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Kimura H, Onozawa M, Matsukawa T, Goto H, Kondo T, Teshima T. Relative impact of THPO mutation causing hereditary thrombocythemia. Exp Hematol 2024; 134:104208. [PMID: 38548144 DOI: 10.1016/j.exphem.2024.104208] [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: 01/25/2024] [Revised: 03/01/2024] [Accepted: 03/05/2024] [Indexed: 04/16/2024]
Abstract
Germline mutations of THPO were reported as causes of hereditary thrombocythemia. Six previously reported distinct sites of the mutation were clustered at the 5`-untranslated region or the exon 3 splicing donor site of the THPO gene. Each mutation was identified in an independent pedigree, and the differences between the mutations were not compared. We cloned six distinct THPO mutations (THPO c.-47delG, THPO c.-31G>T, THPO c.13G>A, THPO c.13+1G>A, THPO c.13+2T>C, and THPO c.13+5G>A) and compared the molecular mechanisms that underlie the increased production of THPO protein. At the transcript level, all of the mutations except THPO c.-47delG showed an exon 3 skipping transcript, including two mutations (THPO c.-31G>T and THPO c.13+5G>A) that were distant from the splicing donor site. THPO c.-47delG showed the same full-length transcript as that of the wild-type transcript. At the protein level, all mutations resulted in a higher level of production of thrombopoietin (THPO) protein compared with wild-type THPO. There are only two distinct patterns of mechanisms for increased production of THPO: exon 3 skipping that deleted upstream suppressive open reading frame (ORF)7 and one base deletion that shifted ORF7 to connect to the initial codon of THPO in-frame. The common mechanisms of hereditary thrombocytosis due to THPO mutations are unleashed THPO translations, which are usually suppressed by upstream out-of-frame ORF7.
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Affiliation(s)
- Hiroyuki Kimura
- Department of Hematology, Graduate School of Medicine, Hokkaido University Faculty of Medicine, Sapporo, Japan
| | - Masahiro Onozawa
- Department of Hematology, Graduate School of Medicine, Hokkaido University Faculty of Medicine, Sapporo, Japan.
| | - Toshihiro Matsukawa
- Department of Hematology, Graduate School of Medicine, Hokkaido University Faculty of Medicine, Sapporo, Japan
| | - Hideki Goto
- Department of Hematology, Graduate School of Medicine, Hokkaido University Faculty of Medicine, Sapporo, Japan
| | - Takeshi Kondo
- Blood Disorders Center, Aiiku Hospital, Sapporo, Japan
| | - Takanori Teshima
- Department of Hematology, Graduate School of Medicine, Hokkaido University Faculty of Medicine, Sapporo, Japan
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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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Kimura H, Onozawa M, Hashiguchi J, Hidaka D, Kanaya M, Matsukawa T, Okada H, Kondo T, Matsuno Y, Teshima T. Hereditary thrombocythemia due to splicing donor site mutation of THPO in a Japanese family. Ann Hematol 2024; 103:89-96. [PMID: 37962621 DOI: 10.1007/s00277-023-05523-9] [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: 09/14/2023] [Accepted: 10/25/2023] [Indexed: 11/15/2023]
Abstract
Thrombopoietin (THPO) is an essential factor for platelet production. Hereditary thrombocythemia (HT) is caused by a germline mutation of THPO, MPL, or JAK2 and is inherited in an autosomal-dominant manner. We identified a Japanese family with HT due to a point mutation of the splicing donor site of the THPO gene (THPO c.13 + 1G > A). Bone marrow biopsy showed increased megakaryocytes mimicking essential thrombocythemia. One affected family member developed chronic myeloid leukemia. We cloned the mutation and developed mutated and wild type THPO expression vectors. Molecular analysis showed that the mutation causes an exon 3 skipping transcript of THPO that abrogates a suppressive untranslated upstream open reading frame. Although the transcript levels of THPO mRNA were comparable, mutated transcripts were more efficiently translated and THPO protein expression was significantly higher than that of the wild type.
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Affiliation(s)
- Hiroyuki Kimura
- Department of Hematology, Hokkaido University Faculty of Medicine, Graduate School of Medicine, Kita 15, Nishi 7, Kita-Ku, Sapporo, Japan
| | - Masahiro Onozawa
- Department of Hematology, Hokkaido University Faculty of Medicine, Graduate School of Medicine, Kita 15, Nishi 7, Kita-Ku, Sapporo, Japan.
| | - Junichi Hashiguchi
- Department of Hematology, Hokkaido University Faculty of Medicine, Graduate School of Medicine, Kita 15, Nishi 7, Kita-Ku, Sapporo, Japan
| | - Daisuke Hidaka
- Department of Hematology, Hokkaido University Faculty of Medicine, Graduate School of Medicine, Kita 15, Nishi 7, Kita-Ku, Sapporo, Japan
| | - Minoru Kanaya
- Blood Disorders Center, Aiiku Hospital, Sapporo, Japan
| | - Toshihiro Matsukawa
- Department of Hematology, Hokkaido University Faculty of Medicine, Graduate School of Medicine, Kita 15, Nishi 7, Kita-Ku, Sapporo, Japan
| | - Hiromi Okada
- Department of Surgical Pathology, Hokkaido University Hospital, Sapporo, Japan
| | - Takeshi Kondo
- Blood Disorders Center, Aiiku Hospital, Sapporo, Japan
| | - Yoshihiro Matsuno
- Department of Surgical Pathology, Hokkaido University Hospital, Sapporo, Japan
| | - Takanori Teshima
- Department of Hematology, Hokkaido University Faculty of Medicine, Graduate School of Medicine, Kita 15, Nishi 7, Kita-Ku, Sapporo, Japan
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Kimura H, Onozawa M, Teshima T. Genetic background of thrombocytosis in mice mimicking hereditary thrombocytosis in humans. Platelets 2023; 34:2276697. [PMID: 37941443 DOI: 10.1080/09537104.2023.2276697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 10/24/2023] [Indexed: 11/10/2023]
Affiliation(s)
- Hiroyuki Kimura
- Department of Hematology, Hokkaido University Faculty of Medicine, Graduate School of Medicine, Sapporo, Japan
| | - Masahiro Onozawa
- Department of Hematology, Hokkaido University Faculty of Medicine, Graduate School of Medicine, Sapporo, Japan
| | - Takanori Teshima
- Department of Hematology, Hokkaido University Faculty of Medicine, Graduate School of Medicine, Sapporo, Japan
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Agashe RP, Lippman SM, Kurzrock R. JAK: Not Just Another Kinase. Mol Cancer Ther 2022; 21:1757-1764. [PMID: 36252553 PMCID: PMC10441554 DOI: 10.1158/1535-7163.mct-22-0323] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 07/07/2022] [Accepted: 10/07/2022] [Indexed: 01/12/2023]
Abstract
The JAK/STAT axis is implicated in cancer, inflammation, and immunity. Numerous cytokines/growth factors affect JAK/STAT signaling. JAKs (JAK1, JAK2, JAK3, and TYK2) noncovalently associate with cytokine receptors, mediate receptor tyrosine phosphorylation, and recruit ≥1 STAT proteins (STAT1, STAT2, STAT3, STAT4, STAT5a, STAT5b, and STAT6). Tyrosine-phosphorylated STATs dimerize and are then transported into the nucleus to function as transcription factors. Signaling is attenuated by specific suppressor of cytokine signaling proteins, creating a negative feedback loop. Both germline mutations and polymorphisms of JAK family members correlate with specific diseases: Systemic lupus erythematosus (TYK2 polymorphisms); severe combined immunodeficiency (JAK3 mutations); pediatric acute lymphoblastic leukemia (TYK2 mutations); and hereditary thrombocytosis (JAK2 mutations). Somatic gain-of-function JAK mutations mainly occur in hematologic malignancies, with the activating JAK2 V617F being a myeloproliferative disorder hallmark; it is also seen in clonal hematopoiesis of indeterminate potential. Several T-cell malignancies, as well as B-cell acute lymphoblastic leukemia, and acute megakaryoblastic leukemia also harbor JAK family somatic alterations. On the other hand, JAK2 copy-number loss is associated with immune checkpoint inhibitor resistance. JAK inhibitors (jakinibs) have been deployed in many conditions with JAK activation; they are approved in myeloproliferative disorders, rheumatoid and psoriatic arthritis, atopic dermatitis, ulcerative colitis, graft-versus-host disease, alopecia areata, ankylosing spondylitis, and in patients hospitalized for COVID-19. Clinical trials are investigating jakinibs in multiple other autoimmune/inflammatory conditions. Furthermore, dermatologic and neurologic improvements have been observed in children with Aicardi-Goutieres syndrome (a genetic interferonopathy) treated with JAK inhibitors.
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Affiliation(s)
| | | | - Razelle Kurzrock
- Medical College of Wisconsin, Milwaukee, Wisconsin
- Win Consortium, Paris, France
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EAHP 2020 workshop proceedings, pediatric myeloid neoplasms. Virchows Arch 2022; 481:621-646. [PMID: 35819517 PMCID: PMC9534825 DOI: 10.1007/s00428-022-03375-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 06/15/2022] [Accepted: 06/28/2022] [Indexed: 12/02/2022]
Abstract
The first section of the bone marrow workshop of the European Association of Haematopathology (EAHP) 2020 Virtual Meeting was dedicated to pediatric myeloid neoplasms. The section covered the whole spectrum of myeloid neoplasms, including myelodysplastic syndromes (MDS), myeloproliferative neoplasms (MPN), myelodysplastic/myeloproliferative neoplasms (MDS/MPN), and acute myeloid leukemia (AML). The workshop cases are hereby presented, preceded by an introduction on these overall rare diseases in this age group. Very rare entities such as primary myelofibrosis, pediatric MDS with fibrosis, and MDS/MPN with JMML-like features and t(4;17)(q12;q21); FIP1L1::RARA fusion, are described in more detail.
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