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Aubin L, Vilas Boas R, Daltro De Oliveira R, Le Brun V, Divoux M, Rey J, Mansier O, Ianotto JC, Pastoret C, Desmares A, Murati A, de Mas V, Tavitian S, Girodon F, Soret Dulphy J, Maslah N, Goncalves Monteiro V, Boyer F, Orvain C, Ranta D, Cayssials É, Le Clech L, Nicol C, Rottier C, Botin Lopez T, Castel B, Rispal P, Beziat G, Bescond C, Laribi K, Benajiba L, Ugo V, Lippert E, Cottin L, Luque Paz D. CALR-mutated patients with low allele burden represent a specific subtype of essential thrombocythemia: A study on behalf of FIM and GBMHM. Am J Hematol 2024; 99:1001-1004. [PMID: 38404143 DOI: 10.1002/ajh.27265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 02/08/2024] [Accepted: 02/13/2024] [Indexed: 02/27/2024]
Abstract
A low allele burden (i.e., <20%) of the CALR driver mutation is found in 10.8% of CALR-mutated MPNs, mostly in essential thrombocythemia, and correlates with a milder phenotype and a more indolent evolution compared to patients with an allele burden ≥20%.
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Affiliation(s)
- Laura Aubin
- Univ Angers, Nantes Université, CHU Angers, Inserm, CNRS, CRCI2NA, Angers, France
- Laboratoire d'Hématologie, CH St Malo, St Malo, France
- Laboratoire d'Hématologie, CHU Rennes, Rennes, France
| | | | | | | | - Marion Divoux
- Hématologie Clinique, CHU Nancy, Nancy, France
- Laboratoire d'Hématologie, CHU Nancy, Nancy, France
| | - Jérôme Rey
- Centre de Recherche en Cancérologie de Marseille (CRCM), Département d'Hématologie, Institut Paoli-Calmettes, CRCM, Inserm, Marseille, France
| | - Olivier Mansier
- Laboratoire d'Hématologie, CHU Bordeaux, Bordeaux, France
- Inserm U1034, Université de Bordeaux, Bordeaux, France
| | | | | | - Anne Desmares
- Laboratoire d'Hématologie, CHU Rennes, Rennes, France
| | - Anne Murati
- Centre de Recherche en Cancérologie de Marseille (CRCM), Département de Biopathologie et Département d'Oncologie Prédictive, Institut Paoli-Calmettes, Inserm, Marseille, France
| | - Véronique de Mas
- Laboratoire d'Hématologie, Institut Universitaire du Cancer de Toulouse Oncopole, CHU Toulouse, Toulouse, France
| | - Suzanne Tavitian
- Service d'Hématologie, Institut Universitaire du Cancer de Toulouse Oncopole, CHU Toulouse, Toulouse, France
| | | | - Juliette Soret Dulphy
- INSERM U944/CNRS UMR7212, Hôpital Saint Louis APHP, Université de Paris, Paris, France
| | - Nabih Maslah
- Laboratoire de Biologie Cellulaire, Université Paris Cité, APHP, Hôpital Saint-Louis, Paris, France
| | | | | | | | - Dana Ranta
- Hématologie Clinique, CHU Nancy, Nancy, France
| | - Émilie Cayssials
- Service d'Oncologie Hématologique et Thérapie Cellulaire, CHU de Poitiers, Poitiers, France
| | | | | | - Camille Rottier
- Laboratoire d'oncobiologie moléculaire, CHU Amiens-Picardie, Amiens, France
| | | | - Brice Castel
- Service de Médecine Interne, CH de Bigorre, Tarbes, France
| | | | | | | | - Kamel Laribi
- Hématologie Clinique, CH Le Mans, Le Mans, France
| | - Lina Benajiba
- INSERM U944/CNRS UMR7212, Hôpital Saint Louis APHP, Université de Paris, Paris, France
| | - Valérie Ugo
- Univ Angers, Nantes Université, CHU Angers, Inserm, CNRS, CRCI2NA, Angers, France
| | - Eric Lippert
- Laboratoire d'Hématologie, CHRU Brest, Brest, France
- INSERM, U1078, Université de Brest, Brest, France
| | - Laurane Cottin
- Univ Angers, Nantes Université, CHU Angers, Inserm, CNRS, CRCI2NA, Angers, France
| | - Damien Luque Paz
- Univ Angers, Nantes Université, CHU Angers, Inserm, CNRS, CRCI2NA, Angers, France
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2
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Verma T, Papadantonakis N, Peker Barclift D, Zhang L. Molecular Genetic Profile of Myelofibrosis: Implications in the Diagnosis, Prognosis, and Treatment Advancements. Cancers (Basel) 2024; 16:514. [PMID: 38339265 PMCID: PMC10854658 DOI: 10.3390/cancers16030514] [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: 12/30/2023] [Revised: 01/22/2024] [Accepted: 01/23/2024] [Indexed: 02/12/2024] Open
Abstract
Myelofibrosis (MF) is an essential element of primary myelofibrosis, whereas secondary MF may develop in the advanced stages of other myeloid neoplasms, especially polycythemia vera and essential thrombocythemia. Over the last two decades, advances in molecular diagnostic techniques, particularly the integration of next-generation sequencing in clinical laboratories, have revolutionized the diagnosis, classification, and clinical decision making of myelofibrosis. Driver mutations involving JAK2, CALR, and MPL induce hyperactivity in the JAK-STAT signaling pathway, which plays a central role in cell survival and proliferation. Approximately 80% of myelofibrosis cases harbor additional mutations, frequently in the genes responsible for epigenetic regulation and RNA splicing. Detecting these mutations is crucial for diagnosing myeloproliferative neoplasms (MPNs), especially in cases where no mutations are present in the three driver genes (triple-negative MPNs). While fibrosis in the bone marrow results from the disturbance of inflammatory cytokines, it is fundamentally associated with mutation-driven hematopoiesis. The mutation profile and order of acquiring diverse mutations influence the MPN phenotype. Mutation profiling reveals clonal diversity in MF, offering insights into the clonal evolution of neoplastic progression. Prognostic prediction plays a pivotal role in guiding the treatment of myelofibrosis. Mutation profiles and cytogenetic abnormalities have been integrated into advanced prognostic scoring systems and personalized risk stratification for MF. Presently, JAK inhibitors are part of the standard of care for MF, with newer generations developed for enhanced efficacy and reduced adverse effects. However, only a minority of patients have achieved a significant molecular-level response. Clinical trials exploring innovative approaches, such as combining hypomethylation agents that target epigenetic regulators, drugs proven effective in myelodysplastic syndrome, or immune and inflammatory modulators with JAK inhibitors, have demonstrated promising results. These combinations may be more effective in patients with high-risk mutations and complex mutation profiles. Expanding mutation profiling studies with more sensitive and specific molecular methods, as well as sequencing a broader spectrum of genes in clinical patients, may reveal molecular mechanisms in cases currently lacking detectable driver mutations, provide a better understanding of the association between genetic alterations and clinical phenotypes, and offer valuable information to advance personalized treatment protocols to improve long-term survival and eradicate mutant clones with the hope of curing MF.
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Affiliation(s)
- Tanvi Verma
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Nikolaos Papadantonakis
- Department of Hematology and Medical Oncology, Winship Cancer Institute of Emory University, Atlanta, GA 30322, USA
| | - Deniz Peker Barclift
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Linsheng Zhang
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
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3
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Stuckey R, Bilbao-Sieyro C, Segura-Díaz A, Gómez-Casares MT. Molecular Studies for the Early Detection of Philadelphia-Negative Myeloproliferative Neoplasms. Int J Mol Sci 2023; 24:12700. [PMID: 37628880 PMCID: PMC10454334 DOI: 10.3390/ijms241612700] [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: 07/23/2023] [Revised: 08/07/2023] [Accepted: 08/09/2023] [Indexed: 08/27/2023] Open
Abstract
JAK2 V617F is the predominant driver mutation in patients with Philadelphia-negative myeloproliferative neoplasms (MPN). JAK2 mutations are also frequent in clonal hematopoiesis of indeterminate potential (CHIP) in otherwise "healthy" individuals. However, the period between mutation acquisition and MPN diagnosis (known as latency) varies widely between individuals, with JAK2 mutations detectable several decades before diagnosis and even from birth in some individuals. Here, we will review the current evidence on the biological factors, such as additional mutations and chronic inflammation, which influence clonal expansion and may determine why some JAK2-mutated individuals will progress to an overt neoplasm during their lifetime while others will not. We will also introduce several germline variants that predispose individuals to CHIP (as well as MPN) identified from genome-wide association studies. Finally, we will explore possible mutation screening or interventions that could help to minimize MPN-associated cardiovascular complications or even delay malignant progression.
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Affiliation(s)
- Ruth Stuckey
- Hematology Department, Hospital Universitario de Gran Canaria Dr. Negrín, 35019 Las Palmas de Gran Canaria, Spain; (R.S.); (C.B.-S.); (A.S.-D.)
| | - Cristina Bilbao-Sieyro
- Hematology Department, Hospital Universitario de Gran Canaria Dr. Negrín, 35019 Las Palmas de Gran Canaria, Spain; (R.S.); (C.B.-S.); (A.S.-D.)
- Morphology Department, Universidad de Las Palmas de Gran Canaria, 35016 Las Palmas de Gran Canaria, Spain
| | - Adrián Segura-Díaz
- Hematology Department, Hospital Universitario de Gran Canaria Dr. Negrín, 35019 Las Palmas de Gran Canaria, Spain; (R.S.); (C.B.-S.); (A.S.-D.)
| | - María Teresa Gómez-Casares
- Hematology Department, Hospital Universitario de Gran Canaria Dr. Negrín, 35019 Las Palmas de Gran Canaria, Spain; (R.S.); (C.B.-S.); (A.S.-D.)
- Department of Medical Sciences, Universidad de Las Palmas de Gran Canaria, 35016 Las Palmas de Gran Canaria, Spain
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Luque Paz D, Kralovics R, Skoda RC. Genetic basis and molecular profiling in myeloproliferative neoplasms. Blood 2023; 141:1909-1921. [PMID: 36347013 PMCID: PMC10646774 DOI: 10.1182/blood.2022017578] [Citation(s) in RCA: 33] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 11/03/2022] [Accepted: 11/03/2022] [Indexed: 11/11/2022] Open
Abstract
BCR::ABL1-negative myeloproliferative neoplasms (MPNs) are clonal diseases originating from a single hematopoietic stem cell that cause excessive production of mature blood cells. The 3 subtypes, that is, polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF), are diagnosed according to the World Health Organization (WHO) and international consensus classification (ICC) criteria. Acquired gain-of-function mutations in 1 of 3 disease driver genes (JAK2, CALR, and MPL) are the causative events that can alone initiate and promote MPN disease without requiring additional cooperating mutations. JAK2-p.V617F is present in >95% of PV patients, and also in about half of the patients with ET or PMF. ET and PMF are also caused by mutations in CALR or MPL. In ∼10% of MPN patients, those referred to as being "triple negative," none of the known driver gene mutations can be detected. The common theme between the 3 driver gene mutations and triple-negative MPN is that the Janus kinase-signal transducer and activator of transcription (JAK/STAT) signaling pathway is constitutively activated. We review the recent advances in our understanding of the early events after the acquisition of a driver gene mutation. The limiting factor that determines the frequency at which MPN disease develops with a long latency is not the acquisition of driver gene mutations, but rather the expansion of the clone. Factors that control the conversion from clonal hematopoiesis to MPN disease include inherited predisposition, presence of additional mutations, and inflammation. The full extent of knowledge of the mutational landscape in individual MPN patients is now increasingly being used to predict outcome and chose the optimal therapy.
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Affiliation(s)
- Damien Luque Paz
- Univ Angers, Nantes Université, CHU Angers, Inserm, CNRS, CRCI2NA, Angers, France
| | - Robert Kralovics
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | - Radek C. Skoda
- Department of Biomedicine, Experimental Hematology, University Hospital Basel and University of Basel, Basel, Switzerland
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5
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Guy A, Helzy K, Mansier O, Bordet JC, Rivière E, Fiore M, James C. Platelet function studies in myeloproliferative neoplasms patients with Calreticulin or JAK2 V617F mutation. Res Pract Thromb Haemost 2023; 7:100060. [PMID: 36908768 PMCID: PMC9992751 DOI: 10.1016/j.rpth.2023.100060] [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: 09/12/2022] [Revised: 12/16/2022] [Accepted: 12/29/2022] [Indexed: 02/02/2023] Open
Abstract
Background JAK2 V617F and Calreticulin (CALR) mutations are the most frequent molecular causes of Phi-negative myeloproliferative neoplasms (MPN). Patients with CALR mutations are at lower risk of thrombosis than patients with JAK2 V617F. We hypothesized that CALR-mutated blood platelets would have platelet function defects that might explain why these patients are at lower risk of thrombosis. Objectives Our main objective was to explore and compare platelet function depending on the MPN molecular marker. Methods We analyzed platelet function in 16 patients with MPN with CALR mutations and 17 patients with JAK2 V617F mutation and compared them with healthy controls. None of these patients was taking antiplatelet therapy. We performed an extensive analysis of platelet function and measured plasmatic soluble P-selectin and CD40L levels. Results We observed significant defects in platelet aggregation, surface glycoprotein expression, fibrinogen binding, and granule content in platelets from patients with MPN compared with that in controls. Moreover, soluble CD40L and P-selectin levels were elevated in patients with MPN compared with that in controls, suggesting an in vivo platelet preactivation. Comparison of platelet function between patients with CALR and JAK2 V617F MPN revealed only minor differences in platelets from patients with CALR. However, these results need to be interpreted within the context of absence of an inflammatory environment that could impact platelet function during MPN. Conclusions These results do not support the hypothesis that calreticulin-mutated platelets have platelet function defects that could explain the lower thrombotic risk of patients with CALR.
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Affiliation(s)
- Alexandre Guy
- Laboratory of Hematology, University Hospital, Bordeaux, France.,University of Bordeaux, INSERM UMR 1034, "Biology of Cardiovascular Diseases", Pessac, France
| | - Khalil Helzy
- Laboratory of Hematology, University Hospital, Bordeaux, France
| | - Olivier Mansier
- Laboratory of Hematology, University Hospital, Bordeaux, France.,University of Bordeaux, INSERM UMR 1034, "Biology of Cardiovascular Diseases", Pessac, France
| | | | - Etienne Rivière
- Internal Medicine and Infectious Diseases Unit, University Hospital, Bordeaux, France
| | - Mathieu Fiore
- Laboratory of Hematology, University Hospital, Bordeaux, France
| | - Chloe James
- Laboratory of Hematology, University Hospital, Bordeaux, France.,University of Bordeaux, INSERM UMR 1034, "Biology of Cardiovascular Diseases", Pessac, France
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6
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Moraes GR, Pasquier F, Marzac C, Deconinck E, Damanti CC, Leroy G, El-Khoury M, El Nemer W, Kiladjian JJ, Raslova H, Najman A, Vainchenker W, Marty C, Bellanné-Chantelot C, Plo I. An inherited gain-of-function risk allele in EPOR predisposes to familial JAK2 V617F myeloproliferative neoplasms. Br J Haematol 2022; 198:131-136. [PMID: 35355248 DOI: 10.1111/bjh.18165] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 02/17/2022] [Accepted: 03/14/2022] [Indexed: 12/16/2022]
Abstract
Myeloproliferative neoplasms (MPN) are mainly sporadic but inherited variants have been associated with higher risk development. Here, we identified an EPOR variant (EPORP488S ) in a large family diagnosed with JAK2V617F -positive polycythaemia vera (PV) or essential thrombocytosis (ET). We investigated its functional impact on JAK2V617F clonal amplification in patients and found that the variant allele fraction (VAF) was low in PV progenitors but increase strongly in mature cells. Moreover, we observed that EPORP488S alone induced a constitutive phosphorylation of STAT5 in cell lines or primary cells. Overall, this study points for searching inherited-risk alleles affecting the JAK2/STAT pathway in MPN.
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Affiliation(s)
- Graciela Rabadan Moraes
- INSERM, UMR1287, Villejuif, France.,Gustave Roussy, Villejuif, France.,INSERM UMR1287, Gustave Roussy, Université de Paris, Villejuif, France.,Laboratoire d'Excellence GR-Ex, Université Paris Cité, Paris, France
| | - Florence Pasquier
- INSERM, UMR1287, Villejuif, France.,Gustave Roussy, Villejuif, France.,Laboratoire d'Excellence GR-Ex, Université Paris Cité, Paris, France.,INSERM UMR1287, Gustave Roussy, Université Paris-Saclay, Villejuif, France
| | - Christophe Marzac
- INSERM, UMR1287, Villejuif, France.,Gustave Roussy, Villejuif, France.,INSERM UMR1287, Gustave Roussy, Université Paris-Saclay, Villejuif, France.,Département d'Hématologie, Gustave Roussy, Villejuif, France
| | - Eric Deconinck
- Département d'Hématologie, CHU Besançon, Besançon, France
| | - Carlotta Caterina Damanti
- INSERM, UMR1287, Villejuif, France.,Gustave Roussy, Villejuif, France.,INSERM UMR1287, Gustave Roussy, Université de Paris, Villejuif, France.,Laboratoire d'Excellence GR-Ex, Université Paris Cité, Paris, France
| | - Gwendoline Leroy
- Département de Génétique Médicale, AP-HP, Hôpital Pitié Salpêtrière, Sorbonne Université, Paris, France
| | - Mira El-Khoury
- INSERM, UMR1287, Villejuif, France.,Gustave Roussy, Villejuif, France.,INSERM UMR1287, Gustave Roussy, Université de Paris, Villejuif, France.,Laboratoire d'Excellence GR-Ex, Université Paris Cité, Paris, France
| | - Wassim El Nemer
- Laboratoire d'Excellence GR-Ex, Université Paris Cité, Paris, France.,UMR_S1134, BIGR, Inserm, Université de Paris, Paris, France.,Institut National de la Transfusion Sanguine, Paris, France.,Etablissement Français du Sang PACA-Corse, Marseille, France.,EFS, CNRS, ADES, 'Biologie des Groupes Sanguins', Aix Marseille University, Marseille, France
| | | | - Hana Raslova
- INSERM, UMR1287, Villejuif, France.,Gustave Roussy, Villejuif, France.,INSERM UMR1287, Gustave Roussy, Université Paris-Saclay, Villejuif, France
| | - Albert Najman
- Service d'Hématologie Clinique et de Thérapie Cellulaire, AP-HP, Hôpital Saint-Antoine, Sorbonne Université, Paris, France
| | - William Vainchenker
- INSERM, UMR1287, Villejuif, France.,Gustave Roussy, Villejuif, France.,Laboratoire d'Excellence GR-Ex, Université Paris Cité, Paris, France.,INSERM UMR1287, Gustave Roussy, Université Paris-Saclay, Villejuif, France
| | - Caroline Marty
- INSERM, UMR1287, Villejuif, France.,Gustave Roussy, Villejuif, France.,Laboratoire d'Excellence GR-Ex, Université Paris Cité, Paris, France.,INSERM UMR1287, Gustave Roussy, Université Paris-Saclay, Villejuif, France
| | - Christine Bellanné-Chantelot
- INSERM, UMR1287, Villejuif, France.,Gustave Roussy, Villejuif, France.,Département de Génétique Médicale, AP-HP, Hôpital Pitié Salpêtrière, Sorbonne Université, Paris, France
| | - Isabelle Plo
- INSERM, UMR1287, Villejuif, France.,Gustave Roussy, Villejuif, France.,Laboratoire d'Excellence GR-Ex, Université Paris Cité, Paris, France.,INSERM UMR1287, Gustave Roussy, Université Paris-Saclay, Villejuif, France
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Ashcroft P, Bonhoeffer S. Constrained optimization of divisional load in hierarchically organized tissues during homeostasis. J R Soc Interface 2022; 19:20210784. [PMID: 35193391 PMCID: PMC8864360 DOI: 10.1098/rsif.2021.0784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
It has been hypothesized that the structure of tissues and the hierarchy of differentiation from stem cell to terminally differentiated cell play a significant role in reducing the incidence of cancer in that tissue. One specific mechanism by which this risk can be reduced is by minimizing the number of divisions—and hence the mutational risk—that cells accumulate as they divide to maintain tissue homeostasis. Here, we investigate a mathematical model of cell division in a hierarchical tissue, calculating and minimizing the divisional load while constraining parameters such that homeostasis is maintained. We show that the minimal divisional load is achieved by binary division trees with progenitor cells incapable of self-renewal. Contrary to the protection hypothesis, we find that an increased stem cell turnover can lead to lower divisional load. Furthermore, we find that the optimal tissue structure depends on the time horizon of the duration of homeostasis, with faster stem cell division favoured in short-lived organisms and more progenitor compartments favoured in longer-lived organisms.
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Affiliation(s)
- Peter Ashcroft
- Institute of Integrative Biology, ETH Zurich, Zurich, Switzerland
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Greenfield G, McMullin MF, Mills K. Molecular pathogenesis of the myeloproliferative neoplasms. J Hematol Oncol 2021; 14:103. [PMID: 34193229 PMCID: PMC8246678 DOI: 10.1186/s13045-021-01116-z] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Accepted: 06/22/2021] [Indexed: 02/07/2023] Open
Abstract
The Philadelphia negative myeloproliferative neoplasms (MPN) compromise a heterogeneous group of clonal myeloid stem cell disorders comprising polycythaemia vera, essential thrombocythaemia and primary myelofibrosis. Despite distinct clinical entities, these disorders are linked by morphological similarities and propensity to thrombotic complications and leukaemic transformation. Current therapeutic options are limited in disease-modifying activity with a focus on the prevention of thrombus formation. Constitutive activation of the JAK/STAT signalling pathway is a hallmark of pathogenesis across the disease spectrum with driving mutations in JAK2, CALR and MPL identified in the majority of patients. Co-occurring somatic mutations in genes associated with epigenetic regulation, transcriptional control and splicing of RNA are variably but recurrently identified across the MPN disease spectrum, whilst epigenetic contributors to disease are increasingly recognised. The prognostic implications of one MPN diagnosis may significantly limit life expectancy, whilst another may have limited impact depending on the disease phenotype, genotype and other external factors. The genetic and clinical similarities and differences in these disorders have provided a unique opportunity to understand the relative contributions to MPN, myeloid and cancer biology generally from specific genetic and epigenetic changes. This review provides a comprehensive overview of the molecular pathophysiology of MPN exploring the role of driver mutations, co-occurring mutations, dysregulation of intrinsic cell signalling, epigenetic regulation and genetic predisposing factors highlighting important areas for future consideration.
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Affiliation(s)
- Graeme Greenfield
- Patrick G Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, UK.
| | | | - Ken Mills
- Patrick G Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, UK
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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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