n = 1]. Overall, MPL-mutations always coexisted with JAK2V617F and/or other MPL-mutations. None of the JAK2V617F plus a second JAK2-mutation carried a TET2-mutation but all patients with JAK2V617F plus an MPL-mutation harbored a somatic TET2-mutation. Four genomic clusters could be identified in the JAK2V617F-positive cohort. Cluster-I (10%) (noncanonical JAK2mutated (mut) + TET2wildtype (wt) ) were younger and had less proliferative disease compared with cluster-IV (5%) (TET2mut + MPLmut ). In conclusion, recurrent concomitant classical and/or noncanonical JAK2- and MPL-mutations could be detected by NGS in 15.7% of JAK2V617F- and MPLW515-positive MF patients with genotype-phenotype associations. Many of the germline and/or somatic mutations might act as "Significantly Mutated Genes" contributing to the pathogenesis and phenotypic heterogeneity. A cost-effective NGS-based approach might be an important step towards patient-tailored medicine.
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Affiliation(s)
- Susann Schulze
- Department of Hematology/Oncology, University Hospital Halle, Halle (Saale), Germany
| | | | - Nadja Jaekel
- Department of Hematology/Oncology, University Hospital Halle, Halle (Saale), Germany
| | - Song-Yau Wang
- Department of Hematology/Oncology, University Hospital of Leipzig, Leipzig, Germany
| | | | | | | | - Dietger Niederwieser
- Department of Hematology/Oncology, University Hospital of Leipzig, Leipzig, Germany
| | - Haifa Kathrin Al-Ali
- Department of Hematology/Oncology, University Hospital Halle, Halle (Saale), Germany
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28
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Vainchenker W, Plo I, Marty C, Varghese LN, Constantinescu SN. The role of the thrombopoietin receptor MPL in myeloproliferative neoplasms: recent findings and potential therapeutic applications. Expert Rev Hematol 2019; 12:437-448. [PMID: 31092065 DOI: 10.1080/17474086.2019.1617129] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Introduction: Classical Myeloproliferative Neoplasms (MPNs) include three disorders: Polycythemia Vera (PV), Essential Thrombocythemia (ET) and Primary Myelofibrosis (PMF). MPNs are associated with constitutive activation of JAK2 leading to persistent cell signaling downstream of the dimeric myeloid cytokine receptors due to mutations in three genes encoding JAK2, calreticulin (CALR) and the thrombopoietin (TPO) receptor (MPL or TPOR). CALR and MPL mutants induce JAK2 activation that depends on MPL expression, thus explaining why they induce megakaryocyte pathologies including ET and PMF, but not PV. In contrast, JAK2 V617F drives all three diseases as it induces persistent signaling via EPOR, G-CSFR (CSF3R) and MPL. Areas Covered: Here, we review how different pathogenic mutations of MPL are translated into active receptors by inducing stable dimerization. We focus on the unique role of MPL on the hematopoietic stem cell (HSC), explaining why MPL is indispensable for the development of all MPNs. Last but not least, we describe how CALR mutants are pathogenic via binding and activation of MPL. Expert Opinion: Altogether, we believe that MPL is an important, but challenging, therapeutic target in MPNs that requires novel strategies to interrupt the specific conformational changes induced by each mutation or pathologic interaction without compromising the key functions of wild type MPL.
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Affiliation(s)
- William Vainchenker
- a UMR1170 , INSERM , Villejuif , France.,b Université Paris-Saclay , Villejuif , France
| | - Isabelle Plo
- a UMR1170 , INSERM , Villejuif , France.,b Université Paris-Saclay , Villejuif , France
| | - Caroline Marty
- a UMR1170 , INSERM , Villejuif , France.,b Université Paris-Saclay , Villejuif , France
| | - Leila N Varghese
- c Ludwig Institute for Cancer Research Brussels , Brussels , Belgium.,d de Duve Institute, Université catholique de Louvain , Brussels , Belgium
| | - Stefan N Constantinescu
- c Ludwig Institute for Cancer Research Brussels , Brussels , Belgium.,d de Duve Institute, Université catholique de Louvain , Brussels , Belgium.,e WELBIO (Walloon Excellence in Life Sciences and Biotechnology) , Brussels , Belgium
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29
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Floss DM, Scheller J. Naturally occurring and synthetic constitutive-active cytokine receptors in disease and therapy. Cytokine Growth Factor Rev 2019; 47:1-20. [PMID: 31147158 DOI: 10.1016/j.cytogfr.2019.05.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 05/15/2019] [Indexed: 02/07/2023]
Abstract
Cytokines control immune related events and are critically involved in a plethora of patho-physiological processes including autoimmunity and cancer development. Mutations which cause ligand-independent, constitutive activation of cytokine receptors are quite frequently found in diseases. Many constitutive-active cytokine receptor variants have been directly connected to disease development and mechanistically analyzed. Nature's solutions to generate constitutive cytokine receptors has been recently adopted by synthetic cytokine receptor biology, with the goal to optimize immune therapeutics. Here, CAR T cell immmunotherapy represents the first example to combine synthetic biology with genetic engineering during therapy. Hence, constitutive-active cytokine receptors are therapeutic targets, but also emerging tools to improve or modulate immunotherapeutic strategies. This review gives a comprehensive insight into the field of naturally occurring and synthetic constitutive-active cytokine receptors.
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Affiliation(s)
- Doreen M Floss
- Institute of Biochemistry and Molecular Biology II, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany.
| | - Jürgen Scheller
- Institute of Biochemistry and Molecular Biology II, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany
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30
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Elsayed AG, Ranavaya A, Jamil MO. MPL Y252H an Md PL F126fs mutations in essential thrombocythemia: Case series and review of literature. Hematol Rep 2019; 11:7868. [PMID: 30996850 PMCID: PMC6434327 DOI: 10.4081/hr.2019.7868] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2018] [Accepted: 02/15/2019] [Indexed: 12/24/2022] Open
Abstract
Essential thrombocythemia (ET) is a clonal bone marrow disease, characterized by increased production of platelets along with other clinical and bone marrow findings. Most patients with ET will have a somatic mutation in one of the known gene locations of JAK2, CALR, or MPL that can upregulate the JAK-STAT pathway. MPL mutation is present in 5% of cases with the most common mutations being W515L and W515K. In this report we describe 2 cases of patients with clinical and laboratory picture of ET. One patient carried MPLY252H mutation which is previously unreported in the adult population but has been shown to be a gain-of-function mutation. The other patient carried MPL F126fs mutation which is not known to be of clinical importance and has not been previously reported.
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Affiliation(s)
- Ahmed G Elsayed
- Hematology Oncology Department, Promedica/University of Toledo, Toledo, OH
| | - Aeesha Ranavaya
- Hematology/Oncology Department, Joan C. Edwards School of Medicine, Marshall University, WV, USA
| | - Muhammad Omer Jamil
- Hematology/Oncology Department, Joan C. Edwards School of Medicine, Marshall University, WV, USA
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31
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Orlova A, Wingelhofer B, Neubauer HA, Maurer B, Berger-Becvar A, Keserű GM, Gunning PT, Valent P, Moriggl R. Emerging therapeutic targets in myeloproliferative neoplasms and peripheral T-cell leukemia and lymphomas. Expert Opin Ther Targets 2017; 22:45-57. [PMID: 29148847 PMCID: PMC5743003 DOI: 10.1080/14728222.2018.1406924] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Introduction: Hematopoietic neoplasms are often driven by gain-of-function mutations of the JAK-STAT pathway together with mutations in chromatin remodeling and DNA damage control pathways. The interconnection between the JAK-STAT pathway, epigenetic regulation or DNA damage control is still poorly understood in cancer cell biology. Areas covered: Here, we focus on a broader description of mutational insights into myeloproliferative neoplasms and peripheral T-cell leukemia and lymphomas, since sequencing efforts have identified similar combinations of driver mutations in these diseases covering different lineages. We summarize how these pathways might be interconnected in normal or cancer cells, which have lost differentiation capacity and drive oncogene transcription. Expert opinion: Due to similarities in driver mutations including epigenetic enzymes, JAK-STAT pathway activation and mutated checkpoint control through TP53, we hypothesize that similar therapeutic approaches could be of benefit in these diseases. We give an overview of how driver mutations in these malignancies contribute to hematopoietic cancer initiation or progression, and how these pathways can be targeted with currently available tools.
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Affiliation(s)
- Anna Orlova
- a Institute of Animal Breeding and Genetics , University of Veterinary Medicine Vienna , Vienna , Austria.,b Ludwig Boltzmann Institute for Cancer Research , Vienna , Austria
| | - Bettina Wingelhofer
- a Institute of Animal Breeding and Genetics , University of Veterinary Medicine Vienna , Vienna , Austria.,b Ludwig Boltzmann Institute for Cancer Research , Vienna , Austria
| | - Heidi A Neubauer
- a Institute of Animal Breeding and Genetics , University of Veterinary Medicine Vienna , Vienna , Austria.,b Ludwig Boltzmann Institute for Cancer Research , Vienna , Austria
| | - Barbara Maurer
- c Institute of Pharmacology and Toxicology , University of Veterinary Medicine Vienna , Vienna , Austria
| | - Angelika Berger-Becvar
- g Department of Chemical & Physical Sciences , University of Toronto Mississauga , Mississauga , Canada.,h Department of Chemistry , University of Toronto , Toronto , Canada
| | - György Miklós Keserű
- d Medicinal Chemistry Research Group, Research Centre for Natural Sciences , Hungarian Academy of Sciences , Budapest , Hungary
| | - Patrick T Gunning
- g Department of Chemical & Physical Sciences , University of Toronto Mississauga , Mississauga , Canada.,h Department of Chemistry , University of Toronto , Toronto , Canada
| | - Peter Valent
- e Department of Internal Medicine I, Division of Hematology and Hemostaseology , Medical University of Vienna , Vienna , Austria.,f Ludwig Boltzmann-Cluster Oncology , Medical University of Vienna , Vienna , Austria
| | - Richard Moriggl
- a Institute of Animal Breeding and Genetics , University of Veterinary Medicine Vienna , Vienna , Austria.,b Ludwig Boltzmann Institute for Cancer Research , Vienna , Austria.,i Medical University Vienna , Vienna , Austria
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32
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Nangalia J, Grinfeld J, Green AR. Pathogenesis of Myeloproliferative Disorders. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2017; 11:101-26. [PMID: 27193452 DOI: 10.1146/annurev-pathol-012615-044454] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Myeloproliferative neoplasms (MPNs) are a set of chronic hematopoietic neoplasms with overlapping clinical and molecular features. Recent years have witnessed considerable advances in our understanding of their pathogenetic basis. Due to their protracted clinical course, the evolution to advanced hematological malignancies, and the accessibility of neoplastic tissue, the study of MPNs has provided a window into the earliest stages of tumorigenesis. With the discovery of mutations in CALR, the majority of MPN patients now bear an identifiable marker of clonal disease; however, the mechanism by which mutated CALR perturbs megakaryopoiesis is currently unresolved. We are beginning to understand better the role of JAK2(V617F) homozygosity, the function of comutations in epigenetic regulators and spliceosome components, and how these mutations cooperate with JAK2(V617F) to modulate MPN phenotype.
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Affiliation(s)
- Jyoti Nangalia
- Department of Haematology, Cambridge Institute for Medical Research and Wellcome Trust/MRC Stem Cell Institute, University of Cambridge, Cambridge CB2 0XY, United Kingdom; .,Department of Haematology, Addenbrooke's Hospital, Cambridge CB2 2QR, United Kingdom
| | - Jacob Grinfeld
- Department of Haematology, Cambridge Institute for Medical Research and Wellcome Trust/MRC Stem Cell Institute, University of Cambridge, Cambridge CB2 0XY, United Kingdom; .,Department of Haematology, Addenbrooke's Hospital, Cambridge CB2 2QR, United Kingdom
| | - Anthony R Green
- Department of Haematology, Cambridge Institute for Medical Research and Wellcome Trust/MRC Stem Cell Institute, University of Cambridge, Cambridge CB2 0XY, United Kingdom; .,Department of Haematology, Addenbrooke's Hospital, Cambridge CB2 2QR, United Kingdom
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33
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McPherson S, McMullin MF, Mills K. Epigenetics in Myeloproliferative Neoplasms. J Cell Mol Med 2017; 21:1660-1667. [PMID: 28677265 PMCID: PMC5571538 DOI: 10.1111/jcmm.13095] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 12/15/2016] [Indexed: 12/16/2022] Open
Abstract
A decade on from the description of JAK2 V617F, the MPNs are circumscribed by an increasingly intricate landscape. There is now evidence that they are likely the result of combined genetic dysregulation, with several mutated genes involved in the regulation of epigenetic mechanisms. Epigenetic changes are not due to a change in the DNA sequence but are reversible modifications that dictate the way in which genes may be expressed (or silenced). Among the epigenetic mechanisms, DNA methylation is probably the best described. Currently known MPN‐associated mutations now include JAK2, MPL, LNK, CBL, CALR, TET2, ASXL1, IDH1, IDH2, IKZF1 and EZH2. Enhancing our knowledge about the mutation profile of patients may allow them to be stratified into risk groups which would aid clinical decision making. Ongoing work will answer whether the use of epigenetic therapies as alterative pathway targets in combination with JAK inhibitors may be more effective than single agent treatment.
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Affiliation(s)
- Suzanne McPherson
- Blood Cancer Research Group, Centre for Cancer Research and Cell Biology, Queens University Belfast, Belfast, UK
| | - Mary Frances McMullin
- Centre for Medical Education, School of Medicine, Dentistry and Biomedical Sciences, Queens University Belfast, Belfast, UK
| | - Ken Mills
- Blood Cancer Research Group, Centre for Cancer Research and Cell Biology, Queens University Belfast, Belfast, UK
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34
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Guglielmelli P, Pietra D, Pane F, Pancrazzi A, Cazzola M, Vannucchi AM, Tura S, Barosi G. Recommendations for molecular testing in classical Ph1-neg myeloproliferative disorders-A consensus project of the Italian Society of Hematology. Leuk Res 2017; 58:63-72. [PMID: 28460339 DOI: 10.1016/j.leukres.2017.04.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 03/26/2017] [Accepted: 04/20/2017] [Indexed: 12/21/2022]
Abstract
The discovery that Philadelphia-negative classical myeloproliferative neoplasms (MPNs) present with several molecular abnormalities, including the mostly represented JAK2V617F mutation, opened new horizons in the diagnosis, prognosis, and monitoring of these disorders. However, the great strides in the knowledge on molecular genetics need parallel progresses on the best approach to methods for detecting and reporting disease-associated mutations, and to shape the most effective and rationale testing pathway in the diagnosis, prognosis and monitoring of MPNs. The MPN taskforce of the Italian Society of Hematology (SIE) assessed the scientific literature and composed a framework of the best, possibly evidence-based, recommendations for optimal molecular methods as well as insights about the applicability and interpretation of those tests in the clinical practice, and clinical decision for testing MPNs patients. The issues dealt with: source of samples and nucleic acid template, the most appropriate molecular abnormalities and related detection methods required for diagnosis, prognosis, and monitoring of MPNs, how to report a diagnostic molecular test, calibration and quality control. For each of these issues, practice recommendations were provided.
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Affiliation(s)
- Paola Guglielmelli
- CRIMM-Centro Ricerca e Innovazione delle Malattie Mieloproliferative, Azienda Ospedaliera-Universitaria Careggi, Florence, Italy; Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Daniela Pietra
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | | | - Alessandro Pancrazzi
- CRIMM-Centro Ricerca e Innovazione delle Malattie Mieloproliferative, Azienda Ospedaliera-Universitaria Careggi, Florence, Italy; Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Mario Cazzola
- Department of Molecular Medicine, University of Pavia, Pavia, Italy; Department of Haematology Oncology, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Policlinico San Matteo, Pavia, Italy
| | - Alessandro M Vannucchi
- CRIMM-Centro Ricerca e Innovazione delle Malattie Mieloproliferative, Azienda Ospedaliera-Universitaria Careggi, Florence, Italy; Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | | | - Giovanni Barosi
- Center for the Study of Myelofibrosis, Biotechnology Research Area, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Policlinico S. Matteo, Pavia, Italy.
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35
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Varghese LN, Defour JP, Pecquet C, Constantinescu SN. The Thrombopoietin Receptor: Structural Basis of Traffic and Activation by Ligand, Mutations, Agonists, and Mutated Calreticulin. Front Endocrinol (Lausanne) 2017; 8:59. [PMID: 28408900 PMCID: PMC5374145 DOI: 10.3389/fendo.2017.00059] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Accepted: 03/17/2017] [Indexed: 12/13/2022] Open
Abstract
A well-functioning hematopoietic system requires a certain robustness and flexibility to maintain appropriate quantities of functional mature blood cells, such as red blood cells and platelets. This review focuses on the cytokine receptor that plays a significant role in thrombopoiesis: the receptor for thrombopoietin (TPO-R; also known as MPL). Here, we survey the work to date to understand how this receptor functions at a molecular level throughout its lifecycle, from traffic to the cell surface, dimerization and binding cognate cytokine via its extracellular domain, through to its subsequent activation of associated Janus kinases and initiation of downstream signaling pathways, as well as the regulation of these processes. Atomic level resolution structures of TPO-R have remained elusive. The identification of disease-causing mutations in the receptor has, however, offered some insight into structure and function relationships, as has artificial means of receptor activation, through TPO mimetics, transmembrane-targeting receptor agonists, and engineering in dimerization domains. More recently, a novel activation mechanism was identified whereby mutated forms of calreticulin form complexes with TPO-R via its extracellular N-glycosylated domain. Such complexes traffic pathologically in the cell and persistently activate JAK2, downstream signal transducers and activators of transcription (STATs), and other pathways. This pathologic TPO-R activation is associated with a large fraction of human myeloproliferative neoplasms.
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Affiliation(s)
- Leila N. Varghese
- Ludwig Institute for Cancer Research, Brussels Branch, Brussels, Belgium
- SIGN Pole, de Duve Institute, Université catholique de Louvain, Brussels, Belgium
| | - Jean-Philippe Defour
- Ludwig Institute for Cancer Research, Brussels Branch, Brussels, Belgium
- SIGN Pole, de Duve Institute, Université catholique de Louvain, Brussels, Belgium
- Department of Clinical Biology, Cliniques universitaires St Luc, Université catholique de Louvain, Brussels, Belgium
| | - Christian Pecquet
- Ludwig Institute for Cancer Research, Brussels Branch, Brussels, Belgium
- SIGN Pole, de Duve Institute, Université catholique de Louvain, Brussels, Belgium
| | - Stefan N. Constantinescu
- Ludwig Institute for Cancer Research, Brussels Branch, Brussels, Belgium
- SIGN Pole, de Duve Institute, Université catholique de Louvain, Brussels, Belgium
- *Correspondence: Stefan N. Constantinescu,
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Plo I, Bellanné-Chantelot C, Mosca M, Mazzi S, Marty C, Vainchenker W. Genetic Alterations of the Thrombopoietin/MPL/JAK2 Axis Impacting Megakaryopoiesis. Front Endocrinol (Lausanne) 2017; 8:234. [PMID: 28955303 PMCID: PMC5600916 DOI: 10.3389/fendo.2017.00234] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 08/28/2017] [Indexed: 12/31/2022] Open
Abstract
Megakaryopoiesis is an original and complex cell process which leads to the formation of platelets. The homeostatic production of platelets is mainly regulated and controlled by thrombopoietin (TPO) and the TPO receptor (MPL)/JAK2 axis. Therefore, any hereditary or acquired abnormality affecting this signaling axis can result in thrombocytosis or thrombocytopenia. Thrombocytosis can be due to genetic alterations that affect either the intrinsic MPL signaling through gain-of-function (GOF) activity (MPL, JAK2, CALR) and loss-of-function (LOF) activity of negative regulators (CBL, LNK) or the extrinsic MPL signaling by THPO GOF mutations leading to increased TPO synthesis. Alternatively, thrombocytosis may paradoxically result from mutations of MPL leading to an abnormal MPL trafficking, inducing increased TPO levels by alteration of its clearance. In contrast, thrombocytopenia can also result from LOF THPO or MPL mutations, which cause a complete defect in MPL trafficking to the cell membrane, impaired MPL signaling or stability, defects in the TPO/MPL interaction, or an absence of TPO production.
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Affiliation(s)
- Isabelle Plo
- INSERM UMR 1170, Gustave Roussy, Villejuif, France
- Université Paris-Saclay, UMR1170, Gustave Roussy, Villejuif, France
- Gustave Roussy, UMR1170, Villejuif, France
| | - Christine Bellanné-Chantelot
- INSERM UMR 1170, Gustave Roussy, Villejuif, France
- Department of Genetics, AP-HP Hôpitaux Universitaires Pitié Salpêtrière - Charles Foix, UPMC Univ Paris 06, Paris, France
| | - Matthieu Mosca
- INSERM UMR 1170, Gustave Roussy, Villejuif, France
- Université Paris-Saclay, UMR1170, Gustave Roussy, Villejuif, France
- Gustave Roussy, UMR1170, Villejuif, France
| | - Stefania Mazzi
- INSERM UMR 1170, Gustave Roussy, Villejuif, France
- Université Paris-Saclay, UMR1170, Gustave Roussy, Villejuif, France
- Université Paris-Diderot, Paris, France
| | - Caroline Marty
- INSERM UMR 1170, Gustave Roussy, Villejuif, France
- Université Paris-Saclay, UMR1170, Gustave Roussy, Villejuif, France
- Gustave Roussy, UMR1170, Villejuif, France
| | - William Vainchenker
- INSERM UMR 1170, Gustave Roussy, Villejuif, France
- Université Paris-Saclay, UMR1170, Gustave Roussy, Villejuif, France
- Gustave Roussy, UMR1170, Villejuif, France
- *Correspondence: William Vainchenker,
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37
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Genetic basis and molecular pathophysiology of classical myeloproliferative neoplasms. Blood 2016; 129:667-679. [PMID: 28028029 DOI: 10.1182/blood-2016-10-695940] [Citation(s) in RCA: 402] [Impact Index Per Article: 50.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2016] [Accepted: 12/06/2016] [Indexed: 02/07/2023] Open
Abstract
The genetic landscape of classical myeloproliferative neoplasm (MPN) is in large part elucidated. The MPN-restricted driver mutations, including those in JAK2, calreticulin (CALR), and myeloproliferative leukemia virus (MPL), abnormally activate the cytokine receptor/JAK2 pathway and their downstream effectors, more particularly the STATs. The most frequent mutation, JAK2V617F, activates the 3 main myeloid cytokine receptors (erythropoietin receptor, granulocyte colony-stimulating factor receptor, and MPL) whereas CALR or MPL mutants are restricted to MPL activation. This explains why JAK2V617F is associated with polycythemia vera, essential thrombocythemia (ET), and primary myelofibrosis (PMF) whereas CALR and MPL mutants are found in ET and PMF. Other mutations in genes involved in epigenetic regulation, splicing, and signaling cooperate with the 3 MPN drivers and play a key role in the PMF pathogenesis. Mutations in epigenetic regulators TET2 and DNMT3A are involved in disease initiation and may precede the acquisition of JAK2V617F. Other mutations in epigenetic regulators such as EZH2 and ASXL1 also play a role in disease initiation and disease progression. Mutations in the splicing machinery are predominantly found in PMF and are implicated in the development of anemia or pancytopenia. Both heterogeneity of classical MPNs and prognosis are determined by a specific genomic landscape, that is, type of MPN driver mutations, association with other mutations, and their order of acquisition. However, factors other than somatic mutations play an important role in disease initiation as well as disease progression such as germ line predisposition, inflammation, and aging. Delineation of these environmental factors will be important to better understand the precise pathogenesis of MPN.
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Cahu X, Constantinescu SN. Oncogenic Drivers in Myeloproliferative Neoplasms: From JAK2 to Calreticulin Mutations. Curr Hematol Malig Rep 2016; 10:335-43. [PMID: 26370832 DOI: 10.1007/s11899-015-0278-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
During the past 10 years, major progress has been accomplished with the discovery of activating mutations that are associated with the vast majority of BCR-ABL negative human myeloproliferative neoplasms (MPNs). The identification in 2005 of JAK2 V617F triggered great interest in the JAK2-STAT5/STAT3 pathway. Discovery in 2006 of mutants of thrombopoietin receptor (TPO-R/MPL) and later on of mutants in negative regulators of JAK-STAT pathway led to the notion that persistent JAK2 activation is a hallmark of MPNs. In 2013, mutations in the gene coding for the chaperone calreticulin were reported in 20-30% of essential thrombocythemia and primary myelofibrosis patients. Here, we will address the question: what do we know about calreticulin that could help us understand its role in MPNs? In addition to oncogenic driver mutations, certain MPNs also exhibit epigenetic mutations. Targeting of both oncogenic drivers and epigenetic defects could be required for effective therapy.
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Affiliation(s)
- Xavier Cahu
- Ludwig Institute for Cancer Research, Avenue Hippocrate 74, UCL 75-4, Brussels, B1200, Belgium.,de Duve Institute, Université catholique de Louvain, Brussels, B1200, Belgium
| | - Stefan N Constantinescu
- Ludwig Institute for Cancer Research, Avenue Hippocrate 74, UCL 75-4, Brussels, B1200, Belgium. .,de Duve Institute, Université catholique de Louvain, Brussels, B1200, Belgium.
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Concurrent MPL W515L and Y591D mutations in a patient with myelofibrosis. Blood Cells Mol Dis 2016; 60:1-2. [PMID: 27519934 DOI: 10.1016/j.bcmd.2016.05.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 05/25/2016] [Indexed: 11/21/2022]
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40
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Deng W, Li R. Juxtamembrane contribution to transmembrane signaling. Biopolymers 2016; 104:317-22. [PMID: 25846274 DOI: 10.1002/bip.22651] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 03/23/2015] [Accepted: 03/30/2015] [Indexed: 12/11/2022]
Abstract
Signaling across the cell membrane mediated by transmembrane receptors plays an important role in diverse biological processes. Recent studies have indicated that, in a number of single-span transmembrane receptors, the intracellular juxtamembrane (JM) sequence linking the transmembrane helix with the rest of the cytoplasmic domain participates directly in the signaling process via several novel mechanisms. This review briefly highlights several modes of JM dynamics in the context of signal transduction that are shared by different types of transmembrane receptors.
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Affiliation(s)
- Wei Deng
- Department of Pediatrics, Aflac Cancer and Blood Disorders Center, Emory University School of Medicine, Atlanta, GA, 30322
| | - Renhao Li
- Department of Pediatrics, Aflac Cancer and Blood Disorders Center, Emory University School of Medicine, Atlanta, GA, 30322
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41
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Alshemmari SH, Rajan R, Emadi A. Molecular Pathogenesis and Clinical Significance of Driver Mutations in Primary Myelofibrosis: A Review. Med Princ Pract 2016; 25:501-509. [PMID: 27756071 PMCID: PMC5588514 DOI: 10.1159/000450956] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 09/21/2016] [Indexed: 12/12/2022] Open
Abstract
Primary myelofibrosis (PMF) is a rare chronic BCR-ABL1-negative myeloproliferative neoplasm characterized by progressive bone marrow fibrosis, inefficient hematopoiesis, and shortened survival. The clinical manifestations of PMF include splenomegaly, consequent to extramedullary hematopoiesis, pancytopenias, and an array of potentially debilitating constitutional symptoms. The diagnosis is based on bone marrow morphology and clinical criteria. Mutations in the JAK2 (V617F), MPL (W515), and CALR (exon 9 indel) genes are found in approximately 90% of patients whereas the remaining 10% are so-called triple negatives. Activation of the JAK/STAT pathway results in overproduction of abnormal megakaryocytes leading to bone marrow fibrosis. These mutations might be accompanied by other mutations, such as ASXL1. The commonly used prognostication scoring for PMF is based on the International Prognostic Scoring System. The subsequently developed Dynamic International Prognostic Scoring System-plus employs clinical as well as cytogenetic variables. In PMF, CALR mutation is associated with superior survival and ASXL1 with inferior outcome. Patients with triple-negative PMF have a higher incidence of leukemic transformation and lower overall survival compared with CALR- or JAK2-mutant patients. The impact of genetic lesions on survival is independent of current prognostic scoring systems. These observations indicate that driver and passenger mutations define distinct disease entities within PMF. Accounting for them is not only relevant to clinical decision-making, but should also be considered in designing clinical trials.
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Affiliation(s)
- Salem H. Alshemmari
- Department of Medicine, Faculty of Medicine, Kuwait University, Md., USA
- *Salem H. Alshemmari, MD, Department of Medicine, Faculty of Medicine, Kuwait University, PO Box 24923, Safat 13110 (Kuwait), E-Mail
| | - Reshmi Rajan
- Stem Cell and Bone Marrow Transplant Laboratory, Kuwait Cancer Center, Safat, Kuwait
| | - Ashkan Emadi
- Marlene and Stewart Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, Md., USA
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42
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Leroy E, Defour JP, Sato T, Dass S, Gryshkova V, Shwe MM, Staerk J, Constantinescu SN, Smith SO. His499 Regulates Dimerization and Prevents Oncogenic Activation by Asparagine Mutations of the Human Thrombopoietin Receptor. J Biol Chem 2015; 291:2974-87. [PMID: 26627830 DOI: 10.1074/jbc.m115.696534] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2015] [Indexed: 01/18/2023] Open
Abstract
Ligand binding to the extracellular domain of the thrombopoietin receptor (TpoR) imparts a specific orientation on the transmembrane (TM) and intracellular domains of the receptors that is required for physiologic activation via receptor dimerization. To map the inactive and active dimeric orientations of the TM helices, we performed asparagine (Asn)-scanning mutagenesis of the TM domains of the murine and human TpoR. Substitution of Asn at only one position (S505N) activated the human receptor, whereas Asn substitutions at several positions activated the murine receptor. Second site mutational studies indicate that His(499) near the N terminus of the TM domain is responsible for protecting the human receptor from activation by Asn mutations. Structural studies reveal that the sequence preceding His(499) is helical in the murine receptor but non-helical in peptides corresponding to the TM domain of the inactive human receptor. The activating S505N mutation and the small molecule agonist eltrombopag both induce helix in this region of the TM domain and are associated with dimerization and activation of the human receptor. Thus, His(499) regulates the activation of human TpoR and provides additional protection against activating mutations, such as oncogenic Asn mutations in the TM domain.
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Affiliation(s)
- Emilie Leroy
- From the Ludwig Institute for Cancer Research, 1200 Brussels, Belgium de Duve Institute, Université catholique de Louvain, 1200 Brussels, Belgium
| | - Jean-Philippe Defour
- From the Ludwig Institute for Cancer Research, 1200 Brussels, Belgium de Duve Institute, Université catholique de Louvain, 1200 Brussels, Belgium
| | - Takeshi Sato
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Sharmila Dass
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York 11794-5215, and
| | - Vitalina Gryshkova
- From the Ludwig Institute for Cancer Research, 1200 Brussels, Belgium de Duve Institute, Université catholique de Louvain, 1200 Brussels, Belgium
| | - Myat M Shwe
- From the Ludwig Institute for Cancer Research, 1200 Brussels, Belgium de Duve Institute, Université catholique de Louvain, 1200 Brussels, Belgium
| | - Judith Staerk
- Stem Cell Group, Nordic European Molecular Biology Laboratory Partnership and Center for Molecular Medicine, 0318 Oslo, Norway
| | - Stefan N Constantinescu
- From the Ludwig Institute for Cancer Research, 1200 Brussels, Belgium de Duve Institute, Université catholique de Louvain, 1200 Brussels, Belgium,
| | - Steven O Smith
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York 11794-5215, and
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43
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Saeidi K. Myeloproliferative neoplasms: Current molecular biology and genetics. Crit Rev Oncol Hematol 2015; 98:375-89. [PMID: 26697989 DOI: 10.1016/j.critrevonc.2015.11.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2015] [Revised: 09/10/2015] [Accepted: 11/09/2015] [Indexed: 12/16/2022] Open
Abstract
Myeloproliferative neoplasms (MPNs) are clonal disorders characterized by increased production of mature blood cells. Philadelphia chromosome-negative MPNs (Ph-MPNs) consist of polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF). A number of stem cell derived mutations have been identified in the past 10 years. These findings showed that JAK2V617F, as a diagnostic marker involving JAK2 exon 14 with a high frequency, is the best molecular characterization of Ph-MPNs. Somatic mutations in an endoplasmic reticulum chaperone, named calreticulin (CALR), is the second most common mutation in patients with ET and PMF after JAK2 V617F mutation. Discovery of CALR mutations led to the increased molecular diagnostic of ET and PMF up to 90%. It has been shown that JAK2V617F is not the unique event in disease pathogenesis. Some other genes' location such as TET oncogene family member 2 (TET2), additional sex combs-like 1 (ASXL1), casitas B-lineage lymphoma proto-oncogene (CBL), isocitrate dehydrogenase 1/2 (IDH1/IDH2), IKAROS family zinc finger 1 (IKZF1), DNA methyltransferase 3A (DNMT3A), suppressor of cytokine signaling (SOCS), enhancer of zeste homolog 2 (EZH2), tumor protein p53 (TP53), runt-related transcription factor 1 (RUNX1) and high mobility group AT-hook 2 (HMGA2) have also identified to be involved in MPNs phenotypes. Here, current molecular biology and genetic mechanisms involved in MNPs with a focus on the aforementioned factors is presented.
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Affiliation(s)
- Kolsoum Saeidi
- Department of Medical Genetics, Kerman University of Medical Sciences, Kerman, Iran.
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44
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Defour JP, Chachoua I, Pecquet C, Constantinescu SN. Oncogenic activation of MPL/thrombopoietin receptor by 17 mutations at W515: implications for myeloproliferative neoplasms. Leukemia 2015; 30:1214-6. [DOI: 10.1038/leu.2015.271] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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45
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What Do Molecular Tests Add to Prognostic Stratification in MF: Is It Time to Add These to Our Clinical Practice? Curr Hematol Malig Rep 2015; 10:380-7. [DOI: 10.1007/s11899-015-0285-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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46
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Ciccone M, Calin GA. MicroRNAs in Myeloid Hematological Malignancies. Curr Genomics 2015; 16:336-48. [PMID: 27047254 PMCID: PMC4763972 DOI: 10.2174/138920291605150710122815] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Revised: 04/20/2015] [Accepted: 04/22/2015] [Indexed: 01/01/2023] Open
Abstract
MicroRNAs are 19-24 nucleotides noncoding RNAs which silence modulate the expression of target genes by binding to the messenger RNAs. Myeloid malignancies include a broad spectrum of acute and chronic disorders originating from from the clonal transformation of a hematopoietic stem cell. Specific genetic abnormalities may define myeloid malignancies, such as translocation t(9;22) that represent the hallmark of chronic myeloid leukemia. Although next-generation sequencing pro-vided new insights in the genetic characterization and pathogenesis of myeloid neoplasms, the molecular mechanisms underlying myeloid neoplasms are lacking in most cases. Recently, several studies have demonstrated that the expression levels of specific miRNAs may vary among patients with myeloid malignancies compared with healthy individuals and partially unveiled how miRNAs participate in the leukemic transformation process. Finally, in vitro experiments and pre-clinical model provided preliminary data of the safety and efficacy of miRNA inhibitory molecules, opening new avenue in the treatment of myeloid hematological malignancies.
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Affiliation(s)
- Maria Ciccone
- Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - George Adrian Calin
- Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
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47
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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.
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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
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48
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Whole-exome sequencing identifies novel MPL and JAK2 mutations in triple-negative myeloproliferative neoplasms. Blood 2015; 127:325-32. [PMID: 26423830 DOI: 10.1182/blood-2015-07-661835] [Citation(s) in RCA: 202] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 09/13/2015] [Indexed: 12/19/2022] Open
Abstract
Essential thrombocythemia (ET) and primary myelofibrosis (PMF) are chronic diseases characterized by clonal hematopoiesis and hyperproliferation of terminally differentiated myeloid cells. The disease is driven by somatic mutations in exon 9 of CALR or exon 10 of MPL or JAK2-V617F in >90% of the cases, whereas the remaining cases are termed "triple negative." We aimed to identify the disease-causing mutations in the triple-negative cases of ET and PMF by applying whole-exome sequencing (WES) on paired tumor and control samples from 8 patients. We found evidence of clonal hematopoiesis in 5 of 8 studied cases based on clonality analysis and presence of somatic genetic aberrations. WES identified somatic mutations in 3 of 8 cases. We did not detect any novel recurrent somatic mutations. In 3 patients with clonal hematopoiesis analyzed by WES, we identified a somatic MPL-S204P, a germline MPL-V285E mutation, and a germline JAK2-G571S variant. We performed Sanger sequencing of the entire coding region of MPL in 62, and of JAK2 in 49 additional triple-negative cases of ET or PMF. New somatic (T119I, S204F, E230G, Y591D) and 1 germline (R321W) MPL mutation were detected. All of the identified MPL mutations were gain-of-function when analyzed in functional assays. JAK2 variants were identified in 5 of 57 triple-negative cases analyzed by WES and Sanger sequencing combined. We could demonstrate that JAK2-V625F and JAK2-F556V are gain-of-function mutations. Our results suggest that triple-negative cases of ET and PMF do not represent a homogenous disease entity. Cases with polyclonal hematopoiesis might represent hereditary disorders.
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49
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Harutyunyan AS, Jäger R, Chen D, Berg T, Rumi E, Gisslinger B, Pietra D, Gisslinger H, Cazzola M, Kralovics R. Allelic imbalance in CALR somatic mutagenesis. Leukemia 2015; 29:1431-5. [PMID: 25567134 PMCID: PMC4430307 DOI: 10.1038/leu.2015.3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- A S Harutyunyan
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - R Jäger
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - D Chen
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - T Berg
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - E Rumi
- Department of Hematology Oncology, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Policlinico San Matteo, Pavia, Italy
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - B Gisslinger
- Division of Hematology and Blood Coagulation, Department of Internal Medicine I, Medical University of Vienna, Vienna, Austria
| | - D Pietra
- Department of Hematology Oncology, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Policlinico San Matteo, Pavia, Italy
| | - H Gisslinger
- Division of Hematology and Blood Coagulation, Department of Internal Medicine I, Medical University of Vienna, Vienna, Austria
| | - M Cazzola
- Department of Hematology Oncology, Fondazione Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Policlinico San Matteo, Pavia, Italy
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - R Kralovics
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
- Division of Hematology and Blood Coagulation, Department of Internal Medicine I, Medical University of Vienna, Vienna, Austria
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50
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Waters M, Brooks A. JAK2 activation by growth hormone and other cytokines. Biochem J 2015; 466:1-11. [PMID: 25656053 PMCID: PMC4325515 DOI: 10.1042/bj20141293] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2014] [Revised: 11/17/2014] [Accepted: 11/24/2014] [Indexed: 12/30/2022]
Abstract
Growth hormone (GH) and structurally related cytokines regulate a great number of physiological and pathological processes. They do this by coupling their single transmembrane domain (TMD) receptors to cytoplasmic tyrosine kinases, either as homodimers or heterodimers. Recent studies have revealed that many of these receptors exist as constitutive dimers rather than being dimerized as a consequence of ligand binding, which has necessitated a new paradigm for describing their activation process. In the present study, we describe a model for activation of the tyrosine kinase Janus kinase 2 (JAK2) by the GH receptor homodimer based on biochemical data and molecular dynamics simulations. Binding of the bivalent ligand reorientates and rotates the receptor subunits, resulting in a transition from a form with parallel TMDs to one where the TMDs separate at the point of entry into the cytoplasm. This movement slides the pseudokinase inhibitory domain of one JAK kinase away from the kinase domain of the other JAK within the receptor dimer-JAK complex, allowing the two kinase domains to interact and trans-activate. This results in phosphorylation and activation of STATs and other signalling pathways linked to this receptor which then regulate postnatal growth, metabolism and stem cell activation. We believe that this model will apply to most if not all members of the class I cytokine receptor family, and will be useful in the design of small antagonists and agonists of therapeutic value.
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Key Words
- class i cytokine receptors
- cytokine receptor signalling
- growth hormone
- growth hormone receptor
- janus kinase 2 (jak2)
- srk family kinases
- cntf, ciliary neurotropic factor
- crh, cytokine receptor homology
- ct-1, cardiotropin-1
- ecd, extracellular domain
- epo, erythropoietin
- fniii, fibronectin iii-like
- gh, growth hormone
- gm-csf, granulocyte-macrophage colony-stimulating factor
- jak, janus kinase
- jm, juxtamembrane
- mab, monoclonal antibody
- osm, oncostatin-m
- pk, pseudokinase
- tmd, transmembrane domain
- tpo, thrombopoietin
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Affiliation(s)
- Michael J. Waters
- *Institute for Molecular Bioscience, The University of Queensland Institute, QLD 4072, Australia
| | - Andrew J. Brooks
- *Institute for Molecular Bioscience, The University of Queensland Institute, QLD 4072, Australia
- †The University of Queensland Diamantina Institute, The University of Queensland, Translational Research Institute, QLD 4072, Australia
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