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Sample records for jak2 v617f mutation

  1. JAK2V617F mutation is associated with special alleles in essential thrombocythemia.

    Hsiao, Hui-Hua; Liu, Yi-Chang; Tsai, Hui-Jen; Lee, Ching-Ping; Hsu, Jui-Feng; Lin, Sheng-Fung

    2011-03-01

    Janus kinase 2 mutation (JAK2V617F) has been identified in myeloproliferative neoplasms. Furthermore, special single nucleoside polymorphisms (SNPs) have been found to be associated with the JAK2V617F mutation. Therefore, the associations among JAK2V617F and special SNPs and the allelic location between them were investigated in patients with essential thrombocythemia (ET). A total of 61 patients with ET and 106 healthy individuals were enrolled. The PCR-RFLP method was applied to investigate the pattern of three SNPs, rs10974944, rs12343867, and rs12340895. Allele-specific PCR was used to examine the allelic location between rs10974944 and JAK2V617F. Among the patients with ET, 34 (55.7%, 34/61) were JAK2V617F positive (heterozygous) while the other 27 (44.3%, 27/61) were negative, and there were no MPLW515L/K mutations noted. The pattern of special SNPs in JAK2V617F(+) was significantly different from that in normal individuals (p <0.05), while there was no difference between JAK2V617F(-) patients and normal individuals. Allele-specific PCR showed high association of a cis-location between the special G-allele of rs10974944 and JAK2V617F(+). Based on this small numbered study, the results show the association between special SNPs and JAK2V617F mutation and a cis-location between the special G-allelic form of rs10974944 and the JAK2V617F mutation. These data highlight a close relationship between them in patients with ET.

  2. JAK2 and MPL gene mutations in V617F-negative myeloproliferative neoplasms.

    Siemiatkowska, A.M.; Bieniaszewska, M.; Hellmann, A.; Limon, J.

    2010-01-01

    We report three novel mutations in JAK2 exons 12, 19 and 25 in V617F-negative patients with polycythemia vera, essential thrombocythemia and idiopathic myelofibrosis. Scanning of JAK2 exons 12-25 and MPL exon 10 revealed the presence of JAK2 alterations in six and MPL W515L/K mutations in five of 34

  3. Prognostic significance of ASXL1, JAK2V617F mutations and JAK2V617F allele burden in Philadelphia-negative myeloproliferative neoplasms

    Yonal-Hindilerden I

    2015-06-01

    Full Text Available Ipek Yonal-Hindilerden, Aynur Daglar-Aday, Basak Akadam-Teker, Ceylan Yilmaz, Meliha Nalcaci, Akif Selim Yavuz, Deniz SarginDivision of Hematology, Department of Internal Medicine, Istanbul Medical Faculty, Istanbul University, Fatih-Istanbul, Turkey Background: Despite insights into the genetic basis of Philadelphia-negative myeloproliferative neoplasms (Ph-negative MPNs, a significant proportion of essential thrombocythemia (ET and primary myelofibrosis (PMF patients present with no known MPN disease alleles. There were no previous studies investigating the impact of ASXL1 mutations in Ph-negative MPNs in Turkey. In the current study, we investigated the prognostic significance of ASXL1 mutations in Turkish MPN patients. We also aimed to determine the prognostic significance of JAK2V617F allele burden and the relationship of JAK2V617F mutation with ASXL1 mutations in Ph-negative MPNs. Methods: About 184 patients from a single center diagnosed with Ph-negative MPNs were screened for ASXL1, JAK2V617F mutations, and JAK2V617F allele burden: 107 ET and 77 PMF. Results: A total of 29 ASXL1 mutations were detected in 24.7% of PMF and 8.4% of ET patients. ASXL1-mutated ET patients showed a trend toward an increase in the incidence of cerebrovascular events and higher total leukocyte counts. ASXL1-mutation in PMF was associated with older age and a higher prevalence of bleeding complications. In univariate analysis, overall survival (OS was significantly reduced in ASXL1-mutated PMF patients. In multivariate analysis, Dynamic International Prognostic Scoring System-plus high-risk category and ASXL1 mutation status were independently associated with shorter survival in PMF. In PMF, mutational status and allele burden of JAK2V617F showed no difference in terms of OS and leukemia-free survival. Conclusion: We conclude that ASXL1 mutations are molecular predictors of short OS in PMF. Keywords: Philadelphia-negative myeloproliferative neoplasms (Ph

  4. JAK2V617F mutation in chronic myeloid leukemia predicts early disease progression

    Pahore, Z.A.A.; Shamsi, T.S.; Taj, M.; Farzana, T.; Ansari, S.H.; Nadeem, M.; Ahmad, M.; Naz, A.

    2011-01-01

    Objective: To determine the association of JAK2V617F mutation along with BCR-ABL translocation or Philadelphia chromosome in chronic myeloid leukemia with early disease progression to advanced stages (accelerated phase or blast crisis) and poor outcome. Study Design: Case series. Place and Duration of Study: National Institute of Blood Diseases and Bone Marrow Transplantation, Karachi, from February 2008 to August 2009. Methodology: All the newly diagnosed cases of BCR-ABL or Philadelphia positive CML were tested for JAK2V617F mutation by Nested PCR. Demographic data, spleen size, hemoglobin levels, white blood cell and platelet counts were recorded. Independent sample t-test was used for age, haemoglobin level and spleen size. Fisher's exact test was applied to compare disease progression in JAK2V617F mutation positive and negative cases. Results: Out of 45 newly diagnosed cases of CML, 40 were in chronic phase, 01 in accelerated phase and 04 in blast crisis. JAK2V617F mutation was detected in 12 (26.7%) patients; 09 (22.5%) in chronic phase, none in accelerated phase and 03 (75%) in blast crisis. During a mean follow-up of 8 months, 03 patients in chronic phase transformed in blast crisis and 02 into accelerated phase. Overall 08 out of 11 (73%) JAK2V617F positive patients either had advanced disease or showed disease progression. Only 2 of 20 (10%) available patients, negative for the mutation, showed disease progression by transforming into blast crisis (p < 0.001). No statistically significant difference was seen in the age, spleen size, haemoglobin levels, white blood cells and platelets counts in JAK2V617F positive patients. Conclusion: JAK2V617F mutation was detected in 26.7% cases of chronic myeloid leukemia. A significant proportion of them showed early disease progression. (author)

  5. Impact of JAK2V617F Mutation Burden on Disease Phenotype in Chinese Patients with JAK2V617F-positive Polycythemia Vera (PV) and Essential thrombocythemia (ET).

    Zhao, Shixiang; Zhang, Xiang; Xu, Yang; Feng, Yufeng; Sheng, Wenhong; Cen, Jiannong; Wu, Depei; Han, Yue

    2016-01-01

    Most patients with polycythemia vera (PV) and half of essential thrombocythemia (ET) possess an activating JAK2V617F mutation. The objective of this study was to better define the effect of JAK2V617F mutant allele burden on clinical phenotypes in Chinese patients, especially thrombosis. By real-time polymerase chain reaction (RT-PCR), the JAK2V617F mutation burden was detected in 170 JAK2V617F-positive patients, including 54 PV and 116 ET. The results showed that JAK2V617F allele burden was higher in PV than in ET (PET (68.5% VS 26.7%) (PET patients showed increased JAK2V617F allele burden in the group with higher hemoglobin (HGB above 150 g/L) (PET. In PV patients, JAK2V617F mutation burden had influence on WBC counts. And the clinical characteristics of ET patients, such as WBC counts, hemoglobin level, splenomegaly and thrombosis, were influenced by JAK2V617F mutation burden. Male, high hemoglobin (HGB above 150 g/L), and increased JAK2V617F mutation burden (JAK2V617F allele burden ≥ 16.5%) were risks of thrombosis (PET patients by Logistic Regression.

  6. High prevalence of arterial thrombosis in JAK2 mutated essential thrombocythaemia: independence of the V617F allele burden

    Larsen, Thomas Stauffer; Pallisgaard, Niels; Møller, Michael Boe

    2008-01-01

    Approximately half of the patients with essential thrombocythaemia (ET) harbor the JAK2 V617F mutation. Despite a phenotypic mimicry of JAK2 V617F positive ET and polycythaemia vera (PV), the data on thromboembolic risk and correlation to JAK2 mutation status are ambiguous. On a strictly WHO defi...

  7. Impact of JAK2V617F Mutational Status on Phenotypic Features in Essential Thrombocythemia and Primary Myelofibrosis

    İpek Yönal

    2016-05-01

    Full Text Available Objective: The JAK2V617F mutation is present in the majority of patients with essential thrombocythemia (ET and primary myelofibrosis (PMF. The impact of this mutation on disease phenotype in ET and PMF is still a matter of discussion. This study aims to determine whether there are differences in clinical presentation and disease outcome between ET and PMF patients with and without the JAK2V617F mutation. Materials and Methods: In this single-center study, a total of 184 consecutive Philadelphia-negative chronic myeloproliferative neoplasms, 107 cases of ET and 77 cases of PMF, were genotyped for JAK2V617F mutation using the JAK2 Ipsogen MutaScreen assay, which involves allele-specific polymerase chain reaction. Results: ET patients positive for JAK2V617F mutation had higher hemoglobin (Hb and hematocrit (Hct levels, lower platelet counts, and more prevalent splenomegaly at diagnosis compared to patients negative for the JAK2V617F mutation, but rates of major thrombotic events, arterial thrombosis, and venous thrombosis were comparable between the groups. At presentation, PMF patients with JAK2V617F mutation had significantly higher Hb and Hct levels and leukocyte counts than patients without the mutation. Similar to the findings of ET patients, thromboembolic rates were similar in PMF patients with and without theJAK2V617F mutation. For ET and PMF patients, no difference was observed in rates of death with respect to JAK2V617F mutational status. Moreover, leukemic transformation rate was not different in our PMF patients with and without JAK2V617F mutation. Conclusion: We conclude that JAK2V617F-mutated ET patients express a polycythemia vera-like phenotype and JAK2V617F mutation in PMF patients is associated with a more pronounced myeloproliferative phenotype.

  8. Increased frequency of co-existing JAK2 exon-12 or MPL exon-10 mutations in patients with low JAK2(V617F) allelic burden.

    Nussenzveig, Roberto H; Pham, Ha T; Perkins, Sherrie L; Prchal, Josef T; Agarwal, Archana M; Salama, Mohamed E

    2016-01-01

    The frequency of co-existing JAK2(V617F)/MPL and JAK2(V617F)/JAK2 exon-12 mutations has not been previously investigated in MPNs. Poor survival was reported in primary myelofibrosis with low JAK2(V617F) allelic burden. However, mutational status of JAK2 exon-12 or MPL were not reported in these patients. This study developed a cost-effective multiplex high resolution melt assay that screens for mutations in JAK2 gene exons-12 and -14 ((V617F)) and MPL gene exon-10. Co-existing mutations with JAK2(V617F) were detected in 2.9% (6/208; two JAK2 exon-12 and four MPL exon-10) patient specimens with known JAK2(V617F) (allelic-burden range: 0.1-96.8%). Co-existing mutations were detected in specimens with MPL exon-10 mutation should be pursued.

  9. JAK2V617F Somatic Mutation In The General Population

    Nielsen, Camilla; Bojesen, Stig E; Nordestgaard, Børge G

    2014-01-01

    of myeloproliferative neoplasm from no disease (n=8 at re-examination) through essential thrombocythemia (n=20) and polycythemia vera (n=13) to primary myelofibrosis (n=7). Among those diagnosed with a myeloproliferative neoplasm only at re-examination in 2012, in the preceding years JAK2V617F mutation burden increased...

  10. Frequency and clinical features of the JAK2 V617F mutation in pediatric patients with sporadic essential thrombocythemia.

    Nakatani, Takuya; Imamura, Toshihiko; Ishida, Hiroyuki; Wakaizumi, Katsuji; Yamamoto, Tohru; Otabe, Osamu; Ishigami, Tsuyoshi; Adachi, Souichi; Morimoto, Akira

    2008-12-01

    Pediatric essential thrombocythemia (ET) is a rare and heterogenous disease entity. While several recent studies have focused on the role of the JAK2 V617F mutation in pediatric ET, the frequency of pediatric ET cases with this mutation and the associated clinical features remain unclear. We examined six childhood cases who had been diagnosed with ET according to WHO criteria (onset age: 0.2-14 years) for the presence of the JAK2 V617F mutation, MPLW515L mutation and JAK2 exon 12 mutations. Two sensitive PCR-based methods were used for the JAK2 V617F genotyping. We also examined the expression of polycythemia rubra vera-1 (PRV-1), which is a diagnostic marker for clonal ET. We found that three of the six cases had the JAK2 V617F mutation and that all six cases expressed PRV-1 in their peripheral granulocytes. Neither MPL W515L mutation nor JAK2 exon 12 mutations was detected in the patients without JAK2 V617F mutation. The two patients who developed thrombocythemia during infancy were JAK2 V617F-negative. These findings suggest that the JAK2 V617F mutation is not rare in childhood sporadic ET cases, and that these cases might be older and myeloproliferative features.

  11. Characterization and Prognosis Significance of JAK2 (V617F), MPL, and CALR Mutations in Philadelphia-Negative Myeloproliferative Neoplasms

    Singdong, Roongrudee; Siriboonpiputtana, Teerapong; Chareonsirisuthigul, Takol; Kongruang, Adcharee; Limsuwanachot, Nittaya; Sirirat, Tanasan; Chuncharunee, Suporn; Rerkamnuaychoke, Budsaba

    2016-10-01

    Background: The discovery of somatic acquired mutations of JAK2 (V617F) in Philadelphia-negative myeloproliferative neoplasms (Ph-negative MPNs) including polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF) has not only improved rational disease classification and prognostication but also brings new understanding insight into the pathogenesis of diseases. Dosage effects of the JAK2 (V617F) allelic burden in Ph-negative MPNs may partially influence clinical presentation, disease progression, and treatment outcome. Material and Methods: Pyrosequencing was performed to detect JAK2 (V617F) and MPL (W515K/L) and capillary electrophoresis to identify CALR exon 9.0 mutations in 100.0 samples of Ph-negative MPNs (38.0 PV, 55 ET, 4 PMF, and 3 MPN-U). Results: The results showed somatic mutations of JAK2 (V617F) in 94.7% of PV, 74.5% of ET, 25.0% of PMF, and all MPN-U. A high proportion of JAK2 (V617F) mutant allele burden (mutational load > 50.0%) was predominantly observed in PV when compared with ET. Although a high level of JAK2 (V617F) allele burden was strongly associated with high WBC counts in both PV and ET, several hematological parameters (hemoglobin, hematocrit, and platelet count) were independent of JAK2 (V617F) mutational load. MPL (W515K/L) mutations could not be detected whereas CALR exon 9.0 mutations were identified in 35.7% of patients with JAK2 negative ET and 33.3% with JAK2 negative PMF. Conclusions: The JAK2 (V617F) allele burden may be involved in progression of MPNs. Furthermore, a high level of JAK2 (V617F) mutant allele appears strongly associated with leukocytosis in both PV and ET. Creative Commons Attribution License

  12. The association of JAK2V617F mutation and leukocytosis with thrombotic events in essential thrombocythemia.

    Hsiao, Hui-Hua; Yang, Ming-Yu; Liu, Yi-Chang; Lee, Ching-Ping; Yang, Wen-Chi; Liu, Ta-Chih; Chang, Chao-Sung; Lin, Sheng-Fung

    2007-11-01

    The Janus kinase 2 mutation, JAK2 (V617F), and megakaryocytic mutations, MPL (W515L/K), have been identified and correlated with a subtype of essential thrombocythemia (ET) patients. We investigated the frequency of mutations in ET patients and analyzed the relationship with their clinical features. Fifty-three ET patients were enrolled in the study. The amplification refractory mutation system was applied for the mutation survey of the JAK2V617F, while the polymerase chain reaction with sequencing was used for the mutation survey of MPLW515L/K. Thirty-five (66%) patients harboring the JAK2 (V617F) mutation, including 3 homozygous and 32 heterozygous changes, but no MPLW515L/K mutation, were found. During follow-up, 17 (32.1%) patients suffered from documented thrombotic events, with 15 having JAK2V617F mutations. Statistical analysis showed that patients with the JAK2 mutation had significantly higher leukocytes, hemoglobin level, and thrombotic event (p = 0.043, p = 0.001, and p = 0.029, respectively). Thrombotic events were also significantly correlated with leukocytosis and older age. The JAK2V617F mutation was noted in a certain population of ET patients and correlated with leukocytosis, high hemoglobin level, and thrombosis. Therefore, detection of the JAK2V617F mutation can affect not only the diagnosis, but also the management of ET patients.

  13. Frequency of JAK2 V617F mutation in patients with Philadelphia positive Chronic Myeloid Leukemia in Pakistan.

    Tabassum, Najia; Saboor, Mohammed; Ghani, Rubina; Moinuddin, Moinuddin

    2014-01-01

    Co-existence of myeloproliferative disorders (MPD) and Janus associated kinase 2 mutation (JAK2 V617F) is a well-established fact. Only few case reports are available showing presence of JAK2 V617F mutation in chronic myeloid leukemia (CML). Purpose of this study was to determine the frequency of JAK2 V617F mutation in Philadelphia Chromosome positive (Ph (+)) CML patients in Pakistan. The study was conducted from August 2009 to July 2010 at Civil Hospital and Baqai Institute of Hematology (BIH) Karachi. Blood samples from 25 patients with CML were collected. Multiplex reverse transcription polymerase chain reaction (RT-PCR) was performed for Breakpoint Cluster Region - Abelson (BCR-ABL) rearrangement. Conventional PCR was performed for JAK2 V617F mutation on BCR-ABL positive samples. All 25 samples showed BCR-ABL rearrangement. Out of these 11 samples (44%) had JAK2 V617F mutation; the remaining 14 (56%) cases showed JAK2 617V wild type. It is concluded that the co-existence of Ph (+)CML and JAK2 V617F mutation is possible.

  14. Characterization and Prognosis Significance of JAK2 (V617F), MPL, and CALR Mutations in Philadelphia-Negative Myeloproliferative Neoplasms

    Singdong, Roongrudee; Siriboonpiputtana, Teerapong; Chareonsirisuthigul, Takol; Kongruang, Adcharee; Limsuwanachot, Nittaya; Sirirat, Tanasan; Chuncharunee, Suporn; Rerkamnuaychoke, Budsaba

    2016-01-01

    Background: The discovery of somatic acquired mutations of JAK2 (V617F) in Philadelphia-negative myeloproliferative neoplasms (Ph-negative MPNs) including polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF) has not only improved rational disease classification and prognostication but also brings new understanding insight into the pathogenesis of diseases. Dosage effects of the JAK2 (V617F) allelic burden in Ph-negative MPNs may partially influence clinical ...

  15. JAK2 V617F, MPL W515L and JAK2 Exon 12 Mutations in Chinese Patients with Primary Myelofibrosis.

    Xia, Jun; Lu, Mi-Ze; Jiang, Yuan-Qiang; Yang, Guo-Hua; Zhuang, Yun; Sun, Hong-Li; Shen, Yun-Feng

    2012-03-01

    JAK2 V617F, MPL W515L and JAK2 exon 12 mutations are novel acquired mutations that induce constitutive cytokine-independent activation of the JAK-STAT pathway in myeloproliferative disorders (MPD). The discovery of these mutations provides novel mechanism for activation of signal transduction in hematopoietic malignancies. This research was to investigate their prevalence in Chinese patients with primary myelofibrosis (PMF). We introduced allele-specific PCR (AS-PCR) combined with sequence analysis to simultaneously screen JAK2 V617F, MPL W515L and JAK2 exon 12 mutations in 30 patients with PMF. Fifteen PMF patients (50.0%) carried JAK2 V617F mutation, and only two JAK2 V617F-negative patients (6.7%) harbored MPL W515L mutation. None had JAK2 exon 12 mutations. Furthermore, these three mutations were not detected in 50 healthy controls. MPL W515L and JAK2 V617F mutations existed in PMF patients but JAK2 exon 12 mutations not. JAK2 V617F and MPL W515L and mutations might contribute to the primary molecular pathogenesis in patients with PMF.

  16. A mutação JAK2 V617F e as síndromes mieloproliferativas JAK2 V617F mutation and the myeloproliferative disorders

    Bárbara C. R. Monte-Mór

    2008-01-01

    Full Text Available Síndromes mieloproliferativas (SMPs são doenças hematopoéticas de origem clonal que apresentam amplificação de uma ou mais linhagens mielóides. Policitemia vera (PV, trombocitemia essencial (TE, mielofibrose idiopática (MF e leucemia mielóide crônica (LMC são consideradas SMPs clássicas e apresentam características clínicas e biológicas comuns. Ao contrário de LMC, cuja etiologia está relacionada à proteína constitutivamente ativa Bcr-Abl, o mecanismo molecular de PV, TE e MF permaneceu por muito tempo desconhecido. Esta revisão se foca na recente descoberta da mutação JAK2 V617F em pacientes com PV, TE e MF, sua relação com o fenótipo mieloproliferativo e implicações na abordagem clínica de pacientes.Myeloproliferative disorders are clonal hematopoietic diseases that are characterized by the amplification of one or more myeloid lineages. Polycythemia vera, essential thrombocythemia, idiopathic myelofibrosis and chronic myeloid leukemia are considered classic myeloproliferative disorders and share common clinical and biological features. While the genetic basis of chronic myeloid leukemia is shown to be the constitutive active protein BCR-ABL, the main molecular lesions in polycythemia vera, essential thrombocythemia and idiopathic myelofibrosis remain unknown. This review focuses on the recent discovery of the JAK2 V617F mutation, its relationship to the myeloproliferative phenotype and implications in the clinical approach of patients.

  17. Coexistance of JAK2V617F mutation and BCR/ABL translocation in one patient

    Murat Albayrak

    2010-09-01

    Full Text Available Dear Editor,The myeloproliferative disorders (MPDs constitute a subcategory of chronic myeloid disorders and include chronic myeloid leukemia (CML, essential thrombocytemia (ET, polycythemia vera (PV and myelofibrosis (MF. In 1960, the discovery of the Philadelphia chromosome (Ph became a cornerstone in CML treatment and led to the development of moleculary targeted therapy. Recently, an acquired mutation in the Janus kinase 2 (JAK2 gene has been discovered in nearly all patents with PV and approximately half of the patients with primary MF and ET. Subsequently, the mutation has been demonstrated in atypical MPDs (chronic neutrophilic leukemia, unclassified, de novo myelodysplastic syndrome or acute myeloid leukemia.1 It has been hoped that targeted inhibition of JAK2V617F should achieve similar disease control as thyrosine kinases has produced in CML.

  18. Pathogenetic Role of JAK2 V617F Mutation in Chronic Myeloproliferative Disorders

    Hui-Chi Hsu

    2007-03-01

    Full Text Available The molecular pathogenesis of chronic myeloproliferative disorders (MPDs is poorly understood. The hematopoietic progenitor cells of patients with polycythemia vera (PV or essential thrombocythemia (ET are characterized by hypersensitiv-ity to hematopoietic growth factors and formation of endogenous erythroid colonies. Recently, 4 groups reported almost simultaneously Janus kinase 2 (JAK2 V617F mutation in more than 80% of PV patients, 30% of patients with ET and in about 50% of patients with idiopathic myelofibrosis. The identification of the JAK2 mutation represents a major advance in the understanding of the molecular pathogenesis of MPDs that will likely permit a new classification and the development of novel therapeutic strategies for these diseases.

  19. The JAK2V617F and CALR exon 9 mutations are shared immunogenic neoantigens in hematological malignancy

    Holmstrom, Morten Orebo; Hasselbalch, Hans Carl; Andersen, Mads Hald

    2017-01-01

    Approximately 90% of patients with the hematological malignancies termed the chronic myeloproliferative neoplasms harbor either the JAK2V617F-mutation or CALR exon 9 mutation. Both of these are recognized by T-cells, which make the mutations ideal targets for cancer immune therapy as they are sha......Approximately 90% of patients with the hematological malignancies termed the chronic myeloproliferative neoplasms harbor either the JAK2V617F-mutation or CALR exon 9 mutation. Both of these are recognized by T-cells, which make the mutations ideal targets for cancer immune therapy...

  20. Detection of CALR and MPL Mutations in Low Allelic Burden JAK2 V617F Essential Thrombocythemia.

    Usseglio, Fabrice; Beaufils, Nathalie; Calleja, Anne; Raynaud, Sophie; Gabert, Jean

    2017-01-01

    Myeloproliferative neoplasms are clonal hematopoietic stem cell disorders characterized by aberrant proliferation and an increased tendency toward leukemic transformation. The genes JAK2, MPL, and CALR are frequently altered in these syndromes, and their mutations are often a strong argument for diagnosis. We analyzed the mutational profiles of these three genes in a cohort of 164 suspected myeloproliferative neoplasms. JAK2 V617F mutation was detected by real-time PCR, whereas high-resolution melting analysis followed by Sanger sequencing were used for searching for mutations in JAK2 exon 12, CALR, and MPL. JAK2 V617F mutation was associated with CALR (n = 4) and MPL (n = 4) mutations in 8 of 103 essential thrombocytosis patients. These cases were harboring a JAK2 V617F allelic burden of MPL genes in myeloproliferative neoplasms and suggest that CALR and MPL should be analyzed not only in JAK2-negative patients but also in low V617F mutation patients. Follow-up of these double-mutation cases will be important for determining whether this group of patients presents particular evolution or complications. Copyright © 2017 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

  1. The JAK2 V617F somatic mutation, mortality and cancer risk in the general population

    Nielsen, Camilla; Birgens, Henrik S; Nordestgaard, Børge G

    2011-01-01

    .1-1.1). Multifactorially adjusted hazard ratios for any cancer, hematologic cancer and myeloproliferative cancer were 3.7 (1.7-8.0), 58 (13-261) and 161 (12-2,197), respectively. Corresponding hazard ratios were 1.2 (0.8-2.0), 2.3 (0.2-25), 1.3 (0.3-5.4) for men versus women, and 1.0 (1.0-1.1), 1.1 (0.9-1.2), 0.9 (0......JAK2 V617F is present in the majority of patients with myeloproliferative cancer; however, its prevalence and clinical significance in the general population is unknown. We screened for presence of the mutation in 10,507 participants from the Copenhagen City Heart Study with up to 17.6 years...

  2. [The quantitative testing of V617F mutation in gen JAK2 using pyrosequencing technique].

    Dunaeva, E A; Mironov, K O; Dribnokhodova, T E; Subbotina, E E; Bashmakova; Ol'hovskiĭ, I A; Shipulin, G A

    2014-11-01

    The somatic mutation V617F in gen JAK2 is a frequent cause of chronic myeloprolific diseases not conditioned by BCR/ABL mutation. The quantitative testing of relative percentage of mutant allele can be used in establishing severity of disease and its prognosis and in prescription of remedy inhibiting activity of JAK2. To quantitatively test mutation the pyrosequencing technique was applied. The developed technique permits detecting and quantitatively, testing percentage of mutation fraction since 7%. The "gray zone" is presented by samples with percentage of mutant allele from 4% to 7%. The dependence of expected percentage of mutant fraction in analyzed sample from observed value of signal is described by equation of line with regression coefficients y = - 0.97, x = -1.32 and at that measurement uncertainty consists ± 0.7. The developed technique is approved officially on clinical material from 192 patients with main forms of myeloprolific diseases not conditioned by BCR/ABL mutation. It was detected 64 samples with mautant fraction percentage from 13% to 91%. The developed technique permits implementing monitoring of therapy of myeloprolific diseases and facilitates to optimize tactics of treatment.

  3. Significance of combined detection of JAK2V617F, MPL and CALR gene mutations in patients with essential thrombocythemia.

    Ji, Liying; Qian, Mengyao; Wu, Nana; Wu, Jianmin

    2017-03-01

    The aim of this study was to analyze the mutation rate of JAK2V617F, MPLW515L/K and CALR genes in adult patients with essential thrombocythemia (ET) and the accuracy of the combined detection by the receiver operating curve. Three hundred and forty-two cases with high-platelets (≥300×10 9 /l) were consecutively selected. The patients were analyzed for routine blood examination, bone marrow biopsy and genetic testing. One hundred and fifty-four cases (45.03%) were diagnosed with ET and 188 cases of secondary thrombocythemia according to the hematopoietic and lymphoid tissue tumor classification standards of 2008. It was found that the mutant type of three genes showed three bands, whereas only one band for wild-type. The JAK2V617F and MPL mutations did not cause a change in the open reading frame and the CALR mutation resulted in its change. The mutation rate of JAK2V617F and CALR in ET group was significantly higher than that in the secondary thrombocythemia group (p<0.05). The positive mutation rate of MPL was only 4.55%. JAK2V617F-positive mutation alone was used to diagnose with ET. The area under the curve (AUC) was 0.721. The sensitivity was 72.4%, the specificity was 79.5% and the cut-off value was 0.25. When CALR-positive mutation alone was used to diagnose ET, the AUC, sensitivity, specificity and cut-off value were 0.664, 68.4, 82.4 and 0.09%, respectively. JAK2V617F combined with CALR mutation were used for diagnosis of ET. The AUC was 0.862, the sensitivity was 85.9%, the specificity was 87.8%, and the cut-off values were 0.21 and 0.07. In conclusion, the positive mutation rate of JAK2V617F and CALR in ET was higher, and the sensitivity, specificity and accuracy of the diagnosis of ET were significantly improved using the detection of JAK2V617F and CALR.

  4. Relationship of JAK2V617F gene mutation with cell proliferation and coagulation function in myeloproliferative neoplasms

    Xiao-Nan Zhang

    2017-05-01

    Full Text Available Objective: To study the relationship of JAK2V617F gene mutation with cell proliferation and coagulation function in myeloproliferative neoplasms. Methods: Patients who were diagnosed with BCR-ABL-negative myeloproliferative neoplasms in Anyang District Hospital between June 2014 and August 2016 were selected, JAK2V617F gene mutation was detected, and according to the test results, the patients were divided into mutation-positive group and mutation-negative group. The expression of JAK2/STATs signaling pathway molecules and cell proliferation genes in bone marrow fluid as well as the coagulation function indexes in peripheral blood were detected. Results: p-JAK2, p-STAT3, p-STAT5, Survivin, C-myc, CyclinD1 and ASXL1 protein expression in myeloproliferative neoplasms of mutation-positive group were significantly higher than those of mutation-negative group, and peripheral blood PT and APTT levels were significantly lower than those of mutation-negative group while TT and FIB levels were not significantly different from those of mutation-negative group. Conclusion: JAK2V617F gene mutation in myeloproliferative neoplasms can promote the cell proliferation and cause the hypercoagulable state.

  5. TG101209, a small molecule JAK2-selective kinase inhibitor potently inhibits myeloproliferative disorder-associated JAK2V617F and MPLW515L/K mutations.

    Pardanani, A; Hood, J; Lasho, T; Levine, R L; Martin, M B; Noronha, G; Finke, C; Mak, C C; Mesa, R; Zhu, H; Soll, R; Gilliland, D G; Tefferi, A

    2007-08-01

    JAK2V617F and MPLW515L/K represent recently identified mutations in myeloproliferative disorders (MPD) that cause dysregulated JAK-STAT signaling, which is implicated in MPD pathogenesis. We developed TG101209, an orally bioavailable small molecule that potently inhibits JAK2 (IC(50)=6 nM), FLT3 (IC(50)=25 nM) and RET (IC(50)=17 nM) kinases, with significantly less activity against other tyrosine kinases including JAK3 (IC(50)=169 nM). TG101209 inhibited growth of Ba/F3 cells expressing JAK2V617F or MPLW515L mutations with an IC(50) of approximately 200 nM. In a human JAK2V617F-expressing acute myeloid leukemia cell line, TG101209-induced cell cycle arrest and apoptosis, and inhibited phosphorylation of JAK2V617F, STAT5 and STAT3. Therapeutic efficacy of TG101209 was demonstrated in a nude mouse model. Furthermore, TG101209 suppressed growth of hematopoietic colonies from primary progenitor cells harboring JAK2V617F or MPL515 mutations.

  6. No Evidence for JAK2(V617F) Mutation in Monoclonal B Cells in 2 Patients with Polycythaemia Vera and Concurrent Monoclonal B Cell Disorder

    Stijnis, C.; Kroes, W. G. M.; Balkassmi, S.; Marijt, E. W. A.; van Rossum, A. P.; Bakker, E.; Vlasveld, L. T.

    2012-01-01

    Occurrence of Philadelphia chromosome-negative myeloproliferative neoplasms (Ph- MPN) and lymphoproliferative disorders, like B cell chronic lymphocytic leukaemia (B-CLL), in the same patient is rare. JAK2(V617F) mutation was recently introduced as a powerful diagnostic tool for Ph- MPN. JAK2(V617F)

  7. Detection of MPL exon10 mutations in 103 Chinese patients with JAK2V617F-negative myeloproliferative neoplasms.

    Chen, Xiuhua; Qi, Xiling; Tan, Yanhong; Xu, Zhifang; Xu, Aining; Zhang, Linlin; Wang, Hongwei

    2011-06-15

    JAK2V617F mutation has been reported in 90% of patients with polycythemia vera (PV) and about 50% of patients with essential thromobocythemia (ET) and primary myelofibrosis (PMF). Recently, acquired mutations in the transmembrane-juxtamembrane region of MPL (MPLW515 mutations) have been reported in approximately 5% of JAK2V617F-negative PMF and about 1% of all cases of ET. MPL is the receptor for thrombopoietin that regulates the production of platelets by bone marrow. It is likely that some mutations more closely related to ET in MPL exon10 may have been missed by current assays. We inferred that there might be other mutations in MPL exon10 for MPN patients in addition to MPLW515 mutations. To investigate its mutation types and prevalence in Chinese patients with myeloproliferative neoplasms (MPN), we performed mutation detection on MPL exon10 in 103 JAK2V617F-negative MPN patients by single strand conformation polymorphism (SSCP) and allele-specific PCR (AS-PCR) combined with sequencing. As a result, one previously unrecognized MPL mutation (12-bp in-frame insertion) was identified in one patient with ET in addition to an MPLW515K mutation identified in one PMF patient. This confirms our hypothesis that BCR/ABL negative and JAK2V617F-negative MPN patients have other mutations besides W515 mutation in MPL exon10 and mutations other than single nucleotide exchange also exist. In addition, MPL mutation was associated with Chinese MPN patients. Copyright © 2011 Elsevier Inc. All rights reserved.

  8. Melting curve analysis after T allele enrichment (MelcaTle as a highly sensitive and reliable method for detecting the JAK2V617F mutation.

    Soji Morishita

    Full Text Available Detection of the JAK2V617F mutation is essential for diagnosing patients with classical myeloproliferative neoplasms (MPNs. However, detection of the low-frequency JAK2V617F mutation is a challenging task due to the necessity of discriminating between true-positive and false-positive results. Here, we have developed a highly sensitive and accurate assay for the detection of JAK2V617F and named it melting curve analysis after T allele enrichment (MelcaTle. MelcaTle comprises three steps: 1 two cycles of JAK2V617F allele enrichment by PCR amplification followed by BsaXI digestion, 2 selective amplification of the JAK2V617F allele in the presence of a bridged nucleic acid (BNA probe, and 3 a melting curve assay using a BODIPY-FL-labeled oligonucleotide. Using this assay, we successfully detected nearly a single copy of the JAK2V617F allele, without false-positive signals, using 10 ng of genomic DNA standard. Furthermore, MelcaTle showed no positive signals in 90 assays screening healthy individuals for JAK2V617F. When applying MelcaTle to 27 patients who were initially classified as JAK2V617F-positive on the basis of allele-specific PCR analysis and were thus suspected as having MPNs, we found that two of the patients were actually JAK2V617F-negative. A more careful clinical data analysis revealed that these two patients had developed transient erythrocytosis of unknown etiology but not polycythemia vera, a subtype of MPNs. These findings indicate that the newly developed MelcaTle assay should markedly improve the diagnosis of JAK2V617F-positive MPNs.

  9. Concurrent MPL515 and JAK2V617F mutations in myelofibrosis: chronology of clonal emergence and changes in mutant allele burden over time.

    Lasho, Terra L; Pardanani, Animesh; McClure, Rebecca F; Mesa, Ruben A; Levine, Ross L; Gilliland, D Gary; Tefferi, Ayalew

    2006-12-01

    MPLW515L/K and JAK2V617F can co-exist in myelofibrosis with myeloid metaplasia (MMM). The chronology of clonal emergence was studied in three such cases using serially stored bone marrow. At diagnosis, a major MPL515 mutant clone was accompanied by a minor JAK2V617F clone in all three instances. At 25 time points over a period of 4-8 years, allele burden fluctuated but remained high for MPLW515L/K and low for JAK2V617F. We conclude that MPLW515L/K and JAK2V617F are both early events in MMM and allele burden, rather than the mere presence of these mutations, might be relevant to phenotypic variation in myeloproliferative disorders.

  10. [Expression of JAK2V617F and MPLW515L/K mutation in 30 suspected cases of early myeloproliferative disorders].

    Fan, Zheng; Zhang, Ri; Shen, Yi-Min; Fei, Hai-Rong; Zhu, Zi-Ling; Cen, Jian-Nong

    2008-09-01

    To investigate the prevalence of JAK2V617F and MPLW515L/K mutation in patients with slightly elevated platelets (BPC) or hemoglobin (Hb) not meeting the criteria of polycythemia vera (PV) or essential thrombocythemia (ET). Genomic DNA from bone marrow or blood mononuclear cells was screened with allele specific polymerase chain reaction (AS-PCR) for JAK2V617F and MPLW515L/K mutation. The history of thrombosis was assessed retrospectively by patients files. Of 30 patients, 14 (46.7%) were positive for the JAK2V617F mutation, none of them had the MPLW515L/ K. Five of these 14 patients had a history of thrombosis. Follow-up results were available in 22 patients. Among them, 12 patients with JAK2V617F mutation turned out to be MPD in 6-24 months; only 2 out of 10 patients without this mutation evolved to MPD. JAK2V617F mutation could be one of the diagnosis criteria of early MPD. No MPLW515L/K expression was found in early MPD.

  11. Mutation Analysis of JAK2V617F, FLT3-ITD, NPM1, and DNMT3A in Chinese Patients with Myeloproliferative Neoplasms

    Min Wang

    2014-01-01

    Full Text Available Since the discovery of JAK2V617F tyrosine kinase-activating mutation, several genes have been found mutated in myeloproliferative neoplasms (MPNs. FLT3-ITD, NPM1, and DNMT3A mutations frequently occurred in AML patients and have been found conferred with myeloproliferative neoplasms in mouse model. Therefore, we sought to search for mutations in JAK2V617F, FLT3-ITD, NPM1, and DNMT3A in 129 cases including 120 classic MPN cases and 9 MDS/MPN cases. JAK2V617F mutation was found in 60% of the 120 classic MPNs. However, none of the patients displayed FLT3-ITD and NPM1 mutations; only 2 patients harbored DNMT3A R882 mutation. Further studies including whole-genome sequence will be conducted to investigate the possible involvement of these genes in MPN.

  12. JAK2 V617F, MPL, and CALR mutations in essential thrombocythaemia and major thrombotic complications: a single-institute retrospective analysis.

    Pósfai, Éva; Marton, Imelda; Király, Péter Attila; Kotosz, Balázs; Kiss-László, Zsuzsanna; Széll, Márta; Borbényi, Zita

    2015-07-01

    Thrombo-haemorrhagic events are the main cause of morbidity and mortality in essential thrombocythemia. The aim of this study was to estimate the incidence of thrombotic events and the impact of the JAK2V617F, MPL (W515L, W515K, W515R, W515A and S505N) and CALR (type-1, type-2) mutations on 101 essential thrombocythaemia patients (72 females and 29 males with a mean age of 61 years) diagnosed in a Southern Hungarian regional academic centre. The incidence of major thrombosis was 13.86 %. Sixty percent of the patients carried the JAK2V617F mutation. The MPL mutations were analysed by sequencing and the W515L was the only one we could identify with an incidence of 3.96 %. Type-2 CALR mutation could be identified in 3 cases among the patients who had JAK2/MPL-unmutated ET. Statistical analyses revealed that the JAK2V617F mutation was associated with significantly increased levels of platelet (p = 0.042), haemoglobin (p = 0.000), red blood cell (p = 0.000) and haematocrit (p = 0.000) and hepatomegaly (p = 0.045) at diagnosis compared to JAK2V617F negative counterparts, however there was no significant association between the JAK2V617F mutation status (relative risk: 1.297, 95 % CI 0.395-4.258; p = 0.668) and subsequent thrombotic complications. The impact of JAK2V617F, MPL W515L and CALR mutations on the clinical findings at the diagnosis of ET was obvious, but their statistically significant role in the prediction of thrombotic events could not be proven in this study. Our results indirectly support the concept that, besides the quantitative and qualitative changes in the platelets, the mechanisms leading to thrombosis are more complex and multifactorial.

  13. JAK2 V617F mutation negative erythrocytosis (or how to more simply perform diagnosis and treat a patient with increased hematocrit

    Zito Luca

    2011-08-01

    Full Text Available Summary This case report focuses on a 71-year old patient affected by unknown dyspnea and erythrocytosis referred by his general practitioner to our center for specialist advice after a hematological examination had excluded polycythemia vera on grounds of negative test for JAK2 V617F/exon 12 mutation. An accurate clinical history and physical examination accompanied by respiratory function tests resulted in diagnosis of JAK2 V617F mutation negative erythrocytosis, and treatment could be started. The discussion examines decisional algorithms when a polyglobulic patient is referred for diagnosis.

  14. Extending Jak2V617F and MplW515 mutation analysis to single hematopoietic colonies and B and T lymphocytes.

    Pardanani, Animesh; Lasho, Terra L; Finke, Christy; Mesa, Ruben A; Hogan, William J; Ketterling, Rhett P; Gilliland, Dwight Gary; Tefferi, Ayalew

    2007-09-01

    JAK2V617F and MPLW515L/K are myeloproliferative disorder (MPD)-associated mutations. We genotyped 552 individual hematopoietic colonies obtained by CD34+ cell culture from 16 affected patients (13 JAK2V617F and 3 MPLW515L/K) to determine (a) the proportion of colonies harboring a particular mutation in the presence or absence of cytokines, (b) the lineage distribution of endogenous colonies for each mutation, and (c) the differences (if any) in the pattern of mutation among the various MPDs, as established by genotyping of individual colonies. Genotyping analysis revealed cohabitation of mutation-negative and mutation-positive endogenous colonies in polycythemia vera as well as other MPDs. Culture of progenitor cells harboring MPLW515L/K yielded virtually no endogenous erythroid colonies in contrast to JAK2V617F-harboring progenitor cells. The mutation pattern (i.e., relative distribution of homozygous, heterozygous, or wild-type colonies) was not a distinguishing feature among the MPDs, and MPLW515 mutations were detected in B and/or T lymphocytes in all three patients tested. These observations suggest that clonal myelopoiesis antedates acquisition of JAK2V617F or MPLW515L/K mutations and that the latter is acquired in a lympho-myeloid progenitor cell.

  15. Coexistence of gain-of-function JAK2 germ line mutations with JAK2(V617F) in polycythemia vera

    Láníková, Lucie; Babošová, Oľga; Swierczek, S.; Wang, L.; Wheeler, D.A.; Divoky, V.; Kořínek, Vladimír; Prchal, J.T.

    2016-01-01

    Roč. 128, č. 18 (2016), s. 2266-2270 ISSN 0006-4971 R&D Projects: GA ČR GJ15-18046Y; GA MŠk LO1419 Institutional support: RVO:68378050 Keywords : JAK2 mutations * polycythemia vera Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 13.164, year: 2016

  16. A new allelic discrimination assay using locked nucleic acid-modified nucleotides (LNA) probes for detection of JAK2 V617F mutation

    Marková, J.; Průková, Dana; Volková, Z.; Schwarz, J.

    2007-01-01

    Roč. 48, č. 3 (2007), s. 638-641 ISSN 1042-8194 Institutional research plan: CEZ:AV0Z50520514 Keywords : Ph1-negative myeloproliferative disorders * JAK2V617F mutation * allelic discrimination Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.512, year: 2007

  17. The JAK2 V617F mutation involves B- and T-lymphocyte lineages in a subgroup of patients with Philadelphia-chromosome negative chronic myeloproliferative disorders

    Larsen, Thomas Stauffer; Christensen, Jacob Haaber; Hasselbalch, Hans Carl

    2007-01-01

    The JAK2 V617F mutation is a frequent genetic event in the three classical Philadelphia-chromosome negative chronic myeloproliferative disorders (Ph(neg.)-CMPD), polycythemia vera (PV), essential thrombocythemia (ET) and idiopathic myelofibrosis (IMF). Its occurrence varies in frequency in regards...

  18. Driver mutations (JAK2V617F, MPLW515L/K or CALR), pentraxin-3 and C-reactive protein in essential thrombocythemia and polycythemia vera.

    Lussana, Federico; Carobbio, Alessandra; Salmoiraghi, Silvia; Guglielmelli, Paola; Vannucchi, Alessandro Maria; Bottazzi, Barbara; Leone, Roberto; Mantovani, Alberto; Barbui, Tiziano; Rambaldi, Alessandro

    2017-02-22

    The driver mutations JAK2V617F, MPLW515L/K and CALR influence disease phenotype of myeloproliferative neoplasms (MPNs) and might sustain a condition of chronic inflammation. Pentraxin 3 (PTX3) and high-sensitivity C-reactive protein (hs-CRP) are inflammatory biomarkers potentially useful for refining prognostic classification of MPNs. We evaluated 305 with essential thrombocythemia (ET) and 172 polycythemia vera (PV) patients diagnosed according to the 2016 WHO criteria and with full molecular characterization for driver mutations. PTX3 levels were significantly increased in carriers of homozygous JAK2V617F mutation compared to all the other genotypes and triple negative ET patients, while hs-CRP levels were independent of the mutational profile. The risk of haematological evolution and death from any cause was about 2- and 1.5-fold increased in individuals with high PTX-3 levels, while the thrombosis rate tended to be lower. High hs-CRP levels were associated with risk of haematological evolution, death and also major thrombosis. After sequential adjustment for potential confounders (age, gender, diagnosis and treatments) and the presence of JAK2V617F homozygous status, high hs-CRP levels remained significant for all outcomes, while JAK2V617F homozygous status as well as treatments were the factors independently accounting for adverse outcomes among patients with high PTX3 levels. These results provide evidence that JAK2V617F mutation influences MPN-associated inflammation with a strong correlation between allele burden and PTX3 levels. Plasma levels of hs-CRP and PTX3 might be of prognostic value for patients with ET and PV, but their validation in future prospective studies is needed.

  19. Driver mutations (JAK2V617F, MPLW515L/K or CALR, pentraxin-3 and C-reactive protein in essential thrombocythemia and polycythemia vera

    Federico Lussana

    2017-02-01

    Full Text Available Abstract Background The driver mutations JAK2V617F, MPLW515L/K and CALR influence disease phenotype of myeloproliferative neoplasms (MPNs and might sustain a condition of chronic inflammation. Pentraxin 3 (PTX3 and high-sensitivity C-reactive protein (hs-CRP are inflammatory biomarkers potentially useful for refining prognostic classification of MPNs. Methods We evaluated 305 with essential thrombocythemia (ET and 172 polycythemia vera (PV patients diagnosed according to the 2016 WHO criteria and with full molecular characterization for driver mutations. Results PTX3 levels were significantly increased in carriers of homozygous JAK2V617F mutation compared to all the other genotypes and triple negative ET patients, while hs-CRP levels were independent of the mutational profile. The risk of haematological evolution and death from any cause was about 2- and 1.5-fold increased in individuals with high PTX-3 levels, while the thrombosis rate tended to be lower. High hs-CRP levels were associated with risk of haematological evolution, death and also major thrombosis. After sequential adjustment for potential confounders (age, gender, diagnosis and treatments and the presence of JAK2V617F homozygous status, high hs-CRP levels remained significant for all outcomes, while JAK2V617F homozygous status as well as treatments were the factors independently accounting for adverse outcomes among patients with high PTX3 levels. Conclusions These results provide evidence that JAK2V617F mutation influences MPN-associated inflammation with a strong correlation between allele burden and PTX3 levels. Plasma levels of hs-CRP and PTX3 might be of prognostic value for patients with ET and PV, but their validation in future prospective studies is needed.

  20. Clinical features of Japanese polycythemia vera and essential thrombocythemia patients harboring CALR, JAK2V617F, JAK2Ex12del, and MPLW515L/K mutations.

    Okabe, Masahiro; Yamaguchi, Hiroki; Usuki, Kensuke; Kobayashi, Yutaka; Kawata, Eri; Kuroda, Junya; Kimura, Shinya; Tajika, Kenji; Gomi, Seiji; Arima, Nobuyoshi; Mori, Sinichiro; Ito, Shigeki; Koizumi, Masayuki; Ito, Yoshikazu; Wakita, Satoshi; Arai, Kunihito; Kitano, Tomoaki; Kosaka, Fumiko; Dan, Kazuo; Inokuchi, Koiti

    2016-01-01

    The risk of complication of polycythemia vera (PV) and essential thrombocythemia (ET) by thrombosis in Japanese patients is clearly lower than in western populations, suggesting that genetic background such as race may influence the clinical features. This study aimed to clarify the relationship between genetic mutations and haplotypes and clinical features in Japanese patients with PV and ET. Clinical features were assessed prospectively among 74 PV and 303 ET patients. There were no clinical differences, including JAK2V617F allele burden, between PV patients harboring the various genetic mutations. However, CALR mutation-positive ET patients had a significantly lower WBC count, Hb value, Ht value, and neutrophil alkaline phosphatase score (NAP), and significantly more platelets, relative to JAK2V617F-positive ET patients and ET patients with no mutations. Compared to normal controls, the frequency of the JAK246/1 haplotype was significantly higher among patients with JAK2V617F, JAK2Ex12del, or MPL mutations, whereas no significant difference was found among CALR mutation-positive patients. CALR mutation-positive patients had a lower incidence of thrombosis relative to JAK2V617F-positive patients. Our findings suggest that JAK2V617F-positive ET patients and CALR mutation-positive patients have different mechanisms of occurrence and clinical features of ET, suggesting the potential need for therapy stratification in the future. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. JAK2V617F mutation in a patient with B-cell chronic lymphocytic leukemia and prefibrotic primary myelofibrosis

    Ristić Slobodan

    2015-01-01

    Full Text Available Introduction. Secondary malignancies, particularly solid tumors, are common in patients with chronic lymphocytic leukemia (CLL, but association of myeloproliferative neoplasms and chronic lymphocytic leukemia in the same patient is very rare. Case Outline. We report of a 67-year-old man with B-cell chronic lymphoid leukemia (B-CLL who developed primary myelofibrosis (PMF nine years after initial diagnosis. Patient received alkylation agents and purine analogue, which can be a predisposing factor for the development of myeloproliferative neoplasms. JAK2V617F mutation was not present initially at the time of CLL diagnosis, but was found after nine years when PMF occurred, which indicates that B-CLL and PMF represent two separate clonal origin neoplasms. Conclusion. Pathogenic mechanisms for the development of myeloproliferative and lymphoproliferative neoplasms in the same patient are unknown. Further research is needed to determine whether these malignancies originate from two different cell clones or arise from the same pluripotent hematopoietic stem cell. [Projekat Ministarstva nauke Republike Srbije, br. III 41004

  2. Development and inter-laboratory validation of unlabeled probe melting curve analysis for detection of JAK2 V617F mutation in polycythemia vera.

    Wu, Zhiyuan; Yuan, Hong; Zhang, Xinju; Liu, Weiwei; Xu, Jinhua; Zhang, Wei; Guan, Ming

    2011-01-01

    JAK2 V617F, a somatic point mutation that leads to constitutive JAK2 phosphorylation and kinase activation, has been incorporated into the WHO classification and diagnostic criteria of myeloid neoplasms. Although various approaches such as restriction fragment length polymorphism, amplification refractory mutation system and real-time PCR have been developed for its detection, a generic rapid closed-tube method, which can be utilized on routine genetic testing instruments with stability and cost-efficiency, has not been described. Asymmetric PCR for detection of JAK2 V617F with a 3'-blocked unlabeled probe, saturate dye and subsequent melting curve analysis was performed on a Rotor-Gene® Q real-time cycler to establish the methodology. We compared this method to the existing amplification refractory mutation systems and direct sequencing. Hereafter, the broad applicability of this unlabeled probe melting method was also validated on three diverse real-time systems (Roche LightCycler® 480, Applied Biosystems ABI® 7500 and Eppendorf Mastercycler® ep realplex) in two different laboratories. The unlabeled probe melting analysis could genotype JAK2 V617F mutation explicitly with a 3% mutation load detecting sensitivity. At level of 5% mutation load, the intra- and inter-assay CVs of probe-DNA heteroduplex (mutation/wild type) covered 3.14%/3.55% and 1.72%/1.29% respectively. The method could equally discriminate mutant from wild type samples on the other three real-time instruments. With a high detecting sensitivity, unlabeled probe melting curve analysis is more applicable to disclose JAK2 V617F mutation than conventional methodologies. Verified with the favorable inter- and intra-assay reproducibility, unlabeled probe melting analysis provided a generic mutation detecting alternative for real-time instruments.

  3. Development and inter-laboratory validation of unlabeled probe melting curve analysis for detection of JAK2 V617F mutation in polycythemia vera.

    Zhiyuan Wu

    Full Text Available BACKGROUND: JAK2 V617F, a somatic point mutation that leads to constitutive JAK2 phosphorylation and kinase activation, has been incorporated into the WHO classification and diagnostic criteria of myeloid neoplasms. Although various approaches such as restriction fragment length polymorphism, amplification refractory mutation system and real-time PCR have been developed for its detection, a generic rapid closed-tube method, which can be utilized on routine genetic testing instruments with stability and cost-efficiency, has not been described. METHODOLOGY/PRINCIPAL FINDINGS: Asymmetric PCR for detection of JAK2 V617F with a 3'-blocked unlabeled probe, saturate dye and subsequent melting curve analysis was performed on a Rotor-Gene® Q real-time cycler to establish the methodology. We compared this method to the existing amplification refractory mutation systems and direct sequencing. Hereafter, the broad applicability of this unlabeled probe melting method was also validated on three diverse real-time systems (Roche LightCycler® 480, Applied Biosystems ABI® 7500 and Eppendorf Mastercycler® ep realplex in two different laboratories. The unlabeled probe melting analysis could genotype JAK2 V617F mutation explicitly with a 3% mutation load detecting sensitivity. At level of 5% mutation load, the intra- and inter-assay CVs of probe-DNA heteroduplex (mutation/wild type covered 3.14%/3.55% and 1.72%/1.29% respectively. The method could equally discriminate mutant from wild type samples on the other three real-time instruments. CONCLUSIONS: With a high detecting sensitivity, unlabeled probe melting curve analysis is more applicable to disclose JAK2 V617F mutation than conventional methodologies. Verified with the favorable inter- and intra-assay reproducibility, unlabeled probe melting analysis provided a generic mutation detecting alternative for real-time instruments.

  4. Comparative study of different methodologies to detect the JAK2 V617F mutation in chronic BCR-ABL1 negative myeloproliferative neoplasms

    Alline Didone

    2016-04-01

    Full Text Available Objectives: A mutation in the JAK2 gene, V617F, has been identified in several BCR-ABL1 negative myeloproliferative neoplasms (MPN: polycythemia vera (PV, essential thrombocythemia (ET, and primary myelofibrosis (PMF. Defining the presence or absence of this mutation is an essential part of clinical diagnostic algorithms and patient management. Here, we aimed to evaluate the performance of three PCR-based assays: Amplification Refractory Mutation System (ARMS, High-Resolution Melting analysis (HRM, and Sanger direct sequencing, and compare their results with those obtained by a PCR restriction fragment polymorphism assay (PCR-RFLP. Design and methods: We used blood samples from 136 patients (PV=20; PMF=20; ET=28, and other MPN suspected cases=68. Results: Comparable results were observed among the four assays in patients with PV, PMF, and MPN suspected cases. In patients with a diagnosis of ET, the JAK2 V617F mutation was detected in 67.8% of them by the PCR-ARMS and PCR-HRM assay and in 64% of them by the conventional Sanger sequence approach. The PCR-ARMS and PCR-HRM assays were 100% concordant. With these tests, only one of the 20 patients with ET and one of the three patients with clinically suspected MPN gave different results compared with those obtained by the PCR-RFLP. Conclusions: Our results have demonstrated that the PCR-ARMS and PCR-HRM assays could detect the JAK2 V617F mutation effectively in MPN patients, but PCR-HRM assays are rapid and the most cost-effective procedures. Keywords: Myeloproliferative, JAK2 V617F, Mutation, Wild type, Screening

  5. Driver mutations (JAK2V617F, MPLW515L/K or CALR), pentraxin-3 and C-reactive protein in essential thrombocythemia and polycythemia vera

    Lussana, Federico; Carobbio, Alessandra; Salmoiraghi, Silvia; Guglielmelli, Paola; Vannucchi, Alessandro Maria; Bottazzi, Barbara; Leone, Roberto; Mantovani, Alberto; Barbui, Tiziano; Rambaldi, Alessandro

    2017-01-01

    Abstract Background The driver mutations JAK2V617F, MPLW515L/K and CALR influence disease phenotype of myeloproliferative neoplasms (MPNs) and might sustain a condition of chronic inflammation. Pentraxin 3 (PTX3) and high-sensitivity C-reactive protein (hs-CRP) are inflammatory biomarkers potentially useful for refining prognostic classification of MPNs. Methods We evaluated 305 with essential thrombocythemia (ET) and 172 polycythemia vera (PV) patients diagnosed according to the 2016 WHO cri...

  6. The thrombopoietin receptor, MPL, is critical for development of a JAK2V617F-induced myeloproliferative neoplasm.

    Sangkhae, Veena; Etheridge, S Leah; Kaushansky, Kenneth; Hitchcock, Ian S

    2014-12-18

    The most frequent contributing factor in Philadelphia chromosome-negative myeloproliferative neoplasms (MPNs) is the acquisition of a V617F mutation in Janus kinase 2 (JAK2) in hematopoietic stem cells (HSCs). Recent evidence has demonstrated that to drive MPN transformation, JAK2V617F needs to directly associate with a functional homodimeric type I cytokine receptor, suggesting that, although acquiring JAK2V617F may promote disease, there are additional cellular components necessary for MPN development. Here we show that loss of the thrombopoietin (TPO) receptor (MPL) significantly ameliorates MPN development in JAK2V617F(+) transgenic mice, whereas loss of TPO only mildly affects the disease phenotype. Specifically, compared with JAK2V617F(+) mice, JAK2V617F(+)Mpl(-/-) mice exhibited reduced thrombocythemia, neutrophilia, splenomegaly, and neoplastic stem cell pool. The importance of MPL is highlighted as JAK2V617FMpl(+/-) mice displayed a significantly reduced MPN phenotype, indicating that Mpl level may have a substantial effect on MPN development and severity. Splenomegaly and the increased neoplastic stem cell pool were retained in JAK2V617F(+)Tpo(-/-) mice, although thrombocytosis was reduced compared with JAK2V617F(+) mice. These results demonstrate that Mpl expression, but not Tpo, is fundamental in the development of JAK2V617F(+) MPNs, highlighting an entirely novel target for therapeutic intervention. © 2014 by The American Society of Hematology.

  7. Limited efficacy of hydroxyurea in lowering of the JAK2 V617F allele burden

    Larsen, Thomas Stauffer; Pallisgaard, Niels; de Stricker, Karin

    2009-01-01

    Besides being an invaluable marker of clonal disease in chronic myeloproliferative disorders (CMPDs), the JAK2 V617F mutation and the mutated allele burden have an impact on disease phenotype and may provide information on prognosis. Recently, hydroxyurea (HU) has been shown to induce a rapid...

  8. Bim and Mcl-1 exert key roles in regulating JAK2V617F cell survival

    Rubert, Joëlle; Qian, Zhiyan; Andraos, Rita; Guthy, Daniel A; Radimerski, Thomas

    2011-01-01

    The JAK2 V617F mutation plays a major role in the pathogenesis of myeloproliferative neoplasms and is found in the vast majority of patients suffering from polycythemia vera and in roughly every second patient suffering from essential thrombocythemia or from primary myelofibrosis. The V617F mutation is thought to provide hematopoietic stem cells and myeloid progenitors with a survival and proliferation advantage. It has previously been shown that activated JAK2 promotes cell survival by upregulating the anti-apoptotic STAT5 target gene Bcl-xL. In this study, we have investigated the role of additional apoptotic players, the pro-apoptotic protein Bim as well as the anti-apoptotic protein Mcl-1. Pharmacological inhibition of JAK2/STAT5 signaling in JAK2 V617F mutant SET-2 and MB-02 cells was used to study effects on signaling, cell proliferation and apoptosis by Western blot analysis, WST-1 proliferation assays and flow cytometry. Cells were transfected with siRNA oligos to deplete candidate pro- and anti-apoptotic proteins. Co-immunoprecipitation assays were performed to assess the impact of JAK2 inhibition on complexes of pro- and anti-apoptotic proteins. Treatment of JAK2 V617F mutant cell lines with a JAK2 inhibitor was found to trigger Bim activation. Furthermore, Bim depletion by RNAi suppressed JAK2 inhibitor-induced cell death. Bim activation following JAK2 inhibition led to enhanced sequestration of Mcl-1, besides Bcl-xL. Importantly, Mcl-1 depletion by RNAi was sufficient to compromise JAK2 V617F mutant cell viability and sensitized the cells to JAK2 inhibition. We conclude that Bim and Mcl-1 have key opposing roles in regulating JAK2 V617F cell survival and propose that inactivation of aberrant JAK2 signaling leads to changes in Bim complexes that trigger cell death. Thus, further preclinical evaluation of combinations of JAK2 inhibitors with Bcl-2 family antagonists that also tackle Mcl-1, besides Bcl-xL, is warranted to assess the therapeutic potential

  9. Discovery and characterization of LY2784544, a small-molecule tyrosine kinase inhibitor of JAK2V617F

    Ma, L; Clayton, J R; Walgren, R A; Zhao, B; Evans, R J; Smith, M C; Heinz-Taheny, K M; Kreklau, E L; Bloem, L; Pitou, C; Shen, W; Strelow, J M; Halstead, C; Rempala, M E; Parthasarathy, S; Gillig, J R; Heinz, L J; Pei, H; Wang, Y; Stancato, L F; Dowless, M S; Iversen, P W; Burkholder, T P

    2013-01-01

    Owing to the prevalence of the JAK2V617F mutation in myeloproliferative neoplasms (MPNs), its constitutive activity, and ability to recapitulate the MPN phenotype in mouse models, JAK2V617F kinase is an attractive therapeutic target. We report the discovery and initial characterization of the orally bioavailable imidazopyridazine, LY2784544, a potent, selective and ATP-competitive inhibitor of janus kinase 2 (JAK2) tyrosine kinase. LY2784544 was discovered and characterized using a JAK2-inhibition screening assay in tandem with biochemical and cell-based assays. LY2784544 in vitro selectivity for JAK2 was found to be equal or superior to known JAK2 inhibitors. Further studies showed that LY2784544 effectively inhibited JAK2V617F-driven signaling and cell proliferation in Ba/F3 cells (IC 50 =20 and 55 nM, respectively). In comparison, LY2784544 was much less potent at inhibiting interleukin-3-stimulated wild-type JAK2-mediated signaling and cell proliferation (IC 50 =1183 and 1309 nM, respectively). In vivo, LY2784544 effectively inhibited STAT5 phosphorylation in Ba/F3-JAK2V617F-GFP (green fluorescent protein) ascitic tumor cells (TED 50 =12.7 mg/kg) and significantly reduced (P<0.05) Ba/F3-JAK2V617F-GFP tumor burden in the JAK2V617F-induced MPN model (TED 50 =13.7 mg/kg, twice daily). In contrast, LY2784544 showed no effect on erythroid progenitors, reticulocytes or platelets. These data suggest that LY2784544 has potential for development as a targeted agent against JAK2V617F and may have properties that allow suppression of JAK2V617F-induced MPN pathogenesis while minimizing effects on hematopoietic progenitor cells

  10. Association of TNF polymorphisms with JAK2 (V617F) myeloproliferative neoplasms in Brazilian patients.

    Macedo, Luciana Conci; de Cesare Quintero, Fernanda; Pagliari-E-Silva, Sara; Pagnano, Katia Borgia Barbosa; Rodrigues, Camila; de Alencar, Josiane Bazzo; Sell, Ana Maria; Visentainer, Jeane Eliete Laguila

    2016-03-01

    The classical chromosome Philadelphia-negative myeloproliferative neoplasms (MPNs) are a group of disorders that share clinical, hematological, and histological features. Proinflammatory cytokines such as tumor necrosis factor-α (TNF-α) are elevated in patients with MPN. The aim of this study was to verify the association between the polymorphisms of TNF gene (-308G/A and -238 G/A) in BCR-ABL-negative MPN in our population. Blood samples obtained from MPN patients were genotyped for the JAK2V617F mutation and both TNF polymorphisms using PCR-RFLP. Thirty three (26.8%) patients with polycythemia vera (PV), 35 (28.7%) essential thrombocythemia (ET), 22 (17.7%) primary myelofibrosis (PMF), and 33 (26.8%) with unclassifiable MPN (MPNu) were included in the study. The JAK2 V617F mutation was detected in 94 (76.42%) patients. Were observed a significant increase on the frequency of the TNF-238 GA genotype in MPN patients compared to controls (OR=2.21, 95% CI=1.02-4.80, P<0.04). The distribution of the genotypes and allelic frequencies of TNF-308 was significantly different among the MPNs, JAK2V617F positive, PV and PMF, and controls. Our data has demonstrated that the polymorphisms on TNF-238 GA, TNF-308 GA were associated to MPN development in this population, triggered by JAK2 V617F mutation. Copyright © 2015. Published by Elsevier Inc.

  11. Jak2 46/1 Haplotype Is Associated With Jak2 V617f--positive Myeloproliferative Neoplasms In Brazilian Patients.

    Macedo, L C; Santos, B C; Pagliarini-e-Silva, S; Pagnano, K B B; Rodrigues, C; Quintero, F C; Ferreira, M E; Baraldi, E C; Ambrosio-Albuquerque, E P; Sell, A M; Visentainer, J E L

    2016-01-01

    This study aimed to verify the association between the JAK2 46/1 haplotype (V617F positive) and some hematological parameters in BCR-ABL-negative chronic myeloproliferative neoplasms (cMPNs) in our population. The blood samples obtained from the patients with cMPN were genotyped for the JAK2 V617F mutation and JAK2 rs10974944 SNP screening using a PCR-RFLP assay. The JAK2 V617F mutation was detected in 80.15% of patients. The G variant of rs10974944 was more frequent in all MPNs, especially t...

  12. The JAK2 V617F allele burden in essential thrombocythemia, polycythemia vera and primary myelofibrosis

    Larsen, Thomas Stauffer; Pallisgaard, Niels; Møller, Michael Boe

    2007-01-01

    BACKGROUND AND OBJECTIVES: The JAK2 V617F tyrosine kinase mutation is present in the great majority of patients with polycythemia vera (PV), and approximately half of the patients with essential thrombocythemia (ET) and primary myelofibrosis (PMF). The three distinct disease entities may be consi......BACKGROUND AND OBJECTIVES: The JAK2 V617F tyrosine kinase mutation is present in the great majority of patients with polycythemia vera (PV), and approximately half of the patients with essential thrombocythemia (ET) and primary myelofibrosis (PMF). The three distinct disease entities may...... = 0.03), CD34 counts (P = 0.03), lactate dehydrogenase and Polycythemia Rubra Vera gene 1 levels (P = 0.03 and P

  13. JAK2 46/1 haplotype is associated with JAK2 V617F--positive myeloproliferative neoplasms in Brazilian patients.

    Macedo, L C; Santos, B C; Pagliarini-e-Silva, S; Pagnano, K B B; Rodrigues, C; Quintero, F C; Ferreira, M E; Baraldi, E C; Ambrosio-Albuquerque, E P; Sell, A M; Visentainer, J E L

    2015-10-01

    This study aimed to verify the association between the JAK2 46/1 haplotype (V617F positive) and some hematological parameters in BCR-ABL-negative chronic myeloproliferative neoplasms (cMPNs) in our population. The blood samples obtained from the patients with cMPN were genotyped for the JAK2 V617F mutation and JAK2 rs10974944 SNP screening using a PCR-RFLP assay. The JAK2 V617F mutation was detected in 80.15% of patients. The G variant of rs10974944 was more frequent in all MPNs, especially those that were JAK2 V617F positive, than in the control population. We also compared the 46/1 haplotype status in each MPN disease entity, polycythemia vera (PV), essential thrombocythemia (ET), primary myelofibrosis (PMF), and MPNu with controls. The G allele frequency relative to controls was significantly enriched in patients with PV and ET, but not in those with PMF and MPNu. PV and ET patients especially, all of whom had the JAK2 V617F mutation, showed significant excess of the G allele. The frequency of JAK2 V617F mutation was associated with elevated hematological parameters, but when we analyze the occurrence of the mutation and the presence of the G allele, just the high hemoglobin was significantly. In agreement with previous reports, JAK2 46/1 haplotype for JAK2 V617F was associated with cMPN positive in Brazilian patients. © 2015 John Wiley & Sons Ltd.

  14. JAK2V617F expression in mice amplifies early hematopoietic cells and gives them a competitive advantage that is hampered by IFNα.

    Hasan, Salma; Lacout, Catherine; Marty, Caroline; Cuingnet, Marie; Solary, Eric; Vainchenker, William; Villeval, Jean-Luc

    2013-08-22

    The acquired gain-of-function V617F mutation in the Janus Kinase 2 (JAK2(V617F)) is the main mutation involved in BCR/ABL-negative myeloproliferative neoplasms (MPNs), but its effect on hematopoietic stem cells as a driver of disease emergence has been questioned. Therefore, we reinvestigated the role of endogenous expression of JAK2(V617F) on early steps of hematopoiesis as well as the effect of interferon-α (IFNα), which may target the JAK2(V617F) clone in humans by using knock-in mice with conditional expression of JAK2(V617F) in hematopoietic cells. These mice develop a MPN mimicking polycythemia vera with large amplification of myeloid mature and precursor cells, displaying erythroid endogenous growth and progressing to myelofibrosis. Interestingly, early hematopoietic compartments [Lin-, LSK, and SLAM (LSK/CD48-/CD150+)] increased with the age. Competitive repopulation assays demonstrated disease appearance and progressive overgrowth of myeloid, Lin-, LSK, and SLAM cells, but not lymphocytes, from a low number of engrafted JAK2(V617F) SLAM cells. Finally, IFNα treatment prevented disease development by specifically inhibiting JAK2(V617F) cells at an early stage of differentiation and eradicating disease-initiating cells. This study shows that JAK2(V617F) in mice amplifies not only late but also early hematopoietic cells, giving them a proliferative advantage through high cell cycling and low apoptosis that may sustain MPN emergence but is lost upon IFNα treatment.

  15. Heterozygous and homozygous JAK2(V617F states modeled by induced pluripotent stem cells from myeloproliferative neoplasm patients.

    Joseph Saliba

    Full Text Available JAK2(V617F is the predominant mutation in myeloproliferative neoplasms (MPN. Modeling MPN in a human context might be helpful for the screening of molecules targeting JAK2 and its intracellular signaling. We describe here the derivation of induced pluripotent stem (iPS cell lines from 2 polycythemia vera patients carrying a heterozygous and a homozygous mutated JAK2(V617F, respectively. In the patient with homozygous JAK2(V617F, additional ASXL1 mutation and chromosome 20 allowed partial delineation of the clonal architecture and assignation of the cellular origin of the derived iPS cell lines. The marked difference in the response to erythropoietin (EPO between homozygous and heterozygous cell lines correlated with the constitutive activation level of signaling pathways. Strikingly, heterozygous iPS cells showed thrombopoietin (TPO-independent formation of megakaryocytic colonies, but not EPO-independent erythroid colony formation. JAK2, PI3K and HSP90 inhibitors were able to block spontaneous and EPO-induced growth of erythroid colonies from GPA(+CD41(+ cells derived from iPS cells. Altogether, this study brings the proof of concept that iPS can be used for studying MPN pathogenesis, clonal architecture, and drug efficacy.

  16. Mesenteric venous thrombosis secondary to an unsuspected JAK2 V617F-positive myeloproliferative disorder.

    2012-01-31

    BACKGROUND: Mesenteric venous thrombosis (MVT) is a rare but potentially fatal cause of mesenteric ischaemia. It presents insidiously and often diagnosis is made at emergency surgery. In half of the cases MVT develops without a causative factor, while in cases in which a pro-thrombotic state is found to exist MVT may be the first clinically detected consequence of that state. The myeloproliferative disorders (MPD) are known to contribute to the development of pro-thrombotic states. Recently, the JAK2 V617F mutation has been associated with the MPDs. CONCLUSION: We describe a case of MVT occurring secondary to an unsuspected MPD, in which the patient was subsequently found to carry this mutation. We highlight the necessity to screen for this mutation in cases of intra-abdominal thromboses so that appropriate systemic anticoagulation may be instituted, and the patient may be followed so as to detect the development of an overt MPD.

  17. JAK2 V617F-dependent upregulation of PU.1 expression in the peripheral blood of myeloproliferative neoplasm patients.

    Tamotsu Irino

    Full Text Available Myeloproliferative neoplasms (MPN are multiple disease entities characterized by clonal expansion of one or more of the myeloid lineages (i.e. granulocytic, erythroid, megakaryocytic and mast cell. JAK2 mutations, such as the common V617F substitution and the less common exon 12 mutations, are frequently detected in such tumor cells and have been incorporated into the diagnostic criteria published by the World Health Organization since 2008. However, the mechanism by which these mutations contribute to MPN development is poorly understood. We examined gene expression profiles of MPN patients focusing on genes in the JAK-STAT signaling pathway using low-density real-time PCR arrays. We identified the following 2 upregulated genes in MPN patients: a known target of the JAK-STAT axis, SOCS3, and a potentially novel target, SPI1, encoding PU.1. Induction of PU.1 expression by JAK2 V617F in JAK2-wildtype K562 cells and its downregulation by JAK2 siRNA transfection in JAK2 V617F-positive HEL cells supported this possibility. We also found that the ABL1 kinase inhibitor imatinib was very effective in suppressing PU.1 expression in BCR-ABL1-positive K562 cells but not in HEL cells. This suggests that PU.1 expression is regulated by both JAK2 and ABL1. The contribution of the two kinases in driving PU.1 expression was dominant for JAK2 and ABL1 in HEL and K562 cells, respectively. Therefore, PU.1 may be a common transcription factor upregulated in MPN. PU.1 is a transcription factor required for myeloid differentiation and is implicated in erythroid leukemia. Therefore, expression of PU.1 downstream of activated JAK2 may explain why JAK2 mutations are frequently observed in MPN patients.

  18. A Multiplex Snapback Primer System for the Enrichment and Detection of JAK2 V617F and MPL W515L/K Mutations in Philadelphia-Negative Myeloproliferative Neoplasms

    Zhiyuan Wu

    2014-01-01

    Full Text Available A multiplex snapback primer system was developed for the simultaneous detection of JAK2 V617F and MPL W515L/K mutations in Philadelphia chromosome- (Ph- negative myeloproliferative neoplasms (MPNs. The multiplex system comprises two snapback versus limiting primer sets for JAK2 and MPL mutation enrichment and detection, respectively. Linear-After exponential (LATE PCR strategy was employed for the primer design to maximize the amplification efficiency of the system. Low ionic strength buffer and rapid PCR protocol allowed for selective amplification of the mutant alleles. Amplification products were analyzed by melting curve analysis for mutation identification. The multiplex system archived 0.1% mutation load sensitivity and <5% coefficient of variation inter-/intra-assay reproducibility. 120 clinical samples were tested by the multiplex snapback primer assay, and verified with amplification refractory system (ARMS, quantitative PCR (qPCR and Sanger sequencing method. The multiplex system, with a favored versatility, provided the molecular diagnosis of Ph-negative MPNs with a suitable implement and simplified the genetic test process.

  19. A Multiplex Snapback Primer System for the Enrichment and Detection of JAK2 V617F and MPL W515L/K Mutations in Philadelphia-Negative Myeloproliferative Neoplasms

    Zhang, Yunqing; Zhang, Xinju; Xu, Xiao; Kang, Zhihua; Li, Shibao; Zhang, Chen; Su, Bing

    2014-01-01

    A multiplex snapback primer system was developed for the simultaneous detection of JAK2 V617F and MPL W515L/K mutations in Philadelphia chromosome- (Ph-) negative myeloproliferative neoplasms (MPNs). The multiplex system comprises two snapback versus limiting primer sets for JAK2 and MPL mutation enrichment and detection, respectively. Linear-After exponential (LATE) PCR strategy was employed for the primer design to maximize the amplification efficiency of the system. Low ionic strength buffer and rapid PCR protocol allowed for selective amplification of the mutant alleles. Amplification products were analyzed by melting curve analysis for mutation identification. The multiplex system archived 0.1% mutation load sensitivity and <5% coefficient of variation inter-/intra-assay reproducibility. 120 clinical samples were tested by the multiplex snapback primer assay, and verified with amplification refractory system (ARMS), quantitative PCR (qPCR) and Sanger sequencing method. The multiplex system, with a favored versatility, provided the molecular diagnosis of Ph-negative MPNs with a suitable implement and simplified the genetic test process. PMID:24729973

  20. The JH2 domain and SH2-JH2 linker regulate JAK2 activity: A detailed kinetic analysis of wild type and V617F mutant kinase domains.

    Sanz Sanz, Arturo; Niranjan, Yashavanthi; Hammarén, Henrik; Ungureanu, Daniela; Ruijtenbeek, Rob; Touw, Ivo P; Silvennoinen, Olli; Hilhorst, Riet

    2014-10-01

    JAK2 tyrosine kinase regulates many cellular functions. Its activity is controlled by the pseudokinase (JH2) domain by still poorly understood mechanisms. The V617F mutation in the pseudokinase domain activates JAK2 and causes myeloproliferative neoplasms. We conducted a detailed kinetic analysis of recombinant JAK2 tyrosine kinase domain (JH1) and wild-type and V617F tandem kinase (JH1JH2) domains using peptide microarrays to define the functions of the kinase domains. The results show that i) JAK2 follows a random Bi-Bi reaction mechanism ii) JH2 domain restrains the activity of the JH1 domain by reducing the affinity for ATP and ATP competitive inhibitors iii) V617F decreases affinity for ATP but increases catalytic activity compared to wild-type and iv) the SH2-JH2 linker region participates in controlling activity by reducing the affinity for ATP. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. [JAK2 V617F and exon 12 genetic variations in Korean patients with BCR/ABL1-negative myeloproliferative neoplasms].

    Kim, Jeong Tae; Cho, Yong Gon; Choi, Sam Im; Lee, Young Jin; Kim, Hye Ran; Jang, Sook Jin; Moon, Dae Soo; Park, Young Jin; Park, Geon

    2010-12-01

    JAK2 genetic variations have been described in a high proportion of patients with BCR/ABL1-negative myeloproliferative neoplasms (MPN). This study was designed to analyze the frequencies of JAK2 V617F and exon 12 variations, and their correlations with clinical characteristics of Korean patients with BCR/ABL1-negative MPN. We examined a total of 154 patients with BCR/ABL1-negative MPN that included 24, 26, 89, and 15 patients with polycythemia vera (PV), primary myelofibrosis (PMF), essential thrombocythemia (ET), and unclassified myeloproliferative neoplasms (MPNU), respectively. We performed allele-specific PCR to detect V617F in all BCR/ABL1-negative patients, and performed direct sequencing to detect exon 12 variations in 47 V617F-negative MPN patients. JAK2 c.1641+179_183del5 variation was detected by restriction fragment length polymorphism assay in 176 healthy subjects. JAK2 V617F was detected in 91 patients (59.1%): PV (91.6%), PMF (46.2%), ET (52.8%), and MPNU (66.7%). In V617F-negative MPN patients, no mutations were found in exon 12. The c.1641+179_183del5 was detected in 68.1% of V617F-negative MPN patients and 45.4% of healthy subjects (P=0.008). JAK2 V617F was closely correlated with age and leukocytosis in BCR/ABL1-negative MPN patients (P<0.05). However, c.1641+179_183del5 was not related to age, sex, or complete blood cell count parameters in V617F-negative MPN patients and healthy subjects. The c.1641+179_183del5 was associated with an increased odds ratio for MPN (odds ratio, 2.6; 95% confidences interval, 1.3-5.1; P=0.007). Frequencies of V617F are similar to reported results. JAK2 exon 12 mutations may be rare and c.1641+179_183del5 may influence the occurrence of MPN in Korean patients with V6 17F-negative MPN.

  2. Molecular genetic tests for JAK2V617F, Exon12_JAK2 and MPLW515K/L are highly informative in the evaluation of patients suspected to have BCR-ABL1-negative myeloproliferative neoplasms.

    dos Santos, Marcos Tadeu; Mitne-Neto, Miguel; Miyashiro, Kozue; Chauffaille, Maria de Lourdes L Ferrari; Rizzatti, Edgar Gil

    2014-02-01

    Polycythaemia vera (PV), essential thrombocythemia (ET) and idiopathic myelofibrosis (MF), are the most common myeloproliferative neoplasms (MPN) in patients without the BCR-ABL1 gene rearrangement. They are caused by clonal expansion of haematopoietic stem cells and share, as a diagnostic criterion, the identification of JAK2V617F mutation. Classically, when other clinical criteria are present, a JAK2V617F negative case requires the analysis of Exon12_JAK2 for the diagnosis of PV, and of MPL515K/L mutations for the diagnosis of ET and MF. Here, we evaluated 78 samples from Brazilian patients suspected to have MPN, without stratification for PV, ET or MF. We found that 28 (35.9%) are JAK2V617F carriers; from the 50 remaining samples, one (2%) showed an Exon12_JAK2 mutation, and another (2%) was positive for MPLW515L mutation. In summary, the investigation of JAK2V617F, Exon12_JAK2 and MPLW515K/L was relevant for the diagnosis of 38.4% of patients suspected to have BCR-ABL1-negative MPN, suggesting that molecular genetic tests are useful for a quick and unequivocal diagnosis of MPN.

  3. Self-renewal of single mouse hematopoietic stem cells is reduced by JAK2V617F without compromising progenitor cell expansion.

    Kent, David G; Li, Juan; Tanna, Hinal; Fink, Juergen; Kirschner, Kristina; Pask, Dean C; Silber, Yvonne; Hamilton, Tina L; Sneade, Rachel; Simons, Benjamin D; Green, Anthony R

    2013-01-01

    Recent descriptions of significant heterogeneity in normal stem cells and cancers have altered our understanding of tumorigenesis, emphasizing the need to understand how single stem cells are subverted to cause tumors. Human myeloproliferative neoplasms (MPNs) are thought to reflect transformation of a hematopoietic stem cell (HSC) and the majority harbor an acquired V617F mutation in the JAK2 tyrosine kinase, making them a paradigm for studying the early stages of tumor establishment and progression. The consequences of activating tyrosine kinase mutations for stem and progenitor cell behavior are unclear. In this article, we identify a distinct cellular mechanism operative in stem cells. By using conditional knock-in mice, we show that the HSC defect resulting from expression of heterozygous human JAK2V617F is both quantitative (reduced HSC numbers) and qualitative (lineage biases and reduced self-renewal per HSC). The defect is intrinsic to individual HSCs and their progeny are skewed toward proliferation and differentiation as evidenced by single cell and transplantation assays. Aged JAK2V617F show a more pronounced defect as assessed by transplantation, but mice that transform reacquire competitive self-renewal ability. Quantitative analysis of HSC-derived clones was used to model the fate choices of normal and JAK2-mutant HSCs and indicates that JAK2V617F reduces self-renewal of individual HSCs but leaves progenitor expansion intact. This conclusion is supported by paired daughter cell analyses, which indicate that JAK2-mutant HSCs more often give rise to two differentiated daughter cells. Together these data suggest that acquisition of JAK2V617F alone is insufficient for clonal expansion and disease progression and causes eventual HSC exhaustion. Moreover, our results show that clonal expansion of progenitor cells provides a window in which collaborating mutations can accumulate to drive disease progression. Characterizing the mechanism(s) of JAK2V617F

  4. Protracted Clonal Trajectory of a JAK2 V617F-Positive Myeloproliferative Neoplasm Developing during Long-Term Remission from Acute Myeloid Leukemia

    Stephen E. Langabeer

    2018-01-01

    Full Text Available Although transformation of the myeloproliferative neoplasms (MPNs to acute myeloid leukemia (AML is well documented, development of an MPN in patients previously treated for, and in remission from, AML is exceedingly rare. A case is described in which a patient was successfully treated for AML and in whom a JAK2 V617F-positive MPN was diagnosed after seven years in remission. Retrospective evaluation of the JAK2 V617F detected a low allele burden at AML diagnosis and following one course of induction chemotherapy. This putative chemoresistant clone subsequently expanded over the intervening seven years, resulting in a hematologically overt MPN. As AML relapse has not occurred, the MPN may have arose in a separate initiating cell from that of the AML. Alternatively, both malignancies possibly evolved from a common precursor defined by a predisposition mutation with divergent evolution into MPN through acquisition of the JAK2 V617F and AML through acquisition of different mutations. This case emphasizes the protracted time frame from acquisition of a disease-driving mutation to overt MPN and further underscores the clonal complexity in MPN evolution.

  5. Deregulation of apoptosis-related genes is associated with PRV1 overexpression and JAK2 V617F allele burden in Essential Thrombocythemia and Myelofibrosis

    Tognon Raquel

    2012-02-01

    Full Text Available Abstract Background Essential Thrombocythemia (ET and Primary Myelofibrosis (PMF are Chronic Myeloproliferative Neoplasms (MPN characterized by clonal myeloproliferation/myeloaccumulation without cell maturation impairment. The JAK2 V617F mutation and PRV1 gene overexpression may contribute to MPN physiopathology. We hypothesized that deregulation of the apoptotic machinery may also play a role in the pathogenesis of ET and PMF. In this study we evaluated the apoptosis-related gene and protein expression of BCL2 family members in bone marrow CD34+ hematopoietic stem cells (HSC and peripheral blood leukocytes from ET and PMF patients. We also tested whether the gene expression results were correlated with JAK2 V617F allele burden percentage, PRV1 overexpression, and clinical and laboratory parameters. Results By real time PCR assay, we observed that A1, MCL1, BIK and BID, as well as A1, BCLW and BAK gene expression were increased in ET and PMF CD34+ cells respectively, while pro-apoptotic BAX and anti-apoptotic BCL2 mRNA levels were found to be lower in ET and PMF CD34+ cells respectively, in relation to controls. In patients' leukocytes, we detected an upregulation of anti-apoptotic genes A1, BCL2, BCL-XL and BCLW. In contrast, pro-apoptotic BID and BIMEL expression were downregulated in ET leukocytes. Increased BCL-XL protein expression in PMF leukocytes and decreased BID protein expression in ET leukocytes were observed by Western Blot. In ET leukocytes, we found a correlation between JAK2 V617F allele burden and BAX, BIK and BAD gene expression and between A1, BAX and BIK and PRV1 gene expression. A negative correlation between PRV1 gene expression and platelet count was observed, as well as a positive correlation between PRV1 gene expression and splenomegaly. Conclusions Our results suggest the participation of intrinsic apoptosis pathway in the MPN physiopathology. In addition, PRV1 and JAK2 V617F allele burden were linked to deregulation

  6. l-Amino acid oxidase isolated from Calloselasma rhodostoma snake venom induces cytotoxicity and apoptosis in JAK2V617F-positive cell lines

    Cristiane Tavares

    2016-06-01

    Full Text Available ABSTRACT BACKGROUND: Myeloproliferative neoplasms are Philadelphia chromosome-negative diseases characterized by hyperproliferation of mature myeloid cells, associated or not with the Janus kinase 2 tyrosine kinase mutation, JAK2V617F. As there is no curative therapy, researchers have been investigating new drugs to treat myeloproliferative neoplasms, including l-amino acid oxidase from Calloselasma rhodostoma snake venom (CR-LAAO, which is a toxin capable of eliciting apoptosis in several tumor cell lines. OBJECTIVE: To evaluate the effects of l-amino acid oxidase from C. rhodostoma snake venom in the apoptotic machinery of JAK2-mutated cell lines. METHODS: The HEL 92.1.7 and SET-2 cell lines were cultured with l-amino acid oxidase and catalase for 12 h at 37 °C in 5% carbon dioxide. The cell viability was assessed by the multi-table tournament method, the level of apoptosis was measured by flow cytometry, and the expression of cysteine-dependent aspartate-specific proteases and cleaved Poly(ADP-ribose polymerase were analyzed by Western blotting. RESULTS: l-Amino acid oxidase from C. rhodostoma snake venom was cytotoxic to HEL 92.1.7 and SET-2 cells (50% inhibitory concentration = 0.15 µg/mL and 1.5 µg/mL, respectively and induced apoptosis in a concentration-dependent manner. Cell treatment with catalase mitigated the l-amino acid oxidase toxicity, indicating that hydrogen peroxide is a key component of its cytotoxic effect.The activated caspases 3 and 8 expression and cleaved PARP in HEL 92.1.7 and SET-2 cells confirmed the apoptosis activation by CR-LAAO. CONCLUSIONS: l-Amino acid oxidase from C. rhodostoma snake venom is a potential antineoplastic agent against HEL 92.1.7 and SET-2 JAK2V617F-positive cells as it activates the extrinsic apoptosis pathway.

  7. Association Of Tnf Polymorphisms With Jak2 (v617f) Myeloproliferative Neoplasms In Brazilian Patients.

    Macedo, Luciana Conci; de Cesare Quintero, Fernanda; Pagliari-E-Silva, Sara; Pagnano, Katia Borgia Barbosa; Rodrigues, Camila; de Alencar, Josiane Bazzo; Sell, Ana Maria; Visentainer, Jeane Eliete Laguila

    2016-01-01

    The classical chromosome Philadelphia-negative myeloproliferative neoplasms (MPNs) are a group of disorders that share clinical, hematological, and histological features. Proinflammatory cytokines such as tumor necrosis factor-α (TNF-α) are elevated in patients with MPN. The aim of this study was to verify the association between the polymorphisms of TNF gene (-308G/A and -238 G/A) in BCR-ABL-negative MPN in our population. Blood samples obtained from MPN patients were genotyped for the JAK2V...

  8. Adrenal incidentaloma and the Janus Kinase 2 V617F mutation: A case-based review of the literature

    Mustafa Unubol

    2013-01-01

    Full Text Available Adrenal incidentaloma was detected in an 81-year-old male patient and a 37-year-old female patient who had been diagnosed with essential thrombocytosis. Each patient′s Janus Kinase 2 (JAK2 V617F mutation was positive, and they were evaluated as having non-functional adrenal incidentaloma. The JAK2 activates the signal transducers and activators of transcription (STAT proteins which then activate the phosphoinositol-3 kinases, Ras, mitogen-activated protein (MAP kinases, and transcription. Constitutive activation causes cell proliferation and dysregulation of apoptosis. It is thought that STAT3 activation-mediated JAK family kinases have a central role in the solid tumor cell series. Permanent activation of STAT3 and STAT5 causes tumor cell proliferation, survival, metastasis, and an increase in tumor-mediated inflammation in solid and hematologic tumors. According to our literature screening, irregular JAK signaling, seen at the pathogenesis of many solid and hematologic tumors, has not been previously evaluated with regard to adrenal tumors. As a result, our cases are the first coexistence of JAK V617F mutation with adrenal incidentaloma in the literature. Because of this, we think that JAK2 mutation must be evaluated to clarify the etiology of adrenal incidentalomas.

  9. Quantitative threefold allele-specific PCR (QuanTAS-PCR) for highly sensitive JAK2 V617F mutant allele detection

    Zapparoli, Giada V; Jorissen, Robert N; Hewitt, Chelsee A; McBean, Michelle; Westerman, David A; Dobrovic, Alexander

    2013-01-01

    The JAK2 V617F mutation is the most frequent somatic change in myeloproliferative neoplasms, making it an important tumour-specific marker for diagnostic purposes and for the detection of minimal residual disease. Sensitive quantitative assays are required for both applications, particularly for the monitoring of minimal residual disease, which requires not only high sensitivity but also very high specificity. We developed a highly sensitive probe-free quantitative mutant-allele detection method, Quantitative Threefold Allele-Specific PCR (QuanTAS-PCR), that is performed in a closed-tube system, thus eliminating the manipulation of PCR products. QuantTAS-PCR uses a threefold approach to ensure allele-specific amplification of the mutant sequence: (i) a mutant allele-specific primer, (ii) a 3′dideoxy blocker to suppress false-positive amplification from the wild-type template and (iii) a PCR specificity enhancer, also to suppress false-positive amplification from the wild-type template. Mutant alleles were quantified relative to exon 9 of JAK2. We showed that the addition of the 3′dideoxy blocker suppressed but did not eliminate false-positive amplification from the wild-type template. However, the addition of the PCR specificity enhancer near eliminated false-positive amplification from the wild-type allele. Further discrimination between true and false positives was enabled by using the quantification cycle (Cq) value of a single mutant template as a cut-off point, thus enabling robust distinction between true and false positives. As 10,000 JAK2 templates were used per replicate, the assay had a sensitivity of 1/10 -4 per replicate. Greater sensitivity could be reached by increasing the number of replicates analysed. Variation in replicates when low mutant-allele templates were present necessitated the use of a statistics-based approach to estimate the load of mutant JAK2 copies. QuanTAS-PCR showed comparable quantitative results when validated against a

  10. Gene expression profiling of loss of TET2 and/or JAK2V617F mutant hematopoietic stem cells from mouse models of myeloproliferative neoplasms

    Takuro Kameda

    2015-06-01

    Full Text Available Myeloproliferative neoplasms (MPNs are clinically characterized by the chronic overproduction of differentiated peripheral blood cells and the gradual expansion of malignant intramedullary/extramedullary hematopoiesis. In MPNs mutations in JAK2 MPL or CALR are detected mutually exclusive in more than 90% of cases [1,2]. Mutations in them lead to the abnormal activation of JAK/STAT signaling and the autonomous growth of differentiated cells therefore they are considered as “driver” gene mutations. In addition to the above driver gene mutations mutations in epigenetic regulators such as TET2 DNMT3A ASXL1 EZH2 or IDH1/2 are detected in about 5%–30% of cases respectively [3]. Mutations in TET2 DNMT3A EZH2 or IDH1/2 commonly confer the increased self-renewal capacity on normal hematopoietic stem cells (HSCs but they do not lead to the autonomous growth of differentiated cells and only exhibit subtle clinical phenotypes [4,6–8,5]. It was unclear how mutations in such epigenetic regulators influenced abnormal HSCs with driver gene mutations how they influenced the disease phenotype or whether a single driver gene mutation was sufficient for the initiation of human MPNs. Therefore we focused on JAK2V617F and loss of TET2—the former as a representative of driver gene mutations and the latter as a representative of mutations in epigenetic regulators—and examined the influence of single or double mutations on HSCs (Lineage−Sca-1+c-Kit+ cells (LSKs by functional analyses and microarray whole-genome expression analyses [9]. Gene expression profiling showed that the HSC fingerprint genes [10] was statistically equally enriched in TET2-knockdown-LSKs but negatively enriched in JAK2V617F–LSKs compared to that in wild-type-LSKs. Double-mutant-LSKs showed the same tendency as JAK2V617F–LSKs in terms of their HSC fingerprint genes but the expression of individual genes differed between the two groups. Among 245 HSC fingerprint genes 100 were more

  11. Stat5 Exerts Distinct, Vital Functions in the Cytoplasm and Nucleus of Bcr-Abl+ K562 and Jak2(V617F)+ HEL Leukemia Cells

    Weber, Axel; Borghouts, Corina; Brendel, Christian; Moriggl, Richard; Delis, Natalia; Brill, Boris; Vafaizadeh, Vida; Groner, Bernd

    2015-01-01

    Signal transducers and activators of transcription (Stats) play central roles in the conversion of extracellular signals, e.g., cytokines, hormones and growth factors, into tissue and cell type specific gene expression patterns. In normal cells, their signaling potential is strictly limited in extent and duration. The persistent activation of Stat3 or Stat5 is found in many human tumor cells and contributes to their growth and survival. Stat5 activation plays a pivotal role in nearly all hematological malignancies and occurs downstream of oncogenic kinases, e.g., Bcr-Abl in chronic myeloid leukemias (CML) and Jak2(V617F) in other myeloproliferative diseases (MPD). We defined the mechanisms through which Stat5 affects growth and survival of K562 cells, representative of Bcr-Abl positive CML, and HEL cells, representative for Jak2(V617F) positive acute erythroid leukemia. In our experiments we suppressed the protein expression levels of Stat5a and Stat5b through shRNA mediated downregulation and demonstrated the dependence of cell survival on the presence of Stat5. Alternatively, we interfered with the functional capacities of the Stat5 protein through the interaction with a Stat5 specific peptide ligand. This ligand is a Stat5 specific peptide aptamer construct which comprises a 12mer peptide integrated into a modified thioredoxin scaffold, S5-DBD-PA. The peptide sequence specifically recognizes the DNA binding domain (DBD) of Stat5. Complex formation of S5-DBD-PA with Stat5 causes a strong reduction of P-Stat5 in the nuclear fraction of Bcr-Abl-transformed K562 cells and a suppression of Stat5 target genes. Distinct Stat5 mediated survival mechanisms were detected in K562 and Jak2(V617F)-transformed HEL cells. Stat5 is activated in the nuclear and cytosolic compartments of K562 cells and the S5-DBD-PA inhibitor most likely affects the viability of Bcr-Abl + K562 cells through the inhibition of canonical Stat5 induced target gene transcription. In HEL cells, Stat5

  12. Establishing optimal quantitative-polymerase chain reaction assays for routine diagnosis and tracking of minimal residual disease in JAK2-V617F-associated myeloproliferative neoplasms: a joint European LeukemiaNet/MPN&MPNr-EuroNet (COST action BM0902) study.

    Jovanovic, J V; Ivey, A; Vannucchi, A M; Lippert, E; Oppliger Leibundgut, E; Cassinat, B; Pallisgaard, N; Maroc, N; Hermouet, S; Nickless, G; Guglielmelli, P; van der Reijden, B A; Jansen, J H; Alpermann, T; Schnittger, S; Bench, A; Tobal, K; Wilkins, B; Cuthill, K; McLornan, D; Yeoman, K; Akiki, S; Bryon, J; Jeffries, S; Jones, A; Percy, M J; Schwemmers, S; Gruender, A; Kelley, T W; Reading, S; Pancrazzi, A; McMullin, M F; Pahl, H L; Cross, N C P; Harrison, C N; Prchal, J T; Chomienne, C; Kiladjian, J J; Barbui, T; Grimwade, D

    2013-10-01

    Reliable detection of JAK2-V617F is critical for accurate diagnosis of myeloproliferative neoplasms (MPNs); in addition, sensitive mutation-specific assays can be applied to monitor disease response. However, there has been no consistent approach to JAK2-V617F detection, with assays varying markedly in performance, affecting clinical utility. Therefore, we established a network of 12 laboratories from seven countries to systematically evaluate nine different DNA-based quantitative PCR (qPCR) assays, including those in widespread clinical use. Seven quality control rounds involving over 21,500 qPCR reactions were undertaken using centrally distributed cell line dilutions and plasmid controls. The two best-performing assays were tested on normal blood samples (n=100) to evaluate assay specificity, followed by analysis of serial samples from 28 patients transplanted for JAK2-V617F-positive disease. The most sensitive assay, which performed consistently across a range of qPCR platforms, predicted outcome following transplant, with the mutant allele detected a median of 22 weeks (range 6-85 weeks) before relapse. Four of seven patients achieved molecular remission following donor lymphocyte infusion, indicative of a graft vs MPN effect. This study has established a robust, reliable assay for sensitive JAK2-V617F detection, suitable for assessing response in clinical trials, predicting outcome and guiding management of patients undergoing allogeneic transplant.

  13. Polycythemia Vera: An Appraisal of the Biology and Management 10 Years After the Discovery of JAK2 V617F

    Stein, Brady L.; Oh, Stephen T.; Berenzon, Dmitriy; Hobbs, Gabriela S.; Kremyanskaya, Marina; Rampal, Raajit K.; Abboud, Camille N.; Adler, Kenneth; Heaney, Mark L.; Jabbour, Elias J.; Komrokji, Rami S.; Moliterno, Alison R.; Ritchie, Ellen K.; Rice, Lawrence; Mascarenhas, John; Hoffman, Ronald

    2015-01-01

    Polycythemia vera (PV) is a chronic myeloproliferative neoplasm that is associated with a substantial symptom burden, thrombohemorrhagic complications, and impaired survival. A decade after the seminal discovery of an activating mutation in the tyrosine kinase JAK2 in nearly all patients with PV, new treatment options are finally beginning to emerge, necessitating a critical reappraisal of the underlying pathogenesis and therapeutic modalities available for PV. Herein, we comprehensively review clinical aspects of PV including diagnostic considerations, natural history, and risk factors for thrombosis. We summarize recent studies delineating the genetic basis of PV, including their implications for evolution to myelofibrosis and secondary acute myeloid leukemia. We assess the quality of evidence to support the use of currently available therapies, including aspirin, phlebotomy, hydroxyurea, and interferon. We analyze recent studies evaluating the safety and efficacy of JAK inhibitors, such as ruxolitinib, and evaluate their role in the context of other available therapies for PV. This review provides a framework for practicing hematologists and oncologists to make rational treatment decisions for patients with PV. PMID:26324368

  14. MPL mutation profile in JAK2 mutation-negative patients with myeloproliferative disorders.

    Ma, Wanlong; Zhang, Xi; Wang, Xiuqiang; Zhang, Zhong; Yeh, Chen-Hsiung; Uyeji, Jennifer; Albitar, Maher

    2011-03-01

    Mutations in the thrombopoietin receptor gene (myeloproliferative leukemia, MPL) have been reported in patients with JAK2 V617F-negative chronic myeloproliferative disorders (MPDs). We evaluated the prevalence of MPL mutations relative to JAK2 mutations in patients with suspected MPDs. A total of 2790 patient samples submitted for JAK2 mutation analysis were tested using real-time polymerase chain reaction and bidirectional sequencing of plasma RNA. JAK2 V617F-negative samples were tested for JAK2 exons 12 to 14 mutations, and those with negative results were then tested for mutations in MPL exons 10 and 11. Of the 2790 patients, 529 (18.96%) had V617F, 12 (0.43%) had small insertions or deletions in exon 12, and 7 (0.25%) had other JAK2 mutations in exons 12 to 14. Of the 2242 JAK2 mutation-negative patients, 68 (3.03%) had MPL mutations. W515L was the predominant MPL mutation (n=46; 68%), and 10 (15%) patients had other W515 variants. The remaining MPL mutations (n=12, 17%) were detected at other locations in exons 10 and 11 and included 3 insertion/deletion mutations. The S505N mutation, associated with familial MPD, was detected in 3 patients. Overall, for every 100 V617F mutations in patients with suspected MPDs, there were 12.9 MPL mutations, 2.3 JAK2 exon 12 mutations, and 1.3 JAK2 exons 13 to 14 mutations. These findings suggest that MPL mutation screening should be performed before JAK2 exons 12 to 14 testing in JAK2 V617F-negative patients with suspected MPDs.

  15. JAK2 Exon 12 Mutations in Polycythemia Vera and Idiopathic Erythrocytosis

    Scott, Linda M.; Tong, Wei; Levine, Ross L.; Scott, Mike A.; Beer, Philip A.; Stratton, Michael R.; Futreal, P. Andrew; Erber, Wendy N.; McMullin, Mary Frances; Harrison, Claire N.; Warren, Alan J.; Gilliland, D. Gary; Lodish, Harvey F.; Green, Anthony R.

    2010-01-01

    BACKGROUND The V617F mutation, which causes the substitution of phenylalanine for valine at position 617 of the Janus kinase (JAK) 2 gene (JAK2), is often present in patients with polycythemia vera, essential thrombocythemia, and idiopathic myelofibrosis. However, the molecular basis of these myeloproliferative disorders in patients without the V617F mutation is unclear. METHODS We searched for new mutations in members of the JAK and signal transducer and activator of transcription (STAT) gene families in patients with V617F-negative polycythemia vera or idiopathic erythrocytosis. The mutations were characterized biochemically and in a murine model of bone marrow transplantation. RESULTS We identified four somatic gain-of-function mutations affecting JAK2 exon 12 in 10 V617F-negative patients. Those with a JAK2 exon 12 mutation presented with an isolated erythrocytosis and distinctive bone marrow morphology, and several also had reduced serum erythropoietin levels. Erythroid colonies could be grown from their blood samples in the absence of exogenous erythropoietin. All such erythroid colonies were heterozygous for the mutation, whereas colonies homozygous for the mutation occur in most patients with V617F-positive polycythemia vera. BaF3 cells expressing the murine erythropoietin receptor and also carrying exon 12 mutations could proliferate without added interleukin-3. They also exhibited increased phosphorylation of JAK2 and extracellular regulated kinase 1 and 2, as compared with cells transduced by wild-type JAK2 or V617F JAK2. Three of the exon 12 mutations included a substitution of leucine for lysine at position 539 of JAK2. This mutation resulted in a myeloproliferative phenotype, including erythrocytosis, in a murine model of retroviral bone marrow transplantation. CONCLUSIONS JAK2 exon 12 mutations define a distinctive myeloproliferative syndrome that affects patients who currently receive a diagnosis of polycythemia vera or idiopathic erythrocytosis

  16. JAK2 mutations and clinical practice in myeloproliferative neoplasms.

    Tefferi, Ayalew

    2007-01-01

    With the discovery in the last 3 years of novel Janus kinase 2 (JAK2) and thrombopoietin receptor (MPL) mutations, the pathogenetic understanding of and clinical practice for myeloproliferative neoplasms (MPNs) have entered a new era. Each one of these newly discovered mutations, including JAK2V617F, MPLW515L, and a JAK2 exon 12 mutation, has been shown to result in constitutive activation of JAK-STAT signaling and also induce a MPN phenotype in mice. Thus, JAK2 is now considered to be a legitimate target for drug development in MPNs, and small molecule JAK2 inhibitors have already gone through successful preclinical testing, and early-phase human trials in primary myelofibrosis have already begun. Furthermore, JAK2 mutation screening has now become a front-line diagnostic test in the evaluation of both "erythrocytosis" and thrombocytosis and the 2001 World Health Organization diagnostic criteria for polycythemia vera, essential thrombocythemia, and primary myelofibrosis have now been revised to incorporate JAK2V617F mutation screening.

  17. The JAK2V617 mutation induces constitutive activation and agonist hypersensitivity in basophils from patients with polycythemia vera

    Pieri, Lisa; Bogani, Costanza; Guglielmelli, Paola; Zingariello, Maria; Rana, Rosa Alba; Bartalucci, Niccolò; Bosi, Alberto; Vannucchi, Alessandro M.

    2009-01-01

    Background The JAK2V617F mutation has been associated with constitutive and enhanced activation of neutrophils, while no information is available concerning other leukocyte subtypes. Design and Methods We evaluated correlations between JAK2V617F mutation and the count of circulating basophils, the number of activated CD63+ basophils, their response in vitro to agonists as well as the effects of a JAK2 inhibitor. Results We found that basophil count was increased in patients with JAK2V617F -positive myeloproliferative neoplasms, particularly in those with polycythemia vera, and was correlated with the V617F burden. The burden of V617F allele was similar in neutrophils and basophils from patients with polycythemia vera, while total JAK2 mRNA content was remarkably greater in the basophils; however, the content of JAK2 protein in basophils was not increased. The number of CD63+ basophils was higher in patients with polycythemia vera than in healthy subjects or patients with essential thrombocythemia or primary myelofibrosis and was correlated with the V617F burden. Ultrastructurally, basophils from patients with polycythemia vera contained an increased number of granules, most of which were empty suggesting cell degranulation in vivo. Ex vivo experiments revealed that basophils from patients with polycythemia vera were hypersensitive to the priming effect of interleukin-3 and to f-MLP-induced activation; pre-treatment with a JAK2 inhibitor reduced polycythemia vera basophil activation. Finally, we found that the number of circulating CD63+ basophils was significantly greater in patients suffering from aquagenic pruritus, who also showed a higher V617F allele burden. Conclusions These data indicate that the number of constitutively activated and hypersensitive circulating basophils is increased in polycythemia vera, underscoring a role of JAK2V617F in these cells’ abnormal function and, putatively, in the pathogenesis of pruritus. PMID:19608683

  18. Vascular events in Korean patients with myeloproliferative neoplasms and their relationship to JAK2 mutation.

    Bang, Soo-Mee; Lee, Jong-Seok; Ahn, Jeong Yeal; Lee, Jae Hoon; Hyun, Myung Soo; Kim, Bong Seog; Park, Moo Rim; Chi, Hyun-Sook; Kim, Ho Young; Kim, Hyo Jung; Lee, Moon Hee; Kim, Hwak; Won, Jong Ho; Yoon, Hwi Joong; Oh, Do-Yeun; Nam, Eun-Mi; Bae, Sung Hwa; Kim, Byoung-Kook

    2009-03-01

    Evaluation of the Janus kinase 2 (JAK2) V617F mutation has been widely used for the diagnosis of myeloproliferative neoplasms (MPN). However, its prognostic relevance to clinical outcome is not completely understood. We investigated the association of JAK2 V617F with vascular events in Korean patients with myeloproliferative neoplasms (MPN). We studied 283 patients from 15 centers, who were diagnosed with MPN. The JAK2 V617F status was evaluated by allele-specific polymerase chain reaction (PCR) and sequencing. The patients' diagnoses were essential thrombocythemia (ET n = 146), polycythemia vera (PV n = 120), primary myelofibrosis (n = 12), and unclassifiable MPN (MPNu n = 5). JAK2 V617F was detected in 89 (61%) patients with ET, 103 (86%) with PV, four (33%) with myelofibrosis, and four (80%) with MPNu. A higher number of leukocytes, haemoglobin levels and BM cellularity as well as an older age, lower platelet counts, and diagnosis of PV were significantly correlated with JAK2 V617F. Eighty-three and 43 episodes of thrombosis and bleeding occurred in 100 patients each before and after the diagnosis. Vascular events more frequently occurred in 37% of patients with JAK2 V617F than in 29% of those without the mutation (p = 0.045). Among 175 patients whose samples were available for sequencing, 28 patients with homozygous JAK2 V617F had vascular events more frequently (57%) than those who were heterozygotes (39%) or had the wild type (27%) (p = 0.03). The multivariate analysis showed that a JAK2 homozygous mutation, hypercholesterolemia and older age were independent risk factors for a vascular event. The results of this study showed that Korean patients with MPN had a similar JAK2 mutation rate and frequency of vascular events when compared to Western patients. The presence of V617F was significantly related to vascular events. Therefore, initial evaluation for the JAK2 mutation and careful monitoring for vascular events should be performed in MPN patients.

  19. Stat5 Exerts Distinct, Vital Functions in the Cytoplasm and Nucleus of Bcr-Abl{sup +} K562 and Jak2(V617F){sup +} HEL Leukemia Cells

    Weber, Axel [Georg-Speyer-Haus, Institute for Tumor Biology and Experimental Therapy, Frankfurt am Main 60596 (Germany); Borghouts, Corina [Ganymed Pharmaceuticals AG, Mainz 55131 (Germany); Brendel, Christian [Boston Children’s Hospital, Division of Hematology/Oncology, Boston, MA 02115 (United States); Moriggl, Richard [Ludwig Boltzmann Institute for Cancer Research (LBI-CR), Vienna 1090 (Austria); Delis, Natalia; Brill, Boris; Vafaizadeh, Vida; Groner, Bernd, E-mail: Groner@em.uni-frankfurt.de [Georg-Speyer-Haus, Institute for Tumor Biology and Experimental Therapy, Frankfurt am Main 60596 (Germany)

    2015-03-19

    Signal transducers and activators of transcription (Stats) play central roles in the conversion of extracellular signals, e.g., cytokines, hormones and growth factors, into tissue and cell type specific gene expression patterns. In normal cells, their signaling potential is strictly limited in extent and duration. The persistent activation of Stat3 or Stat5 is found in many human tumor cells and contributes to their growth and survival. Stat5 activation plays a pivotal role in nearly all hematological malignancies and occurs downstream of oncogenic kinases, e.g., Bcr-Abl in chronic myeloid leukemias (CML) and Jak2(V617F) in other myeloproliferative diseases (MPD). We defined the mechanisms through which Stat5 affects growth and survival of K562 cells, representative of Bcr-Abl positive CML, and HEL cells, representative for Jak2(V617F) positive acute erythroid leukemia. In our experiments we suppressed the protein expression levels of Stat5a and Stat5b through shRNA mediated downregulation and demonstrated the dependence of cell survival on the presence of Stat5. Alternatively, we interfered with the functional capacities of the Stat5 protein through the interaction with a Stat5 specific peptide ligand. This ligand is a Stat5 specific peptide aptamer construct which comprises a 12mer peptide integrated into a modified thioredoxin scaffold, S5-DBD-PA. The peptide sequence specifically recognizes the DNA binding domain (DBD) of Stat5. Complex formation of S5-DBD-PA with Stat5 causes a strong reduction of P-Stat5 in the nuclear fraction of Bcr-Abl-transformed K562 cells and a suppression of Stat5 target genes. Distinct Stat5 mediated survival mechanisms were detected in K562 and Jak2(V617F)-transformed HEL cells. Stat5 is activated in the nuclear and cytosolic compartments of K562 cells and the S5-DBD-PA inhibitor most likely affects the viability of Bcr-Abl{sup +} K562 cells through the inhibition of canonical Stat5 induced target gene transcription. In HEL cells

  20. CALR, JAK2 and MPL mutation status in Argentinean patients with BCR-ABL1- negative myeloproliferative neoplasms.

    Ojeda, Mara Jorgelina; Bragós, Irma Margarita; Calvo, Karina Lucrecia; Williams, Gladis Marcela; Carbonell, María Magdalena; Pratti, Arianna Flavia

    2018-05-01

    To establish the frequency of JAK2, MPL and CALR mutations in Argentinean patients with BCR-ABL1-negative  myeloproliferative neoplasms (MPN) and to compare their clinical and haematological features. Mutations of JAK2V617F, JAK2 exon 12, MPL W515L/K and CALR were analysed in 439 Argentinean patients with BCR-ABL1-negative MPN, including 176 polycythemia vera (PV), 214 essential thrombocythemia (ET) and 49 primary myelofibrosis (PMF). In 94.9% of PV, 85.5% ET and 85.2% PMF, we found mutations in JAK2, MPL or CALR. 74.9% carried JAK2V617F, 12.3% CALR mutations, 2.1% MPL mutations and 10.7% were triple negative. In ET, nine types of CALR mutations were identified, four of which were novel. PMF patients were limited to types 1 and 2, type 2 being more frequent. In ET, patients with CALR mutation were younger and had higher platelet counts than those with JAK2V617F and triple negative. In addition, JAK2V617F patients had high leucocyte and haemoglobin values compared with CALR-mutated and triple-negative patients. In PMF, patients with mutant CALR were associated with higher platelet counts. Our study underscores the importance of JAK2, MPL and CALR genotyping for accurate diagnosis of patients with BCR-ABL1-negative MPN.

  1. Cytogenetics, JAK2 and MPL mutations in polycythemia vera, primary myelofibrosis and essential thrombocythemia

    Leonardo Caires dos Santos

    2011-12-01

    Full Text Available BACKGROUND: The detection of molecular and cytogenetic alterations is important for the diagnosis, prognosis and classification of myeloproliferative neoplasms. OBJECTIVE: The aim of this study was to detect the following mutations: JAK2 V617F, JAK2 exon 12 and MPL W515K/L, besides chromosomal abnormalities. Furthermore, molecular and cytogenetic alterations were correlated with the leukocyte and platelet counts, hemoglobin levels and age in all patients and with the degree of fibrosis in primary myelofibrosis cases. METHODS: Twenty cases of polycythemia vera, 17 of essential thrombocythemia and 21 of primary myelofibrosis were selected in the Hematology Department of the Universidade Federal de São Paulo (UNIFESP between February 2008 and December 2009. The JAK2 V617F, JAK2 exon 12 mutations, MPL W515K and MPL W515L mutations were investigated by real-time PCR and direct sequencing. G-band karyotyping and fluorescence in situ hybridization were used to detect chromosomal abnormalities. RESULTS: Chromosomal abnormalities were observed only in polycythemia vera (11.8% and primary myelofibrosis cases (17.6%, without correlation to clinical data. Chromosomal abnormalities were not detected by fluorescence in situ hybridization. The JAK2 V617F mutation was observed in polycythemia vera (90%, primary myelofibrosis (42.8% and essential thrombocythemia (47%. Patients with JAK2 V617F-negative polycythemia vera had lower platelet and leukocyte counts compared to V617F-positive polycythemia vera (p-value = 0.0001 and p-value = 0.023, respectively. JAK2 V617F-positive and MPL W515L-positive primary myelofibrosis cases had a higher degree of fibrosis than V617F-negative cases (p-value = 0.022. JAK2 exon 12 mutations were not detected in polycythemia vera patients. The MPL W515L mutation was observed in one case of primary myelofibrosis and in one of essential thrombocythemia. The MPL W515K mutation was not found in patients with essential thrombocythemia

  2. Cytogenetics, JAK2 and MPL mutations in polycythemia vera, primary myelofibrosis and essential thrombocythemia.

    Dos Santos, Leonardo Caires; Ribeiro, Juliana Corrêa da Costa; Silva, Neusa Pereira; Cerutti, Janete; da Silva, Maria Regina Regis; Chauffaille, Maria de Lourdes Lopes Ferrari

    2011-01-01

    The detection of molecular and cytogenetic alterations is important for the diagnosis, prognosis and classification of myeloproliferative neoplasms. THE AIM OF THIS STUDY WAS TO DETECT THE FOLLOWING MUTATIONS: JAK2 V617F, JAK2 exon 12 and MPL W515K/L, besides chromosomal abnormalities. Furthermore, molecular and cytogenetic alterations were correlated with the leukocyte and platelet counts, hemoglobin levels and age in all patients and with the degree of fibrosis in primary myelofibrosis cases. Twenty cases of polycythemia vera, 17 of essential thrombocythemia and 21 of primary myelofibrosis were selected in the Hematology Department of the Universidade Federal de São Paulo (UNIFESP) between February 2008 and December 2009. The JAK2 V617F, JAK2 exon 12 mutations, MPL W515K and MPL W515L mutations were investigated by real-time PCR and direct sequencing. G-band karyotyping and fluorescence in situ hybridization were used to detect chromosomal abnormalities. Chromosomal abnormalities were observed only in polycythemia vera (11.8%) and primary myelofibrosis cases (17.6%), without correlation to clinical data. Chromosomal abnormalities were not detected by fluorescence in situ hybridization. The JAK2 V617F mutation was observed in polycythemia vera (90%), primary myelofibrosis (42.8%) and essential thrombocythemia (47%). Patients with JAK2 V617F-negative polycythemia vera had lower platelet and leukocyte counts compared to V617F-positive polycythemia vera (p-value = 0.0001 and p-value = 0.023, respectively). JAK2 V617F-positive and MPL W515L-positive primary myelofibrosis cases had a higher degree of fibrosis than V617F-negative cases (p-value = 0.022). JAK2 exon 12 mutations were not detected in polycythemia vera patients. The MPL W515L mutation was observed in one case of primary myelofibrosis and in one of essential thrombocythemia. The MPL W515K mutation was not found in patients with essential thrombocythemia or primary myelofibrosis. The MPL W515L

  3. Bone marrow histomorphology and JAK2 mutation status in essential thrombocythemia

    Stauffer Larsen, Thomas; Hasselbalch, Hans Carl; Pallisgaard, Niels

    2007-01-01

    for evaluation. 14 patients were reclassified as having prefibrotic idiopathic myelofibrosis (IMF), whilst the ET diagnosis was sustained in 19 patients. The individual bone marrow parameters of the reviewed diagnosis showed no correlation with JAK2 V617F mutation status, which was determined by a highly...

  4. CLINICAL AND LABORATORY FEATURES OF ESSENTIAL THROMBOCYTOSIS AND PRIMARY MYELOFIBROSIS DEPENDING ON JAK2 AND CALR1 MUTATION STATUS

    E. G. lisina

    2017-01-01

    Full Text Available Introduction. JAK2V617F mutation is detected in approximately 50 % of patients with essential thrombocytosis (ET and primary myelofibrosis (PMF. In 2013 most of the JAK2 negative patients showed mutations in the CALR gene. Diagnostic value of JAK2 and CALR mutations is high, but their prognostic significance is not sufficiently clear. Data on impact of JAK2 and CALR mutational status on thrombotic complications in ET and myelofibrosis patients are contradictory.The aim of the study was to identify clinical and laboratory features in patients with ET and PMF in accordance with the mutational status of JAK2V617F and CALR gene.Materials and methods. Patients treated in Almazov National Medical Research Center (St. Petersburg, Chuvash Republican Clinical Hospital (Cheboksary, Irkutsk Regional Clinical Hospital (Irkutsk,  Kirov Research Institute of Hematology and Blood Transfusion (Kirov was included in the retrospective study. CALR mutation (1 and 2 types, MPL W515L/K and JAK2V617F mutation were detected in peripheral blood cells.Results. We identified that 21 % (n = 16 of ET patients had thrombotic complications, and they occurred more often among JAK2V617F positive patients (p <0.05. The median of hemoglobin level in PMF was the lowest in the group of triple negative patients. The level of leukocytes in PMF was higher in the group of triple negative patients than in the group with mutated CALR (p = 0.014.Conclusion. JAK2V617F mutation in ET patients was associated with a high risk of thrombosis. Patients with CALR mutations may have a favorable prognosis regarding to thrombotic complications. Some laboratory features of CALR mutations in ET and PMF patients have been revealed.

  5. JAK2, MPL, and CALR mutations in Chinese Han patients with essential thrombocythemia.

    Wang, Jing; Zhang, Biao; Chen, Bing; Zhou, Rong-Fu; Zhang, Qi-Guo; Li, Juan; Yang, Yong-Gong; Zhou, Min; Shao, Xiao-Yan; Xu, Yong; Xu, Xi-Hui; Ouyang, Jian; Xu, Jingyan; Ye, Qing

    2017-04-01

    Mutations in Janus kinase 2 (JAK2), myeloproliferative leukemia (MPL), and CALR are highly relevant to Philadelphia chromosome (Ph)-negative myeloproliferative neoplasms. Assessing the prevalence of molecular mutations in Chinese Han patients with essential thrombocythemia (ET), and correlating their mutational profile with disease characteristics/phenotype. Of the 110 subjects studied, 62 carried the JAK2 V617F mutation, 21 had CALR mutations, one carried an MPL (W515) mutation, and 28 had non-mutated JAK2, CALR, and MPL (so-called triple-negative ET). Mutations in JAK2 exon 12 were not detected in any patient. Two ET patients had both CALR and JAK2 V617F mutations. Comparing the hematological parameters of the patients with JAK2 mutations with those of the patients with CALR mutations showed that the ET patients with CALR mutations were younger (p = 0.045) and had higher platelet counts (p = 0.043). Genotyping for CALR could be a useful diagnostic tool for JAK2/MPL-negative ET, since the data suggest that CALR is much more prevalent than MPL, therefore testing for CALR should be considered in patients who are JAK2 negative as its frequency is almost 20 times that of MPL mutation.

  6. The Prevalence of JAK2, MPL, and CALR Mutations in Chinese Patients With BCR-ABL1-Negative Myeloproliferative Neoplasms.

    Lin, Yani; Liu, Enbin; Sun, Qi; Ma, Jiao; Li, QingHua; Cao, Zeng; Wang, Jun; Jia, Yujiao; Zhang, Hongju; Song, Zhen; Ai, Xiaofei; Shi, Lihui; Feng, Xiaofang; Li, Chenwei; Wang, Jianxiang; Ru, Kun

    2015-07-01

    To evaluate the mutation frequency of JAK2 V617F, JAK2 exon 12, MPL exon 10, and CALR exon 9 and the value of the combined tests in the diagnosis of BCR-ABL1-negative myeloproliferative neoplasms (MPNs). In the current study, mutations of JAK2 V617F, JAK2 exon 12, MPL exon 10, and CALR exon 9 were analyzed in 929 Chinese patients with BCR-ABL1-negative MPN, including 234 cases of polycythemia vera (PV), 428 ETs, 187 PMFs, and 80 unclassifiable MPNs (MPN-Us). Our result showed that the positive rate of any of four mutations in patients with PV, ET, PMF, and MPN-U was 89.3%, 83.4%, 87.2%, and 77.5%, respectively, which significantly improved the diagnostic rate, especially in ET and PMF. Meanwhile, we also found that the patients without any of four mutations were younger than those with one or more mutations. Unexpectedly, the coexistence of JAK2 V617F and CALR exon 9 was identified in six (0.6%) patients, and JAK2 V617F and MPL exon 10 were present simultaneously in two (0.2%) patients. In addition, we also identified several novel mutation types in CALR exon 9. The combined genetic tests of JAK2 V617F, JAK2 exon 12, MPL exon 10, and CALR exon 9 help improve the diagnostic rate for BCR-ABL1-negative MPN. Copyright© by the American Society for Clinical Pathology.

  7. The mutation profile of JAK2, MPL and CALR in Mexican patients with Philadelphia chromosome-negative myeloproliferative neoplasms.

    Labastida-Mercado, Nancy; Galindo-Becerra, Samantha; Garcés-Eisele, Javier; Colunga-Pedraza, Perla; Guzman-Olvera, Valeria; Reyes-Nuñez, Virginia; Ruiz-Delgado, Guillermo J; Ruiz-Argüelles, Guillermo J

    2015-03-01

    By using molecular markers, it is possible to gain information on both the classification and etiopathogenesis of chronic myeloproliferative neoplasias (MPN). In a group of 27 Mexican mestizo patients with MPNs, we studied seven molecular markers: the BCR/ABL1 fusion gene, the JAK2 V617F mutation, the JAK2 exon 12 mutations, the MPL W515L mutation, the MPL W515K mutation, and the calreticulin (CALR) exon 9 deletion or insertion. Patients with the BCR/ABL1 fusion gene were excluded. We studied 14 patients with essential thrombocythemia (ET), eight with polycythemia vera (PV), four with primary myelofibrosis (MF), and one with undifferentiated MPN. We found twelve individuals with the JAK2 V617F mutation; five of them had been clinically classified as PV, five as ET, and one as MF. One patient with the MPL W515L was identified with a clinical picture of ET. Five patients with the CALR mutation were identified, four ET and one MF. No individuals with either the MPL W515K mutation or the JAK2 exon 12 mutations were identified. The most consistent relationship was that between PV and the JAK2 V617F mutation (p=.01). Despite its small size, the study shows much less prevalence of JAK2 mutation in PV, ET and MF, which does not match international data. Copyright © 2015 King Faisal Specialist Hospital & Research Centre. Published by Elsevier B.V. All rights reserved.

  8. Presence of calreticulin mutations in JAK2-negative polycythemia vera.

    Broséus, Julien; Park, Ji-Hye; Carillo, Serge; Hermouet, Sylvie; Girodon, François

    2014-12-18

    Calreticulin (CALR) mutations have been reported in Janus kinase 2 (JAK2)- and myeloproliferative leukemia (MPL)-negative essential thrombocythemia and primary myelofibrosis. In contrast, no CALR mutations have ever been reported in the context of polycythemia vera (PV). Here, we describe 2 JAK2(V617F)-JAK2(exon12)-negative PV patients who presented with a CALR mutation in peripheral granulocytes at the time of diagnosis. In both cases, the CALR mutation was a 52-bp deletion. Single burst-forming units-erythroid (BFU-E) from 1 patient were grown in vitro and genotyped: the same CALR del 52-bp mutation was noted in 31 of the 37 colonies examined; 30 of 31 BFU-E were heterozygous for CALR del 52 bp, and 1 of 31 BFU-E was homozygous for CALR del 52 bp. In summary, although unknown mutations leading to PV cannot be ruled out, our results suggest that CALR mutations can be associated with JAK2-negative PV. © 2014 by The American Society of Hematology.

  9. JAK2 inhibitor therapy in myeloproliferative disorders: rationale, preclinical studies and ongoing clinical trials.

    Pardanani, A

    2008-01-01

    The recent identification of somatic mutations such as JAK2V617F that deregulate Janus kinase (JAK)-signal transducer and activator of transcription signaling has spurred development of orally bioavailable small-molecule inhibitors that selectively target JAK2 kinase as an approach to pathogenesis-directed therapy of myeloproliferative disorders (MPD). In pre-clinical studies, these compounds inhibit JAK2V617F-mediated cell growth at nanomolar concentrations, and in vivo therapeutic efficacy has been demonstrated in mouse models of JAK2V617F-induced disease. In addition, ex vivo growth of progenitor cells from MPD patients harboring JAK2V617F or MPLW515L/K mutations is also potently inhibited. JAK2 inhibitors currently in clinical trials can be grouped into those designed to primarily target JAK2 kinase (JAK2-selective) and those originally developed for non-MPD indications, but that nevertheless have significant JAK2-inhibitory activity (non-JAK2 selective). This article discusses the rationale for using JAK2 inhibitors for the treatment of MPD, as well as relevant aspects of clinical trial development for these patients. For instance, which group of MPD patients is appropriate for initial Phase I studies? Should JAK2V617F-negative MPD patients be included in the initial studies? What are the likely consequences of 'off-target' JAK3 and wild-type JAK2 inhibition? How should treatment responses be monitored?

  10. Clinical effect of driver mutations of JAK2, CALR, or MPL in primary myelofibrosis.

    Rumi, Elisa; Pietra, Daniela; Pascutto, Cristiana; Guglielmelli, Paola; Martínez-Trillos, Alejandra; Casetti, Ilaria; Colomer, Dolors; Pieri, Lisa; Pratcorona, Marta; Rotunno, Giada; Sant'Antonio, Emanuela; Bellini, Marta; Cavalloni, Chiara; Mannarelli, Carmela; Milanesi, Chiara; Boveri, Emanuela; Ferretti, Virginia; Astori, Cesare; Rosti, Vittorio; Cervantes, Francisco; Barosi, Giovanni; Vannucchi, Alessandro M; Cazzola, Mario

    2014-08-14

    We studied the impact of driver mutations of JAK2, CALR, (calreticulin gene) or MPL on clinical course, leukemic transformation, and survival of patients with primary myelofibrosis (PMF). Of the 617 subjects studied, 399 (64.7%) carried JAK2 (V617F), 140 (22.7%) had a CALR exon 9 indel, 25 (4.0%) carried an MPL (W515) mutation, and 53 (8.6%) had nonmutated JAK2, CALR, and MPL (so-called triple-negative PMF). Patients with CALR mutation had a lower risk of developing anemia, thrombocytopenia, and marked leukocytosis compared with other subtypes. They also had a lower risk of thrombosis compared with patients carrying JAK2 (V617F). At the opposite, triple-negative patients had higher incidence of leukemic transformation compared with either CALR-mutant or JAK2-mutant patients. Median overall survival was 17.7 years in CALR-mutant, 9.2 years in JAK2-mutant, 9.1 years in MPL-mutant, and 3.2 years in triple-negative patients. In multivariate analysis corrected for age, CALR-mutant patients had better overall survival than either JAK2-mutant or triple-negative patients. The impact of genetic lesions on survival was independent of current prognostic scoring systems. These observations indicate that driver 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. © 2014 by The American Society of Hematology.

  11. [Clinical significance of JAK2、CALR and MPL gene mutations in 1 648 Philadelphia chromosome negative myeloproliferative neoplasms patients from a single center].

    Li, M Y; Chao, H Y; Sun, A N; Qiu, H Y; Jin, Z M; Tang, X W; Han, Y; Fu, C C; Chen, S N; Wu, D P

    2017-04-14

    Objective: To explore the prevalences of JAK2, CALR and MPL gene mutations and the mutation types in patients with Philadelphia chromosome negative myeloproliferative neoplasms (MPNs) , and to compare their clinical characteristics of different mutation types with each other and mutation negative group. Methods: The mutations of JAK2 V617F, JAK2 gene at exon 12, CALR gene at exon 9 and MPL gene at exon 10 in 1 648 Ph negative MPNs patients were detected by direct sequencing. Results: ① The JAK2V617F mutation was found in 471 (92.7%) of 508 PV patients, 819 (78.1%) of 1 049 ET patients and 74 (81.3%) of 91 PMF patients respectively, with the total mutation rate as 82.8% (1 364/1 648) . The JAK2 exon12 mutation was found in 9 (1.7%) of 508 PV patients, none was found in ET or PMF patients, with the total mutation rate as 0.5% (9/1 648) . The CALR mutation was found in 132 (12.6%) of 1 049 ET patients and 11 (12.1%) of 91 PMF patients respectively, with the total mutation rate as 8.7% (143/1 648) ; the MPL mutation was found in 9 (0.9%) of 1 049 ET patients and 1 (1.1%) of 91 PMF patients respectively, with the total mutation rate as 0.6% (10/1 648) . The co-occurrence of any two types of driver gene mutations was not detected by direct sequencing. ②The median onset age of patients with JAK2V617F[61 (15-95) y] was significant higher than of with JAK2 exon12 mutation[49 (33-62) y] or without mutations[42 (3-78) y] ( P MPL mutation[59 (22-71) y] ( P >0.05) . Patients with JAK2V617F had higher white blood cell count and hemoglobin level ( P MPL mutation ( P =0.013) . The platelet count of patients with CALR mutation was significantly higher than of with JAK2V617F[966 (400-2 069) ×10(9)/L vs 800 (198-3 730) ×10(9)/L, P MPL gene mutation revealed normal karyotype. Conclusions: Driver gene mutations detection could ensure the diagnosis and prognosis judgment of MPN more reliable, different subtypes of MPNs had different profiles of driver gene mutations, the latter

  12. The C allele of JAK2 rs4495487 is an additional candidate locus that contributes to myeloproliferative neoplasm predisposition in the Japanese population

    Ohyashiki Junko H

    2012-01-01

    Full Text Available Abstract Background Polycythemia vera (PV, essential thrombocythemia (ET, and primary myelofibrosis (PMF are myeloproliferative neoplasms (MPNs characterized in most cases by a unique somatic mutation, JAK2 V617F. Recent studies revealed that JAK2 V617F occurs more frequently in a specific JAK2 haplotype, named JAK2 46/1 or GGCC haplotype, which is tagged by rs10974944 (C/G and/or rs12343867 (T/C. This study examined the impact of single nucleotide polymorphisms (SNPs of the JAK2 locus on MPNs in a Japanese population. Methods We sequenced 24 JAK2 SNPs in Japanese patients with PV. We then genotyped 138 MPN patients (33 PV, 96 ET, and 9 PMF with known JAK2 mutational status and 107 controls for a novel SNP, in addition to two SNPs known to be part of the 46/1 haplotype (rs10974944 and rs12343867. Associations with risk of MPN were estimated by odds ratios and their 95% confidence intervals using logistic regression. Results A novel locus, rs4495487 (T/C, with a mutated T allele was significantly associated with PV. Similar to rs10974944 and rs12343867, rs4495487 in the JAK2 locus is significantly associated with JAK2-positive MPN. Based on the results of SNP analysis of the three JAK2 locus, we defined the "GCC genotype" as having at least one minor allele in each SNP (G allele in rs10974944, C allele in rs4495487, and C allele in rs12343867. The GCC genotype was associated with increased risk of both JAK2 V617F-positive and JAK2 V617F-negative MPN. In ET patients, leukocyte count and hemoglobin were significantly associated with JAK2 V617F, rather than the GCC genotype. In contrast, none of the JAK2 V617F-negative ET patients without the GCC genotype had thrombosis, and splenomegaly was frequently seen in this subset of ET patients. PV patients without the GCC genotype were significantly associated with high platelet count. Conclusions Our results indicate that the C allele of JAK2 rs4495487, in addition to the 46/1 haplotype, contributes

  13. Interferon-α induces marked alterations in circulating regulatory T cells, NK cell subsets, and dendritic cells in patients with JAK2V617F-positive essential thrombocythemia and polycythemia vera

    Riley, Caroline H; Brimnes, Marie K; Hansen, Morten

    2016-01-01

    Long-term therapy with IFN-α2 is associated with sustained major molecular remissions in JAK2-positive ET and PV. The efficacy of IFN-α2 may be partly mediated by modulation of immune cells, which was investigated in twenty patients with ET (n = 6) and PV (n = 14). The frequency of CD4+CD25+Foxp3...

  14. Efficacy of NS-018, a potent and selective JAK2/Src inhibitor, in primary cells and mouse models of myeloproliferative neoplasms

    Nakaya, Y; Shide, K; Niwa, T; Homan, J; Sugahara, S; Horio, T; Kuramoto, K; Kotera, T; Shibayama, H; Hori, K; Naito, H; Shimoda, K

    2011-01-01

    Aberrant activation of Janus kinase 2 (JAK2) caused by somatic mutation of JAK2 (JAK2V617F) or the thrombopoietin receptor (MPLW515L) plays an essential role in the pathogenesis of myeloproliferative neoplasms (MPNs), suggesting that inhibition of aberrant JAK2 activation would have a therapeutic benefit. Our novel JAK2 inhibitor, NS-018, was highly active against JAK2 with a 50% inhibition (IC 50 ) of <1 n, and had 30–50-fold greater selectivity for JAK2 over other JAK-family kinases, such as JAK1, JAK3 and tyrosine kinase 2. In addition to JAK2, NS-018 inhibited Src-family kinases. NS-018 showed potent antiproliferative activity against cell lines expressing a constitutively activated JAK2 (the JAK2V617F or MPLW515L mutations or the TEL–JAK2 fusion gene; IC 50 =11–120 n), but showed only minimal cytotoxicity against most other hematopoietic cell lines without a constitutively activated JAK2. Furthermore, NS-018 preferentially suppressed in vitro erythropoietin-independent endogenous colony formation from polycythemia vera patients. NS-018 also markedly reduced splenomegaly and prolonged the survival of mice inoculated with Ba/F3 cells harboring JAK2V617F. In addition, NS-018 significantly reduced leukocytosis, hepatosplenomegaly and extramedullary hematopoiesis, improved nutritional status, and prolonged survival in JAK2V617F transgenic mice. These results suggest that NS-018 will be a promising candidate for the treatment of MPNs

  15. The Amelioration of Myelofibrosis with Thrombocytopenia by a JAK1/2 Inhibitor, Ruxolitinib, in a Post-polycythemia Vera Myelofibrosis Patient with a JAK2 Exon 12 Mutation.

    Ikeda, Kazuhiko; Ueda, Koki; Sano, Takahiro; Ogawa, Kazuei; Ikezoe, Takayuki; Hashimoto, Yuko; Morishita, Soji; Komatsu, Norio; Ohto, Hitoshi; Takeishi, Yasuchika

    2017-01-01

    Less than 5% of patients with polycythemia vera (PV) show JAK2 exon 12 mutations. Although PV patients with JAK2 exon 12 mutations are known to develop post-PV myelofibrosis (MF) as well as PV with JAK2V617F, the role of JAK inhibitors in post-PV MF patients with JAK2 exon 12 mutations remains unknown. We describe how treatment with a JAK1/2 inhibitor, ruxolitinib, led to the rapid amelioration of marrow fibrosis, erythrocytosis and thrombocytopenia in a 77-year-old man with post-PV MF who carried a JAK2 exon 12 mutation (JAK2H538QK539L). This case suggests that ruxolitinib is a treatment option for post-PV MF in patients with thrombocytopenia or JAK2 exon 12 mutations.

  16. Improved diagnosis of the transition to JAK2 (V⁶¹⁷F homozygosity: the key feature for predicting the evolution of myeloproliferative neoplasms.

    Mariana Selena Gonzalez

    Full Text Available Most cases of BCR-ABL1-negative myeloproliferative neoplasms (MPNs, essential thrombocythemia, polycythemia vera and primary myelofibrosis are associated with JAK2 (V617F mutations. The outcomes of these cases are critically influenced by the transition from JAK2 (V617F heterozygosity to homozygosity. Therefore, a technique providing an unbiased assessment of the critical allele burden, 50% JAK2 (V617F, is highly desirable. In this study, we present an approach to assess the JAK2 (V617F burden from genomic DNA (gDNA and complementary DNA (cDNA using one-plus-one template references for allele-specific quantitative-real-time-PCR (qPCR. Plasmidic gDNA and cDNA constructs encompassing one PCR template for JAK2 (V617F spaced from one template for JAK2(Wild Type were constructed by multiple fusion PCR amplifications. Repeated assessments of the 50% JAK2(V617F burden within the dynamic range of serial dilutions of gDNA and cDNA constructs resulted in 52.53 ± 4.2% and 51.46 ± 4.21%, respectively. The mutation-positive cutoff was estimated to be 3.65% (mean +2 standard deviation using 20 samples from a healthy population. This qPCR approach was compared with the qualitative ARMS-PCR technique and with two standard methods based on qPCR, and highly significant correlations were obtained in all cases. qPCR assays were performed on paired gDNA/cDNA samples from 20 MPN patients, and the JAK2 (V617F expression showed a significant correlation with the allele burden. Our data demonstrate that the qPCR method using one-plus-one template references provides an improved assessment of the clinically relevant transition of JAK2 (V617F from heterozygosity to homozygosity.

  17. Efficacy of the JAK2 inhibitor INCB16562 in a murine model of MPLW515L-induced thrombocytosis and myelofibrosis

    Koppikar, Priya; Abdel-Wahab, Omar; Hedvat, Cyrus; Marubayashi, Sachie; Patel, Jay; Goel, Aviva; Kucine, Nicole; Gardner, Jeffrey R.; Combs, Andrew P.; Vaddi, Kris; Haley, Patrick J.; Burn, Timothy C.; Rupar, Mark; Bromberg, Jacqueline F.; Heaney, Mark L.

    2010-01-01

    The discovery of JAK2 and MPL mutations in patients with myeloproliferative neoplasms (MPNs) provided important insight into the genetic basis of these disorders and led to the development of JAK2 kinase inhibitors for MPN therapy. Although recent studies have shown that JAK2 kinase inhibitors demonstrate efficacy in a JAK2V617F murine bone marrow transplantation model, the effects of JAK2 inhibitors on MPLW515L-mediated myeloproliferation have not been investigated. In this report, we descri...

  18. Cancer gene profiling in non-small cell lung cancers reveals activating mutations in JAK2 and JAK3 with therapeutic implications

    Shuyu D. Li

    2017-10-01

    Full Text Available Abstract Background Next-generation sequencing (NGS of cancer gene panels are widely applied to enable personalized cancer therapy and to identify novel oncogenic mutations. Methods We performed targeted NGS on 932 clinical cases of non-small-cell lung cancers (NSCLCs using the Ion AmpliSeq™ Cancer Hotspot panel v2 assay. Results Actionable mutations were identified in 65% of the cases with available targeted therapeutic options, including 26% of the patients with mutations in National Comprehensive Cancer Network (NCCN guideline genes. Most notably, we discovered JAK2 p.V617F somatic mutation, a hallmark of myeloproliferative neoplasms, in 1% (9/932 of the NSCLCs. Analysis of cancer cell line pharmacogenomic data showed that a high level of JAK2 expression in a panel of NSCLC cell lines is correlated with increased sensitivity to a selective JAK2 inhibitor. Further analysis of TCGA genomic data revealed JAK2 gain or loss due to genetic alterations in NSCLC clinical samples are associated with significantly elevated or reduced PD-L1 expression, suggesting that the activating JAK2 p.V617F mutation could confer sensitivity to both JAK inhibitors and anti-PD1 immunotherapy. We also detected JAK3 germline activating mutations in 6.7% (62/932 of the patients who may benefit from anti-PD1 treatment, in light of recent findings that JAK3 mutations upregulate PD-L1 expression. Conclusion Taken together, this study demonstrated the clinical utility of targeted NGS with a focused hotspot cancer gene panel in NSCLCs and identified activating mutations in JAK2 and JAK3 with clinical implications inferred through integrative analysis of cancer genetic, genomic, and pharmacogenomic data. The potential of JAK2 and JAK3 mutations as response markers for the targeted therapy against JAK kinases or anti-PD1 immunotherapy warrants further investigation.

  19. Peptide nucleic acid probe-based fluorescence melting curve analysis for rapid screening of common JAK2, MPL, and CALR mutations.

    Park, Joonhong; Song, Minsik; Jang, Woori; Chae, Hyojin; Lee, Gun Dong; Kim, KyungTak; Park, Heekyung; Kim, Myungshin; Kim, Yonggoo

    2017-02-01

    We developed and evaluated the feasibility of peptide nucleic acid (PNA)-based fluorescence melting curve analysis (FMCA) to detect common mutations in myeloproliferative neoplasms (MPNs). We have set up two separate reactions of PNA-based FMCA: JAK2 V617F &CALR p.Leu367fs*46 (set A) and MPL W515L/K &CALR p.Lys385fs*47 (set B). Clinical usefulness was validated with allele-specific real-time PCR, fragment analysis, Sanger sequencing in 57 BCR-ABL1-negative MPNs. The limit of detection (LOD) of PNA-based FMCA was approximately 10% for each mutation and interference reactions using mixtures of different mutations were not observed. Non-specific amplification was not observed in normal control. PNA-based FMCA was able to detect all JAK2 V617F (n=20), CALR p.Leu367fs*46 (n=10) and p.Lys385fs*47 (n=8). Three of six MPL mutations were detected except three samples with low mutant concentration in out of LOD. JAK2 exon 12 mutations (n=7) were negative without influencing V617F results. Among six variant CALR exon 9 mutations, two were detected by this method owing to invading of probe binding site. PNA-based FMCA for detecting common JAK2, MPL, and CALR mutations is a rapid, simple, and sensitive technique in BCR-ABL1-negative MPNs with >10% mutant allele at the time of initial diagnosis. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Frequency of janus associated kinase 2 (jak2) mutation in patients of bcr-abl negative myeloproliferative neoplasms

    Sadiq, M.A.; Ahmed, S.; Ali, N.

    2013-01-01

    To determine the frequency of Janus associated kinase 2 mutation in the patients of BCR-ABL negative classical myeloproliferative neoplasms. Study Design: Cross-sectional descriptive study Place and Duration of Study: Molecular Department of Haematology, Armed Forces Institute of Pathology (AFIP), Rawalpindi from Jul 2011 to Jul 2012. Patients and Methods: Ninety three consecutive patients of Polycythaemia vera (PV), Essential thrombocythaemia (ET) and Idiopathic myelofibrosis (IMF) diagnosed by the conventional haematological criteria were included in the study. All patients were screened for G-T point mutation (V617F) in the JAK2 gene on chromosome 9 by an allele specific PCR. Results: Out of the 93 myeloproliferative neoplasm (MPN) patients, 33(35%) had polycythaemia vera, 36(39%) had essential thrombocythaemia and 24(26%) had idiopathic myelofibrosis. JAK2 mutation was seen in 64/93 (69%) patients including 33/33(100%) in PV, 19/36(52.6%) in ET and 12/24(50%) in IMF. Conclusion: Classical myeloproliferative neoplasms are an important group of heamatological disorder in our country. JAK2 gene mutation is seen in significant proportion of these disorders (69%). JAK2 mutation analysis can be used to differentiate between polycythemia vera and secondary polycythemia in most cases with near certainty, where it was found in 100% of the cases. (author)

  1. Whole-exome sequencing identifies novel MPL and JAK2 mutations in triple-negative myeloproliferative neoplasms.

    Milosevic Feenstra, Jelena D; Nivarthi, Harini; Gisslinger, Heinz; Leroy, Emilie; Rumi, Elisa; Chachoua, Ilyas; Bagienski, Klaudia; Kubesova, Blanka; Pietra, Daniela; Gisslinger, Bettina; Milanesi, Chiara; Jäger, Roland; Chen, Doris; Berg, Tiina; Schalling, Martin; Schuster, Michael; Bock, Christoph; Constantinescu, Stefan N; Cazzola, Mario; Kralovics, Robert

    2016-01-21

    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. © 2016 by The American Society of Hematology.

  2. [Prognostic value of JAK2, MPL and CALR mutations in Chinese patients with primary myelofibrosis].

    Xu, Z F; Li, B; Liu, J Q; Li, Y; Ai, X F; Zhang, P H; Qin, T J; Zhang, Y; Wang, J Y; Xu, J Q; Zhang, H L; Fang, L W; Pan, L J; Hu, N B; Qu, S Q; Xiao, Z J

    2016-07-01

    To evaluate the prognostic value of JAK2, MPL and CALR mutations in Chinese patients with primary myelofibrosis (PMF). Four hundred and two Chinese patients with PMF were retrospectively analyzed. The Kaplan-Meier method, the Log-rank test, the likelihood ratio test and the Cox proportional hazards regression model were used to evaluate the prognostic scoring system. This cohort of patients included 209 males and 193 females with a median age of 55 years (range: 15- 89). JAK2V617F mutations were detected in 189 subjects (47.0% ), MPLW515 mutations in 13 (3.2%) and CALR mutations in 81 (20.1%) [There were 30 (37.0%) type-1, 48 (59.3%) type-2 and 3 (3.7%) less common CALR mutations], respectively. 119 subjects (29.6%) had no detectable mutation in JAK2, MPL or CALR. Univariate analysis indicated that patients with CALR type-2 mutations or no detectable mutations had inferior survival compared to those with JAK2, MPL or CALR type- 1 or other less common CALR mutations (the median survival was 74vs 168 months, respectively [HR 2.990 (95% CI 1.935-4.619),P<0.001]. Therefore, patients were categorized into the high-risk with CALR type- 2 mutations or no detectable driver mutations and the low- risk without aforementioned mutations status. The DIPSS-Chinese molecular prognostic model was proposed by adopting mutation categories and DIPSS-Chinese risk group. The median survival of patients classified in low risk (132 subjects, 32.8% ), intermediate- 1 risk (143 subjects, 35.6%), intermediate- 2 risk (106 subjects, 26.4%) and high risk (21 subjects, 5.2%) were not reached, 156 (95% CI 117- 194), 60 (95% CI 28- 91) and 22 (95% CI 10- 33) months, respectively, and there was a statistically significant difference in overall survival among the four risk groups (P<0.001). There was significantly higher predictive power for survival according to the DIPSS-Chinese molecular prognostic model compared with the DIPSS-Chinese model (P=0.005, -2 log-likelihood ratios of 855.6 and 869

  3. Low frequency of c-MPL gene mutations in Iranian patients with Philadelphia-negative myeloproliferative disorders.

    Ghotaslou, A; Nadali, F; Chahardouli, B; Alizad Ghandforosh, N; Rostami, S H; Alimoghaddam, K; Ghavamzadeh, A

    2015-01-01

    Myeloproliferative disorders are a group of diseases characterized by increased proliferation of myeloid lineage. In addition to JAK2V617F mutation, several mutations in the c-MPL gene have been reported in patients with philadelphia-negative chronic myeloproliferative disorders that could be important in the pathogenesis of diseases. The aim of the present study was to investigate the frequency of c-MPL and JAK2V617F mutations in Iranian patients with Philadelphia-negativemyeloproliferative disorders. Peripheral blood samples were collected from 60 patients with Philadelphia-negative MPD) Subgroups ET and PMF) and 25 healthy subjects as control group. The mutation status of c-MPL and Jak2V617F were investigated by using Amplification-refractory mutation system (ARMS) and Allele-Specific PCR (AS-PCR), respectively. The results were confirmed by sequencing. Among 60 patients, 34 (56.6%) and 1(1.7%) had Jak2V617F and c-MPL mutation, respectively. Patients with Jak2V617F mutation had higher WBC counts and hemoglobin concentration than those without the mutation (p= 0.005, p=0.003). In addition, for all healthy subjects in control group, mutations were negative. The present study revealed that the c-MPL mutations unlike the Jak2V617F mutations are rare in Iranian patients with Ph-negative MPNs and the low mutation rate should be considered in the design of screening strategies of MPD patients.

  4. FLT3 and JAK2 Mutations in Acute Myeloid Leukemia Promote Interchromosomal Homologous Recombination and the Potential for Copy Neutral Loss of Heterozygosity.

    Gaymes, Terry J; Mohamedali, Azim; Eiliazadeh, Anthony L; Darling, David; Mufti, Ghulam J

    2017-04-01

    Acquired copy neutral LOH (CN-LOH) is a frequent occurrence in myeloid malignancies and is often associated with resistance to standard therapeutic modalities and poor survival. Here, we show that constitutive signaling driven by mutated FLT3 and JAK2 confers interchromosomal homologous recombination (iHR), a precedent for CN-LOH. Using a targeted recombination assay, we determined significant iHR activity in internal tandem duplication FLT3 (FLT3-ITD) and JAK2V617F-mutated cells. Sister chromatid exchanges, a surrogate measure of iHR, was significantly elevated in primary FLT3-ITD normal karyotype acute myeloid leukemia (NK-AML) compared with wild-type FLT3 NK-AML. HR was harmonized to S phase of the cell cycle to repair broken chromatids and prevent iHR. Increased HR activity in G 0 arrested primary FLT3-ITD NK-AML in contrast to wild-type FLT3 NK-AML. Cells expressing mutated FLT3-ITD demonstrated a relative increase in mutation frequency as detected by thymidine kinase (TK) gene mutation assay. Moreover, resistance was associated with CN-LOH at the TK locus. Treatment of FLT3-ITD- and JAK2V617F-mutant cells with the antioxidant N -acetylcysteine diminished reactive oxygen species (ROS), restoring iHR and HR levels. Our findings show that mutated FLT3-ITD and JAK2 augment ROS production and HR, shifting the cellular milieu toward illegitimate recombination events such as iHR and CN-LOH. Therapeutic reduction of ROS may thus prevent leukemic progression and relapse in myeloid malignancies. Cancer Res; 77(7); 1697-708. ©2017 AACR . ©2017 American Association for Cancer Research.

  5. Massive upper gastrointestinal bleeding due to splenoportal axis thrombosis in a patient with a tested JAK2 mutation: A case report and review literature

    Isabel Macías, PhD

    2016-01-01

    Full Text Available Portal hypertension is a clinical syndrome defined as a portal venous pressure that exceeds 10 mmHg. Cirrhosis is the most common cause of portal hypertension and thrombosis of the splenoportal axis not associated with liver cirrhosis is the second cause of portal hypertension in the Western world. The primary myeloproliferative disorders are the main cause of portal venous thrombosis and somatic mutation of Janus Kinase 2 gene (JAK2 V617F can be found in approximately 90% of polycythemia vera, 50% of essential thrombocyrosis and 50% primary myelofibrosis. A a 55-year-old man with JAK2 mutation-associated splenoportal axis hypertension and bleeding complications due to oesophageal varices is reported. A massive upper bleeding episode made an emergent surgery to be done immediatelly at seventh day. The patient was discharged home at fifteenth day after surgery.

  6. Efficacy of NS-018, a potent and selective JAK2/Src inhibitor, in primary cells and mouse models of myeloproliferative neoplasms.

    Nakaya, Y; Shide, K; Niwa, T; Homan, J; Sugahara, S; Horio, T; Kuramoto, K; Kotera, T; Shibayama, H; Hori, K; Naito, H; Shimoda, K

    2011-07-01

    Aberrant activation of Janus kinase 2 (JAK2) caused by somatic mutation of JAK2 (JAK2V617F) or the thrombopoietin receptor (MPLW515L) plays an essential role in the pathogenesis of myeloproliferative neoplasms (MPNs), suggesting that inhibition of aberrant JAK2 activation would have a therapeutic benefit. Our novel JAK2 inhibitor, NS-018, was highly active against JAK2 with a 50% inhibition (IC(50)) of MPLW515L mutations or the TEL-JAK2 fusion gene; IC(50)=11-120 n), but showed only minimal cytotoxicity against most other hematopoietic cell lines without a constitutively activated JAK2. Furthermore, NS-018 preferentially suppressed in vitro erythropoietin-independent endogenous colony formation from polycythemia vera patients. NS-018 also markedly reduced splenomegaly and prolonged the survival of mice inoculated with Ba/F3 cells harboring JAK2V617F. In addition, NS-018 significantly reduced leukocytosis, hepatosplenomegaly and extramedullary hematopoiesis, improved nutritional status, and prolonged survival in JAK2V617F transgenic mice. These results suggest that NS-018 will be a promising candidate for the treatment of MPNs.

  7. Somatic CALR mutations in myeloproliferative neoplasms with nonmutated JAK2

    Nangalia, J.; Massie, C.E.; Baxter, E.J.; Nice, F.L.; Gundem, G.; Wedge, D.C.; Avezov, E.; Li, J.; Kollmann, K.; Kent, D.G.; Aziz, A.; Godfrey, A.L.; Hinton, J.; Martincorena, I.; Loo, P. Van; Jones, A.V.; Guglielmelli, P.; Tarpey, P.; Harding, H.P.; Fitzpatrick, J.D.; Goudie, C.T.; Ortmann, C.A.; Loughran, S.J.; Raine, K.; Jones, D.R.; Butler, A.P.; Teague, J.W.; O'Meara, S.; McLaren, S.; Bianchi, M.; Silber, Y.; Dimitropoulou, D.; Bloxham, D.; Mudie, L.; Maddison, M.; Robinson, B.; Keohane, C.; Maclean, C.; Hill, K.; Orchard, K.; Tauro, S.; Du, M.Q.; Greaves, M.; Bowen, D.; Huntly, B.J.; Harrison, C.N.; Cross, N.C.; Ron, D.; Vannucchi, A.M.; Papaemmanuil, E.; Campbell, P.J.; Green, A.R.

    2013-01-01

    BACKGROUND: Somatic mutations in the Janus kinase 2 gene (JAK2) occur in many myeloproliferative neoplasms, but the molecular pathogenesis of myeloproliferative neoplasms with nonmutated JAK2 is obscure, and the diagnosis of these neoplasms remains a challenge. METHODS: We performed exome sequencing

  8. Myeloproliferative neoplasms: JAK2 signaling pathway as a central target for therapy.

    Pasquier, Florence; Cabagnols, Xenia; Secardin, Lise; Plo, Isabelle; Vainchenker, William

    2014-09-01

    The discovery of the JAK2V617F mutation followed by the discovery of other genetic abnormalities allowed important progress in the understanding of the pathogenesis and management of myeloproliferative neoplasms (MPN)s. Classical Breakpoint cluster region-Abelson (BCR-ABL)-negative neoplasms include 3 main disorders: essential thrombocythemia (ET), polycythemia vera (PV), and primary myelofibrosis (PMF). Genomic studies have shown that these disorders are more heterogeneous than previously thought with 3 main entities corresponding to different gene mutations: the JAK2 disorder, essentially due to JAK2V617F mutation, which includes nearly all PVs and a majority of ETs and PMFs with a continuum between these diseases and the myeloproliferative leukemia (MPL) and calreticulin (CALR) disorders, which include a fraction of ET and PMF. All of these mutations lead to a JAK2 constitutive activation. Murine models either with JAK2V617F or MPLW515L, but also with JAK2 or MPL germ line mutations found in hereditary thrombocytosis, have demonstrated that they are drivers of myeloproliferation. However, the myeloproliferative driver mutation is still unknown in approximately 15% of ET and PMF, but appears to also target the JAK/Signal Transducer and Activator of Transcription (STAT) pathway. However, other mutations in genes involved in epigenetics or splicing also can be present and can predate or follow mutations in signaling. They are involved either in clonal dominance or in phenotypic changes, more particularly in PMF. They can be associated with leukemic progression and might have an important prognostic value such as additional sex comb-like 1 mutations. Despite this heterogeneity, it is tempting to target JAK2 and its signaling for therapy. However in PMF, Adenosine Tri-Phosphate (ATP)-competitive JAK2 inhibitors have shown their interest, but also their important limitations. Thus, other approaches are required, which are discussed in this review. Copyright © 2014

  9. WHO-defined 'myelodysplastic syndrome with isolated del(5q)' in 88 consecutive patients: survival data, leukemic transformation rates and prevalence of JAK2, MPL and IDH mutations.

    Patnaik, M M; Lasho, T L; Finke, C M; Gangat, N; Caramazza, D; Holtan, S G; Pardanani, A; Knudson, R A; Ketterling, R P; Chen, D; Hoyer, J D; Hanson, C A; Tefferi, A

    2010-07-01

    The 2008 World Health Organization (WHO) criteria were used to identify 88 consecutive Mayo Clinic patients with 'myelodysplastic syndrome with isolated del(5q)' (median age 74 years; 60 females). In all, 60 (68%) patients were followed up to the time of their death. Overall median survival was 66 months; leukemic transformation was documented in five (5.7%) cases. Multivariable analysis identified age >or=70 years (P=0.01), transfusion need at diagnosis (P=0.04) and dysgranulopoiesis (P=0.02) as independent predictors of shortened survival; the presence of zero (low risk), one (intermediate risk) or >or=2 (high risk) risk factors corresponded to median survivals of 102, 52 and 27 months, respectively. Janus kinase 2 (JAK2), thrombopoietin receptor (MPL), isocitrate dehydrogenase 1 (IDH1) and IDH2 mutational analysis was performed on archived bone marrows in 78 patients; JAK2V617F and MPLW515L mutations were shown in five (6.4%) and three (3.8%) patients, respectively, and did not seem to affect phenotype or prognosis. IDH mutations were not detected. Survival was not affected by serum ferritin and there were no instances of death directly related to iron overload. The current study is unique in its strict adherence to WHO criteria for selecting study patients and providing information on long-term survival, practical prognostic factors, baseline risk of leukemic transformation and the prevalence of JAK2, MPL and IDH mutations.

  10. Is it time to revisit contraindications to organ donation from donors with a JAK-2 mutation? Safe use of a liver allograft from a donor with essential thrombocythaemia.

    Haldar, Debashis; Chen, Frederick; Byron, Jane; Elsharkawy, Ahmed Mohamed; Perera, M Thamara Pr

    2015-07-01

    Transplantation can cure end-stage liver disease and hepatocellular carcinoma. However, the balance of organ demand and provision is heavily tipped to the detriment of patients. Patients awaiting transplantation rely on the greater use of marginal donors that may carry a risk to the recipient. UK authorities have decreed donor haematological malignancy an absolute contraindication. The authors describe the first report of a patient being safely transplanted with a liver from a donor who suffered from JAK2 V617F mutation-driven essential thrombocythaemia to a patient with a critical burden of hepatocellular carcinoma. A year after transplantation, the patient has neither evidence of acquisition of the donor's pathology, nor evidence of carcinoma recurrence. The case highlights the responsibility of the recipient team to maximize the use of organs by expert risk assessment. Dissemination of experience should inform future decisions, benefit patients and bolster utility in an era of growing waiting-list mortality. © 2015 Steunstichting ESOT.

  11. Calreticulin mutation analysis in non-mutated Janus kinase 2 essential thrombocythemia patients in Chiang Mai University: analysis of three methods and clinical correlations.

    Rattarittamrong, Ekarat; Tantiworawit, Adisak; Kumpunya, Noppamas; Wongtagan, Ornkamon; Tongphung, Ratchanoo; Phusua, Arunee; Chai-Adisaksopha, Chatree; Hantrakool, Sasinee; Rattanathammethee, Thanawat; Norasetthada, Lalita; Charoenkwan, Pimlak; Lekawanvijit, Suree

    2018-03-09

    The primary objective was to determine the prevalence of calreticulin (CALR) mutation in patients with non-JAK2V617F mutated essential thrombocythemia (ET). The secondary objectives were to evaluate the accuracy of CALR mutation analysis by high-resolution melting (HRM) analysis and real-time polymerase chain reaction (PCR) compared with DNA sequencing and to compare clinical characteristics of CALR mutated and JAK2V617F mutated ET. This was a prospective cohort study involving ET patients registered at Chiang Mai University in the period September 2015-September 2017 who were aged more than 2 years, and did not harbor JAK2V617F mutation. The presence of CALR mutation was established by DNA sequencing, HRM, and real-time PCR for type 1 and type 2 mutation. Clinical data were compared with that from ET patients with mutated JAK2V617F. Twenty-eight patients were enrolled onto the study. CALR mutations were found in 10 patients (35.7%). Three patients had type 1 mutation, 5 patients had type 2 mutation, 1 patient had type 18 mutation, and 1 patients had novel mutations (c.1093 C-G, c.1098_1131 del, c.1135 G-A). HRM could differentiate between the types of mutation in complete agreement with DNA sequencing. Patients with a CALR mutation showed a significantly greater male predominance and had a higher platelet count when compared with 42 JAK2V617F patients. The prevalence of CALR mutation in JAK2V617F-negative ET in this study is 35.7%. HRM is an effective method of detecting CALR mutation and is a more advantageous method of screening for CALR mutation.

  12. Prevalence of Janus kinase 2 mutations in patients with unusual site venous thrombosis

    Ana Lisa Basquiera

    2011-08-01

    Full Text Available We aimed to study patients with splanchnic vein thrombosis (SVT and cerebral vein thrombosis (CVT searching for JAK2 mutations. We evaluated 14 patients (median age: 41.5 years with portal vein thrombosis (PVT = 7; mesenteric vein thrombosis (MVT = 3; and CVT = 4. JAK2 V617F was assessed by allele specific PCR of peripheral blood DNA. In addition, DNA was sequenced for other JAK2 mutations. Other inherited and acquired thrombophilia risk factors were evaluated. JAK2 V617F was positive in four out of seven patients with PVT and in one CVT patient. These five patients had a diagnosis of myeloproliferative disorder (MPD at the moment of the occurrence of thrombosis (n = 2 or later (n = 2. Patients with MVT and CVT were negative for JAK2 V617F, except one patient with CVT and a diagnosis of essential thrombocythemia. No other JAK2 mutations were found in this cohort. Besides MPD, other thrombophilia risk factors were identified in five patients. One patient had MPD as well as thrombophilia risk factor. In this group, 4 out of 7 of the patients with PVT carried the JAK2 V617F mutation with or without overt MPD. However, the investigation of other JAK2 mutations may not be necessary in patients with thrombosis at unusual sites.

  13. Efficacy of the JAK2 inhibitor INCB16562 in a murine model of MPLW515L-induced thrombocytosis and myelofibrosis.

    Koppikar, Priya; Abdel-Wahab, Omar; Hedvat, Cyrus; Marubayashi, Sachie; Patel, Jay; Goel, Aviva; Kucine, Nicole; Gardner, Jeffrey R; Combs, Andrew P; Vaddi, Kris; Haley, Patrick J; Burn, Timothy C; Rupar, Mark; Bromberg, Jacqueline F; Heaney, Mark L; de Stanchina, Elisa; Fridman, Jordan S; Levine, Ross L

    2010-04-08

    The discovery of JAK2 and MPL mutations in patients with myeloproliferative neoplasms (MPNs) provided important insight into the genetic basis of these disorders and led to the development of JAK2 kinase inhibitors for MPN therapy. Although recent studies have shown that JAK2 kinase inhibitors demonstrate efficacy in a JAK2V617F murine bone marrow transplantation model, the effects of JAK2 inhibitors on MPLW515L-mediated myeloproliferation have not been investigated. In this report, we describe the in vitro and in vivo effects of INCB16562, a small-molecule JAK2 inhibitor. INCB16562 inhibited proliferation and signaling in cell lines transformed by JAK2 and MPL mutations. Compared with vehicle treatment, INCB16562 treatment improved survival, normalized white blood cell counts and platelet counts, and markedly reduced extramedullary hematopoeisis and bone marrow fibrosis. We observed inhibition of STAT3 and STAT5 phosphorylation in vivo consistent with potent inhibition of JAK-STAT signaling. These data suggest JAK2 inhibitor therapy may be of value in the treatment of JAK2V617F-negative MPNs. However, we did not observe a decrease in the size of the malignant clone in the bone marrow of treated mice at the end of therapy, which suggests that JAK2 inhibitor therapy, by itself, was not curative in this MPN model.

  14. MPL W515L/K Mutations in Chronic Myeloproliferative Neoplasms

    Timur Selçuk Akpınar

    2013-03-01

    Full Text Available OBJECTIVE: The MPL gene encodes the thrombopoietin receptor. Recently MPL mutations (MPL W515L or MPL W515K were described in patients with essential thrombocythemia (ET and primary (idiopathic myelofibrosis (PMF. The prevalence and the clinical importance of these mutations are not clear. In the present study, we aimed to investigate the frequency and clinical significance of MPL W515L/K mutations in our patients with ET and PMF. METHODS: A total of 77 patients (66 were diagnosed with ET and 11 with PMF and 42 healthy controls were included in the study. Using peripheral blood samples, the presence of MPL W515L/K mutations and JAK-2 V617F mutation were analyzed by real-time polymerase chain reaction. RESULTS: In our study, MPL W515L/K or JAK-2 V617F mutations were not observed in healthy controls. JAK-2 V617F mutation was present in 35 patients, of whom 29 had ET (43.9%, 29/66 and 6 had PMF (54.5%, 6/11. In the patient group, MPL W515L/K mutations were found in only 2 PMF cases, and these cases were negative for JAK-2 V617F mutation. The prevalence of MPL W515L/K mutations in the patient group was 2.6%, and the prevalence of MPL W515L/K mutations among the cases negative for the JAK-2 V617F mutation was found to be 4.8%. The 2 cases with MPL W515L/K mutations had long follow-up times (124 months and 71 months, respectively, had no thrombotic or hemorrhagic complications, and had no additional cytogenetic anomalies. CONCLUSION: MPL W515L/K mutations may be helpful for identifying clonal disease in MPN patients with no established Ph chromosome or JAK-2 V617F mutation.

  15. MPL W515L/K Mutations in Chronic Myeloproliferative Neoplasms.

    Akpınar, Timur Selçuk; Hançer, Veysel Sabri; Nalçacı, Meliha; Diz-Küçükkaya, Reyhan

    2013-03-01

    The MPL gene encodes the thrombopoietin receptor. Recently MPL mutations (MPL W515L or MPL W515K) were described in patients with essential thrombocythemia (ET) and primary (idiopathic) myelofibrosis (PMF). The prevalence and the clinical importance of these mutations are not clear. In the present study, we aimed to investigate the frequency and clinical significance of MPL W515L/K mutations in our patients with ET and PMF. A total of 77 patients (66 were diagnosed with ET and 11 with PMF) and 42 healthy controls were included in the study. Using peripheral blood samples, the presence of MPL W515L/K mutations and JAK-2 V617F mutation were analyzed by real-time polymerase chain reaction. In our study, MPL W515L/K or JAK-2 V617F mutations were not observed in healthy controls. JAK-2 V617F mutation was present in 35 patients, of whom 29 had ET (43.9%, 29/66) and 6 had PMF (54.5%, 6/11). In the patient group, MPL W515L/K mutations were found in only 2 PMF cases, and these cases were negative for JAK-2 V617F mutation. The prevalence of MPL W515L/K mutations in the patient group was 2.6%, and the prevalence of MPL W515L/K mutations among the cases negative for the JAK-2 V617F mutation was found to be 4.8%. The 2 cases with MPL W515L/K mutations had long follow-up times (124 months and 71 months, respectively), had no thrombotic or hemorrhagic complications, and had no additional cytogenetic anomalies. MPL W515L/K mutations may be helpful for identifying clonal disease in MPN patients with no established Ph chromosome or JAK-2 V617F mutation. None declared.

  16. The pseudokinase domain of JAK2 is a dual-specificity protein kinase that negatively regulates cytokine signaling

    Ungureanu, Daniela; Wu, Jinhua; Pekkala, Tuija

    2011-01-01

    Human JAK2 tyrosine kinase mediates signaling through numerous cytokine receptors. The JAK2 JH2 domain functions as a negative regulator and is presumed to be a catalytically inactive pseudokinase, but the mechanism(s) for its inhibition of JAK2 remains unknown. Mutations in JH2 lead to increased...... JAK2 activity, contributing to myeloproliferative neoplasms (MPNs). Here we show that JH2 is a dual-specificity protein kinase that phosphorylates two negative regulatory sites in JAK2: Ser523 and Tyr570. Inactivation of JH2 catalytic activity increased JAK2 basal activity and downstream signaling....... Notably, different MPN mutations abrogated JH2 activity in cells, and in MPN (V617F) patient cells phosphorylation of Tyr570 was reduced, suggesting that loss of JH2 activity contributes to the pathogenesis of MPNs. These results identify the catalytic activity of JH2 as a previously unrecognized...

  17. Frequencies, Laboratory Features, and Granulocyte Activation in Chinese Patients with CALR-Mutated Myeloproliferative Neoplasms.

    Haixiu Guo

    Full Text Available Somatic mutations in the CALR gene have been recently identified as acquired alterations in myeloproliferative neoplasms (MPNs. In this study, we evaluated mutation frequencies, laboratory features, and granulocyte activation in Chinese patients with MPNs. A combination of qualitative allele-specific polymerase chain reaction and Sanger sequencing was used to detect three driver mutations (i.e., CALR, JAK2V617F, and MPL. CALR mutations were identified in 8.4% of cases with essential thrombocythemia (ET and 5.3% of cases with primary myelofibrosis (PMF. Moreover, 25% of polycythemia vera, 29.5% of ET, and 48.1% of PMF were negative for all three mutations (JAK2V617F, MPL, and CALR. Compared with those patients with JAK2V617F mutation, CALR-mutated ET patients displayed unique hematological phenotypes, including higher platelet counts, and lower leukocyte counts and hemoglobin levels. Significant differences were not found between Chinese PMF patients with mutants CALR and JAK2V617F in terms of laboratory features. Interestingly, patients with CALR mutations showed markedly decreased levels of leukocyte alkaline phosphatase (LAP expression, whereas those with JAK2V617F mutation presented with elevated levels. Overall, a lower mutant rate of CALR gene and a higher triple-negative rate were identified in the cohort of Chinese patients with MPNs. This result indicates that an undiscovered mutant gene may have a significant role in these patients. Moreover, these pathological features further imply that the disease biology varies considerably between mutants CALR and JAK2V617F.

  18. CYT387, a selective JAK1/JAK2 inhibitor: in vitro assessment of kinase selectivity and preclinical studies using cell lines and primary cells from polycythemia vera patients.

    Pardanani, A; Lasho, T; Smith, G; Burns, C J; Fantino, E; Tefferi, A

    2009-08-01

    Somatic mutations in Janus kinase 2 (JAK2), including JAK2V617F, result in dysregulated JAK-signal transducer and activator transcription (STAT) signaling, which is implicated in myeloproliferative neoplasm (MPN) pathogenesis. CYT387 is an ATP-competitive small molecule that potently inhibits JAK1/JAK2 kinases (IC(50)=11 and 18 nM, respectively), with significantly less activity against other kinases, including JAK3 (IC(50)=155 nM). CYT387 inhibits growth of Ba/F3-JAK2V617F and human erythroleukemia (HEL) cells (IC(50) approximately 1500 nM) or Ba/F3-MPLW515L cells (IC(50)=200 nM), but has considerably less activity against BCR-ABL harboring K562 cells (IC=58 000 nM). Cell lines harboring mutated JAK2 alleles (CHRF-288-11 or Ba/F3-TEL-JAK2) were inhibited more potently than the corresponding pair harboring mutated JAK3 alleles (CMK or Ba/F3-TEL-JAK3), and STAT-5 phosphorylation was inhibited in HEL cells with an IC(50)=400 nM. Furthermore, CYT387 selectively suppressed the in vitro growth of erythroid colonies harboring JAK2V617F from polycythemia vera (PV) patients, an effect that was attenuated by exogenous erythropoietin. Overall, our data indicate that the JAK1/JAK2 selective inhibitor CYT387 has potential for efficacious treatment of MPN harboring mutated JAK2 and MPL alleles.

  19. JAK2 mutation in a patient with CLL with coexistent myeloproliferative neoplasm (MPN).

    Kodali, Srinivas; Chen, Chi; Rathnasabapathy, Chenthilmurugan; Wang, Jen Chin

    2009-12-01

    JAK2 mutation has not been described in patients with chronic lymphocytic leukemia (CLL). We found JAK2 mutation in a patient with CLL and coexisting myeloproliferative neoplasm (MPN). In this patient, we demonstrated the presence of the JAK2 mutation in CD34(+) progenitor cells, myeloid lineage cells, megakaryocytes, B lymphocytes but not in T lymphocytes. This case represents the first case report of JAK2 mutation in CLL and may also suggest that, JAK2 mutation most likely represents a secondary event from primary gene mutations involving the primitive stem cells which give rise to MPN and CLL. Furthermore, in this case, we believe that we are the first to demonstrate that JAK2 mutation in myeloid and B lymphoid cells but not T lymphocytes in a case of coexisting CLL and MPN.

  20. RECQL5 Suppresses Oncogenic JAK2-Induced Replication Stress and Genomic Instability

    Edwin Chen

    2015-12-01

    Full Text Available JAK2V617F is the most common oncogenic lesion in patients with myeloproliferative neoplasms (MPNs. Despite the ability of JAK2V617F to instigate DNA damage in vitro, MPNs are nevertheless characterized by genomic stability. In this study, we address this paradox by identifying the DNA helicase RECQL5 as a suppressor of genomic instability in MPNs. We report increased RECQL5 expression in JAK2V617F-expressing cells and demonstrate that RECQL5 is required to counteract JAK2V617F-induced replication stress. Moreover, RECQL5 depletion sensitizes JAK2V617F mutant cells to hydroxyurea (HU, a pharmacological inducer of replication stress and the most common treatment for MPNs. Using single-fiber chromosome combing, we show that RECQL5 depletion in JAK2V617F mutant cells impairs replication dynamics following HU treatment, resulting in increased double-stranded breaks and apoptosis. Cumulatively, these findings identify RECQL5 as a critical regulator of genome stability in MPNs and demonstrate that replication stress-associated cytotoxicity can be amplified specifically in JAK2V617F mutant cells through RECQL5-targeted synthetic lethality.

  1. WHO-defined ‘myelodysplastic syndrome with isolated del(5q)' in 88 consecutive patients: survival data, leukemic transformation rates and prevalence of JAK2, MPL and IDH mutations

    Patnaik, M M; Lasho, T L; Finke, C M; Gangat, N; Caramazza, D; Holtan, S G; Pardanani, A; Knudson, R A; Ketterling, R P; Chen, D; Hoyer, J D; Hanson, C A; Tefferi, A

    2010-01-01

    The 2008 World Health Organization (WHO) criteria were used to identify 88 consecutive Mayo Clinic patients with ‘myelodysplastic syndrome with isolated del(5q)' (median age 74 years; 60 females). In all, 60 (68%) patients were followed up to the time of their death. Overall median survival was 66 months; leukemic transformation was documented in five (5.7%) cases. Multivariable analysis identified age ⩾70 years (P=0.01), transfusion need at diagnosis (P=0.04) and dysgranulopoiesis (P=0.02) as independent predictors of shortened survival; the presence of zero (low risk), one (intermediate risk) or ⩾2 (high risk) risk factors corresponded to median survivals of 102, 52 and 27 months, respectively. Janus kinase 2 (JAK2), thrombopoietin receptor (MPL), isocitrate dehydrogenase 1 (IDH1) and IDH2 mutational analysis was performed on archived bone marrows in 78 patients; JAK2V617F and MPLW515L mutations were shown in five (6.4%) and three (3.8%) patients, respectively, and did not seem to affect phenotype or prognosis. IDH mutations were not detected. Survival was not affected by serum ferritin and there were no instances of death directly related to iron overload. The current study is unique in its strict adherence to WHO criteria for selecting study patients and providing information on long-term survival, practical prognostic factors, baseline risk of leukemic transformation and the prevalence of JAK2, MPL and IDH mutations. PMID:20485371

  2. Immune Thrombocytopenia and JAK2V617F Positive Essential Thrombocythemia: Literature Review and Case Report

    M. A. Sobas

    2017-01-01

    Full Text Available We present the case where immune thrombocytopenia (ITP and essential thrombocythemia (ET sequentially appeared in the space of twenty-one years of follow-up. Impaired platelet production is present in both diseases, but clinical presentation and treatment are different. On the basis of this case history a possible role of autoimmunity as a predisposing factor to myeloproliferation has been discussed.

  3. Immune Thrombocytopenia and JAK2V617F Positive Essential Thrombocythemia: Literature Review and Case Report.

    Sobas, M A; Wróbel, T; Zduniak, K; Podolak-Dawidziak, M; Rybka, J; Biedroń, M; Sawicki, M; Dybko, J; Kuliczkowski, K

    2017-01-01

    We present the case where immune thrombocytopenia (ITP) and essential thrombocythemia (ET) sequentially appeared in the space of twenty-one years of follow-up. Impaired platelet production is present in both diseases, but clinical presentation and treatment are different. On the basis of this case history a possible role of autoimmunity as a predisposing factor to myeloproliferation has been discussed.

  4. [MPLW515L point mutation in patients with myeloproliferative disease].

    Xia, Jun; Xu, Wei; Zhang, Su-Jiang; Fan, Lei; Qiao, Chun; Li, Jian-Yong

    2008-12-01

    In order to investigate the frequency of MPLW515L and JAK2V617F point mutations of the patients with myeloproliferative disease (MPD) in Nanjing area, MPLW515L and JAK2V617F point mutations were simultaneously detected by alleles specific polymerase chain reaction (AS-PCR) and sequencing in 190 MPD patients. The results showed that MPLW515L point mutation was detected in 1 out of 102 essential thrombocythemia (ET) patients (1.0%) and was not detected in 32 polycythemia vera (PV) patients, 13 idiopathic myelofibrosis (IMF) patients, 43 chronic myelogenous leukemia (CML) patients. JAK2V617F point mutation was detected in 20 out of 32 PV patients (62.5%), 43 out of 102 ET patients (42.2%), 5 out of 13 IMF patients (38.5%), and was not detected in 43 CML patients. It is concluded that MPLW515L point mutation exists in ET patient, but is not found in PV, IMF and CML. JAK2V617F point mutation exists in PV, ET and IMF, but not in CML.

  5. MPL mutations in myeloproliferative disorders

    Beer, Philip A.; Campbell, Peter J.; Scott, Linda M.

    2008-01-01

    Activating mutations of MPL exon 10 have been described in a minority of patients with idiopathic myelofibrosis (IMF) or essential thrombocythemia (ET), but their prevalence and clinical significance are unclear. Here we demonstrate that MPL mutations outside exon 10 are uncommon in platelet c......DNA and identify 4 different exon 10 mutations in granulocyte DNA from a retrospective cohort of 200 patients with ET or IMF. Allele-specific polymerase chain reaction was then used to genotype 776 samples from patients with ET entered into the PT-1 studies. MPL mutations were identified in 8.5% of JAK2 V617F......(-) patients and a single V617F(+) patient. Patients carrying the W515K allele had a significantly higher allele burden than did those with the W515L allele, suggesting a functional difference between the 2 variants. Compared with V617F(+) ET patients, those with MPL mutations displayed lower hemoglobin...

  6. MPL515 mutations in myeloproliferative and other myeloid disorders: a study of 1182 patients.

    Pardanani, Animesh D; Levine, Ross L; Lasho, Terra; Pikman, Yana; Mesa, Ruben A; Wadleigh, Martha; Steensma, David P; Elliott, Michelle A; Wolanskyj, Alexandra P; Hogan, William J; McClure, Rebecca F; Litzow, Mark R; Gilliland, D Gary; Tefferi, Ayalew

    2006-11-15

    Recently, a gain-of-function MPL mutation, MPLW515L, was described in patients with JAK2V617F-negative myelofibrosis with myeloid metaplasia (MMM). To gain more information on mutational frequency, disease specificity, and clinical correlates, genomic DNA from 1182 patients with myeloproliferative and other myeloid disorders and 64 healthy controls was screened for MPL515 mutations, regardless of JAK2V617F mutational status: 290 with MMM, 242 with polycythemia vera, 318 with essential thrombocythemia (ET), 88 with myelodysplastic syndrome, 118 with chronic myelomonocytic leukemia, and 126 with acute myeloid leukemia (AML). MPL515 mutations, either MPLW515L (n = 17) or a previously undescribed MPLW515K (n = 5), were detected in 20 patients. The diagnosis of patients with mutant MPL alleles at the time of molecular testing was de novo MMM in 12 patients, ET in 4, post-ET MMM in 1, and MMM in blast crisis in 3. Six patients carried the MPLW515L and JAK2V617F alleles concurrently. We conclude that MPLW515L or MPLW515K mutations are present in patients with MMM or ET at a frequency of approximately 5% and 1%, respectively, but are not observed in patients with polycythemia vera (PV) or other myeloid disorders. Furthermore, MPL mutations may occur concurrently with the JAK2V617F mutation, suggesting that these alleles may have functional complementation in myeloproliferative disease.

  7. Spectrum of mutations in RARS-T patients includes TET2 and ASXL1 mutations.

    Szpurka, Hadrian; Jankowska, Anna M; Makishima, Hideki; Bodo, Juraj; Bejanyan, Nelli; Hsi, Eric D; Sekeres, Mikkael A; Maciejewski, Jaroslaw P

    2010-08-01

    While a majority of patients with refractory anemia with ring sideroblasts and thrombocytosis harbor JAK2V617F and rarely MPLW515L, JAK2/MPL-negative cases constitute a diagnostic problem. 23 RARS-T cases were investigated applying immunohistochemical phospho-STAT5, sequencing and SNP-A-based karyotyping. Based on the association of TET2/ASXL1 mutations with MDS/MPN we studied molecular pattern of these genes. Two patients harbored ASXL1 and another 2 TET2 mutations. Phospho-STAT5 activation was present in one mutated TET2 and ASXL1 case. JAK2V617F/MPLW515L mutations were absent in TET2/ASXL1 mutants, indicating that similar clinical phenotype can be produced by various MPN-associated mutations and that additional unifying lesions may be present in RARS-T. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  8. Zap-70 positive chronic lymphocytic leukemia co-existing with Jak 2 V671F positive essential thrombocythemia: A common defective stem cell?

    Tabaczewski, Piotr; Nadesan, Sushani; Lim, Seah H

    2008-01-01

    Essential thrombocythemia (ET) co-existing with chronic lymphocytic leukemia (CLL) is extremely rare. We report two cases of ET with Jak 2 V617F in Zap-70+ CLL. ET is a myeloproliferative stem cell disease. Zap-70 expression in CLL correlates with non-mutated immunoglobulin genes. The occurrence of a less mature CLL in patients with a pluripotential stem cell disease raises the possibility that an initial “trigger hit” occurred in a pre-Jak 2 common early progenitor in these patients. Subsequ...

  9. mTOR inhibitors alone and in combination with JAK2 inhibitors effectively inhibit cells of myeloproliferative neoplasms.

    Costanza Bogani

    Full Text Available BACKGROUND: Dysregulated signaling of the JAK/STAT pathway is a common feature of chronic myeloproliferative neoplasms (MPN, usually associated with JAK2V617F mutation. Recent clinical trials with JAK2 inhibitors showed significant improvements in splenomegaly and constitutional symptoms in patients with myelofibrosis but meaningful molecular responses were not documented. Accordingly, there remains a need for exploring new treatment strategies of MPN. A potential additional target for treatment is represented by the PI3K/AKT/mammalian target of rapamycin (mTOR pathway that has been found constitutively activated in MPN cells; proof-of-evidence of efficacy of the mTOR inhibitor RAD001 has been obtained recently in a Phase I/II trial in patients with myelofibrosis. The aim of the study was to characterize the effects in vitro of mTOR inhibitors, used alone and in combination with JAK2 inhibitors, against MPN cells. FINDINGS: Mouse and human JAK2V617F mutated cell lines and primary hematopoietic progenitors from MPN patients were challenged with an allosteric (RAD001 and an ATP-competitive (PP242 mTOR inhibitor and two JAK2 inhibitors (AZD1480 and ruxolitinib. mTOR inhibitors effectively reduced proliferation and colony formation of cell lines through a slowed cell division mediated by changes in cell cycle transition to the S-phase. mTOR inhibitors also impaired the proliferation and prevented colony formation from MPN hematopoietic progenitors at doses significantly lower than healthy controls. JAK2 inhibitors produced similar antiproliferative effects in MPN cell lines and primary cells but were more potent inducers of apoptosis, as also supported by differential effects on cyclinD1, PIM1 and BcLxL expression levels. Co-treatment of mTOR inhibitor with JAK2 inhibitor resulted in synergistic activity against the proliferation of JAK2V617F mutated cell lines and significantly reduced erythropoietin-independent colony growth in patients with

  10. JAK and MPL mutations in myeloid malignancies.

    Tefferi, Ayalew

    2008-03-01

    The Janus family of non-receptor tyrosine kinases (JAK1, JAK2, JAK3 and tyrosine kinase 2) transduces signals downstream of type I and II cytokine receptors via signal transducers and activators of transcription (STATs). JAK3 is important in lymphoid and JAK2 in myeloid cell proliferation and differentiation. The thrombopoietin receptor MPL is one of several JAK2 cognate receptors and is essential for myelopoiesis in general and megakaryopoiesis in particular. Germline loss-of-function (LOF) JAK3 and MPL mutations cause severe combined immunodeficiency and congenital amegakaryocytic thrombocytopenia, respectively. Germline gain-of-function (GOF) MPL mutation (MPLS505N) causes familial thrombocytosis. Somatic JAK3 (e.g. JAK3A572V, JAK3V722I, JAK3P132T) and fusion JAK2 (e.g. ETV6-JAK2, PCM1-JAK2, BCR-JAK2) mutations have respectively been described in acute megakaryocytic leukemia and acute leukemia/chronic myeloid malignancies. However, current attention is focused on JAK2 (e.g. JAK2V617F, JAK2 exon 12 mutations) and MPL (e.g. MPLW515L/K/S, MPLS505N) mutations associated with myeloproliferative neoplasms (MPNs). A JAK2 mutation, primarily JAK2V617F, is invariably associated with polycythemia vera (PV). The latter mutation also occurs in the majority of patients with essential thrombocythemia (ET) or primary myelofibrosis (PMF). MPL mutational frequency in MPNs is substantially less (<10%). In general, despite a certain degree of genotype - phenotype correlations, the prognostic relevance of harbouring one of these mutations, or their allele burden when present, remains dubious. Regardless, based on the logical assumption that amplified JAK-STAT signalling is central to the pathogenesis of PV, ET and PMF, several anti-JAK2 tyrosine kinase inhibitors have been developed and are currently being tested in humans with these disorders.

  11. Prevalence and clinical correlates of JAK2 mutations in Down syndrome acute lymphoblastic leukemia

    Gaikwad, Amos; Rye, Cassia L.; Devidas, Meenakshi; Heerema, Nyla A.; Carroll, Andrew J.; Izraeli, Shai; Plon, Sharon E.; Basso, Giuseppe; Pession, Andrea; Rabin, Karen R.

    2009-01-01

    Summary Recurrent, prognostically significant chromosomal abnormalities occur in approximately 75% of pediatric acute lymphoblastic leukemia (ALL), but only infrequently in children with Down syndrome (DS) and ALL. Recently, novel somatic activating mutations in Janus kinase 2 (JAK2) were reported in 18% of DS ALL. Here we report identification and clinical correlates of JAK2 mutations in an independent cohort. JAK2 activating mutations occurred in 10 of 53 DS ALL cases (18.9%). Mutations were overrepresented in males (p<0.03), occurred once in association with high hyperdiploidy, and were not significantly correlated with age, initial white blood count, or event-free survival. Our results confirm significance of JAK-STAT pathway activation in DS ALL. PMID:19120350

  12. Mechanisms of mutations in myeloproliferative neoplasms.

    Levine, Ross L

    2009-12-01

    In recent years, a series of studies have provided genetic insight into the pathogenesis of myeloproliferative neoplasms (MPNs). It is now known that JAK2V617F mutations are present in 90% of patients with polycythaemia vera (PV), 60% of patients with essential thrombocytosis (ET) and 50% of patients with myelofibrosis (MF). Despite the high prevalence of JAK2V617F mutations in these three myeloid malignancies, several questions remain. For example, how does one mutation contribute to the pathogenesis of three clinically distinct diseases, and how do some patients develop these diseases in the absence of a JAK2V617F mutation? Single nucleotide polymorphisms at various loci and somatic mutations, such as those in MPLW515L/K, TET2 and in exon 12 of JAK2, may also contribute to the pathogenesis of these MPNs. There are likely additional germline and somatic genetic factors important to the MPN phenotype. Additional studies of large MPN and control cohorts with new techniques will help identify these factors.

  13. Emergence of MPLW515 mutation in a patient with CALR deletion: Evidence of secondary acquisition of MPL mutation in the CALR clone.

    Partouche, Nicolas; Conejero, Carole; Barathon, Quentin; Moroch, Julien; Tulliez, Michel; Cordonnier, Catherine; Giraudier, Stephane

    2018-02-01

    Myeloproliferative neoplasms are characterized by transduction pathway recognized as mutually exclusive molecular abnormalities such as BCR-ABL translocation, JAK2V617F or JAK2 exon 12 mutations, MPL w515, and CALR mutations. However, in some rare cases, associations of such mutations are found in 1 patient. This can be related to 2 pathologies (at least 2 different clones harboring 2 mutations) or associated mutations in 1 clone. We describe here such an association of CALR and MPL mutations in a patient harboring the second mutation in a subclone during the phenotypic evolution of the myeloproliferative neoplasms. Copyright © 2017 John Wiley & Sons, Ltd.

  14. Deep sequencing reveals double mutations in cis of MPL exon 10 in myeloproliferative neoplasms.

    Pietra, Daniela; Brisci, Angela; Rumi, Elisa; Boggi, Sabrina; Elena, Chiara; Pietrelli, Alessandro; Bordoni, Roberta; Ferrari, Maurizio; Passamonti, Francesco; De Bellis, Gianluca; Cremonesi, Laura; Cazzola, Mario

    2011-04-01

    Somatic mutations of MPL exon 10, mainly involving a W515 substitution, have been described in JAK2 (V617F)-negative patients with essential thrombocythemia and primary myelofibrosis. We used direct sequencing and high-resolution melt analysis to identify mutations of MPL exon 10 in 570 patients with myeloproliferative neoplasms, and allele specific PCR and deep sequencing to further characterize a subset of mutated patients. Somatic mutations were detected in 33 of 221 patients (15%) with JAK2 (V617F)-negative essential thrombocythemia or primary myelofibrosis. Only one patient with essential thrombocythemia carried both JAK2 (V617F) and MPL (W515L). High-resolution melt analysis identified abnormal patterns in all the MPL mutated cases, while direct sequencing did not detect the mutant MPL in one fifth of them. In 3 cases carrying double MPL mutations, deep sequencing analysis showed identical load and location in cis of the paired lesions, indicating their simultaneous occurrence on the same chromosome.

  15. Spectrum of mutations in RARS-T patients includes TET2 and ASXL1 mutations

    Szpurka, Hadrian; Jankowska, Anna M.; Makishima, Hideki; Bodo, Juraj; Bejanyan, Nelli; Hsi, Eric D.; Sekeres, Mikkael A.; Maciejewski, Jaroslaw P.

    2010-01-01

    While a majority of patients with refractory anemia with ring sideroblasts and thrombocytosis harbor JAK2V617F and rarely MPLW515L, JAK2/MPL-negative cases constitute a diagnostic problem. 23 RARS-T cases were investigated applying immunohistochemical phospho-STAT5, sequencing and SNP-A-based karyotyping. Based on the association of TET2/ASXL1 mutations with MDS/MPN we studied molecular pattern of these genes. Two patients harbored ASXL1 and another 2 TET2 mutations. Phospho-STAT5 activation ...

  16. An MPL W515L mutation in refractory anemia with ringed sideroblasts associated with marked thrombocytosis: A case report.

    Hao, Lin; Sen, Sandeep; Sugumar, Dhivya

    2015-02-01

    The current study presents the case of a 63-year-old patient exhibiting refractory anemia with ringed sideroblasts associated with marked thrombocytosis (RARS-T), who was positive for the MPL W515L mutation, but negative for the JAK2 V617F mutation. Following diagnosis, the patient remained asymptomatic for over three years, however, in August 2012, the patient relapsed and was administered with supportive treatment in the form of subcutaneous darbepoetin α at a dose of 300 μg/week, which resulted in an increased hemoglobin concentration, allowing the patient to remain transfusion-independent. The MPL W515L mutation has been reported in two previous cases of myelodysplastic/myeloproliferative neoplasms (MDS/MPN) with ringed sideroblasts, however, to the best of our knowledge, the current report is the first to present a case of RARS-T with an MPL W515L mutation. A clinical trial designed to evaluate the efficacy of a targeted agent against the JAK2 V617F mutation is currently ongoing, with the aim of providing a novel therapeutic strategy for treating MDS/MPN patients. As MPL is located upstream of the JAK-STAT signaling pathway, it is a possible therapeutic target in MDS/MPN patients positive for an MPL W515L mutation, but negative for a JAK2 V617F mutation.

  17. Presence of atypical thrombopoietin receptor (MPL) mutations in triple-negative essential thrombocythemia patients.

    Cabagnols, Xénia; Favale, Fabrizia; Pasquier, Florence; Messaoudi, Kahia; Defour, Jean Philippe; Ianotto, Jean Christophe; Marzac, Christophe; Le Couédic, Jean Pierre; Droin, Nathalie; Chachoua, Ilyas; Favier, Remi; Diop, M'boyba Khadija; Ugo, Valérie; Casadevall, Nicole; Debili, Najet; Raslova, Hana; Bellanné-Chantelot, Christine; Constantinescu, Stefan N; Bluteau, Olivier; Plo, Isabelle; Vainchenker, William

    2016-01-21

    Mutations in signaling molecules of the cytokine receptor axis play a central role in myeloproliferative neoplasm (MPN) pathogenesis. Polycythemia vera is mainly related to JAK2 mutations, whereas a wider mutational spectrum is detected in essential thrombocythemia (ET) with mutations in JAK2, the thrombopoietin (TPO) receptor (MPL), and the calreticulin (CALR) genes. Here, we studied the mutational profile of 17 ET patients negative for JAK2V617F, MPLW515K/L, and CALR mutations, using whole-exome sequencing and next-generation sequencing (NGS) targeted on JAK2 and MPL. We found several signaling mutations including JAK2V617F at very low allele frequency, 1 homozygous SH2B3 mutation, 1 MPLS505N, 1 MPLW515R, and 2 MPLS204P mutations. In the remaining patients, 4 presented a clonal and 7 a polyclonal hematopoiesis, suggesting that certain triple-negative ETs are not MPNs. NGS on 26 additional triple-negative ETs detected only 1 MPLY591N mutation. Functional studies on MPLS204P and MPLY591N revealed that they are weak gain-of-function mutants increasing MPL signaling and conferring either TPO hypersensitivity or independence to expressing cells, but with a low efficiency. Further studies should be performed to precisely determine the frequency of MPLS204 and MPLY591 mutants in a bigger cohort of MPN. © 2016 by The American Society of Hematology.

  18. Screening and monitoring of MPL W515L mutation with real-time PCR in patients with myelofibrosis undergoing allogeneic-SCT.

    Alchalby, H; Badbaran, A; Bock, O; Fehse, B; Bacher, U; Zander, A R; Kröger, N

    2010-09-01

    Monitoring of minimal residual disease (MRD) after allogeneic (allo)-SCT for myelofibrosis (MF) allows recognizing the depth of remission and thus guides application of appropriate therapeutic interventions. MPL W515L/K mutations, which are detected in 5-10% of JAK2V617F-negative patients, may be useful for this purpose. Using a highly sensitive quantitative PCR method, we tested 90 patients with MF who underwent allo-SCT for the presence of MPL W515L/K mutations. Two patients with primary MF were found to harbor MPLW515L while no patient was positive for MPLW515K mutation. Both patients were JAK2V617F negative and cleared the mutation rapidly after allo-SCT and remained negative for a median follow-up of 19 months. The results of molecular monitoring correlated well with other remission parameters such as normalization of peripheral blood counts and morphology and complete donor chimerism. We conclude that MPLW515L can be cleared after allo-SCT and hence may be used as an MRD marker in a proportion of JAK2V617F-negative MF patients.

  19. MPLW515L is a novel somatic activating mutation in myelofibrosis with myeloid metaplasia.

    Pikman, Yana; Lee, Benjamin H; Mercher, Thomas; McDowell, Elizabeth; Ebert, Benjamin L; Gozo, Maricel; Cuker, Adam; Wernig, Gerlinde; Moore, Sandra; Galinsky, Ilene; DeAngelo, Daniel J; Clark, Jennifer J; Lee, Stephanie J; Golub, Todd R; Wadleigh, Martha; Gilliland, D Gary; Levine, Ross L

    2006-07-01

    The JAK2V617F allele has recently been identified in patients with polycythemia vera (PV), essential thrombocytosis (ET), and myelofibrosis with myeloid metaplasia (MF). Subsequent analysis has shown that constitutive activation of the JAK-STAT signal transduction pathway is an important pathogenetic event in these patients, and that enzymatic inhibition of JAK2V617F may be of therapeutic benefit in this context. However, a significant proportion of patients with ET or MF are JAK2V617F-negative. We hypothesized that activation of the JAK-STAT pathway might also occur as a consequence of activating mutations in certain hematopoietic-specific cytokine receptors, including the erythropoietin receptor (EPOR), the thrombopoietin receptor (MPL), or the granulocyte-colony stimulating factor receptor (GCSFR). DNA sequence analysis of the exons encoding the transmembrane and juxtamembrane domains of EPOR, MPL, and GCSFR, and comparison with germline DNA derived from buccal swabs, identified a somatic activating mutation in the transmembrane domain of MPL (W515L) in 9% (4/45) of JAKV617F-negative MF. Expression of MPLW515L in 32D, UT7, or Ba/F3 cells conferred cytokine-independent growth and thrombopoietin hypersensitivity, and resulted in constitutive phosphorylation of JAK2, STAT3, STAT5, AKT, and ERK. Furthermore, a small molecule JAK kinase inhibitor inhibited MPLW515L-mediated proliferation and JAK-STAT signaling in vitro. In a murine bone marrow transplant assay, expression of MPLW515L, but not wild-type MPL, resulted in a fully penetrant myeloproliferative disorder characterized by marked thrombocytosis (Plt count 1.9-4.0 x 10(12)/L), marked splenomegaly due to extramedullary hematopoiesis, and increased reticulin fibrosis. Activation of JAK-STAT signaling via MPLW515L is an important pathogenetic event in patients with JAK2V617F-negative MF. The bone marrow transplant model of MPLW515L-mediated myeloproliferative disorders (MPD) exhibits certain features of human MF

  20. MPLW515L is a novel somatic activating mutation in myelofibrosis with myeloid metaplasia.

    Yana Pikman

    2006-07-01

    Full Text Available The JAK2V617F allele has recently been identified in patients with polycythemia vera (PV, essential thrombocytosis (ET, and myelofibrosis with myeloid metaplasia (MF. Subsequent analysis has shown that constitutive activation of the JAK-STAT signal transduction pathway is an important pathogenetic event in these patients, and that enzymatic inhibition of JAK2V617F may be of therapeutic benefit in this context. However, a significant proportion of patients with ET or MF are JAK2V617F-negative. We hypothesized that activation of the JAK-STAT pathway might also occur as a consequence of activating mutations in certain hematopoietic-specific cytokine receptors, including the erythropoietin receptor (EPOR, the thrombopoietin receptor (MPL, or the granulocyte-colony stimulating factor receptor (GCSFR.DNA sequence analysis of the exons encoding the transmembrane and juxtamembrane domains of EPOR, MPL, and GCSFR, and comparison with germline DNA derived from buccal swabs, identified a somatic activating mutation in the transmembrane domain of MPL (W515L in 9% (4/45 of JAKV617F-negative MF. Expression of MPLW515L in 32D, UT7, or Ba/F3 cells conferred cytokine-independent growth and thrombopoietin hypersensitivity, and resulted in constitutive phosphorylation of JAK2, STAT3, STAT5, AKT, and ERK. Furthermore, a small molecule JAK kinase inhibitor inhibited MPLW515L-mediated proliferation and JAK-STAT signaling in vitro. In a murine bone marrow transplant assay, expression of MPLW515L, but not wild-type MPL, resulted in a fully penetrant myeloproliferative disorder characterized by marked thrombocytosis (Plt count 1.9-4.0 x 10(12/L, marked splenomegaly due to extramedullary hematopoiesis, and increased reticulin fibrosis.Activation of JAK-STAT signaling via MPLW515L is an important pathogenetic event in patients with JAK2V617F-negative MF. The bone marrow transplant model of MPLW515L-mediated myeloproliferative disorders (MPD exhibits certain features of

  1. Characteristics and clinical correlates of MPL 515W>L/K mutation in essential thrombocythemia.

    Vannucchi, Alessandro M; Antonioli, Elisabetta; Guglielmelli, Paola; Pancrazzi, Alessandro; Guerini, Vittoria; Barosi, Giovanni; Ruggeri, Marco; Specchia, Giorgina; Lo-Coco, Francesco; Delaini, Federica; Villani, Laura; Finotto, Silvia; Ammatuna, Emanuele; Alterini, Renato; Carrai, Valentina; Capaccioli, Gloria; Di Lollo, Simonetta; Liso, Vincenzo; Rambaldi, Alessandro; Bosi, Alberto; Barbui, Tiziano

    2008-08-01

    Among 994 patients with essential thrombocythemia (ET) who were genotyped for the MPLW515L/K mutation, 30 patients carrying the mutation were identified (3.0%), 8 of whom also displayed the JAK2V671F mutation. MPLW515L/K patients presented lower hemoglobin levels and higher platelet counts than did wild type (wt) MPL; these differences were highly significant compared with MPLwt/JAK2V617F-positive patients. Reduced hemoglobin and increased platelet levels were preferentially associated with the W515L and W515K alleles, respectively. MPL mutation was a significant risk factor for microvessel disturbances, suggesting platelet hyperreactivity associated with constitutively active MPL; arterial thromboses were increased only in comparison to MPLwt/JAK2wt patients. MPLW515L/K patients presented reduced total and erythroid bone marrow cellularity, whereas the numbers of megakaryocytes, megakaryocytic clusters, and small-sized megakaryocytes were all significantly increased. These data indicate that MPLW515L/K mutations do not define a distinct phenotype in ET, although some differences depended on the JAK2V617F mutational status of the counterpart.

  2. Laboratory practice guidelines for detecting and reporting JAK2 and MPL mutations in myeloproliferative neoplasms: a report of the Association for Molecular Pathology.

    Gong, Jerald Z; Cook, James R; Greiner, Timothy C; Hedvat, Cyrus; Hill, Charles E; Lim, Megan S; Longtine, Janina A; Sabath, Daniel; Wang, Y Lynn

    2013-11-01

    Recurrent mutations in JAK2 and MPL genes are genetic hallmarks of BCR-ABL1-negative myeloproliferative neoplasms. Detection of JAK2 and MPL mutations has been incorporated into routine diagnostic algorithms for these diseases. This Special Article summarizes results from a nationwide laboratory survey of JAK2 and MPL mutation analysis. Based on the current practice pattern and the literature, this Special Article provides recommendations and guidelines for laboratory practice for detection of mutations in the JAK2 and MPL genes, including clinical manifestations for prompting the mutation analysis, current and recommended methodologies for testing the mutations, and standardization for reporting the test results. This Special Article also points to future directions for genomic testing in BCR-ABL1-negative myeloproliferative neoplasms. Copyright © 2013 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

  3. Calreticulin Mutations in Myeloproliferative Neoplasms

    Noa Lavi

    2014-10-01

    Full Text Available With the discovery of the JAK2V617F mutation in patients with Philadelphia chromosome-negative (Ph− myeloproliferative neoplasms (MPNs in 2005, major advances have been made in the diagnosis of MPNs, in understanding of their pathogenesis involving the JAK/STAT pathway, and finally in the development of novel therapies targeting this pathway. Nevertheless, it remains unknown which mutations exist in approximately one-third of patients with non-mutated JAK2 or MPL essential thrombocythemia (ET and primary myelofibrosis (PMF. At the end of 2013, two studies identified recurrent mutations in the gene encoding calreticulin (CALR using whole-exome sequencing. These mutations were revealed in the majority of ET and PMF patients with non-mutated JAK2 or MPL but not in polycythemia vera patients. Somatic 52-bp deletions (type 1 mutations and recurrent 5-bp insertions (type 2 mutations in exon 9 of the CALR gene (the last exon encoding the C-terminal amino acids of the protein calreticulin were detected and found always to generate frameshift mutations. All detected mutant calreticulin proteins shared a novel amino acid sequence at the C-terminal. Mutations in CALR are acquired early in the clonal history of the disease, and they cause activation of JAK/STAT signaling. The CALR mutations are the second most frequent mutations in Ph− MPN patients after the JAK2V617F mutation, and their detection has significantly improved the diagnostic approach for ET and PMF. The characteristics of the CALR mutations as well as their diagnostic, clinical, and pathogenesis implications are discussed in this review.

  4. Determining the role of inflammation in the selection of JAK2 mutant cells in myeloproliferative neoplasms.

    Zhang, Jie; Fleischman, Angela G; Wodarz, Dominik; Komarova, Natalia L

    2017-07-21

    Myeloproliferative neoplasm (MPN) is a hematologic malignancy characterized by the clonal outgrowth of hematopoietic cells with a somatically acquired mutation most commonly in JAK2 (JAK2 V617F ). This mutation endows upon myeloid progenitors cytokine independent growth and consequently leads to excessive production of myeloid lineage cells. It has been previously suggested that inflammation may play a role in the clonal evolution of JAK2 V617F mutants. In particular, it is possible that one or more cellular kinetic parameters of hematopoietic stem cells (HSCs) are affected by inflammation, such as division or death rates of cells, and the probability of HSC differentiation. This suggests a mechanism that can steer the outcome of the cellular competition in favor of the mutants, initiating the disease. In this paper we create a number of mathematical evolutionary models, from very abstract to more concrete, that describe cellular competition in the context of inflammation. It is possible to build a model axiomatically, where only very general assumptions are imposed on the modeling components and no arbitrary (and generally unknown) functional forms are used, and still generate a set of testable predictions. In particular, we show that, if HSC death is negligible, the evolutionary advantage of mutant cells can only be conferred by an increase in differentiation probability of HSCs in the presence of inflammation, and if death plays a significant role in the dynamics, an additional mechanism may be an increase of HSC's division-to-death ratio in the presence of inflammation. Further, we show that in the presence of inflammation, the wild type cell population is predicted to shrink under inflammation (even in the absence of mutants). Finally, it turns out that if only the differentiation probability is affected by the inflammation, then the resulting steady state population of wild type cells will contain a relatively smaller percentage of HSCs under inflammation. If

  5. EXEL-8232, a small-molecule JAK2 inhibitor, effectively treats thrombocytosis and extramedullary hematopoiesis in a murine model of myeloproliferative neoplasm induced by MPLW515L.

    Wernig, G; Kharas, M G; Mullally, A; Leeman, D S; Okabe, R; George, T; Clary, D O; Gilliland, D G

    2012-04-01

    About 10% of patients with essential thrombocythemia (ET) or myelofibrosis (MF) that lack mutations in JAK2 harbor an activating mutation in the thrombopoietin receptor, MPLW515L. Distinct from the JAK2V617F retroviral transplant model, the MPLW515L model recapitulates many features of ET and MF, including severe fibrosis and thrombocytosis. We have tested EXEL-8232, an experimental potent JAK2 inhibitor, for efficacy in suppression of thrombocytosis in vivo and for its ability to attenuate MPLW515L myeloproliferative disease. EXEL-8232 was administered for 28 days q12 h by oral gavage at doses of 30 or 100 mg/kg, prospectively. Animals treated with EXEL-8232 at 100 mg/kg had normalized high platelet counts, eliminated extramedullary hematopoiesis in the spleen and eliminated bone marrow fibrosis, whereas the wild-type controls did not develop thrombocytopenia. Consistent with a clinical response in this model, we validated surrogate end points for response to treatment, including a reduction of endogenous colony growth and signaling inhibition in immature erythroid and myeloid primary cells both in vitro and upon treatment in vivo. We conclude that EXEL-8232 has efficacy in treatment of thrombocytosis in vivo in a murine model of ET and MF, and may be of therapeutic benefit for patients with MPL-mutant MPN.

  6. Development of a Targeted Next-Generation Sequencing Assay to Detect Diagnostically Relevant Mutations of JAK2, CALR, and MPL in Myeloproliferative Neoplasms.

    Frawley, Thomas; O'Brien, Cathal P; Conneally, Eibhlin; Vandenberghe, Elisabeth; Percy, Melanie; Langabeer, Stephen E; Haslam, Karl

    2018-02-01

    The classical Philadelphia chromosome-negative myeloproliferative neoplasms (MPNs), consisting of polycythemia vera, essential thrombocythemia, and primary myelofibrosis, are a heterogeneous group of neoplasms that harbor driver mutations in the JAK2, CALR, and MPL genes. The detection of mutations in these genes has been incorporated into the recent World Health Organization (WHO) diagnostic criteria for MPN. Given a pressing clinical need to screen for mutations in these genes in a routine diagnostic setting, a targeted next-generation sequencing (NGS) assay for the detection of MPN-associated mutations located in JAK2 exon 14, JAK2 exon 12, CALR exon 9, and MPL exon 10 was developed to provide a single platform alternative to reflexive, stepwise diagnostic algorithms. Polymerase chain reaction (PCR) primers were designed to target mutation hotspots in JAK2 exon 14, JAK2 exon 12, MPL exon 10, and CALR exon 9. Multiplexed PCR conditions were optimized by using qualitative PCR followed by NGS. Diagnostic genomic DNA from 35 MPN patients, known to harbor driver mutations in one of the target genes, was used to validate the assay. One hundred percent concordance was observed between the previously-identified mutations and those detected by NGS, with no false positives, nor any known mutations missed (specificity = 100%, CI = 0.96, sensitivity = 100%, CI = 0.89). Improved resolution of mutation sequences was also revealed by NGS analysis. Detection of diagnostically relevant driver mutations of MPN is enhanced by employing a targeted multiplex NGS approach. This assay presents a robust solution to classical MPN mutation screening, providing an alternative to time-consuming sequential analyses.

  7. Mutation of the SHP-2 binding site in growth hormone (GH) receptor prolongs GH-promoted tyrosyl phosphorylation of GH receptor, JAK2, and STAT5B

    Stofega, M R; Herrington, J; Billestrup, Nils

    2000-01-01

    phosphorylation. Consistent with the effects on STAT5B phosphorylation, tyrosine-to-phenylalanine mutation of tyrosine 595 prolongs the duration of tyrosyl phosphorylation of GHR and JAK2. These data suggest that tyrosine 595 is a major site of interaction of GHR with SHP-2, and that GHR-bound SHP-2 negatively......Binding of GH to GH receptor (GHR) rapidly and transiently activates multiple signal transduction pathways that contribute to the growth-promoting and metabolic effects of GH. While the events that initiate GH signal transduction, such as activation of the Janus tyrosine kinase JAK2, are beginning...

  8. Synergistic effect of pacritinib with erlotinib on JAK2-mediated resistance in epidermal gowth factor receptor mutation-positive non-small cell lung Cancer.

    Ochi, Nobuaki; Isozaki, Hideko; Takeyama, Masami; Singer, Jack W; Yamane, Hiromichi; Honda, Yoshihiro; Kiura, Katsuyuki; Takigawa, Nagio

    2016-06-10

    The combination effect of pacritinib, a novel JAK2/FLT3 inhibitor, with erlotinib, the epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI), on non-small cell lung cancer cells with EGFR activating mutations was investigated. The combination showed synergistic effects on JAK2-mediated EGFR TKI-resistant PC-9/ER3 cells in some cases. The combination markedly suppressed pAKT and pERK although pSTAT3 expression was similar regardless of treatment with the pacritinib, pacritinib + erlotinib, or control in PC-9/ER3 cells. Receptor tyrosine kinase array profiling demonstrated that pacritinib suppressed MET in the PC-9/ER3 cells. The combined treatment of pacritinib and erlotinib in PC-9/ER3 xenografts showed more tumor shrinkage compared with each drug as monotherapy. Western blotting revealed that pMET in tumor samples was inhibited. These results suggest MET suppression by pacritinib may play a role in overcoming the EGFR-TKI resistance mediated by JAK2 in the PC-9/ER3 cells. In conclusion, pacritinib combined with EGFR-TKI might be a potent strategy against JAK2-mediated EGFR-TKI resistance. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Calreticulin Mutations in Bulgarian MPN Patients.

    Pavlov, Ivan; Hadjiev, Evgueniy; Alaikov, Tzvetan; Spassova, Sylva; Stoimenov, Angel; Naumova, Elissaveta; Shivarov, Velizar; Ivanova, Milena

    2018-01-01

    Somatic mutations in JAK2, MPL and CALR are recurrently identified in most of the cases with Philadelphia chromosome negative myeloproliferative neoplasms (MPNs). We applied four molecular genetic methods for identification of CALR exon 9 mutations, including high resolution melt (HRM) analysis, Sanger sequencing, semiconductor target genes sequencing and whole exome sequencing. A total of 78 patients with myeloid malignancies were included in the study. We identified 14 CALR exon 9 mutated cases out of 78 studied patients with myeloid malignancies. All mutated patients were diagnosed with MPN being either PMF (n = 7) or ET (n = 7). Nine cases had type 1 mutations and 5 cases had type 2 mutations. CALR exon 9, MPL exon 10 and JAK2 p. V617F were mutually exclusive. There were no statistically significant differences in the hematological parameters between the cases with CALR and JAK2 or MPL mutations. Notably, all four techniques were fully concordant in the detection of CALR mutations. This is one of the few reports on the CALR mutations frequency in South-eastern populations. Our study shows that the frequency and patterns of these mutations is identical to those in the patients' cohorts from Western countries. Besides we demonstrated the utility of four different methods for their detection.

  10. Resolution of bone marrow fibrosis in a patient receiving JAK1/JAK2 inhibitor treatment with ruxolitinib.

    Wilkins, Bridget S; Radia, Deepti; Woodley, Claire; Farhi, Sarah El; Keohane, Clodagh; Harrison, Claire N

    2013-12-01

    Ruxolitinib, a JAK1/JAK2 inhibitor, is currently the only pharmacological agent approved for the treatment of myelofibrosis. Approval was based on findings from two phase 3 trials comparing ruxolitinib with placebo (COMFORT-I) and with best available therapy (COMFORT-II) for the treatment of primary or secondary myelofibrosis. In those pivotal trials, ruxolitinib rapidly improved splenomegaly, disease-related symptoms, and quality of life and prolonged survival compared with both placebo and conventional treatments. However, for reasons that are currently unclear, there were only modest histomorphological changes in the bone marrow, and only a subset of patients had significant reductions in JAK2 V617F clonal burden. Here we describe a patient with post-polycythemia vera myelofibrosis who received ruxolitinib at our institution (Guy's and St. Thomas' NHS Foundation Trust, London, United Kingdom) as part of the COMFORT-II study. While on treatment, the patient had dramatic improvements in splenomegaly and symptoms shortly after starting ruxolitinib. With longer treatment, the patient had marked reductions in JAK2 V617F allele burden, and fibrosis of the bone marrow resolved after approximately 3 years of ruxolitinib treatment. To our knowledge, this is the first detailed case report of resolution of fibrosis with a JAK1/JAK2 inhibitor. ClinicalTrials.gov Identifier: NCT00934544.

  11. Enu mutagenesis identifies a novel platelet phenotype in a loss-of-function Jak2 allele.

    Nicole M Anderson

    Full Text Available Utilizing ENU mutagenesis, we identified a mutant mouse with elevated platelets. Genetic mapping localized the mutation to an interval on chromosome 19 that encodes the Jak2 tyrosine kinase. We identified a A3056T mutation resulting in a premature stop codon within exon 19 of Jak2 (Jak2(K915X, resulting in a protein truncation and functionally inactive enzyme. This novel platelet phenotype was also observed in mice bearing a hemizygous targeted disruption of the Jak2 locus (Jak2(+/-. Timed pregnancy experiments revealed that Jak2(K915X/K915X and Jak2(-/- displayed embryonic lethality; however, Jak2(K915X/K915X embryos were viable an additional two days compared to Jak2(-/- embryos. Our data suggest that perturbing JAK2 activation may have unexpected consequences in elevation of platelet number and correspondingly, important implications for treatment of hematological disorders with constitutive Jak2 activity.

  12. Minimal residual disease and normalization of the bone marrow after long-term treatment with alpha-interferon2b in polycythemia vera. A report on molecular response patterns in seven patients in sustained complete hematological remission

    Larsen, Thomas Stauffer; Møller, Michael Boe; de Stricker, Karin

    2009-01-01

    Polycythemia vera (PV) is characterized by the presence of the JAK2V617F mutation in virtually all patients. Several studies have shown that the JAK2V617F mutational load decreases during treatment with alpha-interferon 2. We report on molecular and histomorphological bone marrow responses in seven...

  13. Autophosphorylation of JAK2 on tyrosines 221 and 570 regulates its activity

    Argetsinger, Lawrence S; Kouadio, Jean-Louis K; Steen, Hanno

    2004-01-01

    or which of the 49 tyrosines in JAK2 are autophosphorylated. In this study, mass spectrometry and two-dimensional peptide mapping were used to determine that tyrosines 221, 570, and 1007 in JAK2 are autophosphorylated. Phosphorylation of tyrosine 570 is particularly robust. In response to growth hormone......, JAK2 was rapidly and transiently phosphorylated at tyrosines 221 and 570, returning to basal levels by 60 min. Analysis of the sequences surrounding tyrosines 221 and 570 in JAK2 and tyrosines in other proteins that are phosphorylated in response to ligands that activate JAK2 suggests that the YXX......[L/I/V] motif is one of the motifs recognized by JAK2. Experiments using JAK2 with tyrosines 221 and 570 mutated to phenylalanine suggest that tyrosines 221 and 570 in JAK2 may serve as regulatory sites in JAK2, with phosphorylation of tyrosine 221 increasing kinase activity and phosphorylation of tyrosine 570...

  14. A novel del(8)(q23.2q24.11) contributing to disease progression in a case of JAK2/TET2 double mutated chronic myelomonocytic leukemia

    Toft-Petersen, Marie; Kjeldsen, Eigil; Nederby, Line

    2014-01-01

    We have identified a novel 7.7 Mb del(8)(q23.2q24.11) in a patient progressing to acute myeloid leukemia (AML) following a 12-year stable phase of chronic myelomonocytic leukemia (CMML). A surprisingly high JAK2+ allelic burden of 92% at the time of AML led us to delineate the molecular aberrations...... relevant for leukemogenesis. While a frameshift mutation in the TET2 gene was stably present throughout the course of disease the JAK2 mutation was acquired after initial diagnosis of CMML. At progression aCGH revealed del(8q)(q23.2q24.11) encompassing various cancer relevant genes of which RAD21 and CSMD3...

  15. Minimal residual disease after long-term interferon-alpha2 treatment

    Utke Rank, Cecilie; Weis Bjerrum, Ole; Larsen, Thomas Stauffer

    2016-01-01

    Essential thrombocythemia (ET) and polycythemia vera (PV) are Philadelphia chromosome-negative chronic myeloproliferative neoplasms (MPNs) characterized by the JAK2 V617F mutation, which can be found in more than 98% of PV patients and in ∼ 50% of ET patients. Assessment of the JAK2 V617F allele...

  16. Tyrosine phosphorylation of Jak2 in the JH2 domain inhibits cytokine signaling.

    Feener, Edward P; Rosario, Felicia; Dunn, Sarah L; Stancheva, Zlatina; Myers, Martin G

    2004-06-01

    Jak family tyrosine kinases mediate signaling by cytokine receptors to regulate diverse biological processes. Although Jak2 and other Jak kinase family members are phosphorylated on numerous sites during cytokine signaling, the identity and function of most of these sites remains unknown. Using tandem mass spectroscopic analysis of activated Jak2 protein from intact cells, we identified Tyr(221) and Tyr(570) as novel sites of Jak2 phosphorylation. Phosphorylation of both sites was stimulated by cytokine treatment of cultured cells, and this stimulation required Jak2 kinase activity. While we observed no gross alteration of signaling upon mutation of Tyr(221), Tyr(570) lies within the inhibitory JH2 domain of Jak2, and mutation of this site (Jak2(Y570F)) results in constitutive Jak2-dependent signaling in the absence of cytokine stimulation and enhances and prolongs Jak2 activation during cytokine stimulation. Mutation of Tyr(570) does not alter the ability of SOCS3 to bind or inhibit Jak2, however. Thus, the phosphorylation of Tyr(570) in vivo inhibits Jak2-dependent signaling independently of SOCS3-mediated inhibition. This Tyr(570)-dependent mechanism of Jak2 inhibition likely represents an important mechanism by which cytokine function is regulated.

  17. Autophosphorylation of JAK2 on tyrosines 221 and 570 regulates its activity.

    Argetsinger, Lawrence S; Kouadio, Jean-Louis K; Steen, Hanno; Stensballe, Allan; Jensen, Ole N; Carter-Su, Christin

    2004-06-01

    The tyrosine kinase JAK2 is a key signaling protein for at least 20 receptors in the cytokine/hematopoietin receptor superfamily and is a component of signaling by insulin receptor and several G-protein-coupled receptors. However, there is only limited knowledge of the physical structure of JAK2 or which of the 49 tyrosines in JAK2 are autophosphorylated. In this study, mass spectrometry and two-dimensional peptide mapping were used to determine that tyrosines 221, 570, and 1007 in JAK2 are autophosphorylated. Phosphorylation of tyrosine 570 is particularly robust. In response to growth hormone, JAK2 was rapidly and transiently phosphorylated at tyrosines 221 and 570, returning to basal levels by 60 min. Analysis of the sequences surrounding tyrosines 221 and 570 in JAK2 and tyrosines in other proteins that are phosphorylated in response to ligands that activate JAK2 suggests that the YXX[L/I/V] motif is one of the motifs recognized by JAK2. Experiments using JAK2 with tyrosines 221 and 570 mutated to phenylalanine suggest that tyrosines 221 and 570 in JAK2 may serve as regulatory sites in JAK2, with phosphorylation of tyrosine 221 increasing kinase activity and phosphorylation of tyrosine 570 decreasing kinase activity and thereby contributing to rapid termination of ligand activation of JAK2.

  18. JAK2 aberrations in childhood B-cell precursor acute lymphoblastic leukemia

    de Goffau-Nobel, Willemieke; Hoogkamer, Alex Q.; Boer, Judith M.; Boeree, Aurélie; van de Ven, Cesca; Koudijs, Marco J.; Besselink, Nicolle J.M.; de Groot-Kruseman, Hester A.; Zwaan, Christian Michel; Horstmann, Martin A.; Pieters, Rob; den Boer, Monique L.

    2017-01-01

    JAK2 abnormalities may serve as target for precision medicines in pediatric B-cell precursor acute lymphoblastic leukemia (BCP-ALL). In the current study we performed a screening for JAK2 mutations and translocations, analyzed the clinical outcome and studied the efficacy of two JAK inhibitors in primary BCP-ALL cells. Importantly, we identify a number of limitations of JAK inhibitor therapy. JAK2 mutations mainly occurred in the poor prognostic subtypes BCR-ABL1-like and non- BCR-ABL1-like B-other (negative for sentinel cytogenetic lesions). JAK2 translocations were restricted to BCR-ABL1-like cases. Momelotinib and ruxolitinib were cytotoxic in both JAK2 translocated and JAK2 mutated cells, although efficacy in JAK2 mutated cells highly depended on cytokine receptor activation by TSLP. However, our data also suggest that the effect of JAK inhibition may be compromised by mutations in alternative survival pathways and microenvironment-induced resistance. Furthermore, inhibitors induced accumulation of phosphorylated JAK2Y1007, which resulted in a profound re-activation of JAK2 signaling upon release of the inhibitors. This preclinical evidence implies that further optimization and evaluation of JAK inhibitor treatment is necessary prior to its clinical integration in pediatric BCP-ALL. PMID:29163799

  19. Van gen naar ziekte; JAK2 en polycythaemia vera

    Koene, H. R.; Biemond, B. J.; van der Schoot, C. E.

    2007-01-01

    The identification of a point mutation in the JAK2 gene in most patients with polycythaemia vera (PV) has led to increased insight into the pathogenesis of the disease. The mutation causes cytokine-independent growth and proliferation of haematopoietic precursor cells, leading to erythrocytosis. The

  20. Acquired copy-neutral loss of heterozygosity of chromosome 1p as a molecular event associated with marrow fibrosis in MPL-mutated myeloproliferative neoplasms.

    Rumi, Elisa; Pietra, Daniela; Guglielmelli, Paola; Bordoni, Roberta; Casetti, Ilaria; Milanesi, Chiara; Sant'Antonio, Emanuela; Ferretti, Virginia; Pancrazzi, Alessandro; Rotunno, Giada; Severgnini, Marco; Pietrelli, Alessandro; Astori, Cesare; Fugazza, Elena; Pascutto, Cristiana; Boveri, Emanuela; Passamonti, Francesco; De Bellis, Gianluca; Vannucchi, Alessandro; Cazzola, Mario

    2013-05-23

    We studied mutations of MPL exon 10 in patients with essential thrombocythemia (ET) or primary myelofibrosis (PMF), first investigating a cohort of 892 consecutive patients. MPL mutation scanning was performed on granulocyte genomic DNA by using a high-resolution melt assay, and the mutant allele burden was evaluated by using deep sequencing. Somatic mutations of MPL, all but one involving codon W515, were detected in 26/661 (4%) patients with ET, 10/187 (5%) with PMF, and 7/44 (16%) patients with post-ET myelofibrosis. Comparison of JAK2 (V617F)-mutated and MPL-mutated patients showed only minor phenotypic differences. In an extended group of 62 MPL-mutated patients, the granulocyte mutant allele burden ranged from 1% to 95% and was significantly higher in patients with PMF or post-ET myelofibrosis compared with those with ET. Patients with higher mutation burdens had evidence of acquired copy-neutral loss of heterozygosity (CN-LOH) of chromosome 1p in granulocytes, consistent with a transition from heterozygosity to homozygosity for the MPL mutation in clonal cells. A significant association was found between MPL-mutant allele burden greater than 50% and marrow fibrosis. These observations suggest that acquired CN-LOH of chromosome 1p involving the MPL location may represent a molecular mechanism of fibrotic transformation in MPL-mutated myeloproliferative neoplasms.

  1. The JAK2 GGCC (46/1 Haplotype in Myeloproliferative Neoplasms: Causal or Random?

    Luisa Anelli

    2018-04-01

    Full Text Available The germline JAK2 haplotype known as “GGCC or 46/1 haplotype” (haplotypeGGCC_46/1 consists of a combination of single nucleotide polymorphisms (SNPs mapping in a region of about 250 kb, extending from the JAK2 intron 10 to the Insulin-like 4 (INLS4 gene. Four main SNPs (rs3780367, rs10974944, rs12343867, and rs1159782 generating a “GGCC” combination are more frequently indicated to represent the JAK2 haplotype. These SNPs are inherited together and are frequently associated with the onset of myeloproliferative neoplasms (MPN positive for both JAK2 V617 and exon 12 mutations. The association between the JAK2 haplotypeGGCC_46/1 and mutations in other genes, such as thrombopoietin receptor (MPL and calreticulin (CALR, or the association with triple negative MPN, is still controversial. This review provides an overview of the frequency and the role of the JAK2 haplotypeGGCC_46/1 in the pathogenesis of different myeloid neoplasms and describes the hypothetical mechanisms at the basis of the association with JAK2 gene mutations. Moreover, possible clinical implications are discussed, as different papers reported contrasting data about the correlation between the JAK2 haplotypeGGCC_46/1 and blood cell count, survival, or disease progression.

  2. JAK2 and MPL protein levels determine TPO-induced megakaryocyte proliferation vs differentiation.

    Besancenot, Rodolphe; Roos-Weil, Damien; Tonetti, Carole; Abdelouahab, Hadjer; Lacout, Catherine; Pasquier, Florence; Willekens, Christophe; Rameau, Philippe; Lecluse, Yann; Micol, Jean-Baptiste; Constantinescu, Stefan N; Vainchenker, William; Solary, Eric; Giraudier, Stéphane

    2014-09-25

    Megakaryopoiesis is a 2-step differentiation process, regulated by thrombopoietin (TPO), on binding to its cognate receptor myeloproliferative leukemia (MPL). This receptor associates with intracytoplasmic tyrosine kinases, essentially janus kinase 2 (JAK2), which regulates MPL stability and cell-surface expression, and mediates TPO-induced signal transduction. We demonstrate that JAK2 and MPL mediate TPO-induced proliferation arrest and megakaryocytic differentiation of the human megakaryoblastic leukemia cell line UT7-MPL. A decrease in JAK2 or MPL protein expression, and JAK2 chemical inhibition, suppress this antiproliferative action of TPO. The expression of JAK2 and MPL, which progressively increases along normal human megakaryopoiesis, is decreased in platelets of patients diagnosed with JAK2- or MPL-mutated essential thrombocytemia and primary myelofibrosis, 2 myeloproliferative neoplasms in which megakaryocytes (MKs) proliferate excessively. Finally, low doses of JAK2 chemical inhibitors are shown to induce a paradoxical increase in MK production, both in vitro and in vivo. We propose that JAK2 and MPL expression levels regulate megakaryocytic proliferation vs differentiation in both normal and pathological conditions, and that JAK2 chemical inhibitors could promote a paradoxical thrombocytosis when used at suboptimal doses. © 2014 by The American Society of Hematology.

  3. Efficacy of vorinostat in a murine model of polycythemia vera

    Akada, Hajime; Akada, Saeko; Gajra, Ajeet; Bair, Alicia; Graziano, Stephen; Hutchison, Robert E.

    2012-01-01

    The discovery of the JAK2V617F mutation in most patients with Ph-negative myeloproliferative neoplasms has led to the development of JAK2 kinase inhibitors. However, JAK2 inhibitor therapy has shown limited efficacy and dose-limiting hematopoietic toxicities in clinical trials. In the present study, we describe the effects of vorinostat, a small-molecule inhibitor of histone deacetylase, against cells expressing JAK2V617F and in an animal model of polycythemia vera (PV). We found that vorinostat markedly inhibited proliferation and induced apoptosis in cells expressing JAK2V617F. In addition, vorinostat significantly inhibited JAK2V617F-expressing mouse and human PV hematopoietic progenitors. Biochemical analyses revealed significant inhibition of phosphorylation of JAK2, Stat5, Stat3, Akt, and Erk1/2 in vorinostat-treated, JAK2V617F-expressing human erythroleukemia (HEL) cells. Expression of JAK2V617F and several other genes, including GATA1, KLF1, FOG1, SCL, C/EPBα, PU.1, and NF-E2, was significantly down-regulated, whereas the expression of SOCS1 and SOCS3 was up-regulated by vorinostat treatment. More importantly, we observed that vorinostat treatment normalized the peripheral blood counts and markedly reduced splenomegaly in Jak2V617F knock-in mice compared with placebo treatment. Vorinostat treatment also decreased the mutant allele burden in mice. Our results suggest that vorinostat may have therapeutic potential for the treatment of PV and other JAK2V617F-associated myeloproliferative neoplasms. PMID:22408262

  4. Proinflammatory Cytokine IL-6 and JAK-STAT Signaling Pathway in Myeloproliferative Neoplasms

    Vladan P. Čokić

    2015-01-01

    Full Text Available The recent JAK1/2 inhibitor trial in myeloproliferative neoplasms (MPNs showed that reducing inflammation can be more beneficial than targeting gene mutants. We evaluated the proinflammatory IL-6 cytokine and JAK-STAT signaling pathway related genes in circulating CD34+ cells of MPNs. Regarding laboratory data, leukocytosis has been observed in polycythemia vera (PV and JAK2V617F mutation positive versus negative primary myelofibrosis (PMF patients. Moreover, thrombocytosis was reduced by JAK2V617F allele burden in essential thrombocythemia (ET and PMF. 261 significantly changed genes have been detected in PV, 82 in ET, and 94 genes in PMF. The following JAK-STAT signaling pathway related genes had augmented expression in CD34+ cells of MPNs: CCND3 and IL23A regardless of JAK2V617F allele burden; CSF3R, IL6ST, and STAT1/2 in ET and PV with JAK2V617F mutation; and AKT2, IFNGR2, PIM1, PTPN11, and STAT3 only in PV. STAT5A gene expression was generally reduced in MPNs. IL-6 cytokine levels were increased in plasma, as well as IL-6 protein levels in bone marrow stroma of MPNs, dependent on JAK2V617F mutation presence in ET and PMF patients. Therefore, the JAK2V617F mutant allele burden participated in inflammation biomarkers induction and related signaling pathways activation in MPNs.

  5. Domains of the growth hormone receptor required for association and activation of JAK2 tyrosine kinase

    VanderKuur, J A; Wang, X; Zhang, L

    1994-01-01

    Growth hormone (GH) has recently been shown to activate the GH receptor (GHR)-associated tyrosine kinase JAK2. In the present study, regions of the GHR required for JAK2 association with GHR were identified. GH-dependent JAK2 association with GHR was detected in Chinese hamster ovary (CHO) cells...... and RIN-5AH cells, the ability of JAK2 to associate with the mutated GHR was found to correlate with GH-dependent activation of JAK2, tyrosyl phosphorylation of GHR (in the case of GHR1-638 and GHR1-454), and the ability of the GHR to copurify with tyrosine kinase activity. In CHO cells expressing mutated......, and that tyrosines in the N-terminal half of the cytoplasmic domain of the GHR are phosphorylated by JAK2. The finding that a specific interaction with the C-terminal half of GHR appears to be necessary for p97 phosphorylation indicates that while JAK2 activation may be necessary for a full biological response to GH...

  6. Detection of MPL mutations by a novel allele-specific PCR-based strategy.

    Furtado, Larissa V; Weigelin, Helmut C; Elenitoba-Johnson, Kojo S J; Betz, Bryan L

    2013-11-01

    MPL mutation testing is recommended in patients with suspected primary myelofibrosis or essential thrombocythemia who lack the JAK2 V617F mutation. MPL mutations can occur at allelic levels below 15%, which may escape detection by commonly used mutation screening methods such as Sanger sequencing. We developed a novel multiplexed allele-specific PCR assay capable of detecting most recurrent MPL exon 10 mutations associated with primary myelofibrosis and essential thrombocythemia (W515L, W515K, W515A, and S505N) down to a sensitivity of 2.5% mutant allele. Test results were reviewed from 15 reference cases and 1380 consecutive specimens referred to our laboratory for testing. Assay performance was compared to Sanger sequencing across a series of 58 specimens with MPL mutations. Positive cases consisted of 45 with W515L, 6 with S505N, 5 with W515K, 1 with W515A, and 1 with both W515L and S505N. Seven cases had mutations below 5% that were undetected by Sanger sequencing. Ten additional cases had mutation levels between 5% and 15% that were not consistently detected by sequencing. All results were easily interpreted in the allele-specific test. This assay offers a sensitive and reliable solution for MPL mutation testing. Sanger sequencing appears insufficiently sensitive for robust MPL mutation detection. Our data also suggest the relative frequency of S505N mutations may be underestimated, highlighting the necessity for inclusion of this mutation in MPL test platforms. Copyright © 2013 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

  7. Involvement of mast cells by the malignant process in patients with Philadelphia chromosome negative myeloproliferative neoplasms.

    Wang, J; Ishii, T; Zhang, W; Sozer, S; Dai, Y; Mascarenhas, J; Najfeld, V; Zhao, Z J; Hoffman, R; Wisch, N; Xu, M

    2009-09-01

    The Philadelphia chromosome negative myeloproliferative neoplasms (MPNs) are clonal hematologic malignancies frequently characterized by a mutation in JAK2 (JAK2V617F). Peripheral blood (PB) CD34(+) cells from patients with polycythemia vera (PV) and primary myelofibrosis (PMF) generated in vitro significantly fewer mast cells (MCs) than normal PB CD34(+) cells. The numbers of MC progenitors assayed from MPN CD34(+) cells were, however, similar to that assayed from normal CD34(+) cells. A higher percentage of the cultured MPN MCs expressed FcvarepsilonRIalpha, CD63 and CD69 than normal MCs, suggesting that cultured MPN MCs are associated with an increased state of MC activation. Further analysis showed that a higher proportion of cultured PV and PMF MCs underwent apoptosis in vitro. By using JAK2V617F, MplW515L and chromosomal abnormalities as clonality markers, we showed that the malignant process involved MPN MCs. JAK2V617F-positive MC colonies were assayable from the PB CD34(+) cells of each of the 17 JAK2V617F positive MPN patients studied. Furthermore, erlotinib, a JAK2 inhibitor, was able to inhibit JAK2V617F-positive PV MC progenitor cells, indicating that malignant MC progenitor cells are a potential cellular target for such JAK2 inhibitor-directed therapy.

  8. Status og perspektiver for behandling af de kroniske myeloproliferative neoplasier

    Ocias, Lukas Frans; Holmström, Morten Orebo; Riley, Caroline Hasselbalch

    2015-01-01

    of these malignancies has focused on lowering their inherent thromboembolic risk but with the discovery of the JAK2-V617F mutation and most recently the calreticulin mutations new therapeutic options such as interferon-alpha, JAK2-inhibitors and statins are being contemplated. This article reviews these new treatment...

  9. Molecular diagnostics of myeloproliferative neoplasms

    Langabeer, S. E.; Andrikovics, H.; Asp, J.

    2015-01-01

    Since the discovery of the JAK2 V617F mutation in the majority of the myeloproliferative neoplasms (MPN) of polycythemia vera, essential thrombocythemia and primary myelofibrosis ten years ago, further MPN-specific mutational events, notably in JAK2 exon 12, MPL exon 10 and CALR exon 9 have been...

  10. Role of JAK-STAT signaling in the pathogenesis of myeloproliferative disorders.

    Levine, Ross L; Wernig, Gerlinde

    2006-01-01

    The identification of JAK2V617F mutations in polycythemia vera (PV), essential thrombocytosis (ET), and myelofibrosis (MF) represents an important advance in our understanding of these myeloproliferative disorders (MPD). Most, if not all, patients with PV and a significant number of patients with ET and MF are JAK2V617F positive, and the mutation likely arises in the hematopoietic stem cell compartment. JAK2V617F is a constitutively active tyrosine kinase that is able to activate JAK-STAT signaling most efficiently when co-expressed with the erythropoietin receptor (EPOR), the thrombopoietin receptor (MPL), or the granulocyte colony-stimulating factor receptor (GCSFR). Data from murine models supports the central role of JAK2V617F in the pathogenesis of MPD, as expression of JAK2V617F in a bone marrow transplantation assay results in polycythemia and myelofibrosis in recipient mice. Activation of JAK-STAT signaling by JAK2V617F in some, but not all MPD patients with ET and MF led to the identification of the constitutively active MPLW515L allele in ET and MF. Small molecule inhibitors of JAK-STAT signaling are currently being developed, which offer potential for molecularly targeted therapy for patients with PV, ET, and MF. Despite these advances, many questions remain regarding the role of a single disease allele in three phenotypically distinct MPD, the potential clinical efficacy of JAK2 inhibitors, and the identity of oncogenic alleles in JAK2V617F/MPLW515-negative MPD.

  11. Combined Targeting of JAK2 and Bcl-2/Bcl-xL to Cure Mutant JAK2-Driven Malignancies and Overcome Acquired Resistance to JAK2 Inhibitors

    Michaela Waibel

    2013-11-01

    Full Text Available To design rational therapies for JAK2-driven hematological malignancies, we functionally dissected the key survival pathways downstream of hyperactive JAK2. In tumors driven by mutant JAK2, Stat1, Stat3, Stat5, and the Pi3k and Mek/Erk pathways were constitutively active, and gene expression profiling of TEL-JAK2 T-ALL cells revealed the upregulation of prosurvival Bcl-2 family genes. Combining the Bcl-2/Bcl-xL inhibitor ABT-737 with JAK2 inhibitors mediated prolonged disease regressions and cures in mice bearing primary human and mouse JAK2 mutant tumors. Moreover, combined targeting of JAK2 and Bcl-2/Bcl-xL was able to circumvent and overcome acquired resistance to single-agent JAK2 inhibitor treatment. Thus, inhibiting the oncogenic JAK2 signaling network at two nodal points, at the initiating stage (JAK2 and the effector stage (Bcl-2/Bcl-xL, is highly effective and provides a clearly superior therapeutic benefit than targeting just one node. Therefore, we have defined a potentially curative treatment for hematological malignancies expressing constitutively active JAK2.

  12. Primary myelofibrosis with or without mutant MPL: comparison of survival and clinical features involving 603 patients.

    Pardanani, A; Guglielmelli, P; Lasho, T L; Pancrazzi, A; Finke, C M; Vannucchi, A M; Tefferi, A

    2011-12-01

    MPL and JAK2V617F mutation analysis was performed in 603 patients with primary myelofibrosis (PMF) seen at the Mayo Clinic, USA (n=329) or University of Florence, Italy (n=274). Mutant MPL was detected in 49 (8.1%) patients and JAK2V617F in 350 (58%); 4 patients showed both mutations. MPLW515L/K was the commonest mutation; 2 patients showed novel mutations (L513ins and Q516-P518insAAAA). The US and Italy patient cohorts were separately analyzed for comparison of survival and clinical features between MPL-mutated, JAK2-mutated and JAK2/MPL-unmutated cases. JAK2/MPL-unmutated patients were significantly younger than their JAK2-mutated counterparts, in both patient cohorts (PMPL was associated with older age (PMPL has narrow and inconsistent phenotypic effect in PMF and does not influence overall or leukemia-free survival.

  13. Clinical utility of routine MPL exon 10 analysis in the diagnosis of essential thrombocythaemia and primary myelofibrosis.

    Boyd, Elaine M; Bench, Anthony J; Goday-Fernández, Andrea; Anand, Shubha; Vaghela, Krishna J; Beer, Phillip; Scott, Mike A; Bareford, David; Green, Anthony R; Huntly, Brian; Erber, Wendy N

    2010-04-01

    Approximately 50% of essential thrombocythaemia and primary myelo-fibrosis patients do not have a JAK2 V617F mutation. Up to 5% of these are reported to have a MPL exon 10 mutation but testing for MPL is not routine as there are multiple mutation types. The ability to routinely assess both JAK2 and MPL mutations would be beneficial in the differential diagnosis of unexplained thrombocytosis or myelofibrosis. We developed and applied a high resolution melt (HRM) assay, capable of detecting all known MPL mutations in a single analysis, for the detection of MPL exon 10 mutations. We assessed 175 ET and PMF patients, including 67 that were JAK2 V617F-negative by real time polymerase chain reaction (PCR). Overall, 19/175 (11%) patients had a MPL exon 10 mutation, of whom 16 were JAK2 V617F-negative (16/67; 24%). MPL mutation types were W515L (11), W515K (4), W515R (2) and W515A (1). One patient had both W515L and S505N MPL mutations and these were present in the same haemopoietic colonies. Real time PCR for JAK2 V617F analysis and HRM for MPL exon 10 status identified one or more clonal marker in 71% of patients. This combined genetic approach increases the sensitivity of meeting the World Health Organization diagnostic criteria for these myeloproliferative neoplasms.

  14. [Evidence on chronic myeloproliferative neoplasms from landmark clinical trials].

    Yamaguchi, Hiroki

    2015-08-01

    Mutations in the JAK2 gene are thought to underlie the development of chronic myeloproliferative neoplasms (cMPN). Indeed, ≥95% of polycythemia vera patients, and half or more of essential thrombocythemia and primary myelofibrosis (PMF) patients, harbor the JAK2V617F mutation. Besides the JAK2V617F mutation, the JAK2 exon 12 deletion, the MPLW515L/K, and CALR mutation have been discovered and shown to be involved in the pathogenesis of these diseases. Based on these advancements in the study of cMPN, the JAK2 inhibitor was developed as a new therapy for PMF. Moreover, recent advancements in our ability to diagnose cMPN have paralleled the development of large clinical trials for patients with cMPN. This article provides explanatory information from these large clinical trials that is useful for the actual clinical practice of caring for patients with cMPN in Japan.

  15. Calreticulin and Jak2 as Chaperones for MPL: Insights into MPN Pathogenesis

    2017-11-01

    neoplasms (MPNs) as classified by the world health organization. One of the biggest challenges is to understand how Jak2, MPL and CALR mutant proteins...7/Tpo cells using genetic engineering. The left panel in Fig.2 show the presence of a sub- population of UT-7/Tpo cells that express the T1 mutant...lower panels) cells at day 5 post-editing. The homozygous K39N mutation could be found in both populations , as expected. However, in the edited

  16. Crystal Structure of the FERM-SH2 Module of Human Jak2.

    McNally, Randall; Toms, Angela V; Eck, Michael J

    2016-01-01

    Jak-family tyrosine kinases mediate signaling from diverse cytokine receptors. Binding of Jaks to their cognate receptors is mediated by their N-terminal region, which contains FERM and SH2 domains. Here we describe the crystal structure of the FERM-SH2 region of Jak2 at 3.0Å resolution. The structure reveals that these domains and their flanking linker segments interact intimately to form an integrated structural module. The Jak2 FERM-SH2 structure closely resembles that recently described for Tyk2, another member of the Jak family. While the overall architecture and interdomain orientations are preserved between Jak2 and Tyk2, we identify residues in the putative receptor-binding groove that differ between the two and may contribute to the specificity of receptor recognition. Analysis of Jak mutations that are reported to disrupt receptor binding reveals that they lie in the hydrophobic core of the FERM domain, and are thus expected to compromise the structural integrity of the FERM-SH2 unit. Similarly, analysis of mutations in Jak3 that are associated with severe combined immunodeficiency suggests that they compromise Jak3 function by destabilizing the FERM-SH2 structure.

  17. LOSS OF JAK2 REGULATION VIA VHL-SOCS1 E3 UBIQUITIN HETEROCOMPLEX UNDERLIES CHUVASH POLYCYTHEMIA

    Russell, Ryan C.; Sufan, Roxana I.; Zhou, Bing; Heir, Pardeep; Bunda, Severa; Sybingco, Stephanie S.; Greer, Samantha N.; Roche, Olga; Heathcote, Samuel A.; Chow, Vinca W.K.; Boba, Lukasz M.; Richmond, Terri D.; Hickey, Michele M.; Barber, Dwayne L.; Cheresh, David A.; Simon, M. Celeste; Irwin, Meredith S.; Kim, William Y.; Ohh, Michael

    2011-01-01

    SUMMARY Chuvash polycythemia (CP) is a rare congenital form of polycythemia caused by homozygous R200W and H191D mutations in the von Hippel-Lindau (VHL) gene whose gene product is the principal negative regulator of hypoxia-inducible factor. However, the molecular mechanisms underlying some of the hallmark features of CP such as hypersensitivity to erythropoietin are unclear. Here, we show that VHL directly binds suppressor of cytokine signalling 1 (SOCS1) to form a heterodimeric E3 ligase that targets phosphorylated (p)JAK2 for ubiquitin-mediated destruction. In contrast, CP-associated VHL mutants have altered affinity for SOCS1 and fail to engage and degrade pJAK2. Systemic administration of a highly selective JAK2 inhibitor, TG101209, reverses the disease phenotype in vhlR200W/R200W knock-in mice, a model that faithfully recapitulates human CP. These results reveal VHL as a SOCS1-cooperative negative regulator of JAK2 and provide compelling biochemical and preclinical evidence for JAK2- targeted therapy in CP patients. PMID:21685897

  18. Hepatic JAK2 protects against atherosclerosis through circulating IGF-1.

    Sivasubramaniyam, Tharini; Schroer, Stephanie A; Li, Angela; Luk, Cynthia T; Shi, Sally Yu; Besla, Rickvinder; Dodington, David W; Metherel, Adam H; Kitson, Alex P; Brunt, Jara J; Lopes, Joshua; Wagner, Kay-Uwe; Bazinet, Richard P; Bendeck, Michelle P; Robbins, Clinton S; Woo, Minna

    2017-07-20

    Atherosclerosis is considered both a metabolic and inflammatory disease; however, the specific tissue and signaling molecules that instigate and propagate this disease remain unclear. The liver is a central site of inflammation and lipid metabolism that is critical for atherosclerosis, and JAK2 is a key mediator of inflammation and, more recently, of hepatic lipid metabolism. However, precise effects of hepatic Jak2 on atherosclerosis remain unknown. We show here that hepatic Jak2 deficiency in atherosclerosis-prone mouse models exhibited accelerated atherosclerosis with increased plaque macrophages and decreased plaque smooth muscle cell content. JAK2's essential role in growth hormone signalling in liver that resulted in reduced IGF-1 with hepatic Jak2 deficiency played a causal role in exacerbating atherosclerosis. As such, restoring IGF-1 either pharmacologically or genetically attenuated atherosclerotic burden. Together, our data show hepatic Jak2 to play a protective role in atherogenesis through actions mediated by circulating IGF-1 and, to our knowledge, provide a novel liver-centric mechanism in atheroprotection.

  19. A der(18)t(9;18)(p13;p11) and a der(9;18)(p10;q10) in polycythemia vera associated with a hyperproliferative phenotype in transformation to postpolycythemic myelofibrosis

    Larsen, Thomas Stauffer; Hasselbalch, Hans Carl; Pallisgaard, Niels

    2007-01-01

    Chromosomal aberrations in polycythemia vera (PV) are heterogenous and nonrandom. A prognostic predictive value of these aberrations has not been established. The V617F mutation in the JAK2 gene on chromosome 9p24.1 was identified recently in peripheral blood leukocytes in the majority of patients...

  20. Regenerative nodular hyperplasia, portal vein thrombosis and primary myelofibrosis: an unusual triple association.

    Sández Montagut, Víctor Manuel; Giráldez Gallego, Álvaro; Ontanilla Clavijo, Guilermo

    2018-03-01

    We report a case of a regenerative nodular hyperplasia with a portal vein cavernomatosis with a subsequent progression to symptomatic, occlusive thrombosis of the superior mesenteric vein. A thorough investigation resulted in a final diagnosis of primary myelofibrosis associated with the V617F mutation in the JAK2 gene.

  1. Genetic Alterations of the Thrombopoietin/MPL/JAK2 Axis Impacting Megakaryopoiesis.

    Plo, Isabelle; Bellanné-Chantelot, Christine; Mosca, Matthieu; Mazzi, Stefania; Marty, Caroline; Vainchenker, William

    2017-01-01

    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.

  2. Burning feet in polycythemia vera – peripheral sensorimotor axonal neuropathy with erythromelalgia

    Wollina U

    2015-02-01

    Full Text Available Uwe Wollina Department of Dermatology and Allergology, Academic Teaching Hospital Dresden-Friedrichstadt, Dresden, Germany Abstract: Polycythemia vera is a rare myeloproliferative disease. Cutaneous symptoms are uncommon. We report about a 72-year-old female patient with JAK2V617F-positive polycythemia who developed peripheral sensorimotor axonal neuropathy and erythromelalgia. Possible causes and treatment are discussed. Keywords: bone marrow diseases, myeloproliferative diseases, JAK2 mutations, burning sensations, peripheral neuropathy

  3. Virtual screening and optimization of Type II inhibitors of JAK2 from a natural product library.

    Ma, Dik-Lung; Chan, Daniel Shiu-Hin; Wei, Guo; Zhong, Hai-Jing; Yang, Hui; Leung, Lai To; Gullen, Elizabeth A; Chiu, Pauline; Cheng, Yung-Chi; Leung, Chung-Hang

    2014-11-21

    Amentoflavone has been identified as a JAK2 inhibitor by structure-based virtual screening of a natural product library. In silico optimization using the DOLPHIN model yielded analogues with enhanced potency against JAK2 activity and HCV activity in cellulo. Molecular modeling and kinetic experiments suggested that the analogues may function as Type II inhibitors of JAK2.

  4. Transforming and tumorigenic activity of JAK2 by fusion to BCR: molecular mechanisms of action of a novel BCR-JAK2 tyrosine-kinase.

    Álvaro Cuesta-Domínguez

    Full Text Available Chromosomal translocations in tumors frequently produce fusion genes coding for chimeric proteins with a key role in oncogenesis. Recent reports described a BCR-JAK2 fusion gene in fatal chronic and acute myeloid leukemia, but the functional behavior of the chimeric protein remains uncharacterized. We used fluorescence in situ hybridization and reverse transcription polymerase chain reaction (RT-PCR assays to describe a BCR-JAK2 fusion gene from a patient with acute lymphoblastic leukemia. The patient has been in complete remission for six years following treatment and autologous transplantation, and minimal residual disease was monitored by real-time RT-PCR. BCR-JAK2 codes for a protein containing the BCR oligomerization domain fused to the JAK2 tyrosine-kinase domain. In vitro analysis of transfected cells showed that BCR-JAK2 is located in the cytoplasm. Transduction of hematopoietic Ba/F3 cells with retroviral vectors carrying BCR-JAK2 induced IL-3-independent cell growth, constitutive activation of the chimeric protein as well as STAT5 phosphorylation and translocation to the nuclei, where Bcl-xL gene expression was elicited. Primary mouse progenitor cells transduced with BCR-JAK2 also showed increased proliferation and survival. Treatment with the JAK2 inhibitor TG101209 abrogated BCR-JAK2 and STAT5 phosphorylation, decreased Bcl-xL expression and triggered apoptosis of transformed Ba/F3 cells. Therefore, BCR-JAK2 is a novel tyrosine-kinase with transforming activity. It deregulates growth factor-dependent proliferation and cell survival, which can be abrogated by the TG101209 inhibitor. Moreover, transformed Ba/F3 cells developed tumors when injected subcutaneously into nude mice, thus proving the tumorigenic capacity of BCR-JAK2 in vivo. Together these findings suggest that adult and pediatric patients with BCR-ABL-negative leukemia and JAK2 overexpression may benefit from targeted therapies.

  5. Macrophage JAK2 deficiency protects against high-fat diet-induced inflammation.

    Desai, Harsh R; Sivasubramaniyam, Tharini; Revelo, Xavier S; Schroer, Stephanie A; Luk, Cynthia T; Rikkala, Prashanth R; Metherel, Adam H; Dodington, David W; Park, Yoo Jin; Kim, Min Jeong; Rapps, Joshua A; Besla, Rickvinder; Robbins, Clinton S; Wagner, Kay-Uwe; Bazinet, Richard P; Winer, Daniel A; Woo, Minna

    2017-08-09

    During obesity, macrophages can infiltrate metabolic tissues, and contribute to chronic low-grade inflammation, and mediate insulin resistance and diabetes. Recent studies have elucidated the metabolic role of JAK2, a key mediator downstream of various cytokines and growth factors. Our study addresses the essential role of macrophage JAK2 in the pathogenesis to obesity-associated inflammation and insulin resistance. During high-fat diet (HFD) feeding, macrophage-specific JAK2 knockout (M-JAK2 -/- ) mice gained less body weight compared to wildtype littermate control (M-JAK2 +/+ ) mice and were protected from HFD-induced systemic insulin resistance. Histological analysis revealed smaller adipocytes and qPCR analysis showed upregulated expression of some adipogenesis markers in visceral adipose tissue (VAT) of HFD-fed M-JAK2 -/- mice. There were decreased crown-like structures in VAT along with reduced mRNA expression of some macrophage markers and chemokines in liver and VAT of HFD-fed M-JAK2 -/- mice. Peritoneal macrophages from M-JAK2 -/- mice and Jak2 knockdown in macrophage cell line RAW 264.7 also showed lower levels of chemokine expression and reduced phosphorylated STAT3. However, leptin-dependent effects on augmenting chemokine expression in RAW 264.7 cells did not require JAK2. Collectively, our findings show that macrophage JAK2 deficiency improves systemic insulin sensitivity and reduces inflammation in VAT and liver in response to metabolic stress.

  6. Calpain-mediated proteolysis of polycystin-1 C-terminus induces JAK2 and ERK signal alterations

    Kim, Hyunho [Transplantation Research Institute, Seoul National University Medical Research Center, Seoul (Korea, Republic of); Department of Medicine, University of Maryland, Baltimore, MD (United States); Kang, Ah-Young [Transplantation Research Institute, Seoul National University Medical Research Center, Seoul (Korea, Republic of); Department of Medicine, Program of Immunology, Graduate School, Seoul National University, Seoul (Korea, Republic of); Ko, Ah-ra [Clinical Research Center, Samsung Biomedical Research Institute, Seoul (Korea, Republic of); Park, Hayne Cho [Transplantation Research Institute, Seoul National University Medical Research Center, Seoul (Korea, Republic of); Research Coordination Center for Rare Diseases, Seoul National University Hospital, Seoul (Korea, Republic of); So, Insuk [Department of Physiology, Seoul National University College of Medicine, Seoul (Korea, Republic of); Park, Jong Hoon [Department of Biological Science, Sookmyung Women’s University, Seoul (Korea, Republic of); Cheong, Hae Il [Research Coordination Center for Rare Diseases, Seoul National University Hospital, Seoul (Korea, Republic of); Department of Pediatrics, Seoul National University Children’s Hospital, Seoul (Korea, Republic of); Kidney Research Institute, Medical Research Center, Seoul National University College of Medicine, Seoul (Korea, Republic of); Hwang, Young-Hwan [Research Coordination Center for Rare Diseases, Seoul National University Hospital, Seoul (Korea, Republic of); Department of Internal Medicine, Eulji General Hospital, Eulji University College of Medicine, Seoul (Korea, Republic of); and others

    2014-01-01

    Autosomal dominant polycystic kidney disease (ADPKD), a hereditary renal disease caused by mutations in PKD1 (85%) or PKD2 (15%), is characterized by the development of gradually enlarging multiple renal cysts and progressive renal failure. Polycystin-1 (PC1), PKD1 gene product, is an integral membrane glycoprotein which regulates a number of different biological processes including cell proliferation, apoptosis, cell polarity, and tubulogenesis. PC1 is a target of various proteolytic cleavages and proteosomal degradations, but its role in intracellular signaling pathways remains poorly understood. Herein, we demonstrated that PC1 is a novel substrate for μ- and m-calpains, which are calcium-dependent cysteine proteases. Overexpression of PC1 altered both Janus-activated kinase 2 (JAK2) and extracellular signal-regulated kinase (ERK) signals, which were independently regulated by calpain-mediated PC1 degradation. They suggest that the PC1 function on JAK2 and ERK signaling pathways might be regulated by calpains in response to the changes in intracellular calcium concentration. - Highlights: • Polycystin-1 is a target of ubiquitin-independent degradation by calpains. • The PEST domain is required for calpain-mediated degradation of polycystin-1. • Polycystin-1 may independently regulate JAK2 and ERK signaling pathways.

  7. Tyrosine Phosphorylation of Jak2 in the JH2 Domain Inhibits Cytokine Signaling

    Feener, Edward P.; Rosario, Felicia; Dunn, Sarah L.; Stancheva, Zlatina; Myers, Martin G.

    2004-01-01

    Jak family tyrosine kinases mediate signaling by cytokine receptors to regulate diverse biological processes. Although Jak2 and other Jak kinase family members are phosphorylated on numerous sites during cytokine signaling, the identity and function of most of these sites remains unknown. Using tandem mass spectroscopic analysis of activated Jak2 protein from intact cells, we identified Tyr221 and Tyr570 as novel sites of Jak2 phosphorylation. Phosphorylation of both sites was stimulated by c...

  8. The Jak2 Inhibitor, G6, Alleviates Jak2-V617F–Mediated Myeloproliferative Neoplasia by Providing Significant Therapeutic Efficacy to the Bone Marrow

    Annet Kirabo

    2011-11-01

    Full Text Available We recently developed a Janus kinase 2 (Jak2 small-molecule inhibitor called G6 and found that it inhibits Jak2-V617F– mediated pathologic cell growth in vitro, ex vivo, and in vivo. However, its ability to inhibit Jak2-V617F–mediated myeloproliferative neoplasia, with particular emphasis in the bone marrow, has not previously been examined. Here, we investigated the efficacy of G6 in a transgenic mouse model of Jak2-V617F–mediated myeloproliferative neoplasia. We found that G6 provided therapeutic benefit to the peripheral blood as determined by elimination of leukocytosis, thrombocytosis, and erythrocytosis. G6 normalized the pathologically high plasma concentrations of interleukin 6 (IL-6. In the liver, G6 eliminated Jak2-V617F–driven extramedullary hematopoiesis. With respect to the spleen, G6 significantly reduced both the spleno-megaly and megakaryocytic hyperplasia. In the critically important bone marrow, G6 normalized the pathologically high levels of phospho-Jak2 and phospho–signal transducer and activator of transcription 5 (STAT5. It significantly reduced the megakaryocytic hyperplasia in the marrow and completely normalized the M/E ratio. Most importantly, G6 selectively reduced the mutant Jak2 burden by 67% on average, with virtual elimination of mutant Jak2 cells in one third of all treated mice. Lastly, clonogenic assays using marrow stem cells from the myeloproliferative neoplasm mice revealed a time-dependent elimination of the clonogenic growth potential of these cells by G6. Collectively, these data indicate that G6 exhibits exceptional efficacy in the peripheral blood, liver, spleen, and, most importantly, in the bone marrow, thereby raising the possibility that this compound may alter the natural history of Jak2-V617F–mediated myeloproliferative neoplasia.

  9. Autophosphorylation of JAK2 on Tyrosines 221 and 570 Regulates Its Activity

    Argetsinger, Lawrence S.; Kouadio, Jean-Louis K.; Steen, Hanno; Stensballe, Allan; Jensen, Ole N.; Carter-Su, Christin

    2004-01-01

    The tyrosine kinase JAK2 is a key signaling protein for at least 20 receptors in the cytokine/hematopoietin receptor superfamily and is a component of signaling by insulin receptor and several G-protein-coupled receptors. However, there is only limited knowledge of the physical structure of JAK2 or which of the 49 tyrosines in JAK2 are autophosphorylated. In this study, mass spectrometry and two-dimensional peptide mapping were used to determine that tyrosines 221, 570, and 1007 in JAK2 are a...

  10. Elevated serum IL-10 levels in diffuse large B-cell lymphoma: a mechanism of aberrant JAK2 activation.

    Gupta, Mamta; Han, Jing Jing; Stenson, Mary; Maurer, Matthew; Wellik, Linda; Hu, Guangzhen; Ziesmer, Steve; Dogan, Ahmet; Witzig, Thomas E

    2012-03-22

    Cytokines are deregulated in cancers and can contribute to tumor growth. In patients with diffuse large-cell lymphoma (DLBCL), we observed higher levels of JAK/STAT pathway-related serum cytokines (ie, IL-6, IL-10, epidermal growth factor, and IL-2) compared with controls. Of these, only IL-10 activated the JAK2 pathway in lymphoma cells in vitro. Patients with high serum IL-10 had shorter event-free survival (EFS) than patients with low levels (P > .01) and high IL-10 was correlated with high lactase dehydrogenase (P = .0085) and higher International Prognostic Index scores (P = .01). To explore the mechanism by which IL-10 may contribute to an inferior EFS, we investigated the effect of IL-10 on the JAK2 pathway and found that the IL-10/IL-10 receptor complex up-regulated JAK2 signaling. Neutralizing Ab to IL-10 inhibited constitutive and IL-10-induced JAK2/STAT3 phosphorylation. JAK2 inhibition dephosphorylated JAK2 and STAT3 and caused an inhibitory effect on phospho-JAK2-positive DLBCL cells; there was a minimal effect on phospho-JAK2-negative cells. Apoptosis induced by JAK2 inhibition was dependent on inhibition of autocrine IL-10 and c-myc expression and independent of Bcl-2 family expression. These results provide the rationale for testing JAK2 inhibitors in DLBCL patients, and indicate that serum IL-10 may be a biomarker to identify patients more likely to respond to JAK2-targeted therapy.

  11. A natural product-like JAK2/STAT3 inhibitor induces apoptosis of malignant melanoma cells.

    Ke-Jia Wu

    Full Text Available The JAK2/STAT3 signaling pathway plays a critical role in tumorigenesis, and has been suggested as a potential molecular target for anti-melanoma therapeutics. However, few JAK2 inhibitors were being tested for melanoma therapy. In this study, eight amentoflavone analogues were evaluated for their activity against human malignant melanoma cells. The most potent analogue, compound 1, inhibited the phosphorylation of JAK2 and STAT3 in human melanoma cells, but had no discernible effect on total JAK2 and STAT3 levels. A cellular thermal shift assay was performed to identify that JAK2 is engaged by 1 in cell lysates. Moreover, compound 1 showed higher antiproliferative activity against human melanoma A375 cells compared to a panel of cancer and normal cell lines. Compound 1 also activated caspase-3 and cleaved PARP, which are markers of apoptosis, and suppressed the anti-apoptotic Bcl-2 level. Finally, compound 1 induced apoptosis in 80% of treated melanoma cells. To our knowledge, compound 1 is the first amentoflavone-based JAK2 inhibitor to be investigated for use as an anti-melanoma agent.

  12. Janus Kinase 2 (JAK2) Dissociates Hepatosteatosis from Hepatocellular Carcinoma in Mice.

    Shi, Sally Yu; Luk, Cynthia T; Schroer, Stephanie A; Kim, Min Jeong; Dodington, David W; Sivasubramaniyam, Tharini; Lin, Lauren; Cai, Erica P; Lu, Shun-Yan; Wagner, Kay-Uwe; Bazinet, Richard P; Woo, Minna

    2017-03-03

    Hepatocellular carcinoma is an end-stage complication of non-alcoholic fatty liver disease (NAFLD). Inflammation plays a critical role in the progression of non-alcoholic fatty liver disease and the development of hepatocellular carcinoma. However, whether steatosis per se promotes liver cancer, and the molecular mechanisms that control the progression in this disease spectrum remain largely elusive. The Janus kinase signal transducers and activators of transcription (JAK-STAT) pathway mediates signal transduction by numerous cytokines that regulate inflammation and may contribute to hepatocarcinogenesis. Mice with hepatocyte-specific deletion of JAK2 (L-JAK2 KO) develop extensive fatty liver spontaneously. We show here that this simple steatosis was insufficient to drive carcinogenesis. In fact, L-JAK2 KO mice were markedly protected from chemically induced tumor formation. Using the methionine choline-deficient dietary model to induce steatohepatitis, we found that steatohepatitis development was completely arrested in L-JAK2 KO mice despite the presence of steatosis, suggesting that JAK2 is the critical factor required for inflammatory progression in the liver. In line with this, L-JAK2 KO mice exhibited attenuated inflammation after chemical carcinogen challenge. This was associated with increased hepatocyte apoptosis without elevated compensatory proliferation, thus thwarting expansion of transformed hepatocytes. Taken together, our findings identify an indispensable role of JAK2 in hepatocarcinogenesis through regulating critical inflammatory pathways. Targeting the JAK-STAT pathway may provide a novel therapeutic option for the treatment of hepatocellular carcinoma. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  13. Crucial factors of the inflammatory microenvironment (IL-1β/TNF-α/TIMP-1) promote the maintenance of the malignant hemopoietic clone of myelofibrosis: an in vitro study.

    Sollazzo, Daria; Forte, Dorian; Polverelli, Nicola; Romano, Marco; Perricone, Margherita; Rossi, Lara; Ottaviani, Emanuela; Luatti, Simona; Martinelli, Giovanni; Vianelli, Nicola; Cavo, Michele; Palandri, Francesca; Catani, Lucia

    2016-07-12

    Along with molecular abnormalities (mutations in JAK2, Calreticulin (CALR) and MPL genes), chronic inflammation is the major hallmark of Myelofibrosis (MF). Here, we investigated the in vitro effects of crucial factors of the inflammatory microenvironment (Interleukin (IL)-1β, Tumor Necrosis Factor (TNF)-α, Tissue Inhibitor of Metalloproteinases (TIMP)-1 and ATP) on the functional behaviour of MF-derived circulating CD34+ cells.We found that, regardless mutation status, IL-1β or TNF-α increases the survival of MF-derived CD34+ cells. In addition, along with stimulation of cell cycle progression to the S-phase, IL-1β or TNF-α ± TIMP-1 significantly stimulate(s) the in vitro clonogenic ability of CD34+ cells from JAK2V617 mutated patients. Whereas in the JAK2V617F mutated group, the addition of IL-1β or TNF-α + TIMP-1 decreased the erythroid compartment of the CALR mutated patients. Megakaryocyte progenitors were stimulated by IL-1β (JAK2V617F mutated patients only) and inhibited by TNF-α. IL-1β + TNF-α + C-X-C motif chemokine 12 (CXCL12) ± TIMP-1 highly stimulates the in vitro migration of MF-derived CD34+ cells. Interestingly, after migration toward IL-1β + TNF-α + CXCL12 ± TIMP-1, CD34+ cells from JAK2V617F mutated patients show increased clonogenic ability.Here we demonstrate that the interplay of these inflammatory factors promotes and selects the circulating MF-derived CD34+ cells with higher proliferative activity, clonogenic potential and migration ability. Targeting these micro-environmental interactions may be a clinically relevant approach.

  14. Myeloproliferative Disease: An Unusual Cause of Raynaud’s Phenomenon and Digital Ischaemia

    Beynon, Celia; Huws, Gwenan; Lawson, Tom

    2016-01-01

    We describe a 59-year-old female who presented with ischaemic digits, preceded by a 6-month history of Raynaud's phenomenon affecting her fingers and toes. There were no clinical or laboratory features of primary vasculitis or connective tissue disease, Doppler imaging was normal, and bloods were unremarkable aside from a platelet count of 786 ? 109/L (150?400) and white cells of 16 ? 109/L (4?11). In view of the thrombocytosis a JAK2 mutation assay was requested which confirmed a JAK2 V617F ...

  15. A phase II study of the oral JAK1/JAK2 inhibitor ruxolitinib in advanced relapsed/refractory Hodgkin lymphoma

    E. van den Neste (Eric); J.-L. André (Jean-Luc); Gastinne, T. (Thomas); A. Stamatoullas (Aspasia); C. Haioun (Corinne); Belhabri, A. (Amine); O. Reman (Oumédaly); O. Casasnovas (O.); H. Ghesquieres; G.E.G. Verhoef (Gregor); Claessen, M.-J. (Marie-José); H.A. Poirel (Hélène A); M.-C. Copin; Dubois, R. (Romain); P. Vandenberghe (Peter); Stoian, I.-A. (Ioanna-Andrea); Cottereau, A.S. (Anne S.); Bailly, S. (Sarah); L. Knoops (Laurent); F. Morschhauser (Frank)

    2018-01-01

    textabstractJAK2 constitutive activation/overexpression is common in classical Hodgkin lymphoma, and several cytokines stimulate Hodgkin lymphoma cells by recognizing JAK1-/JAK2-bound receptors. JAK blockade may thus be therapeutically beneficial in Hodgkin lymphoma. In this phase II study we

  16. JAK2 mediates lung fibrosis, pulmonary vascular remodelling and hypertension in idiopathic pulmonary fibrosis: an experimental study.

    Milara, Javier; Ballester, Beatriz; Morell, Anselm; Ortiz, José L; Escrivá, Juan; Fernández, Estrella; Perez-Vizcaino, Francisco; Cogolludo, Angel; Pastor, Enrique; Artigues, Enrique; Morcillo, Esteban; Cortijo, Julio

    2018-06-01

    Pulmonary hypertension (PH) is a common disorder in patients with idiopathic pulmonary fibrosis (IPF) and portends a poor prognosis. Recent studies using vasodilators approved for PH have failed in improving IPF mainly due to ventilation ( V )/perfusion ( Q ) mismatching and oxygen desaturation. Janus kinase type 2 (JAK2) is a non-receptor tyrosine kinase activated by a broad spectrum of profibrotic and vasoactive mediators, but its role in PH associated to PH is unknown. The study of JAK2 as potential target to treat PH in IPF. JAK2 expression was increased in pulmonary arteries (PAs) from IPF (n=10; 1.93-fold; P=0.0011) and IPF+PH (n=9; 2.65-fold; Ppulmonary artery endothelial cells (HPAECs) and human pulmonary artery smooth muscle cells (HPASMCs) from patients with IPF in vitro treated with the JAK2 inhibitor JSI-124 or siRNA-JAK2 and stimulated with transforming growth factor beta. Both JSI-124 and siRNA-JAK2 inhibited the HPAEC to mesenchymal transition and the HPASMCs to myofibroblast transition and proliferation. JAK2 inhibition induced small PA relaxation in precision-cut lung slice experiments. PA relaxation was dependent of the large conductance calcium-activated potassium channel (BK Ca ). JAK2 inhibition activated BK Ca channels and reduced intracellular Ca 2+ . JSI-124 1 mg/kg/day, reduced bleomycin-induced lung fibrosis, PA remodelling, right ventricular hypertrophy, PA hypertension and V / Q mismatching in rats. The animal studies followed the ARRIVE guidelines. JAK2 participates in PA remodelling and tension and may be an attractive target to treat IPF associated to PH. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  17. Genetic Alterations of the Thrombopoietin/MPL/JAK2 Axis Impacting Megakaryopoiesis

    Plo, Isabelle; Bellanné-Chantelot, Christine; Mosca, Matthieu; Mazzi, Stefania; Marty, Caroline; Vainchenker, William

    2017-01-01

    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) act...

  18. Autophagy Facilitates IFN-γ-induced Jak2-STAT1 Activation and Cellular Inflammation*

    Chang, Yu-Ping; Tsai, Cheng-Chieh; Huang, Wei-Ching; Wang, Chi-Yun; Chen, Chia-Ling; Lin, Yee-Shin; Kai, Jui-In; Hsieh, Chia-Yuan; Cheng, Yi-Lin; Choi, Pui-Ching; Chen, Shun-Hua; Chang, Shih-Ping; Liu, Hsiao-Sheng; Lin, Chiou-Feng

    2010-01-01

    Autophagy is regulated for IFN-γ-mediated antimicrobial efficacy; however, its molecular effects for IFN-γ signaling are largely unknown. Here, we show that autophagy facilitates IFN-γ-activated Jak2-STAT1. IFN-γ induces autophagy in wild-type but not in autophagy protein 5 (Atg5−/−)-deficient mouse embryonic fibroblasts (MEFs), and, autophagy-dependently, IFN-γ induces IFN regulatory factor 1 and cellular inflammatory responses. Pharmacologically inhibiting autophagy using 3-methyladenine, a known inhibitor of class III phosphatidylinositol 3-kinase, confirms these effects. Either Atg5−/− or Atg7−/− MEFs are, independent of changes in IFN-γ receptor expression, resistant to IFN-γ-activated Jak2-STAT1, which suggests that autophagy is important for IFN-γ signal transduction. Lentivirus-based short hairpin RNA for Atg5 knockdown confirmed the importance of autophagy for IFN-γ-activated STAT1. Without autophagy, reactive oxygen species increase and cause SHP2 (Src homology-2 domain-containing phosphatase 2)-regulated STAT1 inactivation. Inhibiting SHP2 reversed both cellular inflammation and the IFN-γ-induced activation of STAT1 in Atg5−/− MEFs. Our study provides evidence that there is a link between autophagy and both IFN-γ signaling and cellular inflammation and that autophagy, because it inhibits the expression of reactive oxygen species and SHP2, is pivotal for Jak2-STAT1 activation. PMID:20592027

  19. A phase 2 study of ruxolitinib, an oral JAK1 and JAK2 Inhibitor, in patients with advanced polycythemia vera who are refractory or intolerant to hydroxyurea.

    Verstovsek, Srdan; Passamonti, Francesco; Rambaldi, Alessandro; Barosi, Giovanni; Rosen, Peter J; Rumi, Elisa; Gattoni, Elisabetta; Pieri, Lisa; Guglielmelli, Paola; Elena, Chiara; He, Shui; Contel, Nancy; Mookerjee, Bijoyesh; Sandor, Victor; Cazzola, Mario; Kantarjian, Hagop M; Barbui, Tiziano; Vannucchi, Alessandro M

    2014-02-15

    Polycythemia vera (PV) is a myeloproliferative neoplasm associated with somatic gain-of-function mutations of Janus kinase-2 (JAK2). Therapeutic options are limited in patients with advanced disease. Ruxolitinib, an oral JAK1/JAK2 inhibitor, is active in preclinical models of PV. The long-term efficacy and safety of ruxolitinib in patients with advanced PV who are refractory or intolerant to hydroxyurea were studied in a phase 2 trial. Response was assessed using modified European LeukemiaNet criteria, which included a reduction in hematocrit to cell and platelet counts, and reduction in PV-associated symptoms. Thirty-four patients received ruxolitinib for a median of 152 weeks (range, 31 weeks-177 weeks) or 35.0 months (range, 7.1 months-40.7 months). Hematocrit night sweats, and bone pain were observed within 4 weeks of the initiation of therapy and maintained with continued treatment. Ruxolitinib treatment also reduced elevated levels of inflammatory cytokines and granulocyte activation. Thrombocytopenia and anemia were the most common adverse events.Thrombocytopenia of grade 3 or anemia of grade 3 (according to National Cancer Institute Common Terminology Criteria for Adverse Events,version 3.0) occurred in 3 patients each (9%) (1 patient had both) and were managed with dose modification. Ruxolitinib was generally well tolerated and provided rapid and durable clinical benefits in patients with advanced PV who were refractory or intolerant to hydroxyurea.

  20. Involvement of JAK2 upstream of the PI 3-kinase in cell-cell adhesion regulation by gastrin

    Ferrand, Audrey; Kowalski-Chauvel, Aline; Bertrand, Claudine; Pradayrol, Lucien; Fourmy, Daniel; Dufresne, Marlene; Seva, Catherine

    2004-01-01

    The Janus kinase/signal transducers and activators of transcription (JAK/STAT) signaling pathway has been implicated in cell transformation and proliferation. Besides aberrant cell proliferation, loss of cell-cell adhesion during epithelial-mesenchymal transition (EMT) is an important event which occurs during development of epithelial cancers. However, the role of JAK-dependent pathways in this process is not known. We analyzed the involvement of these pathways in the regulation of E-cadherin-dependent cell-cell adhesion by gastrin, a mitogenic factor for gastrointestinal (GI) tract. We identified JAK2/STAT3 as a new pathway in gastrin signaling. We demonstrated that JAK2 functions as an upstream mediator of the phosphatidylinositol 3 (PI 3)-kinase activity in gastrin signaling. Indeed, we observed a coprecipitation of both kinases and an inhibition of gastrin-induced PI 3-kinase activation when JAK2 activity is blocked. We also demonstrated that loss of cell-cell adhesion and the increase in cell motility induced by gastrin required the activation of JAK2 and the PI 3-kinase. Indeed, the modifications in localization of adherens junctions proteins and the migration, observed in gastrin-stimulated cells, were reversed by inhibition of both kinases. These results described the involvement of JAK2 in the modulation of cell-cell adhesion in epithelial cells. They support a possible role of JAK2 in the epithelial-mesenchymal transition which occurs during malignant development

  1. Two Clinical Phenotypes in Polycythemia Vera

    Spivak, Jerry L.; Considine, Michael; Williams, Donna M.; Talbot, Conover C.; Rogers, Ophelia; Moliterno, Alison R.; Jie, Chunfa; Ochs, Michael F.

    2014-01-01

    BACKGROUND Polycythemia vera is the ultimate phenotypic consequence of the V617F mutation in Janus kinase 2 (encoded by JAK2), but the extent to which this mutation influences the behavior of the involved CD34+ hematopoietic stem cells is unknown. METHODS We analyzed gene expression in CD34+ peripheral-blood cells from 19 patients with polycythemia vera, using oligonucleotide microarray technology after correcting for potential confounding by sex, since the phenotypic features of the disease differ between men and women. RESULTS Men with polycythemia vera had twice as many up-regulated or down-regulated genes as women with polycythemia vera, in a comparison of gene expression in the patients and in healthy persons of the same sex, but there were 102 genes with differential regulation that was concordant in men and women. When these genes were used for class discovery by means of unsupervised hierarchical clustering, the 19 patients could be divided into two groups that did not differ significantly with respect to age, neutrophil JAK2 V617F allele burden, white-cell count, platelet count, or clonal dominance. However, they did differ significantly with respect to disease duration; hemoglobin level; frequency of thromboembolic events, palpable splenomegaly, and splenectomy; chemotherapy exposure; leukemic transformation; and survival. The unsupervised clustering was confirmed by a supervised approach with the use of a top-scoring-pair classifier that segregated the 19 patients into the same two phenotypic groups with 100% accuracy. CONCLUSIONS Removing sex as a potential confounder, we identified an accurate molecular method for classifying patients with polycythemia vera according to disease behavior, independently of their JAK2 V617F allele burden, and identified previously unrecognized molecular pathways in polycythemia vera outside the canonical JAK2 pathway that may be amenable to targeted therapy. PMID:25162887

  2. RANKL downregulates cell surface CXCR6 expression through JAK2/STAT3 signaling pathway during osteoclastogenesis

    Li, Changhong; Zhao, Jinxia; Sun, Lin; Yao, Zhongqiang; Liu, Rui [Department of Rheumatology and Immunology, Peking University Third Hospital, Beijing 100191 (China); Huang, Jiansheng [Department of Pediatrics, Washington University School of Medicine, St. Louis, MO (United States); Liu, Xiangyuan, E-mail: liu-xiangyuan@263.net [Department of Rheumatology and Immunology, Peking University Third Hospital, Beijing 100191 (China)

    2012-12-14

    Highlights: Black-Right-Pointing-Pointer CXCR6 is down-regulated during RANKL-induced osteoclastogenesis in RAW264.7 cells. Black-Right-Pointing-Pointer CXCR6 reduction was nearly reversed by inhibition of JAK2/STAT3 signaling pathway. Black-Right-Pointing-Pointer CXCL16 alone does not positively regulate osteoclastogenesis. -- Abstract: The receptor activator of nuclear factor-{kappa}B ligand (RANKL), as a member of the tumor necrosis factor (TNF) family, plays an essential role in osteoclast differentiation and function. Chemokines and their receptors have recently been shown to play critical roles in osteoclastogenesis, however, whether CXCL16-CXCR6 plays role in RANKL-mediated osteoclastogenesis is unknown. In this study, we first reported that RANKL decreased CXCR6 in a dose-dependent manner, which may be through deactivation of Akt and STAT3 signaling induced by CXCL16. Interestingly, RANKL-mediated CXCR6 reduction may be associated to the activation of STAT3 by phosphorylation. When STAT3 activation was blocked by JAK2/STAT3 inhibitor AG490, RANKL failed to shut down CXCR6 expression during osteoclastogenesis. However, CXCL16 alone did not augment RANKL-mediated osteoclast differentiation and did not alter RANKL-receptor RANK mRNA expression. These results demonstrate that reduction of CXCL16-CXCR6 is critical in RANKL-mediated osteoclastogenesis, which is mainly through the activation of JAK2/STAT3 signaling. CXCL16-CXCR6 axis may become a novel target for the therapeutic intervention of bone resorbing diseases such as rheumatoid arthritis and osteoporosis.

  3. Splanchnic venous thrombosis driven by a constitutively activated ...

    sated chronic liver disease found to have SVT- portal vein thrombosis and how JAK2 V617F was useful in unmasking an ... to over proliferation of the myeloid series. .... gression to acute leukemia and myelofibrosis. .... factors and treatment.

  4. Analysis of genomic aberrations and gene expression profiling identifies novel lesions and pathways in myeloproliferative neoplasms

    Rice, K L; Lin, X; Wolniak, K; Ebert, B L; Berkofsky-Fessler, W; Buzzai, M; Sun, Y; Xi, C; Elkin, P; Levine, R; Golub, T; Gilliland, D G; Crispino, J D; Licht, J D; Zhang, W

    2011-01-01

    Polycythemia vera (PV), essential thrombocythemia and primary myelofibrosis, are myeloproliferative neoplasms (MPNs) with distinct clinical features and are associated with the JAK2V617F mutation. To identify genomic anomalies involved in the pathogenesis of these disorders, we profiled 87 MPN patients using Affymetrix 250K single-nucleotide polymorphism (SNP) arrays. Aberrations affecting chr9 were the most frequently observed and included 9pLOH (n=16), trisomy 9 (n=6) and amplifications of 9p13.3–23.3 (n=1), 9q33.1–34.13 (n=1) and 9q34.13 (n=6). Patients with trisomy 9 were associated with elevated JAK2V617F mutant allele burden, suggesting that gain of chr9 represents an alternative mechanism for increasing JAK2V617F dosage. Gene expression profiling of patients with and without chr9 abnormalities (+9, 9pLOH), identified genes potentially involved in disease pathogenesis including JAK2, STAT5B and MAPK14. We also observed recurrent gains of 1p36.31–36.33 (n=6), 17q21.2–q21.31 (n=5) and 17q25.1–25.3 (n=5) and deletions affecting 18p11.31–11.32 (n=8). Combined SNP and gene expression analysis identified aberrations affecting components of a non-canonical PRC2 complex (EZH1, SUZ12 and JARID2) and genes comprising a ‘HSC signature' (MLLT3, SMARCA2 and PBX1). We show that NFIB, which is amplified in 7/87 MPN patients and upregulated in PV CD34+ cells, protects cells from apoptosis induced by cytokine withdrawal

  5. Preclinical evaluation of local JAK1 and JAK2 inhibition in cutaneous inflammation.

    Fridman, Jordan S; Scherle, Peggy A; Collins, Robert; Burn, Timothy; Neilan, Claire L; Hertel, Denise; Contel, Nancy; Haley, Patrick; Thomas, Beth; Shi, Jack; Collier, Paul; Rodgers, James D; Shepard, Stacey; Metcalf, Brian; Hollis, Gregory; Newton, Robert C; Yeleswaram, Swamy; Friedman, Steven M; Vaddi, Kris

    2011-09-01

    JAKs are required for signaling initiated by several cytokines (e.g., IL-4, IL-12, IL-23, thymic stromal lymphopoietin (TSLP), and IFNγ) implicated in the pathogenesis of inflammatory skin diseases such as psoriasis and atopic dermatitis (AD). Direct antagonism of cytokines, such as IL-12 and IL-23 using ustekinumab, has proven effective in randomized studies in psoriasis patients. We hypothesized that local inhibition of cytokine signaling using topical administration of INCB018424, a small molecule inhibitor of JAK1 and JAK2, would provide benefit similar to systemic cytokine neutralization. In cellular assays, INCB018424 inhibits cytokine-induced JAK/signal transducers and activators of transcription (STAT) signaling and the resultant production of inflammatory proteins (e.g., IL-17, monocyte chemotactic protein-1, and IL-22) in lymphocytes and monocytes, with half-maximal inhibitory concentration values keratinocyte proliferation in a murine contact hypersensitivity model and inhibited tissue inflammation induced by either intradermal IL-23 or TSLP. Topical INCB018424 was also well tolerated in a 28-day safety study in Gottingen minipigs. These results suggest that localized JAK1/JAK2 inhibition may be therapeutic in a range of inflammatory skin disorders such as psoriasis and AD. Clinical evaluation of topical INCB018424 is ongoing.

  6. Mpl traffics to the cell surface through conventional and unconventional routes.

    Cleyrat, Cédric; Darehshouri, Anza; Steinkamp, Mara P; Vilaine, Mathias; Boassa, Daniela; Ellisman, Mark H; Hermouet, Sylvie; Wilson, Bridget S

    2014-09-01

    Myeloproliferative neoplasms (MPNs) are often characterized by JAK2 or calreticulin (CALR) mutations, indicating aberrant trafficking in pathogenesis. This study focuses on Mpl trafficking and Jak2 association using two model systems: human erythroleukemia cells (HEL; JAK2V617F) and K562 myeloid leukemia cells (JAK2WT). Consistent with a putative chaperone role for Jak2, Mpl and Jak2 associate on both intracellular and plasma membranes (shown by proximity ligation assay) and siRNA-mediated knockdown of Jak2 led to Mpl trapping in the endoplasmic reticulum (ER). Even in Jak2 sufficient cells, Mpl accumulates in punctate structures that partially colocalize with ER-tracker, the ER exit site marker (ERES) Sec31a, the autophagy marker LC3 and LAMP1. Mpl was fused to miniSOG, a genetically encoded tag for correlated light and electron microscopy. Results suggest that a fraction of Mpl is taken up into autophagic structures from the ER and routed to autolyososomes. Surface biotinylation shows that both immature and mature Mpl reach the cell surface; in K562 cells Mpl is also released in exosomes. Both forms rapidly internalize upon ligand addition, while recovery is primarily attributed to immature Mpl. Mpl appears to reach the plasma membrane via both conventional ER-Golgi and autolysosome secretory pathways, as well as recycling. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  7. Transformation of an Unclassified Myeloproliferative Neoplasm with a Rare BCR-JAK2 Fusion Transcript Resulting from the Translocation (9;22)(p24;q11)

    A. N. Chamseddine; P. Etancelin; D. Penther; F. Parmentier; C. Kuadjovi; V. Camus; N. Contentin; P. Lenain; C. Bastard; H. Tilly; F. Jardin

    2015-01-01

    BCR-ABL1 negative myeloproliferative neoplasms (MPNs) are known to contain alterations of the tyrosine kinase JAK2 (located on 9p24) that result in constitutive activation of the encoded protein. JAK2 fusions are reported in acute and chronic leukemias of myeloid and lymphoid phenotypes. Here, we report an unclassified case of MPN (MPN-U) showing a t(9;22)(p24;q11), which generates a BCR-JAK2 fusion gene by fusing the BCR at intron 13 to JAK2 at intron 17 on the derivative chromosome 22. Most...

  8. JAK inhibitors for the treatment of myeloproliferative neoplasms and other disorders [version 1; referees: 2 approved

    William Vainchenker

    2018-01-01

    Full Text Available JAK inhibitors have been developed following the discovery of the JAK2V617F in 2005 as the driver mutation of the majority of non-BCR-ABL1 myeloproliferative neoplasms (MPNs. Subsequently, the search for JAK2 inhibitors continued with the discovery that the other driver mutations (CALR and MPL also exhibited persistent JAK2 activation. Several type I ATP-competitive JAK inhibitors with different specificities were assessed in clinical trials and exhibited minimal hematologic toxicity. Interestingly, these JAK inhibitors display potent anti-inflammatory activity. Thus, JAK inhibitors targeting preferentially JAK1 and JAK3 have been developed to treat inflammation, autoimmune diseases, and graft-versus-host disease. Ten years after the beginning of clinical trials, only two drugs have been approved by the US Food and Drug Administration: one JAK2/JAK1 inhibitor (ruxolitinib in intermediate-2 and high-risk myelofibrosis and hydroxyurea-resistant or -intolerant polycythemia vera and one JAK1/JAK3 inhibitor (tofacitinib in methotrexate-resistant rheumatoid arthritis. The non-approved compounds exhibited many off-target effects leading to neurological and gastrointestinal toxicities, as seen in clinical trials for MPNs. Ruxolitinib is a well-tolerated drug with mostly anti-inflammatory properties. Despite a weak effect on the cause of the disease itself in MPNs, it improves the clinical state of patients and increases survival in myelofibrosis. This limited effect is related to the fact that ruxolitinib, like the other type I JAK2 inhibitors, inhibits equally mutated and wild-type JAK2 (JAK2WT and also the JAK2 oncogenic activation. Thus, other approaches need to be developed and could be based on either (1 the development of new inhibitors specifically targeting JAK2V617F or (2 the combination of the actual JAK2 inhibitors with other therapies, in particular with molecules targeting pathways downstream of JAK2 activation or the stability of JAK2

  9. Identification of SH2-Bbeta as a substrate of the tyrosine kinase JAK2 involved in growth hormone signaling.

    Rui, L; Mathews, L S; Hotta, K; Gustafson, T A; Carter-Su, C

    1997-01-01

    Activation of the tyrosine kinase JAK2 is an essential step in cellular signaling by growth hormone (GH) and multiple other hormones and cytokines. Murine JAK2 has a total of 49 tyrosines which, if phosphorylated, could serve as docking sites for Src homology 2 (SH2) or phosphotyrosine binding domain-containing signaling molecules. Using a yeast two-hybrid screen of a rat adipocyte cDNA library, we identified a splicing variant of the SH2 domain-containing protein SH2-B, designated SH2-Bbeta,...

  10. The role of JAK1/2 inhibitors in the treatment of chronic myeloproliferative neoplasms.

    Keohane, Clodagh; Mesa, Ruben; Harrison, Claire

    2013-01-01

    In 2005, the description of the JAK2V617F mutation for the first time provided a molecular key to enable more rapid diagnosis and target for novel therapeutics in the myeloproliferative neoplasms. In 2007, the first-in-class agent INC18424, ruxolitinib, JAKafi, or JAKAVI was first tested in patients with intermediate-risk 2 or high-risk myelofibrosis regardless of whether they possessed the JAK2V617F mutation. Patients treated with this agent had major reduction in splenomegaly as well as impressive reduction, and in some cases resolution, of symptoms. This study was followed by the two Controlled Myelofibrosis Study with Oral JAK Inhibitor Therapy (COMFORT) trials (the first-ever phase III trials in myelofibrosis), which confirmed results in these aspects were superior to either placebo or standard care, and updated results show a survival advantage with this therapy. This paper discusses these results and data from other JAK inhibitors while speculating on the future of these therapies. It also reflects on the fact that the true targets and agents' mode of action are uncertain. Unlike targeted therapy for chronic myeloid leukemia (CML), these agents do not deliver molecular remission, and it is not clear whether their predominant benefit is mediated via JAK2, JAK1, or both. Nonetheless, the advent of the JAK inhibitor is a welcome advance and has made a dramatic improvement to the therapeutic landscape of these conditions.

  11. Splanchnic vein thrombosis as a first manifestation of Primary myelofibrosis

    Campos-Cabrera, Gregorio; Campos-Cabrera, Virginia; Campos-Cabrera, Salvador; Campos-Villagómez, José-Luis; Romero-González, Alejandra

    2017-01-01

    Myeloproliferative neoplasms are chronic disorders of clonal hematopoietic stem cells, characterized by an overproduction of functional granulocytes, red blood cells and / or platelets, and one of the major complications is the occurrence of venous and arterial thrombotic problems caused by increased platelet aggregation and thrombin generation. In this study 11 cases of primary myelofibrosis (PM) were evaluated and 2 debuted with splanchnic venous thrombosis (SVT); so after seeing the results of this study and of world literature, it is suggested that in patients with SVT, diagnostic methods for PM like the JAK2V617F mutation should be included. Copyright: © 2017 SecretarÍa de Salud

  12. AKT is a therapeutic target in myeloproliferative neoplasms.

    Khan, I; Huang, Z; Wen, Q; Stankiewicz, M J; Gilles, L; Goldenson, B; Schultz, R; Diebold, L; Gurbuxani, S; Finke, C M; Lasho, T L; Koppikar, P; Pardanani, A; Stein, B; Altman, J K; Levine, R L; Tefferi, A; Crispino, J D

    2013-09-01

    The majority of patients with BCR-ABL1-negative myeloproliferative neoplasms (MPN) harbor mutations in JAK2 or MPL, which lead to constitutive activation of the JAK/STAT, PI3K and ERK signaling pathways. JAK inhibitors by themselves are inadequate in producing selective clonal suppression in MPN and are associated with hematopoietic toxicities. MK-2206 is a potent allosteric AKT inhibitor that was well tolerated, including no evidence of myelosuppression, in a phase I study of solid tumors. Herein, we show that inhibition of PI3K/AKT signaling by MK-2206 affected the growth of both JAK2V617F- or MPLW515L-expressing cells via reduced phosphorylation of AKT and inhibition of its downstream signaling molecules. Moreover, we demonstrate that MK-2206 synergizes with ruxolitinib in suppressing the growth of JAK2V617F-mutant SET2 cells. Importantly, MK-2206 suppressed colony formation from hematopoietic progenitor cells in patients with primary myelofibrosis and alleviated hepatosplenomegaly and reduced megakaryocyte burden in the bone marrows, livers and spleens of mice with MPLW515L-induced MPN. Together, these findings establish AKT as a rational therapeutic target in the MPNs.

  13. Overexpression of B7-H3 augments anti-apoptosis of colorectal cancer cells by Jak2-STAT3.

    Zhang, Ting; Jiang, Bo; Zou, Shi-Tao; Liu, Fen; Hua, Dong

    2015-02-14

    To investigate the role of the overexpression of B7-H3 in apoptosis in colorectal cancer cell lines and the underlying molecular mechanisms. SW620 cells that highly overexpressed B7-H3 (SW620-B7-H3-EGFP) and HCT8 cells stably transfected with B7-H3 shRNA (HCT8-shB7-H3) were previously constructed in our laboratory. Cells transfected with pIRES2-EGFP were used as negative controls (SW620-NC and HCT8-NC). Real-time PCR and western blotting analysis were used to detect the mRNA and protein expressions of the apoptosis regulator proteins Bcl-2, Bcl-xl and Bax. A cell proliferation assay was used to evaluate the survival rate and drug sensitivity of the cells. The effect of drug resistance was detected by a cell cycle assay. Active caspase-3 western blotting was used to reflect the anti-apoptotic ability of cells. Western blotting was also performed to determine the expression of proteins associated with the Jak2-STAT3 signaling pathway and the apoptosis regulator proteins after the treatment with AG490, a Jak2 specific inhibitor, in B7-H3 overexpressing cells. The data were analyzed by GraphPad Prism 6 using a non-paired t-test. Whether by overexpression in SW620 cells or downregulation in HCT8, B7-H3 significantly affected the expression of anti- and pro-apoptotic proteins, at both the transcriptional and translational levels, compared with the negative control (P overexpression increased the drug resistance of cells and resulted in a higher survival rate (P overexpression inhibited apoptosis in colorectal cancer cell lines (P overexpression improved Jak2 and STAT3 phosphorylation and, in turn, increased the expression of the downstream anti-apoptotic proteins B-cell CLL/lymphoma 2 (Bcl-2) and Bcl-xl, based on western blotting (P overexpressing cells with the Jak2-specific inhibitor AG490, the phosphorylation of Jak2 and STAT3, and the expression of Bcl-2 and Bcl-xl, decreased accordingly (P overexpression of B7-H3 induces resistance to apoptosis in colorectal cancer

  14. The Influence of Compound Shougong Powder on JAK2-STAT3 Signaling Pathway in Mice with Lewis Lung Cancer

    SHEN Di

    2014-12-01

    Full Text Available Objective: To observe the influence of Compound Shougong Powder on JAK2-STAT3 signaling pathway in mice with Lewis lung cancer. Methods: Fifty C57BL/6J mice were inoculated with Lewis lung cancer cell line according to the conventional method, 40 mice bearing cancer successfully were selected 6 d later and randomly divided into 5groups, namely negative control group, cis-platinum group, high-dose Compound Shougong Powder group, middle-dose Compound Shougong Powder group and low-dose Compound Shougong Powder group, 8 mice in each group. Negative control group was drenched with normal saline (NS. Compound Shougong Powder groups were drenched with Compound Shougong Powder, 4 mg/kg for high-dose group, 2 mg/kg for middle-dose group, 1 mg/kg for low-dose group, once per day for 14 d; cis-platinum group was orally administrated 4 mg/kg/w, intraperitoneal injection of 0.1 mL for each, once per week for 2 weeks. Mice’s responses to the treatment, activity levels, mental states and so on during the treatment were observed, tumor inhibition rate was calculated, pathomorphological changes of tumor tissues were observed under light microscope after HE staining, and the expression levels of JAK2 and STAT3 proteins were detected by Western Blot. Results: After drug administration, smooth, glossy body hair and good spirit were observed in cisplatin group and high-dose Compound Shougong Powder group; glossier body hair and less activity level in middle- and low- dose Compound Shougong Powder group, and great toxic and side effects, reduced activity level and weary spirit in negative control group. The tumor inhibition rate of cisplatin group, high-, middle- and low-dose Compound Shougong Powder group and negative control group was 57.69%, 53.53%, 48.40%, 38.46% and 38.46%, respectively. The expression levels of JAK2 and STAT3 proteins in drug groups showed decreases to different degrees, and the decreases of JAK2 were more significant. Conclusion: Compound

  15. Total glucosides of paeony regulates JAK2/STAT3 activation and macrophage proliferation in diabetic rat kidneys.

    Wang, Kun; Wu, Yong-Gui; Su, Jing; Zhang, Jing-Jing; Zhang, Pei; Qi, Xiang-Ming

    2012-01-01

    Total glucosides of paeony (TGP) is the major active constituent of Paeonia lactiflora Pall., which has shown renoprotection in experimental diabetic nephropathy. Activation of Janus kinase/signal transducers and activators of transcription (JAK/STAT) is an important mechanism by which hyperglycemia contributes to renal damage. Macrophages also play an essential role in the pathogenesis of diabetic nephropathy. Herein, we investigated the ability of TGP to modulate JAK2/STAT3 activation and macrophage proliferation in rats with streptozotocin (STZ)-induced diabetes. TGP (50, 100, and 200 mg/kg) was administered orally once a day for eight weeks. Levels of p-JAK2 and p-STAT3 were determined by Western blot analysis. Immunohistochemistry and double immunohistochemistry were used to identify p-STAT3, ED-1, PCNA/ED-1, and p-STAT3/ED-1-positive (+) cells. The elevated 24-h urinary albumin excretion rate was markedly attenuated by treatment with 50, 100, and 200 mg/kg TGP. Western blot analysis showed that the significantly increased levels of p-JAK2, p-STAT3 proteins in the kidneys of diabetic rats were significantly inhibited by 50, 100, and 200 mg/kg TGP treatment. The marked accumulation and proliferation of macrophages in diabetic kidneys were significantly inhibited by TGP treatment. ED-1+/p-STAT3+ cells were significantly increased in the kidneys from the model group but were significantly inhibited by TGP treatment. These results show that TGP significantly inhibited diabetic nephropathy progression and suggest that these protective effects are associated with the ability of TGP to inhibit the JAK2/STAT3 pathway and macrophage proliferation and action.

  16. Pantoprazole blocks the JAK2/STAT3 pathway to alleviate skeletal muscle wasting in cancer cachexia by inhibiting inflammatory response.

    Guo, Dunwei; Wang, Chaoyi; Wang, Qiang; Qiao, Zhongpeng; Tang, Hua

    2017-06-13

    Cancer cachexia is often present in patients with advanced malignant tumors, and the subsequent body weight reduction results in poor quality of life. However, there has been no progress in developing effective clinical therapeutic strategies for skeletal muscle wasting in cancer cachexia. Herein, we explored the functions of pantoprazole on cancer cachexia skeletal muscle wasting. The mouse colon adenocarcinoma cell line C26 was inoculated in the right forelimb of male BALB/C mice to establish a cancer cachexia model. The animals were treated with or without different concentrations of pantoprazole orally, and the body weight, tumor growth, spontaneous activity, and muscle functions were determined at various time points. Two weeks later, the levels of serum IL-6 and TNF-α, the mRNA levels of gastrocnemius JAK2 and STAT3, and the expression levels of p-JAK2, p-STAT3, Fbx32, and MuRF1 were examined with ELISA assay, qRT-PCR assay, and Western blotting, respectively. Further studies were performed to assess the levels of Fbx32 and MuRF1 expression and morphological changes. Pantoprazole can alleviate cancer cachexia-induced body weight reduction and inhibit skeletal muscle wasting in a dose-dependent manner. Our results indicated that pantoprazole treatment can decrease the levels of serum IL-6 and TNF-α (56.3% and 67.6%, respectively), and inhibit the activation of the JAK2/STAT3 signaling pathway. Moreover, the expression levels of MuRF1 and Fbx32 were also suppressed after pantoprazole treatment. Our findings suggested that pantoprazole can alleviate cancer cachexia skeletal muscle wasting by inhibiting the inflammatory response and blocking the JAK2/STAT3 or ubiquitin proteasome pathway.

  17. Thrombocytosis and thrombosis.

    Vannucchi, Alessandro M; Barbui, Tiziano

    2007-01-01

    The aim of this review is to discuss current diagnostic approaches to, and classification of, patients presenting with thrombocytosis, in light of novel information derived from the discovery of specific molecular abnormalities in chronic myeloproliferative disorders (CMPD), which represent the most common cause of primary thrombocytosis. The JAK2V617F and the MPLW515L/K mutations have been found in patients with essential thrombocythemia, polycythemia vera, and primary myelofibrosis, and less frequently in other myeloproliferative disorders complicated by thrombocytosis. However, neither mutation is disease specific nor is it universally present in patients with elevated platelet counts due to a CMPD; therefore, distinguishing between reactive and primary forms of thrombocytosis, as well as among the different clinical entities that constitute the CMPD, still requires a multifaceted diagnostic approach that includes as a key step the accurate evaluation of bone marrow histology. The role of elevated platelet counts in thrombosis, which represent the predominant complication of CMPD,significantly affecting prognosis and quality of life as well as, paradoxically, in the pathogenesis of the hemorrhagic manifestations, will be discussed. Established and novel potential risk factors for thrombosis, including the clinical relevance of the JAK2V617F mutation, and current management strategies for thrombocytosis are also briefly discussed.

  18. Resveratrol induces cell cycle arrest and apoptosis in malignant NK cells via JAK2/STAT3 pathway inhibition.

    Quoc Trung, Ly; Espinoza, J Luis; Takami, Akiyoshi; Nakao, Shinji

    2013-01-01

    Natural killer (NK) cell malignancies, particularly aggressive NK cell leukaemias and lymphomas, have poor prognoses. Although recent regimens with L-asparaginase substantially improved outcomes, novel therapeutic approaches are still needed to enhance clinical response. Resveratrol, a naturally occurring polyphenol, has been extensively studied for its anti-inflammatory, cardioprotective and anti-cancer activities. In this study, we investigated the potential anti-tumour activities of resveratrol against the NK cell lines KHYG-1, NKL, NK-92 and NK-YS. Resveratrol induced robust G0/G1 cell cycle arrest, significantly suppressed cell proliferation and induced apoptosis in a dose- and time-dependent manner for all four cell lines. In addition, resveratrol suppressed constitutively active STAT3 in all the cell lines and inhibited JAK2 phosphorylation but had no effect on other upstream mediators of STAT3 activation, such as PTEN, TYK2, and JAK1. Resveratrol also induced downregulation of the anti-apoptotic proteins MCL1 and survivin, two downstream effectors of the STAT3 pathway. Finally, resveratrol induced synergistic effect on the apoptotic and antiproliferative activities of L-asparaginase against KHYG-1, NKL and NK-92 cells. These results suggest that resveratrol may have therapeutic potential against NK cell malignancies. Furthermore, our finding that resveratrol is a bonafide JAK2 inhibitor extends its potential benefits to other diseases with dysregulated JAK2 signaling.

  19. Resveratrol induces cell cycle arrest and apoptosis in malignant NK cells via JAK2/STAT3 pathway inhibition.

    Ly Quoc Trung

    Full Text Available Natural killer (NK cell malignancies, particularly aggressive NK cell leukaemias and lymphomas, have poor prognoses. Although recent regimens with L-asparaginase substantially improved outcomes, novel therapeutic approaches are still needed to enhance clinical response. Resveratrol, a naturally occurring polyphenol, has been extensively studied for its anti-inflammatory, cardioprotective and anti-cancer activities. In this study, we investigated the potential anti-tumour activities of resveratrol against the NK cell lines KHYG-1, NKL, NK-92 and NK-YS. Resveratrol induced robust G0/G1 cell cycle arrest, significantly suppressed cell proliferation and induced apoptosis in a dose- and time-dependent manner for all four cell lines. In addition, resveratrol suppressed constitutively active STAT3 in all the cell lines and inhibited JAK2 phosphorylation but had no effect on other upstream mediators of STAT3 activation, such as PTEN, TYK2, and JAK1. Resveratrol also induced downregulation of the anti-apoptotic proteins MCL1 and survivin, two downstream effectors of the STAT3 pathway. Finally, resveratrol induced synergistic effect on the apoptotic and antiproliferative activities of L-asparaginase against KHYG-1, NKL and NK-92 cells. These results suggest that resveratrol may have therapeutic potential against NK cell malignancies. Furthermore, our finding that resveratrol is a bonafide JAK2 inhibitor extends its potential benefits to other diseases with dysregulated JAK2 signaling.

  20. The PLA2R1-JAK2 pathway upregulates ERRα and its mitochondrial program to exert tumor-suppressive action.

    Griveau, A; Devailly, G; Eberst, L; Navaratnam, N; Le Calvé, B; Ferrand, M; Faull, P; Augert, A; Dante, R; Vanacker, J M; Vindrieux, D; Bernard, D

    2016-09-22

    Little is known about the biological role of the phospholipase A2 receptor (PLA2R1) transmembrane protein. In recent years, PLA2R1 has been shown to have an important role in regulating tumor-suppressive responses via JAK2 activation, but the underlying mechanisms are largely undeciphered. In this study, we observed that PLA2R1 increases the mitochondrial content, judged by increased levels of numerous mitochondrial proteins, of the mitochondrial structural component cardiolipin, of the mitochondrial DNA content, and of the mitochondrial DNA replication and transcription factor TFAM. This effect of PLA2R1 relies on a transcriptional program controlled by the estrogen-related receptor alpha1 (ERRα) mitochondrial master regulator. Expression of ERRα and of its nucleus-encoded mitochondrial targets is upregulated upon PLA2R1 ectopic expression, and this effect is mediated by JAK2. Conversely, downregulation of PLA2R1 decreases the level of ERRα and of its nucleus-encoded mitochondrial targets. Finally, blocking the ERRα-controlled mitochondrial program largely inhibits the PLA2R1-induced tumor-suppressive response. Together, our data document ERRα and its mitochondrial program as downstream effectors of the PLA2R1-JAK2 pathway leading to oncosuppression.

  1. Myeloproliferative Disease: An Unusual Cause of Raynaud’s Phenomenon and Digital Ischaemia

    Celia Beynon

    2016-01-01

    Full Text Available We describe a 59-year-old female who presented with ischaemic digits, preceded by a 6-month history of Raynaud’s phenomenon affecting her fingers and toes. There were no clinical or laboratory features of primary vasculitis or connective tissue disease, Doppler imaging was normal, and bloods were unremarkable aside from a platelet count of 786 × 109/L (150–400 and white cells of 16 × 109/L (4–11. In view of the thrombocytosis a JAK2 mutation assay was requested which confirmed a JAK2 V617F mutation, suggesting essential thrombocytosis (ET as the cause. She received treatment with hydroxycarbamide which normalised her platelet count and led to a complete resolution of her Raynaud’s symptoms. Raynaud’s phenomenon is a rare manifestation of ET. Myeloproliferative disorders such as ET should be considered in the differential diagnosis of Raynaud’s phenomenon and vasculitis.

  2. Secondary Hypertension, Erythrocytosis, and Unilateral Renal Cystic Disease in a Submariner: A Case Report.

    Forbes, Angela S; Yeo, Fred E

    Erythrocytosis, or increased red blood cell mass, may be primary as in the case of polycythemia vera (PV), or secondary due to a variety of causes related to erythropoietin (EPO) secretion and hypoxia. Chronic pulmonary disease and certain EPO-secreting tumors should be addressed and excluded early during the course of evaluation for a patient presenting with increased red blood cell mass. Inclusion of the JAK2 V617F gene mutation in the recent World Health Organization criteria for the diagnosis of PV allows for facilitated diagnosis and guides therapy. EPO levels can be helpful in diagnosis and guiding therapy, but in the case of cystic renal diseases, EPO levels are often not elevated, creating diagnostic uncertainty. This report describes a case of symptoms directly attributable to erythrocytosis in the setting of negative JAK2 mutation and normal EPO levels. The subsequent discovery of a large cystic renal kidney and PV were the leading diagnostic considerations. 2016.

  3. The effect of curcumol on protein expression of JAK2/STAT3 signaling pathway in human ovarian cancer line SKOV3

    Feng-juan HAN

    2013-12-01

    Full Text Available Objective: To study the effects of curcumol on the protein expression of JAK2 and STAT3 in SKOV3 and to investigate its treatment on molecular mechanism of ovarian cancer. Methods: Choose curcumol of different concentrations to act on human ovarian cancer cell line SKOV3, and extract the corresponding cell protein, and detect the protein expression of JAK2 and STAT3 by western blotting. Results: The protein expression of JAK2 and STAT3 in SKOV3 are significantly inhabited by curcumol, and its strength will enhance with the increase in drug concentration, and it shows in a dose-dependent manner. Conclusion: Curcumol can significantly inhabit the proliferation of SKOV3 cells, and induce apoptosis, and achieve its mechanism by regulating the protein expression of JAK2 and STAT3.

  4. Physiopathology, Etiologic Factors, Diagnosis, and Course of Polycythemia Vera as Related to Therapy According to William Dameshek, 1940-1950

    Jan Jacques Michiels

    2013-06-01

    Full Text Available According to Dameshek, true polycythemia (polycythemia vera: PV is a chronic myeloproliferative disorder of the total bone marrow without any evidence of invasiveness, in which erythrocytosis, leukocytosis, and thrombocytosis are all simultaneously present. A possible hereditary or transmitted tendency may be present, but actual familial polycythemia is rare. As to the etiology, Dameshek proposed 2 highly speculative possibilities in 1950: the presence of excessive bone marrow stimulation by an unknown factor or factors, and a lack or a diminution in the normal inhibitory factor or factors. Dameshek’s hypothesis was confirmed in 2005 by Vainchenker in France by the discovery of the acquired JAK2V617F mutation as the cause of 3 phenotypes of classical myeloproliferative neoplasms: essential thrombocythemia, PV, and myelofibrosis. The JAK2V617F mutation induces a loss of inhibitory activity of the JH2 pseudokinase part on the JH1 kinase part of Janus kinase 2 (JAK2. This leads to enhanced activity of the normal JH1 kinase activity of JAK2, which makes the mutated hematopoietic stem cells hypersensitive to the hematopoietic growth factors thrombopoietin, erythropoietin, insulin-like growth factor-1, stem cell factor, and granulocyte colony-stimulating factor, resulting in trilinear myeloproliferation. In retrospect, the situation observed by Dameshek where all “stops” to blood production in the bone marrow are pulled in PV is caused by the JAK2V617F mutation. Dameshek considered PV patients as fundamentally normal and therefore the treatment should be as physiologic as possible. For this reason, a systematic phlebotomy/iron deficiency method of treatment was recommended; the use of radioactive phosphorus is reserved for refractory cases and cases of major thrombosis. If the patient lives long enough and does not succumb to the effects of thrombosis or other complications, the marrow will gradually show signs of diminished activity. The blood

  5. miR-204 inhibits angiogenesis and promotes sensitivity to cetuximab in head and neck squamous cell carcinoma cells by blocking JAK2-STAT3 signaling.

    Wu, Qingwei; Zhao, Yingying; Wang, Peihua

    2018-03-01

    This study aims to investigate the roles of miR-204 in tumor angiogenesis of head and neck squamous cell carcinoma (HNSCC). Here, we found that miR-204 level was reduced in HNSCC tissues relative to that in normal adjacent tissues. Overexpression of miR-204 promoted tumor angiogenesis in HNSCC cells. Mechanistically, JAK2 was identified as a direct target of miR-204, and miR-204 overexpression blocked JAK2/STAT3 pathway. Moreover, overexpression of JAK2 attenuated the inhibition of miR-204 on tumor angiogenesis of HNSCC. Furthermore, overexpression of miR-204 enhanced sensitivity of cetuximab in HNSCC cells, this effect was attenuated by JAK2 overexpression too. Importantly, JAK2 expression was negatively correlated with miR-204 level in HNSCC tissues. Therefore, miR-204 acts as a tumor suppressor by blocking JAK2/STAT3 pathway in HNSCC cells. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  6. Screening for calreticulin mutations in a cohort of patients suspected ...

    Background. The discovery of calreticulin (CALR) has shown it to be the second most frequent mutation after the Janus Kinase 2 (JAK2) mutation in myeloproliferative neoplasms (MPNs). Its structure indicates various functions, of which two are to ensure calcium homeostasis and proper folding of other target proteins.

  7. Upregulation of miR-375 level ameliorates morphine analgesic tolerance in mouse dorsal root ganglia by inhibiting the JAK2/STAT3 pathway

    Li HQ

    2017-05-01

    Full Text Available Haiqin Li, Rong Tao, Jing Wang, Lingjie Xia Department of Clinical Pain, The People’s Hospital of Henan Province, Zhengzhou, People’s Republic of China Abstract: Several lines of evidence indicate that microRNAs (miRNAs modulate tolerance to the analgesic effects of morphine via regulation of pain-related genes, making dysregulation of miRNA levels a clinical target for controlling opioid tolerance. However, the precise mechanisms by which miRNAs regulate opioid tolerance are unclear. In the present study, we noted that the miR-375 level was downregulated but the expression of Janus kinase 2 (JAK2 was upregulated in mouse dorsal root ganglia (DRG following chronic morphine treatment. The miR-375 levels and JAK2 expression were correlated with the progression of morphine tolerance, and upregulation of miR-375 level could significantly hinder morphine tolerance. This was ameliorated by JAK2 knockdown. Prolonged morphine exposure induced the expression of brain-derived neurotrophic factor (BDNF in a time-dependent manner in the DRG. This was regulated by the miR-375 and JAK2–signal transducer and activator of transcription 3 (STAT3 pathway, and inhibition of this pathway decreased BDNF production, and thus, attenuated morphine tolerance. More importantly, we found that miR-375 could target JAK2 and increase BDNF expression in a JAK2/STAT3 pathway-dependent manner. Keywords: morphine tolerance, miR-375, JAK2, BDNF

  8. The IGF-I/JAK2-STAT3/miR-21 signaling pathway may be associated with human renal cell carcinoma cell growth.

    Su, Ying; Zhao, An; Cheng, Guoping; Xu, Jingjing; Ji, Enming; Sun, Wenyong

    2017-07-04

    Renal cell carcinoma (RCC) is the highest mortality rate of the genitourinary cancers, and the treatment options are very limited. Thus, identification of molecular mechanisms underlying RCC tumorigenesis, is critical for identifying biomarkers for RCC diagnosis and prognosis. To validate whether the IGF-I/JAK2-STAT3/miR-21 signaling pathway is associated with human RCC cell growth. qRT-PCR and Western blotting were used to detect the mRNA and protein expression levels, respectively. The MTT assay was performed to determine cell survival rate. The Annexin V-FITC/PI apoptosis detection kit was used to detect cell apoptosis. We employed RCC tissues and cell lines (A498; ACHN; Caki-1; Caki-2 and 786-O) in the study. IGF-I, and its inhibitor (NT-157) were administrated to detect the effects of IGF-I on the expression of miR-21 and p-JAK2. JAK2 inhibitor (AG490), and si-STAT3 were used to detect the effects of JAK2/STAT3 signaling pathway on the expression of miR-21. In our study, we firstly showed that the expression levels of IGF-I and miR-21 were up-regulated in RCC tissues and cell lines. After exogenous IGF-I treatment, the expression levels of miR-21, p-IGF-IR and p-JAK2 were significantly increased, whereas NT-157 treatment showed the reversed results. Further study indicated that JAK2 inhibitor or si-STAT3 significantly reversed the IGF-I-induced miR-21 expression level. Finally, we found that IGF-I treatment significantly prompted human RCC cell survival and inhibited cell apoptosis, and NT-157 treatment showed the reversed results. The IGF-I/JAK2-STAT3/miR-21 signaling pathway may be associated with human RCC cell growth.

  9. Secoisolariciresinol diglucoside prevents the oxidative stress-induced apoptosis of myocardial cells through activation of the JAK2/STAT3 signaling pathway.

    Huang, Guiqiong; Huang, Xiaofang; Liu, Min; Hua, Yue; Deng, Bo; Jin, Wen; Yan, Wen; Tan, Zhangbin; Wu, Yifen; Liu, Bin; Zhou, Yingchun

    2018-06-01

    Myocardial cell apoptosis mediated by oxidative stress has previously been identified as a key process in ischemic heart disease. Secoisolariciresinol diglucoside (SDG), a polyphenolic plant lignan primarily found in flaxseed, has been demonstrated to effectively protect myocardial cells from apoptosis. In the present study, the role of the Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) was investigated in mediating the protective effect of SDG. Findings of the present study revealed that treatment with H2O2 reduced cell viability and induced apoptosis in H9C2 rat cardiomyocytes. However, SDG was able to reduce the effect of H2O2 in a dose‑dependent manner. H2O2 reduced the expression level of phosphorylated STAT3 and inhibited the levels of B‑cell lymphoma‑extra‑large and induced myeloid leukemia cell differentiation protein, which are the STAT3 target genes. Conversely, SDG rescued phosphorylation of STAT3 and increased the levels of STAT3 target genes. Treatment with SDG alone led to a dose‑dependent increased phosphorylation of JAK2 and STAT3, without activating Src. Furthermore, the anti‑apoptotic effects of SDG were partially abolished by a JAK2/STAT3 inhibitor. In addition, molecular docking revealed that SDG may bind to the protein kinase domain of JAK2, at a binding energy of ‑8.258 kcal/mol. Molecular dynamics simulations revealed that JAK2‑SDG binding was stable. In conclusion, activation of the JAK2/STAT3 signaling pathway contributed to the anti‑apoptotic activity of SDG, which may be a potential JAK2 activator.

  10. The Hepatocyte Growth Factor (HGF/Met Axis: A Neglected Target in the Treatment of Chronic Myeloproliferative Neoplasms?

    Marjorie Boissinot

    2014-08-01

    Full Text Available Met is the receptor of hepatocyte growth factor (HGF, a cytoprotective cytokine. Disturbing the equilibrium between Met and its ligand may lead to inappropriate cell survival, accumulation of genetic abnormalities and eventually, malignancy. Abnormal activation of the HGF/Met axis is established in solid tumours and in chronic haematological malignancies, including myeloma, acute myeloid leukaemia, chronic myelogenous leukaemia (CML, and myeloproliferative neoplasms (MPNs. The molecular mechanisms potentially responsible for the abnormal activation of HGF/Met pathways are described and discussed. Importantly, inCML and in MPNs, the production of HGF is independent of Bcr-Abl and JAK2V617F, the main molecular markers of these diseases. In vitro studies showed that blocking HGF/Met function with neutralizing antibodies or Met inhibitors significantly impairs the growth of JAK2V617F-mutated cells. With personalised medicine and curative treatment in view, blocking activation of HGF/Met could be a useful addition in the treatment of CML and MPNs for those patients with high HGF/MET expression not controlled by current treatments (Bcr-Abl inhibitors in CML; phlebotomy, hydroxurea, JAK inhibitors in MPNs.

  11. The Hepatocyte Growth Factor (HGF)/Met Axis: A Neglected Target in the Treatment of Chronic Myeloproliferative Neoplasms?

    Boissinot, Marjorie [Translational Neuro-Oncology Group, Leeds Institute of Cancer and Pathology, University of Leeds, Level 5 Wellcome Trust Brenner Building, St James’s Hospital, Leeds LS9 7TF (United Kingdom); Vilaine, Mathias [Institute of Research on Cancer and Aging (IRCAN), CNRS-Inserm-UNS UMR 7284, U 1081, Centre A. Lacassagne, 33 Avenue Valombrose, Nice 06189 (France); Hermouet, Sylvie, E-mail: sylvie.hermouet@univ-nantes.fr [Centre Hospitalier Universitaire (CHU), Place Alexis Ricordeau, Nantes 44093 (France); Inserm UMR892, Centre de Recherche en Cancérologie Nantes-Angers, Institut de Recherche en Santé, Université de Nantes, 8 quai Moncousu, Nantes cedex 44007 (France)

    2014-08-12

    Met is the receptor of hepatocyte growth factor (HGF), a cytoprotective cytokine. Disturbing the equilibrium between Met and its ligand may lead to inappropriate cell survival, accumulation of genetic abnormalities and eventually, malignancy. Abnormal activation of the HGF/Met axis is established in solid tumours and in chronic haematological malignancies, including myeloma, acute myeloid leukaemia, chronic myelogenous leukaemia (CML), and myeloproliferative neoplasms (MPNs). The molecular mechanisms potentially responsible for the abnormal activation of HGF/Met pathways are described and discussed. Importantly, inCML and in MPNs, the production of HGF is independent of Bcr-Abl and JAK2V617F, the main molecular markers of these diseases. In vitro studies showed that blocking HGF/Met function with neutralizing antibodies or Met inhibitors significantly impairs the growth of JAK2V617F-mutated cells. With personalised medicine and curative treatment in view, blocking activation of HGF/Met could be a useful addition in the treatment of CML and MPNs for those patients with high HGF/MET expression not controlled by current treatments (Bcr-Abl inhibitors in CML; phlebotomy, hydroxurea, JAK inhibitors in MPNs)

  12. Deficiency of PTP1B Attenuates Hypothalamic Inflammation via Activation of the JAK2-STAT3 Pathway in Microglia.

    Tsunekawa, Taku; Banno, Ryoichi; Mizoguchi, Akira; Sugiyama, Mariko; Tominaga, Takashi; Onoue, Takeshi; Hagiwara, Daisuke; Ito, Yoshihiro; Iwama, Shintaro; Goto, Motomitsu; Suga, Hidetaka; Sugimura, Yoshihisa; Arima, Hiroshi

    2017-02-01

    Protein tyrosine phosphatase 1B (PTP1B) regulates leptin signaling in hypothalamic neurons via the JAK2-STAT3 pathway. PTP1B has also been implicated in the regulation of inflammation in the periphery. However, the role of PTP1B in hypothalamic inflammation, which is induced by a high-fat diet (HFD), remains to be elucidated. Here, we showed that STAT3 phosphorylation (p-STAT3) was increased in microglia in the hypothalamic arcuate nucleus of PTP1B knock-out mice (KO) on a HFD, accompanied by decreased Tnf and increased Il10 mRNA expression in the hypothalamus compared to wild-type mice (WT). In hypothalamic organotypic cultures, incubation with TNFα led to increased p-STAT3, accompanied by decreased Tnf and increased Il10 mRNA expression, in KO compared to WT. Incubation with p-STAT3 inhibitors or microglial depletion eliminated the differences in inflammation between genotypes. These data indicate an important role of JAK2-STAT3 signaling negatively regulated by PTP1B in microglia, which attenuates hypothalamic inflammation under HFD conditions. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  13. Deficiency of PTP1B Attenuates Hypothalamic Inflammation via Activation of the JAK2-STAT3 Pathway in Microglia

    Taku Tsunekawa

    2017-02-01

    Full Text Available Protein tyrosine phosphatase 1B (PTP1B regulates leptin signaling in hypothalamic neurons via the JAK2-STAT3 pathway. PTP1B has also been implicated in the regulation of inflammation in the periphery. However, the role of PTP1B in hypothalamic inflammation, which is induced by a high-fat diet (HFD, remains to be elucidated. Here, we showed that STAT3 phosphorylation (p-STAT3 was increased in microglia in the hypothalamic arcuate nucleus of PTP1B knock-out mice (KO on a HFD, accompanied by decreased Tnf and increased Il10 mRNA expression in the hypothalamus compared to wild-type mice (WT. In hypothalamic organotypic cultures, incubation with TNFα led to increased p-STAT3, accompanied by decreased Tnf and increased Il10 mRNA expression, in KO compared to WT. Incubation with p-STAT3 inhibitors or microglial depletion eliminated the differences in inflammation between genotypes. These data indicate an important role of JAK2-STAT3 signaling negatively regulated by PTP1B in microglia, which attenuates hypothalamic inflammation under HFD conditions.

  14. Calreticulin and Jak2 as Chaperones for MPL: Insights into MPN Pathogenesis

    2016-09-01

    stimulated calcium mobilization will be evaluated in megakaryocyte cell lines expressing WT and mutant calreticulin using ratio imaging methods. Using both...Mpl, fitting well with Aim 2 of this project. Highlights from the new manuscript showed this novel mutation results in entrapment of the mutant Mpl

  15. Splenomegaly in myelofibrosis—new options for therapy and the therapeutic potential of Janus kinase 2 inhibitors

    Randhawa Jasleen

    2012-08-01

    Full Text Available Abstract Splenomegaly is a common sign of primary myelofibrosis (PMF, post-polycythemia vera myelofibrosis (post-PV MF, and post-essential thrombocythemia myelofibrosis (post-ET MF that is associated with bothersome symptoms, which have a significant negative impact on patients’ quality of life. It may also be present in patients with advanced polycythemia vera (PV or essential thrombocythemia (ET. Until recently, none of the therapies used to treat MF were particularly effective in reducing splenomegaly. The discovery of an activating Janus kinase 2 (JAK2 activating mutation (JAK2V617F that is present in almost all patients with PV and in about 50-60 % of patients with ET and PMF led to the initiation of several trials investigating the clinical effectiveness of various JAK2 (or JAK1/JAK2 inhibitors for the treatment of patients with ET, PV, and MF. Some of these trials have documented significant clinical benefit of JAK inhibitors, particularly in terms of regression of splenomegaly. In November 2011, the US Food and Drug Administration approved the use of the JAK1- and JAK2-selective inhibitor ruxolitinib for the treatment of patients with intermediate or high-risk myelofibrosis, including PMF, post-PV MF, and post-ET MF. This review discusses current therapeutic options for splenomegaly associated with primary or secondary MF and the treatment potential of the JAK inhibitors in this setting.

  16. Identification of JAK2 as a mediator of FIP1L1-PDGFRA-induced eosinophil growth and function in CEL.

    Bin Li

    Full Text Available The Fip1-like1 (FIP1L1-platelet-derived growth factor receptor alpha fusion gene (F/P arising in the pluripotent hematopoietic stem cell (HSC,causes 14% to 60% of patients with hypereosinophilia syndrome (HES. These patients, classified as having F/P (+ chronic eosinophilic leukemia (CEL, present with clonal eosinophilia and display a more aggressive disease phenotype than patients with F/P (- HES patients. The mechanisms underlying predominant eosinophil lineage targeting and the cytotoxicity of eosinophils in this leukemia remain unclear. Given that the Janus tyrosine kinase (JAK/signal transducers and activators of transcription (Stat signaling pathway is key to cytokine receptor-mediated eosinophil development and activated Stat3 and Stat5 regulate the expression of genes involved in F/P malignant transformation, we investigated whether and how JAK proteins were involved in the pathogenesis of F/P-induced CEL. F/P activation of JAK2, Stat3 and Stat5, were confirmed in all the 11 F/P (+ CEL patients examined. In vitro inhibition of JAK2 in EOL-1, primary F/P(+ CEL cells (PC and T674I F/P Imatinib resistant cells(IR by either JAK2-specific short interfering RNA (siRNA or the tryphostin derivative AG490(AG490, significantly reduced cellular proliferation and induced cellular apoptosis. The F/P can enhance the IL-5-induced JAK2 activation, and further results indicated that JAK2 inhibition blocked IL-5-induced cellular migration and activation of the EOL-1 and PC cells in vitro. F/P-stimulation of the JAK2 suppressed cells led to a significantly reduction in Stat3 activation, but relatively normal induction of Stat5 activation. Interestingly, JAK2 inhibition also reduced PI3K, Akt and NF-κB activity in a dose-dependent manner, and suppressed expression levels of c-Myc and Survivin. These results strongly suggest that JAK2 is activated by F/P and is required for F/P stimulation of cellular proliferation and infiltration, possibly through

  17. The dipeptide Pro-Asp promotes IGF-1 secretion and expression in hepatocytes by enhancing JAK2/STAT5 signaling pathway.

    Wang, Songbo; Wang, Guoqing; Zhang, Mengyuan; Zhuang, Lu; Wan, Xiaojuan; Xu, Jingren; Wang, Lina; Zhu, Xiaotong; Gao, Ping; Xi, Qianyun; Zhang, Yongliang; Shu, Gang; Jiang, Qingyan

    2016-11-15

    It has been implicated that IGF-1 secretion can be regulated by dietary protein. However, whether the dipeptides, one of digested products of dietary protein, have influence on IGF-1 secretion remain largely unknown. Our study aimed to investigate the effects of the dipeptide Pro-Asp on IGF-1 secretion and expression in hepatocytes and to explore the possible underlying mechanisms. Our findings demonstrated that Pro-Asp promoted the secretion and gene expression of IGF-1 in HepG2 cells and primary porcine hepatocytes. Meanwhile, Pro-Asp activated the ERK and Akt signaling pathways, downstream of IGF-1. In addition, Pro-Asp enhanced GH-mediated JAK2/STAT5 signaling pathway, while inhibition of JAK2/STAT5 blocked the promotive effect of Pro-Asp on IGF-1 secretion and expression. Moreover, acute injection of Pro-Asp stimulated IGF-1 expression and activated JAK2/STAT5 signaling pathway in mice liver. Together, these results suggested that the dipeptide Pro-Asp promoted IGF-1 secretion and expression in hepatocytes by enhancing GH-mediated JAK2/STAT5 signaling pathway. Copyright © 2016. Published by Elsevier Ireland Ltd.

  18. The effect of quercetin nanoparticle on cervical cancer progression by inducing apoptosis, autophagy and anti-proliferation via JAK2 suppression.

    Luo, Cheng-Lin; Liu, Yu-Qiong; Wang, Peng; Song, Chun-Hua; Wang, Kai-Juan; Dai, Li-Ping; Zhang, Jian-Ying; Ye, Hua

    2016-08-01

    Cervical cancer is a cause of cancer death, making it as the one of the most common cause for death among women globally. Though many studies before have explored a lot for cervical cancer prevention and treatment, there are still a lot far from to know based on the molecular mechanisms. Janus kinase 2 (JAK2) has been reported to play an essential role in the progression of apoptosis, autophagy and proliferation for cells. We loaded gold-quercetin into poly (dl-lactide-co-glycolide) nanoparticles to cervical cancer cells due to the propertities of quercetin in ameliorating cellular processes and the easier absorbance of nanoparticles. Here, in our study, quercetin nanoparticles (NQ) were administrated to cells to investigate the underlying mechanism by which the cervical cancer was regulated. First, JAK2-inhibited carvical cancer cell lines were involved for our experiments in vitro and in vivo. Western blotting, quantitative RT-PCR (qRT-PCR), ELISA, Immunohistochemistry, and flow-cytometric analysis were used to determine the key signaling pathway regulated by JAK2 for cervical cancer progression. And the role of quercetin nanoparticles was determined during the process. Data here indicated that JAK2, indeed, expressed highly in cancer cell lines compared to the normal cervical cells. And apoptosis and autophagy were found in JAK2-inhibited cancer cells through activating Caspase-3, and suppressing Cyclin-D1 and mTOR regulated by Signal Transducer and Activator of Transcription (STAT) 3/5 and phosphatidylinositide 3-kinase/protein kinases (PI3K/AKT) signaling pathway. The cervical cancer cells proliferation was inhibited. Further, tumor size and weight were reduced by inhibition of JAK2 in vivo experiments. Notably, administration with quercetin nanoparticles displayed similar role with JAK2 suppression, which could inhibit cervical cancer cells proliferation, invasion and migration. In addition, autophogy and apoptosis were induced, promoting cervical cancer cell

  19. Inhibition of DNA methyltransferase induces G2 cell cycle arrest and apoptosis in human colorectal cancer cells via inhibition of JAK2/STAT3/STAT5 signalling.

    Xiong, Hua; Chen, Zhao-Fei; Liang, Qin-Chuan; Du, Wan; Chen, Hui-Min; Su, Wen-Yu; Chen, Guo-Qiang; Han, Ze-Guang; Fang, Jing-Yuan

    2009-09-01

    DNA methyltransferase inhibitors (MTIs) have recently emerged as promising chemotherapeutic or preventive agents for cancer, despite their poorly characterized mechanisms of action. The present study shows that DNA methylation is integral to the regulation of SH2-containing protein tyrosine phosphatase 1 (SHP1) expression, but not for regulation of suppressors of cytokine signalling (SOCS)1 or SOCS3 in colorectal cancer (CRC) cells. SHP1 expression correlates with down-regulation of Janus kinase/signal transducers and activators of transcription (JAK2/STAT3/STAT5) signalling, which is mediated in part by tyrosine dephosphorylation events and modulation of the proteasome pathway. Up-regulation of SHP1 expression was achieved using a DNA MTI, 5-aza-2'-deoxycytidine (5-aza-dc), which also generated significant down-regulation of JAK2/STAT3/STAT5 signalling. We demonstrate that 5-aza-dc suppresses growth of CRC cells, and induces G2 cell cycle arrest and apoptosis through regulation of downstream targets of JAK2/STAT3/STAT5 signalling including Bcl-2, p16(ink4a), p21(waf1/cip1) and p27(kip1). Although 5-aza-dc did not significantly inhibit cell invasion, 5-aza-dc did down-regulate expression of focal adhesion kinase and vascular endothelial growth factor in CRC cells. Our results demonstrate that 5-aza-dc can induce SHP1 expression and inhibit JAK2/STAT3/STAT5 signalling. This study represents the first evidence towards establishing a mechanistic link between inhibition of JAK2/STAT3/STAT5 signalling and the anticancer action of 5-aza-dc in CRC cells that may lead to the use of MTIs as a therapeutic intervention for human colorectal cancer.

  20. Sustained major molecular response on interferon alpha-2b in two patients with polycythemia vera

    Larsen, Thomas Stauffer; Bjerrum, O W; Pallisgaard, N

    2008-01-01

    Quantitative assessment of the JAK2 V617F allele burden during disease evolution and ongoing myelosuppressive treatment is likely to be implemented in the future clinical setting. Interferon alpha has demonstrated efficacy in treatment of both chronic myeloid leukemia and the Philadelphia chromos...... with a JAK2 V617F allele burden below 1.0% in two patients with polycythemia vera treated with interferon alpha-2b (IFN-2b). Discontinuation of IFN-2b in one of the patients was followed by a sustained long-lasting (12 months of follow-up) major molecular response....

  1. Navigating the evolving paradigms in the diagnosis and treatment of myeloproliferative disorders.

    Mesa, Ruben A

    2007-01-01

    The diagnosis and management of the BCR-ABL-negative myeloproliferative disorders (MPDs) of polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF) are at an explosive crossroads of scientific investigation and evolving paradigms since the discovery of the tyrosine kinase-activating JAK2V617F mutation in 2005. Additional discovery of relevant molecular lesions (JAK2 exon 12 mutations and c-MplW515L/K) have only further enriched our understanding of MPD pathogenesis. The improved diagnostic certainty these molecular markers provide have resulted in the modification, and simplification, of the World Health Organization (WHO) diagnostic algorithms for MPDs. Despite these scientific advances, however, the initial management of MPDs continues to rely upon a risk-based strategy to minimize the risk of vascular events with control of erythrocytosis, targeted antiplatelet therapy, and risk-based myelosuppressive therapy. No current medical therapy has altered the natural trend of the MPDs to lead to overt severe myelofibrosis or acute leukemia. Investigations into targeted therapies for MPDs are proceeding at a brisk pace with agents aimed at immunomodulation, decreasing marrow stromal reaction to the aberrant clone, DNA hypomethylation, or the inhibition of tyrosine kinases. Specific inhibition of JAK2 itself appears promising by in vitro investigations, and clinical trials with multiple agents are planned to commence enrollment in 2007. The potential impact of JAK2 inhibitors on the manifestations of the MPDs is unclear, but is awaited with great interest.

  2. Proteomic analysis reveals heat shock protein 70 has a key role in polycythemia Vera.

    Gallardo, Miguel; Barrio, Santiago; Fernandez, Marisol; Paradela, Alberto; Arenas, Alicia; Toldos, Oscar; Ayala, Rosa; Albizua, Enriqueta; Jimenez, Ana; Redondo, Santiago; Garcia-Martin, Rosa Maria; Gilsanz, Florinda; Albar, Juan Pablo; Martinez-Lopez, Joaquin

    2013-11-19

    JAK-STAT signaling through the JAK2V617F mutation is central to the pathogenesis of myeloproliferative neoplasms (MPN). However, other events could precede the JAK2 mutation. The aim of this study is to analyze the phenotypic divergence between polycytemia vera (PV) and essential thrombocytemia (ET) to find novel therapeutics targets by a proteomic and functional approach to identify alternative routes to JAK2 activation. Through 2D-DIGE and mass spectrometry of granulocyte protein from 20 MPN samples, showed differential expression of HSP70 in PV and ET besides other 60 proteins. Immunohistochemistry of 46 MPN bone marrow samples confirmed HSP70 expression. The median of positive granulocytes was 80% in PV (SD 35%) vs. 23% in ET (SD 34.25%). In an ex vivo model KNK437 was used as an inhibition model assay of HSP70, showed dose-dependent inhibition of cell growth and burst formation unit erythroid (BFU-E) in PV and ET, increased apoptosis in the erythroid lineage, and decreased pJAK2 signaling, as well as a specific siRNA for HSP70. These data suggest a key role for HSP70 in proliferation and survival of the erythroid lineage in PV, and may represent a potential therapeutic target in MPN, especially in PV.

  3. Novel fused oxazepino-indoles (FOIs) attenuate liver carcinogenesis via IL-6/JAK2/STAT3 signaling blockade as evidenced through data-based mathematical modeling.

    Singh, Ashok K; Bhadauria, Archana Singh; Kumar, Umesh; Raj, Vinit; Maurya, Vimal; Kumar, Dinesh; Maity, Biswanath; Prakash, Anand; De, Arnab; Samanta, Amalesh; Saha, Sudipta

    2018-05-15

    To potentiate the well-documented tumor protecting ability of paullones, literatures demand for rational modifications in paullone ring structure and exploration of a precise mechanism underlying their antitumor effects. Thus, recently we synthesized novel paullone-like scaffold, 5H-benzo [2, 3][1,4]oxazepino[5,6-b]indoles, where compounds 13a and 14a attenuated the growth of liver cancer specific Hep-G2 cells in vitro and formed stable binding complex with IL-6. Henceforth, we hypothesized that this action is probably due to the blockade of IL-6 mediated JAK2/STAT3 signaling cascade. A preclinical study was conducted using NDEA-induced HCC rat model by oral administration of FOIs at 10 mg/kg dose for 15 days. The molecular insights were confirmed through ELISA, qRT-PCR, western blot analyses. The study was further confirmed by data-based mathematical modeling using the quantitative data obtained from western blot analysis. 1 H NMR based metabolomics study was also performed to unveil metabolite discriminations among various studied groups. We identified that the HCC condition was produced due to the IL-6 induced activation of JAK2 and STAT3 which, in turn, was due to enhanced phosphorylation of JAK2 and STAT3. The treatment with FOIs led to the significant blockade of the IL-6 mediated JAK2/STAT3 signaling pathway. Besides, FOIs showed their potential ability in restoring perturbed metabolites linked to HCC. In particular, the anticancer efficacy of compound 13a was comparable or somewhat better than marketed chemotherapeutics, 5-flurouracil. These findings altogether opened up possibilities of developing fused oxazepino-indoles (FOIs) as new candidate molecule for plausible alternative of paullones to treat liver cancer. Copyright © 2018 Elsevier Inc. All rights reserved.

  4. Inhibitory Effect of Curcumol on Jak2-STAT Signal Pathway Molecules of Fibroblast-Like Synoviocytes in Patients with Rheumatoid Arthritis

    Heng Wang

    2012-01-01

    Full Text Available Hyperplasia of synovial membrane in rheumatoid arthritis (RA is a critical pathological foundation for inducing articular injury. The janus kinase and signal transducer and activator of transcription (Jak-STAT pathway plays a critical role in synovial membrane proliferation induced by platelet-derived growth factor (PDGF. To explore the anti-cell proliferation mechanism of curcumol, a pure monomer extracted from Chinese medical plant zedoary rhizome, the changes of Jak2-STAT1/3 signal pathway-related molecules in synoviocytes were observed in vitro. In this study, the fibroblast-like synoviocytes (FLS in patients with RA were collected and cultured. The following parameters were measured: cell proliferation (WST-1 assay, cell cycles (fluorescence-activated cell sorting, FACS, STAT1 and STAT3 activities (electrophoretic mobility shift assay, EMSA, and the protein expressions of phosphorylated Jak2, STAT1, and STAT3 (Western blot. It was shown that curcumol could inhibit the RA-FLS proliferation and DNA synthesis induced by PDGF-BB in a dose-dependent manner in vitro. The transcription factors activities of STAT1 and STAT3 were obviously elevated after PDGF-BB stimulation (P<0.05. Super-shift experiments identified the STAT1 or STAT3 proteins in the complex. Furthermore, the different concentration curcumol could downregulate the DNA binding activities of STAT1 and STAT3 (P<0.05 and inhibit the phosphorylation of Jak2 while it had no effect on the protein expressions of STAT1 and STAT3. Positive correlations were found between changes of cell proliferation and DNA-binding activities of STAT1 and STAT3, respectively (P<0.01. In conclusion, curcumol might suppress the FLS proliferation and DNA synthesis induced by PDGF-BB through attenuating Jak2 phosphorylation, downregulating STAT1 and STAT3 DNA-binding activities, which could provide theoretical foundation for clinical treatment of RA.

  5. Hydrogen sulfide postconditioning protects isolated rat hearts against ischemia and reperfusion injury mediated by the JAK2/STAT3 survival pathway

    Heng-Fei Luan

    2012-10-01

    Full Text Available The JAK2/STAT3 signal pathway is an important component of survivor activating factor enhancement (SAFE pathway. The objective of the present study was to determine whether the JAK2/STAT3 signaling pathway participates in hydrogen sulfide (H2S postconditioning, protecting isolated rat hearts from ischemic-reperfusion injury. Male Sprague-Dawley rats (230-270 g were divided into 6 groups (N = 14 per group: time-matched perfusion (Sham group, ischemia/reperfusion (I/R group, NaHS postconditioning group, NaHS with AG-490 group, AG-490 (5 µM group, and dimethyl sulfoxide (DMSO; <0.2% group. Langendorff-perfused rat hearts, with the exception of the Sham group, were subjected to 30 min of ischemia followed by 90 min of reperfusion after 20 min of equilibrium. Heart rate, left ventricular developed pressure (LVDP, left ventricular end-diastolic pressure (LVEDP, and the maximum rate of increase or decrease of left ventricular pressure (± dp/dt max were recorded. Infarct size was determined using triphenyltetrazolium chloride (TTC staining. Myocardial TUNEL staining was used as the in situ cell death detection method and the percentage of TUNEL-positive nuclei to all nuclei counted was used as the apoptotic index. The expression of STAT3, bcl-2 and bax was determined by Western blotting. After reperfusion, compared to the I/R group, H2S significantly improved functional recovery and decreased infarct size (23.3 ± 3.8 vs 41.2 ± 4.7%, P < 0.05 and apoptotic index (22.1 ± 3.6 vs 43.0 ± 4.8%, P < 0.05. However, H2S-mediated protection was abolished by AG-490, the JAK2 inhibitor. In conclusion, H2S postconditioning effectively protects isolated I/R rat hearts via activation of the JAK2/STAT3 signaling pathway.

  6. Aspirin down Regulates Hepcidin by Inhibiting NF-κB and IL6/JAK2/STAT3 Pathways in BV-2 Microglial Cells Treated with Lipopolysaccharide

    Wan-Ying Li

    2016-12-01

    Full Text Available Aspirin down regulates transferrin receptor 1 (TfR1 and up regulates ferroportin 1 (Fpn1 and ferritin expression in BV-2 microglial cells treated without lipopolysaccharides (LPS, as well as down regulates hepcidin and interleukin 6 (IL-6 in cells treated with LPS. However, the relevant mechanisms are unknown. Here, we investigate the effects of aspirin on expression of hepcidin and iron regulatory protein 1 (IRP1, phosphorylation of Janus kinase 2 (JAK2, signal transducer and activator of transcription 3 (STAT3 and P65 (nuclear factor-κB, and the production of nitric oxide (NO in BV-2 microglial cells treated with and without LPS. We demonstrated that aspirin inhibited hepcidin mRNA as well as NO production in cells treated with LPS, but not in cells without LPS, suppresses IL-6, JAK2, STAT3, and P65 (nuclear factor-κB phosphorylation and has no effect on IRP1 in cells treated with or without LPS. These findings provide evidence that aspirin down regulates hepcidin by inhibiting IL6/JAK2/STAT3 and P65 (nuclear factor-κB pathways in the cells under inflammatory conditions, and imply that an aspirin-induced reduction in TfR1 and an increase in ferritin are not associated with IRP1 and NO.

  7. Inhibition of the JAK2/STAT3/SOSC1 Signaling Pathway Improves Secretion Function of Vascular Endothelial Cells in a Rat Model of Pregnancy-Induced Hypertension

    Jian-Ying Luo

    2016-11-01

    Full Text Available Background/Aims: The present study aimed to investigate the effects of the JAK2/STAT3/SOSC1 signaling pathway on the secretion function of vascular endothelial cells (VECs in a rat model of pregnancy-induced hypertension (PIH. Methods: A PIH rat model was established. Forty-eight pregnant Sprague-Dawley female rats were selected and assigned into four groups: the normal group (normal non-pregnant rats, the non-PIH group (pregnant rats without PIH, the PIH group (pregnant rats with PIH and the AG490 group (pregnant rats with PIH treated with AG490. Systolic blood pressure (SBP and urinary protein (UP were measured. The expressions of JAK2/STAT3/SOSC1 signaling pathway-related proteins in placenta tissues were detect by Western blotting. Radioimmunoassay was applied to detect serum levels of nitric oxide (NO, super oxide dismutase (SOD, placental growth factor (PGF, thromboxane B2 (TXB2 and endothelin (ET. Enzyme-linked immunosorbent assay (ELISA was used to determine serum levels of interleukin-6 (IL-6, interleukin-10 (IL-10 and tumor necrosis factor-α (TNF-α. Results: Compared with the normal and non-PIH groups, the PIH and AG490 groups had higher SBP and UP levels at 17th and 25th day of pregnancy. The expressions of p/t-JAK2, p/t-STAT3 and SOSC1 in the PIH and AG490 groups were higher than those in the non-PIH group, while the expressions of p/t-JAK2, p/t-STAT3 and SOSC1 in the AG490 group were lower than those in the PIH group. Compared with the non-PIH group, serum levels of ET, TXB2, IL-6 and TNF-α were increased in the PIH and AG490 groups, while serum levels of NO, SOD, 6-keto-PGF1a and IL-10 levels were reduced. Furthermore, the AG490 had lower serum levels of ET, TXB2, IL-6 and TNF-α and higher serum levels of NO, SOD, 6-keto-PGF1a and IL-10 than those in the PIH group. Conclusion: Our study provides evidence that inhibition of the JAK2/STAT3/SOSC1 signaling pathway could improve the secretion function of VECs in PIH rats.

  8. Inhibition of the JAK2/STAT3 pathway in ovarian cancer results in the loss of cancer stem cell-like characteristics and a reduced tumor burden

    Abubaker, Khalid; Luwor, Rodney B; Zhu, Hongjian; McNally, Orla; Quinn, Michael A; Burns, Christopher J; Thompson, Erik W; Findlay, Jock K; Ahmed, Nuzhat

    2014-01-01

    Current treatment of ovarian cancer patients with chemotherapy leaves behind a residual tumor which results in recurrent ovarian cancer within a short time frame. We have previously demonstrated that a single short-term treatment of ovarian cancer cells with chemotherapy in vitro resulted in a cancer stem cell (CSC)-like enriched residual population which generated significantly greater tumor burden compared to the tumor burden generated by control untreated cells. In this report we looked at the mechanisms of the enrichment of CSC-like residual cells in response to paclitaxel treatment. The mechanism of survival of paclitaxel-treated residual cells at a growth inhibitory concentration of 50% (GI50) was determined on isolated tumor cells from the ascites of recurrent ovarian cancer patients and HEY ovarian cancer cell line by in vitro assays and in a mouse xenograft model. Treatment of isolated tumor cells from the ascites of ovarian cancer patients and HEY ovarian cancer cell line with paclitaxel resulted in a CSC-like residual population which coincided with the activation of Janus activated kinase 2 (JAK2) and signal transducer and activation of transcription 3 (STAT3) pathway in paclitaxel surviving cells. Both paclitaxel-induced JAK2/STAT3 activation and CSC-like characteristics were inhibited by a low dose JAK2-specific small molecule inhibitor CYT387 (1 μM) in vitro. Subsequent, in vivo transplantation of paclitaxel and CYT387-treated HEY cells in mice resulted in a significantly reduced tumor burden compared to that seen with paclitaxel only-treated transplanted cells. In vitro analysis of tumor xenografts at protein and mRNA levels demonstrated a loss of CSC-like markers and CA125 expression in paclitaxel and CYT387-treated cell-derived xenografts, compared to paclitaxel only-treated cell-derived xenografts. These results were consistent with significantly reduced activation of JAK2 and STAT3 in paclitaxel and CYT387-treated cell-derived xenografts

  9. High resolution melting analysis: a rapid and accurate method to detect CALR mutations.

    Cristina Bilbao-Sieyro

    Full Text Available The recent discovery of CALR mutations in essential thrombocythemia (ET and primary myelofibrosis (PMF patients without JAK2/MPL mutations has emerged as a relevant finding for the molecular diagnosis of these myeloproliferative neoplasms (MPN. We tested the feasibility of high-resolution melting (HRM as a screening method for rapid detection of CALR mutations.CALR was studied in wild-type JAK2/MPL patients including 34 ET, 21 persistent thrombocytosis suggestive of MPN and 98 suspected secondary thrombocytosis. CALR mutation analysis was performed through HRM and Sanger sequencing. We compared clinical features of CALR-mutated versus 45 JAK2/MPL-mutated subjects in ET.Nineteen samples showed distinct HRM patterns from wild-type. Of them, 18 were mutations and one a polymorphism as confirmed by direct sequencing. CALR mutations were present in 44% of ET (15/34, 14% of persistent thrombocytosis suggestive of MPN (3/21 and none of the secondary thrombocytosis (0/98. Of the 18 mutants, 9 were 52 bp deletions, 8 were 5 bp insertions and other was a complex mutation with insertion/deletion. No mutations were found after sequencing analysis of 45 samples displaying wild-type HRM curves. HRM technique was reproducible, no false positive or negative were detected and the limit of detection was of 3%.This study establishes a sensitive, reliable and rapid HRM method to screen for the presence of CALR mutations.

  10. Acute non-atherosclerotic ST-segment elevation myocardial infarction in an adolescent with concurrent hemoglobin H-Constant Spring disease and polycythemia vera

    Ekarat Rattarittamrong

    2015-09-01

    Full Text Available Thrombosis is a major complication of polycythemia vera (PV and also a well-known complication of thalassemia. We reported a case of non-atherosclerotic ST-segment elevation myocardial infarction (STEMI in a 17- year-old man with concurrent post-splenectomized hemoglobin H-Constant Spring disease and JAK2 V617F mutation-positive PV. The patient initially presented with extreme thrombocytosis (platelet counts greater than 1,000,000/μL and three months later developed an acute STEMI. Coronary artery angiography revealed an acute clot in the right coronary artery without atherosclerotic plaque. He was treated with plateletpheresis, hydroxyurea and antiplatelet agents. The platelet count decreased and his symptoms improved. This case represents the importance of early diagnosis, awareness of the increased risk for thrombotic complications, and early treatment of PV in patients who have underlying thalassemia with marked thrombocytosis.

  11. [Hungarian Philadelphia negative chronic myeloproliferative neoplasia registry. Evaluation of the Polycythemia vera patients].

    Dombi, Péter; Illés, Árpád; Demeter, Judit; Homor, Lajos; Simon, Zsófia; Kellner, Ádám; Karádi, Éva; Valasinyószki, Erika; Udvardy, Miklós; Egyed, Miklós

    2017-06-01

    Intruduction and aim: The Hungarian National Registry for Philadelphia chromosome negative myeloproliferative neoplasms has been developed. The aim of the recent study is to assess the clinical characteristics of Hungarian patients with polycythemia vera. Data of 351 JAK2 V617F and exon 12 mutation positive polycythemia vera patients were collected online from 15 haematology centres reporting epidemiologic, clinical characteristics, diagnostic tools, therapeutic interventions, thromboembolic complications, disease transformations. Vascular events prior to and after diagnosis were evaluated upon the Landolfi risk assessment scale. 116 thromboembolic events were reported in 106 PV patients prior to diagnosis and 152 occasions in 102 patients during follow-up. The frequency of major arterial events were significantly reduced (ppolycythemia vera. The Landolfi risk stratification was proven to be useful. Based on evaluated data, accuracy of diagnostic criteria and compliance to risk-adapted therapeutic guidelines are needed. Orv Hetil. 2017; 158(23): 901-909.

  12. Combination therapy with interferon and JAK1-2 inhibitor is feasible

    Bjørn, M E; de Stricker, K; Kjær, L

    2014-01-01

    We report a 55 year old woman with post-ET PV for 12 years, who experienced resolution of severe constitutional symptoms within 3 days, a marked reduction in splenomegaly and a rapid decline in the JAK2V617F allele burden during combination therapy with interferon-alpha2a and ruxolitinib. Within ...

  13. Long term molecular responses in a cohort of Danish patients with essential thrombocythemia, polycythemia vera and myelofibrosis treated with recombinant interferon alpha

    Stauffer Larsen, Thomas; Iversen, Katrine F; Hansen, Esben

    2013-01-01

    Within recent years data has accumulated demonstrating the efficacy of recombinant interferon alpha2 (rIFN-alpha2) in the treatment of chronic myeloproliferative neoplasms (MPNs). We report on clinical and molecular data in the largest cohort of JAK2 V617F mutant MPN Danish patients (n=102) being...

  14. Interferon and the treatment of polycythemia vera, essential thrombocythemia and myelofibrosis

    Silver, Richard T; Kiladjian, Jean-Jacques; Hasselbalch, Hans K

    2013-01-01

    . In polycythemia vera, this has resulted in a significant clinical, hematologic, morphologic and molecular response manifested by reduction in the JAK2(V617F) allele burden, sustained even after discontinuation of recombinant IFN. In essential thrombocythemia, platelet count reduction is prompt and durable without...

  15. Sustained major molecular response on interferon alpha-2b in two patients with polycythemia vera

    Larsen, T.S.; Pallisgaard, N.; Andersen, M.T.

    2008-01-01

    with a JAK2 V617F allele burden below 1.0% in two patients with polycythemia vera treated with interferon alpha-2b (IFN-2b). Discontinuation of IFN-2b in one of the patients was followed by a sustained long-lasting (12 months of follow-up) major molecular response Udgivelsesdato: 2008/10...

  16. Interferon-alpha in the treatment of Philadelphia-negative chronic myeloproliferative neoplasms. Status and perspectives

    Hasselbalch, Hans Carl; Larsen, Thomas Stauffer; Riley, Caroline Hasselbalch

    2011-01-01

    The Philadelphia-negative chronic myeloproliferative neoplasms encompass essential thrombocythemia (ET), polycythemia vera (PV) and primary myelofibrosis (PMF). A major break-through in the understanding of the pathogenesis of these neoplasms occurred in 2005 by the discovery of the JAK2 V617F...

  17. A new era for IFN-α in the treatment of Philadelphia-negative chronic myeloproliferative neoplasms

    Hasselbalch, H.C.

    2011-01-01

    In recent years, several studies have shown that IFN-α2 is able to induce molecular remissions with undetectable JAK2V617F in a subset of patients with essential thrombocythemia (ET) and polycythemia vera (PV), even with normalization of the bone marrow and sustained molecular remissions after...

  18. Dexmedetomidine reduces the neuronal apoptosis related to cardiopulmonary bypass by inhibiting activation of the JAK2–STAT3 pathway

    Chen Y

    2017-09-01

    Full Text Available Yanhua Chen,1,* Xu Zhang,2,* Bingdong Zhang,1 Guodong He,2 Lifang Zhou,2 Yubo Xie2 1Department of Anesthesiology, Cardiovascular Institute, 2Department of Anesthesiology, the First Affiliated Hospital of Guangxi Medical University, Nanning, China *These authors contributed equally to this work Abstract: Cardiopulmonary bypass (CPB constitutes one of the primary methodologies pertaining to cardiac surgery. However, this form of surgery can cause damage to the body. Many studies have reported that dexmedetomidine confers cerebral protection. In this study, we aimed to investigate the effect and mechanism of dexmedetomidine on neuronal apoptosis caused by CPB. Here, rats were treated with different doses of dexmedetomidine by intravenous infusion 2 hours after CPB. We observed that dexmedetomidine treatment to rats reduces the S100ß, NSE levels in plasma, and neuronal apoptosis following CPB in a dose-dependent manner. Furthermore, we observed that the beneficial effect of dexmedetomidine treatment following CPB was associated with a reduction in IL6, an inflammatory cytokine in plasma and cortex. Our results suggest that dexmedetomidine provides neuroprotective effects by inhibiting inflammation and reducing neuronal apoptosis. There was a correlation between the protective effect on the brain and the dose of dexmedetomidine. In addition, dexmedetomidine administration inhibits phosphorylation of JAK2 and STAT3 proteins in the hippocampus of rats 2 hours after CPB. Therefore, we speculate that the JAK2–STAT3 pathway plays an important role in the neuroprotective effects of dexmedetomidine following brain injury induced by CPB. Keywords: apoptosis, cardiopulmonary bypass, dexmedetomidine, neuroprotective effect, JAK2, STAT3

  19. Hepatic Stellate Cell Coculture Enables Sorafenib Resistance in Huh7 Cells through HGF/c-Met/Akt and Jak2/Stat3 Pathways

    Weibo Chen

    2014-01-01

    Full Text Available Purpose. Tumor microenvironment confers drug resistance to kinase inhibitors by increasing RKT ligand levels that result in the activation of cell-survival signaling including PI3K and MAPK signals. We assessed whether HSC-LX2 coculture conferred sorafenib resistance in Huh7 and revealed the mechanism underlying the drug resistance. Experimental Design. The effect of LX2 on sorafenib resistance was determined by coculture system with Huh7 cells. The rescue function of LX2 supernatants was assessed by MTT assay and fluorescence microscopy. The underlying mechanism was tested by administration of pathway inhibitors and manifested by Western blotting. Results. LX2 coculture significantly induced sorafenib resistance in Huh7 by activating p-Akt that led to reactivation of p-ERK. LX2 secreted HGF into the culture medium that triggered drug resistance, and exogenous HGF could also induce sorafenib resistance. The inhibition of p-Akt blocked sorafenib resistance caused by LX2 coculture. Increased phosphorylation of Jak2 and Stat3 was also detected in LX2 cocultured Huh7 cells. The Jak inhibitor tofacitinib reversed sorafenib resistance by blocking Jak2 and Stat3 activation. The combined administration of sorafenib and p-Stat3 inhibitor S3I-201 augmented induced apoptosis even in the presence of sorafenib resistance. Conclusions. HSC-LX2 coculture induced sorafenib resistance in Huh7 through multiple pathways: HGF/c-Met/Akt pathway and Jak2/Stat3 pathway. A combined administration of sorafenib and S3I-201 was able to augment sorafenib-induced apoptosis even in the presence of LX2 coculture.

  20. Recent advances in understanding myelofibrosis and essential thrombocythemia [version 1; referees: 2 approved

    William Vainchenker

    2016-04-01

    Full Text Available The classic BCR-ABL-negative myeloproliferative neoplasms (MPNs, a form of chronic malignant hemopathies, have been classified into polycythemia vera (PV, essential thrombocythemia (ET, and primary myelofibrosis (PMF. ET and PMF are two similar disorders in their pathogenesis, which is marked by a key role of the megakaryocyte (MK lineage. Whereas ET is characterized by MK proliferation, PMF is also associated with aberrant MK differentiation (myelodysplasia, leading to the release of cytokines in the marrow environment, which causes the development of myelofibrosis. Thus, PMF is associated with both myeloproliferation and different levels of myelodysplastic features. MPNs are mostly driven by mutated genes called MPN drivers, which abnormally activate the cytokine receptor/JAK2 pathway and their downstream effectors. The recent discovery of CALR mutations has closed a gap in our knowledge and has shown that this mutated endoplasmic reticulum chaperone activates the thrombopoietin receptor MPL and JAK2. These genetic studies have shown that there are two main types of MPNs: JAK2V617F-MPNs, including ET, PV, and PMF, and the MPL-/CALR-MPNs, which include only ET and PMF. These MPN driver mutations are associated with additional mutations in genes involved in epigenetics, splicing, and signaling, which can precede or follow the acquisition of MPN driver mutations. They are involved in clonal expansion or phenotypic changes or both, leading to myelofibrosis or leukemic transformation or both. Only a few patients with ET exhibit mutations in non-MPN drivers, whereas the great majority of patients with PMF harbor one or several mutations in these genes. However, the entire pathogenesis of ET and PMF may also depend on other factors, such as the patient’s constitutional genetics, the bone marrow microenvironment, the inflammatory response, and age. Recent advances allowed a better stratification of these diseases and new therapeutic approaches with

  1. CXCL12 suppresses cisplatin-induced apoptosis through activation of JAK2/STAT3 signaling in human non-small-cell lung cancer cells

    Wang M

    2017-06-01

    Full Text Available Meng Wang,1 Tie Lin,2 Yicun Wang,3 Song Gao,4 Zhaoyang Yang,1 Xuan Hong,1 Gongyan Chen1 1Department of Respiratory Medicine, Harbin Medical University Cancer Hospital, 2Department of Surgery, The First Affiliated Hospital of Harbin Medical University, Harbin, 3Jilin Provincial Key Laboratory on Molecular and Chemical Genetics, The Second Hospital of Jilin University, Changchun, 4Department of Clinical Oncology, Shengjing Hospital, China Medical University, Shenyang, People’s Republic of China Aims: Poor efficacy of chemotherapy drugs in non-small-cell lung cancer (NSCLC is the key reason for the failure of treatment, but the mechanism of this remains largely unknown. Stromal cell-derived factor 1-alpha (SDF-1α/CXCL12 is a small chemotactic cytokine protein that plays an important role in tumor progression. In this study, we investigated the anti-apoptotic mechanism of the CXCL12/CXCR4 axis in response to cisplatin, a commonly used chemotherapeutic drug, in human lung adenocarcinoma A549 cells.Methods: CXCL12 blocks cisplatin-induced apoptosis in A549, and the results were shown by propidium iodide/annexin V staining in vitro. The mechanism of CXCL12 stimulating phosphorylation of STAT3 through CXCR4/JAK2 was demonstrated by immunofluorescence and Western blotting. The expression of CXCL12 and p-STAT3 in clinical specimens was examined by immunohistochemistry.Results: CXCL12 significantly decreased the ratio of apoptotic cells and stimulation of phospho-signal transducer and activator of transcription (p-STAT-3 in a time-dependent manner through interaction with CXCR4. Among the signaling molecules downstream of CXCR4, the JAK2/STAT3 pathway plays a predominant role in the anti-apoptotic effect of CXCL12. Analysis of clinical specimens revealed that increased CXCL12 and p-STAT3 expression correlates with enhanced lung cancer progression.Conclusion: These data suggest that CXCR4 contributes to CXCL12-mediated anti-apoptosis by activating JAK2

  2. Inhibitory effects of a selective Jak2 inhibitor on adrenocorticotropic hormone production and proliferation of corticotroph tumor AtT20 cells

    Asari Y

    2017-09-01

    Full Text Available Yuko Asari, Kazunori Kageyama, Yuki Nakada, Mizuki Tasso, Shinobu Takayasu, Kanako Niioka, Noriko Ishigame, Makoto Daimon Department of Endocrinology and Metabolism, Graduate School of Medicine, Hirosaki University, Hirosaki, Japan Purpose: The primary cause of Cushing’s disease is adrenocorticotropic hormone (ACTH-producing pituitary adenomas. EGFR signaling induces POMC mRNA-transcript levels and ACTH secretion from corticotroph tumors. The Jak–STAT pathway is located downstream of EGFR signaling; therefore, a Jak2 inhibitor could be an effective therapy for EGFR-related tumors. In this study, we determined the effect of a potent and selective Jak2 inhibitor, SD1029, on ACTH production and proliferation in mouse AtT20 corticotroph tumor cells.Materials and methods: AtT20 pituitary corticotroph tumor cells were cultured after transfection with PTTG1- or GADD45β-specific siRNA. Expression levels of mouse POMC, PTTG1, and GADD45β mRNAs were evaluated using quantitative real-time polymerase chain reaction. ACTH levels were measured using ACTH ELISA. Western blot analysis was performed to examine protein expression of phosphorylated STAT3/STAT3. Viable cells and DNA fragmentation were measured using a cell-proliferation assay and cell-death detection ELISA, respectively. Cellular DNA content was analyzed using fluorescence-activated cell sorting.Results: SD1029 decreased POMC and PTTG1 mRNA and ACTH levels, while increasing GADD45β levels. The drug also decreased AtT20-cell proliferation and induced apoptosis, but did not alter cell-cycle progression. SD1029 also inhibited STAT3 phosphorylation. PTTG1 knockdown inhibited POMC mRNA levels and cell proliferation. However, combined treatment with PTTG1 knockdown and SD1029 had no additive effect on POMC mRNA levels or cell proliferation. GADD45β knockdown inhibited the SD1029-induced decrease in POMC mRNA levels and also partially inhibited the decrease in cell proliferation.Conclusion: Both

  3. Sesquiterpene dimmer (DSF-27) inhibits the release of neuroinflammatory mediators from microglia by targeting spleen tyrosine kinase (Syk) and Janus kinase 2 (Jak2): Two major non-receptor tyrosine signaling proteins involved in inflammatory events

    Zeng, Ke-Wu [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing 100191 (China); Wang, Shu [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing 100191 (China); Department of Medicinal Chemistry and Pharmaceutical Analysis, Logistics College of Chinese People' s Armed Police Forces, Tianjin 300162 (China); Dong, Xin; Jiang, Yong; Jin, Hong-Wei [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing 100191 (China); Tu, Peng-Fei, E-mail: pengfeitu@vip.163.com [State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing 100191 (China)

    2014-03-15

    Non-receptor protein tyrosine kinases (NRPTKs)-dependent inflammatory signal transduction cascades play key roles in immunoregulation. However, drug intervention through NRPTKs-involved immunoregulation mechanism in microglia (the major immune cells of the central nervous system) has not been widely investigated. A main aim of the present study is to elucidate the contribution of two major NRPTKs (Syk and Jak2) in neuroinflammation suppression by a bioactive sesquiterpene dimmer (DSF-27). We found that LPS-stimulated BV-2 cells activated Syk and further initiated Akt/NF-κB inflammatory pathway. This Syk-dependent Akt/NF-κB inflammatory pathway can be effectively ameliorated by DSF-27. Moreover, Jak2 was activated by LPS, which was followed by transcriptional factor Stat3 activation. The Jak2/Stat3 signal was suppressed by DSF-27 through inhibition of Jak2 and Stat3 phosphorylation, promotion of Jak/Stat3 inhibitory factors PIAS3 expression, and down-regulation of ERK and p38 MAPK phosphorylation. Furthermore, DSF-27 protected cortical and mesencephalic dopaminergic neurons against neuroinflammatory injury. Taken together, our findings indicate NRPTK signaling pathways including Syk/NF-κB and Jak2/Stat3 cascades are potential anti-neuroinflammatory targets in microglia, and may also set the basis for the use of sesquiterpene dimmer as a therapeutic approach for neuroinflammation via interruption of these pathways. - Highlights: • Sesquiterpene dimmer DSF-27 inhibits inflammatory mediators' production in microglia. • Syk-dependent Akt/NF-κB pathway is important for DSF-27's anti-inflammation activity. • Jak2/Stat3 pathway is important for DSF-27's anti-inflammation activity. • Jak2/Stat3 signaling pathway is partly regulated by ERK and p38 MAPKs and PIAS3. • DSF-27 protects neurons against microglia-mediated neuroinflammatory injury.

  4. Neoplasias mieloproliferativas: revisão dos critérios diagnósticos e dos aspectos clínicos Myeloproliferative neoplasms: a review of diagnostic criteria and clinical aspects

    Maria de Lourdes L. F. Chauffaille

    2010-01-01

    with effective maturation. The progression of all is characterized by marrow fibrosis or leukemic transformation. According to the WHO classification, the MPNs include: chronic myeloid leukemia (CML, polycythemia vera (PV, essential thrombocythemia (ET, idiopathic myelofibrosis (IM, chronic neutrophilic leukemia (CNL, chronic eosinophilic leukemia not otherwise categorized (CEL-NC, mastocytosis (M and myeloproliferative neoplasm unclassifiable (MPNU. It is worth noting that the molecular basis of CML (BCR/ABL1, as well as PV,ET, IM (JAK2V617F and exon 12, MPL W515L/K and M (KITD816V have been identified and have, in common, constitutive activation of tyrosine kinase due to acquired hematopoietic stem cell defects. The JAK2V617F mutation is observed in around 90% of PV cases and in around 50-60% of IM and ET leading to the question why a single molecular lesion induces three different clinical manifestations. There is already evidence that additional genetic and epigenetic events contribute to the pathogenesis, including MPL W515L/K mutation. Some clinical aspects, the pathophysiology and diagnostic criteria of MPNs are presented in this paper.

  5. Egr2 enhances insulin resistance via JAK2/STAT3/SOCS-1 pathway in HepG2 cells treated with palmitate.

    Lu, Lin; Ye, Xinhua; Yao, Qing; Lu, Aijiao; Zhao, Zhen; Ding, Yang; Meng, Chuchen; Yu, Wenlong; Du, Yunfeng; Cheng, JinLuo

    2018-05-01

    Insulin resistance is generally responsible for the pathogenesis of type 2 diabetes mellitus (T2DM). Early growth response proteins-2 (Egr2) has been reported to be able to increase the expression of the suppressors of cytokine signaling-1 (SOCS-1), and impair insulin signaling pathway through suppression of insulin receptor substrates (IRS), including IRS-1 and IRS-2. However, whether Egr2 is directly involved in the development of insulin resistance, and how its potential contributions to insulin resistance still remain unknown. Here, our present investigation found that the expression levels of Egr2 were up-regulated when insulin resistance occurs, and knockdown of Egr2 abolished the effect of insulin resistance in HepG2 cells induced with palmitate (PA). Importantly, inhibition of Egr2 decreased the expression of SOCS-1 as well as reduced phosphorylation of JAK2 and STAT3. And, our data indicated that silencing of Egr2 accelerated hepatic glucose uptake and reversed the impaired lipid metabolism upon insulin resistance. In summary, the present study confirms that Egr2 could deteriorate insulin resistance via the pathway of JAK2/STAT3/SOCS-1 and may shed light on resolving insulin resistance and further the pathogenesis of T2DM. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Ginkgolide B Suppresses TLR4-Mediated Inflammatory Response by Inhibiting the Phosphorylation of JAK2/STAT3 and p38 MAPK in High Glucose-Treated HUVECs

    Kun Chen

    2017-01-01

    Full Text Available Aim. Ginkgolide B is a Ginkgo biloba leaf extract that has been identified as a natural platelet-activating factor receptor (PAFR antagonist. We investigated the effect of ginkgolide B on high glucose-induced TLR4 activation in human umbilical vein endothelial cells (HUVECs. Methods. Protein expression was analyzed by immunoblotting. Small-interfering RNA (siRNA was used to knock down PAFR and TLR4 expression. Results. Ginkgolide B suppressed the expression of TLR4 and MyD88 that was induced by high glucose. Ginkgolide B also reduced the levels of platelet endothelial cell adhesion molecule-1, interleukin-6, and monocyte chemotactic protein 1. Further, we examined the association between PAFR and TLR4 by coimmunoprecipitation. The result showed that high glucose treatment caused the binding of PAFR and TLR4, whereas ginkgolide B abolished this binding. The functional analysis indicated that PAFR siRNA treatment reduced TLR4 expression, and TLR4 siRNA treatment decreased PAFR expression in high glucose-treated HUVECs, further supporting the coimmunoprecipitation data. Ginkgolide B inhibited the phosphorylation of Janus kinase 2 (JAK2/signal transducer and activator of transcription 3 (STAT3 and p38 mitogen-activated protein kinase (MAPK. Conclusion. Ginkgolide B exerted protective effects by inhibiting the TLR4-mediated inflammatory response in high glucose-treated endothelial cells. The mechanism of action of ginkgolide B might be associated with inhibition of the JAK2/STAT3 and p38 MAPK phosphorylation.

  7. Proteasome Inhibitor YSY01A Abrogates Constitutive STAT3 Signaling via Down-regulation of Gp130 and JAK2 in Human A549 Lung Cancer Cells

    Wei Huang

    2017-08-01

    Full Text Available Proteasome inhibition interfering with many cell signaling pathways has been extensively explored as a therapeutic strategy for cancers. Proteasome inhibitor YSY01A is a novel agent that has shown remarkable anti-tumor effects; however, its mechanisms of action are not fully understood. Here we report that YSY01A is capable of suppressing cancer cell survival by induction of apoptosis. Paradoxically, we find that YSY01A abrogates constitutive activation of STAT3 via proteasome-independent degradation of gp130 and JAK2, but not transcriptional regulation, in human A549 non-small cell lung cancer cells. The reduction in gp130 and JAK2 can be restored by co-treatment with 3-methyladenine, an early-stage autophagy lysosome and type I/III PI3K inhibitor. YSY01A also effectively inhibits cancer cell migration and lung xenograft tumor growth with little adverse effect on animals. Thus, our findings suggest that YSY01A represents a promising candidate for further development of novel anticancer therapeutics targeting the proteasome.

  8. Efficacy of ALK5 inhibition in myelofibrosis

    Zhao, Wanke; Ho, Wanting Tina; Han, Ying; Murdun, Cem; Mailloux, Adam W.; Zhang, Ling; Wang, Xuefeng; Budhathoki, Anjali; Pradhan, Kith; Rapaport, Franck; Wang, Huaquan; Shao, Zonghong; Ren, Xiubao; Steidl, Ulrich; Levine, Ross L.; Zhao, Zhizhuang Joe; Verma, Amit; Epling-Burnette, Pearlie K.

    2017-01-01

    Myelofibrosis (MF) is a bone marrow disorder characterized by clonal myeloproliferation, aberrant cytokine production, extramedullary hematopoiesis, and bone marrow fibrosis. Although somatic mutations in JAK2, MPL, and CALR have been identified in the pathogenesis of these diseases, inhibitors of the Jak2 pathway have not demonstrated efficacy in ameliorating MF in patients. TGF-β family members are profibrotic cytokines and we observed significant TGF-β1 isoform overexpression in a large cohort of primary MF patient samples. Significant overexpression of TGF-β1 was also observed in murine clonal MPLW515L megakaryocytic cells. TGF-β1 stimulated the deposition of excessive collagen by mesenchymal stromal cells (MSCs) by activating the TGF-β receptor I kinase (ALK5)/Smad3 pathway. MSCs derived from MPLW515L mice demonstrated sustained overproduction of both collagen I and collagen III, effects that were abrogated by ALK5 inhibition in vitro and in vivo. Importantly, use of galunisertib, a clinically active ALK5 inhibitor, significantly improved MF in both MPLW515L and JAK2V617F mouse models. These data demonstrate the role of malignant hematopoietic stem cell (HSC)/TGF-β/MSC axis in the pathogenesis of MF, and provide a preclinical rationale for ALK5 blockade as a therapeutic strategy in MF. PMID:28405618

  9. Deregulated expression of A1, Bcl-2, Bcl-xL, and Mcl-1 antiapoptotic proteins and Bid, Bad, and Bax proapoptotic genes in polycythemia vera patients

    Elainy Patricia Lino Gasparotto

    2011-12-01

    Full Text Available Apoptosis deregulation might have a role in the pathophysiology of polycythemia vera (PV. This study evaluated Bcl-2 molecule expression in CD34+ cells and leukocytes in 12 PV patients. Gene expression was investigated by real time PCR using SybrGreen Quantitect kit and protein expression was evaluated by western-blotting. JAK2 V617F mutation was detected according to Baxter et al (2005. CD34+ cells from PV patients presented higher levels of A1 and Mcl-1 expression (median: 22.6 and 5.2, respectively in comparison with controls (0.9 and 0.5, p=0.004 and p=0.020; while Bcl-2 and Bcl-xL expression decreased in PV patients (0.18 and 1.19 compared with controls (1.39 and 2.01, p=0.006 and p=0.020. CD34+ cells in PV patients showed an elevated Bid expression (14.4 in comparison with healthy subjects (1.0; p=0.002. Patients' leukocytes showed an A1 augmentation (7.41, p=0.001 and a reduced expression of Bax (0.19; p=0.040 and Bad (0.2; p=0.030. There was no correlation between JAK2 V617F allele burden and molecular expression. PV patients showed alterations in Bcl-2 members' expression, which may interfere with control of apoptotic machinery and contribute to disease pathogenesis.A desregulação da apoptose parece participar da fisiopatologia da policitemia vera (PV. Este estudo avaliou a expressão das moléculas da família Bcl-2 em células hematopoéticas CD34 + e leucócitos de 12 pacientes com PV. Foram realizados: a quantificação da expressão gênica por PCR em tempo real utilizando kit Sybrgreen Quantitect, avaliação da expressão de proteínas por western-blot e detecção da mutação JAK2 V617F segundo Baxter et al. (2005. Células CD34 + dos pacientes com PV apresentaram maior expressão de A1 e Mcl-1 (mediana: 22,6 e 5,2, respectivamente em comparação com controles (0,9 e 0,5, p = 0,004 e p = 0,020 e expressão de Bcl-2 e Bcl-xL diminuída nestes pacientes (0,18 e 1,19 em relação aos controles (1,39 e 2,01, p = 0,006 e p = 0

  10. Molecular diagnostics of myeloproliferative neoplasms.

    Langabeer, Stephen E; Andrikovics, Hajnalka; Asp, Julia; Bellosillo, Beatriz; Carillo, Serge; Haslam, Karl; Kjaer, Lasse; Lippert, Eric; Mansier, Olivier; Oppliger Leibundgut, Elisabeth; Percy, Melanie J; Porret, Naomi; Palmqvist, Lars; Schwarz, Jiri; McMullin, Mary F; Schnittger, Susanne; Pallisgaard, Niels; Hermouet, Sylvie

    2015-10-01

    Since the discovery of the JAK2 V617F mutation in the majority of the myeloproliferative neoplasms (MPN) of polycythemia vera, essential thrombocythemia and primary myelofibrosis ten years ago, further MPN-specific mutational events, notably in JAK2 exon 12, MPL exon 10 and CALR exon 9 have been identified. These discoveries have been rapidly incorporated into evolving molecular diagnostic algorithms. Whilst many of these mutations appear to have prognostic implications, establishing MPN diagnosis is of immediate clinical importance with selection, implementation and the continual evaluation of the appropriate laboratory methodology to achieve this diagnosis similarly vital. The advantages and limitations of these approaches in identifying and quantitating the common MPN-associated mutations are considered herein with particular regard to their clinical utility. The evolution of molecular diagnostic applications and platforms has occurred in parallel with the discovery of MPN-associated mutations, and it therefore appears likely that emerging technologies such as next-generation sequencing and digital PCR will in the future play an increasing role in the molecular diagnosis of MPN. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. Oncogenes in myeloproliferative disorders.

    Tefferi, Ayalew; Gilliland, D Gary

    2007-03-01

    Myeloproliferative disorders (MPDs) constitute a group of hematopoietic malignancies that feature enhanced proliferation and survival of one or more myeloid lineage cells. William Dameshek is credited for introducing the term "MPDs" in 1951 when he used it to group chronic myeloid leukemia (CML), polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF) under one clinicopathologic category. Since then, other myeloid neoplasms have been added to the MPD member list: chronic neutrophilic (CNL), eosinophilic (CEL) and myelomonocytic (CMML) leukemias; juvenile myelomonocytic leukemia (JMML); hypereosinophilic syndrome (HES); systemic mastocytosis (SM); and others. Collectively, MPDs are stem cell-derived clonal proliferative diseases whose shared and diverse phenotypic characteristics can be attributed to dysregulated signal transduction--a consequence of acquired somatic mutations. The most recognized among the latter is BCR-ABL, the disease-causing mutation in CML. Other mutations of putative pathogenetic relevance in MPDs include: JAK2V617F in PV, ET, and PMF; JAK2 exon 12 mutations in PV; MPLW515L/K in PMF and ET; KITD816V in SM; FIP1L1-PDGFRA in CEL-SM; rearrangements of PDGFRB in CEL-CMML and FGFR1 in stem cell leukemia-lymphoma syndrome; and RAS/PTPN11/NF1 mutations in JMML. This increasing repertoire of mutant molecules has streamlined translational research and molecularly targeted drug development in MPDs.

  12. Lung Clear “Sugar” Cell Tumor and Jak V617f Positive Essential Thrombocythemia: A simple Coıncıdence?

    Volkan Yazak

    2013-04-01

    Full Text Available The primary clear cell tumor of the lung is an extremely rare benign tumor, which is called “sugar tumor”, because of the large content of glycogen. Here we are presenting essential thrombocythemia and lung clear cell tumor which was not reported before to the best of our knowledge. A 44 years old woman admitted to the clinic with complaint of lassitude lasting for 2 months. In her physical examination the spleen was 3 cm palpable from the costa arch In laboratory findings number of platelet was 1014000 mm³. A 3.5 cm in diameter pulmonary nodule is detected in right upper lobe in the graphy of the lungs. Subsequently  computed tomography  (CT of thorax was carried out. Due to the benign features in the display of  the detected nodule, a total excision with curative and diagnostic intentions was performed. Microscopically the tumor were composed of nests of rounded or oval cells with distinct cell borders and optically clear cytoplasm. The nuclei were small. Immunohistochemically the tumor cells expressed HMB-45, NSE and focal S100 antigen. It was diagnosed as clear  “sugar” cell tumor. In conclusion, in lung clear cell tumor, it is important to make evaluation in terms of myeloproliferative disease in adults whose thrombocytosis continue after the treatment.

  13. High Frequency of Copy-Neutral Loss of Heterozygosity in Patients with Myelofibrosis.

    Rego de Paula Junior, Milton; Nonino, Alexandre; Minuncio Nascimento, Juliana; Bonadio, Raphael S; Pic-Taylor, Aline; de Oliveira, Silviene F; Wellerson Pereira, Rinaldo; do Couto Mascarenhas, Cintia; Forte Mazzeu, Juliana

    2018-01-01

    Myelofibrosis is the rarest and most severe type of Philadelphia-negative classical myeloproliferative neoplasms. Although mutually exclusive driver mutations in JAK2, MPL, or CALR that activate JAK-STAT pathway have been related to the pathogenesis of the disease, chromosome abnormalities have also been associated with the phenotype and prognosis of the disease. Here, we report the use of a chromosomal microarray platform consisting of both oligo and SNP probes to improve the detection of chromosome abnormalities in patients with myelofibrosis. Sixteen patients with myelofibrosis were tested, and the results were compared to karyotype analysis. Driver mutations in JAK2, MPL, or CALR were investigated by PCR and MLPA. Conventional cytogenetics revealed chromosome abnormalities in 3 out of 16 cases (18.7%), while chromosomal microarray analysis detected copy-number variations (CNV) or copy-neutral loss of heterozygosity (CN-LOH) alterations in 11 out of 16 (68.7%) patients. These included 43 CN-LOH, 14 deletions, 1 trisomy, and 1 duplication. Ten patients showed multiple chromosomal abnormalities, varying from 2 to 13 CNVs or CN-LOHs. Mutational status for JAK2, CALR, and MPL by MLPA revealed a total of 3/16 (18.7%) patients positive for the JAK2 V617F mutation, 9 with CALR deletion or insertion and 1 positive for MPL mutation. Considering that most of the CNVs identified were smaller than the karyotype resolution and the high frequency of CN-LOHs in our study, we propose that chromosomal microarray platforms that combine oligos and SNP should be used as a first-tier genetic test in patients with myelofibrosis. © 2018 S. Karger AG, Basel.

  14. CRH promotes human colon cancer cell proliferation via IL-6/JAK2/STAT3 signaling pathway and VEGF-induced tumor angiogenesis.

    Fang, Xianjun; Hong, Yali; Dai, Li; Qian, Yuanyuan; Zhu, Chao; Wu, Biao; Li, Shengnan

    2017-11-01

    Corticotrophin-releasing hormone (CRH) has been demonstrated to participate in various diseases. Our previous study showed that its receptor CRHR1 mediated the development of colitis-associated cancer in mouse model. However, the detailed mechanisms remain unclear. In this study, we explored the oncogenetic role of CRH/CRHR1 signaling in colon cancer cells. Cell proliferation and colony formation assays revealed that CRH contributed to cell proliferation. Moreover, tube formation assay showed that CRH-treated colon cancer cell supernatant significantly promoted tube formation of human umbilical vein endothelial cells (HUVECs). And these effects could be reversed by the CRHR1 specific antagonist Antalarmin. Further investigation showed that CRH significantly upregulated the expressions of interlukin-6 (IL-6) and vascular endothelial growth factor (VEGF) through activating nuclear factor-kappa B (NF-κB). The CRH-induced IL-6 promoted phosphorylation of janus kinase 2 (JAK2) and signal transducers and activators of transcription 3 (STAT3). STAT3 inhibition by Stattic significantly inhibited the CRH-induced cell proliferation. In addition, silence of VEGF resulted in declined tube formation induced by CRH. Taken together, CRH/CRHR1 signaling promoted human colon cancer cell proliferation via NF-κB/IL-6/JAK2/STAT3 signaling pathway and tumor angiogenesis via NF-κB/VEGF signaling pathway. Our results provide evidence to support a critical role for the CRH/CRHR1 signaling in colon cancer progression and suggest its potential utility as a new therapeutic target for colon cancer. © 2017 Wiley Periodicals, Inc.

  15. Calcineurin inhibitors recruit protein kinases JAK2 and JNK, TLR signaling and the UPR to activate NF-κB-mediated inflammatory responses in kidney tubular cells

    González-Guerrero, Cristian; Ocaña-Salceda, Carlos; Berzal, Sergio; Carrasco, Susana; Fernández-Fernández, Beatriz

    2013-01-01

    The calcineurin inhibitors (CNIs) cyclosporine (CsA) and tacrolimus are key drugs in current immunosuppressive regimes for solid organ transplantation. However, they are nephrotoxic and promote death and profibrotic responses in tubular cells. Moreover, renal inflammation is observed in CNI nephrotoxicity but the mechanisms are poorly understood. We have now studied molecular pathways leading to inflammation elicited by the CNIs in cultured and kidney tubular cells. Both CsA and tacrolimus elicited a proinflammatory response in tubular cells as evidenced by a transcriptomics approach. Transcriptomics also suggested several potential pathways leading to expression of proinflammatory genes. Validation and functional studies disclosed that in tubular cells, CNIs activated protein kinases such as the JAK2/STAT3 and TAK1/JNK/AP-1 pathways, TLR4/Myd88/IRAK signaling and the Unfolded Protein Response (UPR) to promote NF-κB activation and proinflammatory gene expression. CNIs also activated an Nrf2/HO-1-dependent compensatory response and the Nrf2 activator sulforaphane inhibited JAK2 and JNK activation and inflammation. A murine model of CsA nephrotoxicity corroborated activation of the proinflammatory pathways identified in cell cultures. Human CNIs nephrotoxicity was also associated with NF-κB, STAT3 and IRE1α activation. In conclusion, CNIs recruit several intracellular pathways leading to previously non-described proinflammatory actions in renal tubular cells. Identification of these pathways provides novel clues for therapeutic intervention to limit CNIs nephrotoxicity. - Highlights: • Molecular mechanisms modulating CNI renal inflammation were investigated. • Kinases, immune receptors and ER stress mediate the inflammatory response to CNIs. • Several intracellular pathways activate NF-κB in CNIs-treated tubular cells. • A NF-κB-dependent cytokine profile characterizes CNIs-induced inflammation. • CNI nephrotoxicity was associated to inflammatory

  16. Risk Factors for and Management of MPN-Associated Bleeding and Thrombosis.

    Martin, Karlyn

    2017-10-01

    The Philadelphia chromosome-negative myeloproliferative neoplasms (MPN) are characterized by both thrombotic and bleeding complications. The purpose of this review is to describe the risk factors associated with bleeding and thrombosis in MPN, as well as to review prevention strategies and management of these complications. Well-described risk factors for thrombotic complications include older age and history of prior thrombosis, along with traditional cardiovascular and venous thromboembolic risk factors. More recently, JAK2 V617F mutation has been found to carry an increased risk of thrombotic complications, whereas CALR has a lower risk than JAK2 mutation. Factors associated with an increased risk of bleeding in MPN include a prior history of bleeding, acquired von Willebrand syndrome, and primary myelofibrosis. Recent findings suggest that thrombocytosis carries a higher risk of bleeding than thrombosis in MPN, and aspirin may exacerbate this risk of bleeding, particularly in CALR-mutated ET. Much of the management of MPN focuses on predicting risk of bleeding and thrombosis and initiating prophylaxis to prevent complications in those at high risk of thrombosis. Emerging evidence suggests that sub-populations may have bleeding risk that outweighs thrombotic risk, particularly in setting of antiplatelet therapy. Future work is needed to better characterize this balance. At present, a thorough assessment of the risks of bleeding and thrombosis should be undertaken for each patient, and herein, we review risk factors for and management of these complications.

  17. Inactivation of JAK2/STAT3 Signaling Axis and Downregulation of M1 mAChR Cause Cognitive Impairment in klotho Mutant Mice, a Genetic Model of Aging

    Park, Seok-Joo; Shin, Eun-Joo; Min, Sun Seek; An, Jihua; Li, Zhengyi; Hee Chung, Yoon; Hoon Jeong, Ji; Bach, Jae-Hyung; Nah, Seung-Yeol; Kim, Won-Ki; Jang, Choon-Gon; Kim, Yong-Sun; Nabeshima, Yo-ichi; Nabeshima, Toshitaka; Kim, Hyoung-Chun

    2013-01-01

    We previously reported cognitive dysfunction in klotho mutant mice. In the present study, we further examined novel mechanisms involved in cognitive impairment in these mice. Significantly decreased janus kinase 2 (JAK2) and signal transducer and activator of transcription3 (STAT3) phosphorylation were observed in the hippocampus of klotho mutant mice. A selective decrease in protein expression and binding density of the M1 muscarinic cholinergic receptor (M1 mAChR) was observed in these mice. Cholinergic parameters (ie, acetylcholine (ACh), choline acetyltransferase (ChAT), and acetylcholinesterase (AChE)) and NMDAR-dependent long-term potentiation (LTP) were significantly impaired in klotho mutant mice. McN-A-343 (McN), an M1 mAChR agonist, significantly attenuated these impairments. AG490 (AG), a JAK2 inhibitor, counteracted the attenuating effects of McN, although AG did not significantly alter the McN-induced effect on AChE. Furthermore, AG significantly inhibited the attenuating effects of McN on decreased NMDAR-dependent LTP, protein kinase C βII, p-ERK, p-CREB, BDNF, and p-JAK2/p-STAT3-expression in klotho mutant mice. In addition, k252a, a BDNF receptor tyrosine kinase B (TrkB) inhibitor, significantly counteracted McN effects on decreased ChAT, ACh, and M1 mAChR and p-JAK2/p-STAT3 expression. McN-induced effects on cognitive impairment in klotho mutant mice were consistently counteracted by either AG or k252a. Our results suggest that inactivation of the JAK2/STAT3 signaling axis and M1 mAChR downregulation play a critical role in cognitive impairment observed in klotho mutant mice. PMID:23389690

  18. LPS-induced release of IL-6 from glia modulates production of IL-1beta in a JAK2-dependent manner

    Minogue, Aedín M

    2012-06-14

    AbstractBackgroundCompelling evidence has implicated neuroinflammation in the pathogenesis of a number of neurodegenerative conditions. Chronic activation of both astrocytes and microglia leads to excessive secretion of proinflammatory molecules such as TNFα, IL-6 and IL-1β with potentially deleterious consequences for neuronal viability. Many signaling pathways involving the mitogen-activated protein kinases (MAPKs), nuclear factor κB (NFκB) complex and the Janus kinases (JAKs)\\/signal transducers and activators of transcription (STAT)-1 have been implicated in the secretion of proinflammatory cytokines from glia. We sought to identify signaling kinases responsible for cytokine production and to delineate the complex interactions which govern time-related responses to lipopolysaccharide (LPS).MethodsWe examined the time-related changes in certain signaling events and the release of proinflammatory cytokines from LPS-stimulated co-cultures of astrocytes and microglia isolated from neonatal rats.ResultsTNFα was detected in the supernatant approximately 1 to 2 hours after LPS treatment while IL-1β and IL-6 were detected after 2 to 3 and 4 to 6 hours, respectively. Interestingly, activation of NFκB signaling preceded release of all cytokines while phosphorylation of STAT1 was evident only after 2 hours, indicating that activation of JAK\\/STAT may be important in the up-regulation of IL-6 production. Additionally, incubation of glia with TNFα induced both phosphorylation of JAK2 and STAT1 and the interaction of JAK2 with the TNFα receptor (TNFR1). Co-treatment of glia with LPS and recombinant IL-6 protein attenuated the LPS-induced release of both TNFα and IL-1β while potentiating the effect of LPS on suppressor of cytokine signaling (SOCS)3 expression and IL-10 release.ConclusionsThese data indicate that TNFα may regulate IL-6 production through activation of JAK\\/STAT signaling and that the subsequent production of IL-6 may impact on the release of

  19. Transjugular local thrombolysis with/without TIPS in patients with acute non-cirrhotic, non-malignant portal vein thrombosis.

    Klinger, Christoph; Riecken, Bettina; Schmidt, Arthur; De Gottardi, Andrea; Meier, Benjamin; Bosch, Jaime; Caca, Karel

    2017-12-01

    Therapeutic anticoagulation is the standard treatment in patients with acute non-cirrhotic portal vein thrombosis (PVT). In critically ill patients, anticoagulation only may not suffice to achive rapid and stable recanalization. This study evaluates efficacy and safety of transjugular interventional therapy in acute non-cirrhotic PVT. This retrospective study includes 17 consecutive patients with acute noncirrhotic, non-malignant PVT. Main indication for interventional therapy was imminent intestinal infarction (n=10). Treatment consisted of a combination of transjugular thrombectomy, local fibrinolysis and - depending on thrombus resolution - transjugular intrahepatic portosystemic shunt. Recanalization was successful in 94.1%. One- and two-year secondary PV patency rates were 88.2%. Major complications (n=3) resolved spontaneously in all but one patient (heparin induced thrombocytopenia type 2 with intestinal infarction). Symptoms improved in all patients. However, segmental bowel resection had to be performed in two (11.8%). During a median follow-up of 28.6 months, no patient experienced portal hypertensive complications. Presence of JAK2 V617F mutation predicted both short-term and long-term technical success. Transjugular recanalization is safe and effective in patients with acute non-cirrhotic, non-malignant PVT. It should be considered especially in patients with imminent bowel infarction and low likelihood of recanalization following therapeutic anticoagulation. Patients with JAK2 mutation ought to be followed meticulously. Copyright © 2017 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

  20. Trichostatin A, a histone deacetylase inhibitor, suppresses JAK2/STAT3 signaling via inducing the promoter-associated histone acetylation of SOCS1 and SOCS3 in human colorectal cancer cells.

    Xiong, Hua; Du, Wan; Zhang, Yan-Jie; Hong, Jie; Su, Wen-Yu; Tang, Jie-Ting; Wang, Ying-Chao; Lu, Rong; Fang, Jing-Yuan

    2012-02-01

    Aberrant janus kinase/signal transducers and activators of transcription (JAK/STAT) signaling is involved in the oncogenesis of several cancers. Suppressors of cytokine signaling (SOCS) genes and SH2-containing protein tyrosine phosphatase 1 (SHP1) proteins, which are negative regulators of JAK/STAT signaling, have been reported to have tumor suppressor functions. However, in colorectal cancer (CRC) cells, the mechanisms that regulate SOCS and SHP1 genes, and the cause of abnormalities in the JAK/STAT signaling pathway, remain largely unknown. The present study shows that trichostatin A (TSA), a histone deacetylase (HDAC) inhibitor, leads to the hyperacetylation of histones associated with the SOCS1 and SOCS3 promoters, but not the SHP1 promoter in CRC cells. This indicates that histone modifications are involved in the regulation of SOCS1 and SOCS3. Moreover, upregulation of SOCS1 and SOCS3 expression was achieved using TSA, which also significantly downregulated JAK2/STAT3 signaling in CRC cells. We also demonstrate that TSA suppresses the growth of CRC cells, and induces G1 cell cycle arrest and apoptosis through the regulation of downstream targets of JAK2/STAT3 signaling, including Bcl-2, survivin and p16(ink4a) . Therefore, our data demonstrate that TSA may induce SOCS1 and SOCS3 expression by inducing histone modifications and consequently inhibits JAK2/STAT3 signaling in CRC cells. These results also establish a mechanistic link between the inhibition of JAK2/STAT3 signaling and the anticancer action of TSA in CRC cells. Copyright © 2011 Wiley Periodicals, Inc.

  1. A case of mistaken identity: When lupus masquerades as primary myelofibrosis

    Edy Hasrouni

    2013-08-01

    Full Text Available Introduction: Autoimmune myelofibrosis is an uncommon hematologic disease characterized by anemia, bone marrow myelofibrosis, and an autoimmune feature. Myelofibrosis is often associated with other conditions, including infections, nutritional/endocrine dysfunction, toxin/drug exposure, and connective tissue diseases, including scleroderma and systemic lupus erythematosus. Absence of clonal markers ( JAK2 and heterogeneity of the symptoms often complicate the diagnosis. Case presentation: Here, we present two cases of systemic lupus erythematosus–induced autoimmune myelofibrosis. The first case is of a 36-year-old African American female with diagnosis of systemic lupus erythematosus at the age of 12 years. The second patient is a 44-year-old African American male with family history of systemic lupus erythematosus who developed anemia and constitutional symptoms later on. Both patients showed hypercellularity and fibrotic changes of the bone marrow. Moreover, mutational analysis showed that both patients were wild type for JAK2 (V617F and exon 12 and MPL (exon 10. Conclusions: These two cases illustrate that anemic patients with fibrotic changes in the bone marrow without other clinicopathologic features associated with primary myelofibrosis in the presence of clinical manifestations and history of an autoimmune disease should suggest an autoimmune myelofibrosis. These cases demonstrate that a good clinical history combined with molecular technologies and pathomorphologic criteria are helpful in distinguishing between primary myelofibrosis and a nonclonal myelofibrosis from an associated condition.

  2. Corydalis hendersonii Hemsl. protects against myocardial injury by attenuating inflammation and fibrosis via NF-κB and JAK2-STAT3 signaling pathways.

    Bai, Ruifeng; Yin, Xu; Feng, Xiao; Cao, Yuan; Wu, Yan; Zhu, Zhixiang; Li, Chun; Tu, Pengfei; Chai, Xingyun

    2017-07-31

    Corydalis hendersonii Hemsl. (CH) with heat clearing and detoxifying effects are well described in Tibetan folk medicine. It has been used for centuries in China largely for the treatment of high altitude polycythemia, a pathophysiological condition referred to "plethora" in Tibetan medicine, hypertension, hepatitis, edema, gastritis, and other infectious diseases. To investigate the cardioprotective effects of Corydalis hendersonii extract in an ICR mouse model of myocardial ischemic injury. Ethanol [85% (v/v)] extract of CH whole plant was prepared, and their chemical profile was analyzed with use of HPLC-DAD and IT-TOF-ESI-MS. A mouse model of AMI was established by ligation of the left ventricular dysfunction (LAD) coronary artery. Mice were randomly divided into six groups (n = 12 per group): sham group, model group, CH groups treated with three doses of CH (100, 200, and 400mg/kg, intragastric), and a positive control group (captopril, 16.67mg/kg, intragastric). Heart function was evaluated by measurement of ejection fraction (EF) and fractional shortening (FS) by echocardiography. Serum levels of creatine kinase-MB (CK-MB) and lactate dehydrogenase (LDH), plasma levels of angiotensin II (AngII), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1ß (IL-1ß) and expressions of matrix metalloproteinase-2 (MMP-2) and MMP-9 in the cardiac tissue homogenate, protein expressions of signal-transduction proteins, p65, IκBα, JAK2, and STAT3 in heart tissues were measured by ELISA and Western blot analyses. Inflammatory cell infiltration and changes in collagen deposition in the myocardial ischemic heart tissues were observed by histopathological examination. Platelet aggregation in vitro was also assessed. CH treatment showed a dose-dependent cardioprotective effect. It significantly reduced left ventricular end-diastolic diameter (LVEDd) and left ventricular end-diastolic diameter (LVEDs), improved EF and FS as compared to those in the model

  3. Anti-cancer effect of bee venom toxin and melittin in ovarian cancer cells through induction of death receptors and inhibition of JAK2/STAT3 pathway

    Jo, Miran; Park, Mi Hee; Kollipara, Pushpa Saranya; An, Byeong Jun; Song, Ho Sueb; Han, Sang Bae; Kim, Jang Heub; Song, Min Jong; Hong, Jin Tae

    2012-01-01

    We investigated whether bee venom and melittin, a major component of bee venom, inhibit cell growth through enhancement of death receptor expressions in the human ovarian cancer cells, SKOV3 and PA-1. Bee venom (1–5 μg/ml) and melittin (0.5–2 μg/ml) inhibited the growth of SKOV3 and PA-1 ovarian cancer cells by the induction of apoptotic cell death in a dose dependent manner. Consistent with apoptotic cell death, expression of death receptor (DR) 3 and DR6 was increased in both cancer cells, but expression of DR4 was increased only in PA-1 cells. Expression of DR downstream pro-apoptotic proteins including caspase-3, 8, and Bax was concomitantly increased, but the phosphorylation of JAK2 and STAT3 and the expression of Bcl-2 were inhibited by treatment with bee venom and melittin in SKOV3 and PA-1 cells. Expression of cleaved caspase-3 was increased in SKOV3, but cleaved caspase-8 was increased in PA-1 cells. Moreover, deletion of DR3, DR4, and DR6 by small interfering RNA significantly reversed bee venom and melittin-induced cell growth inhibitory effect as well as down regulation of STAT3 by bee venom and melittin in SKOV3 and PA-1 ovarian cancer cell. These results suggest that bee venom and melittin induce apoptotic cell death in ovarian cancer cells through enhancement of DR3, DR4, and DR6 expression and inhibition of STAT3 pathway. -- Highlights: ► Some studies have showed that bee venom and/or melittin have anti-cancer effects. ► We found that bee venom and melittin inhibited cell growth in ovarian cancer cells. ► Bee venom and melittin induce apoptosis in SKOV3 and PA-1.

  4. Anti-cancer effect of bee venom toxin and melittin in ovarian cancer cells through induction of death receptors and inhibition of JAK2/STAT3 pathway.

    Jo, Miran; Park, Mi Hee; Kollipara, Pushpa Saranya; An, Byeong Jun; Song, Ho Sueb; Han, Sang Bae; Kim, Jang Heub; Song, Min Jong; Hong, Jin Tae

    2012-01-01

    We investigated whether bee venom and melittin, a major component of bee venom, inhibit cell growth through enhancement of death receptor expressions in the human ovarian cancer cells, SKOV3 and PA-1. Bee venom (1-5 μg/ml) and melittin (0.5-2 μg/ml) inhibited the growth of SKOV3 and PA-1 ovarian cancer cells by the induction of apoptotic cell death in a dose dependent manner. Consistent with apoptotic cell death, expression of death receptor (DR) 3 and DR6 was increased in both cancer cells, but expression of DR4 was increased only in PA-1 cells. Expression of DR downstream pro-apoptotic proteins including caspase-3, 8, and Bax was concomitantly increased, but the phosphorylation of JAK2 and STAT3 and the expression of Bcl-2 were inhibited by treatment with bee venom and melittin in SKOV3 and PA-1 cells. Expression of cleaved caspase-3 was increased in SKOV3, but cleaved caspase-8 was increased in PA-1 cells. Moreover, deletion of DR3, DR4, and DR6 by small interfering RNA significantly reversed bee venom and melittin-induced cell growth inhibitory effect as well as down regulation of STAT3 by bee venom and melittin in SKOV3 and PA-1 ovarian cancer cell. These results suggest that bee venom and melittin induce apoptotic cell death in ovarian cancer cells through enhancement of DR3, DR4, and DR6 expression and inhibition of STAT3 pathway. Copyright © 2011 Elsevier Inc. All rights reserved.

  5. ETS transcription factor ELF5 induces lumen formation in a 3D model of mammary morphogenesis and its expression is inhibited by Jak2 inhibitor TG101348.

    Chean, Jennifer; Chen, Charng-Jui; Shively, John E

    2017-10-01

    The loss of expression of a single gene can revert normal tissue to a malignant phenotype. For example, while normal breast has high lumenal expression of CEACAM1, the majority of breast cancers exhibit the early loss of this gene with the concurrent loss of their lumenal phenotype. MCF7 cells that lack CEACAM1 expression and fail to form lumena in 3D culture, regain the normal phenotype when transfected with CEACAM1. In order to probe the mechanism of this gain of function, we treated these cells with the clinically relevant Jak2 inhibitor TG101348 (TG), expecting that disruption of the prolactin receptor signaling pathway would interfere with the positive effects of transfection of MCF7 cells with CEACAM1. Indeed, lumen formation was inhibited, resulting in the down regulation of a set of genes, likely involved in the complex process of lumen formation. As expected, inhibition of the expression of many of these genes also inhibited lumen formation, confirming their involvement in a single pathway. Among the genes identified by the inhibition assay, ETS transcription factor ELF5 stood out, since it has been identified as a master regulator of mammary morphogenesis, and is associated with prolactin receptor signaling. When ELF5 was transfected into the parental MCF7 cells that lack CEACAM1, lumen formation was restored, indicating that ELF5 can replace CEACAM1 in this model system of lumenogenesis. We conclude that the event(s) that led to the loss of expression of CEACAM1 is epistatic in that multiple genes associated with a critical pathway were affected, but that restoration of the normal phenotype can be achieved with reactivation of certain genes at various nodal points in tissue morphogenesis. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Identification of MPL R102P Mutation in Hereditary Thrombocytosis.

    Bellanné-Chantelot, Christine; Mosca, Matthieu; Marty, Caroline; Favier, Rémi; Vainchenker, William; Plo, Isabelle

    2017-01-01

    The molecular basis of hereditary thrombocytosis is germline mutations affecting the thrombopoietin (TPO)/TPO receptor (MPL)/JAK2 signaling axis. Here, we report one family presenting two cases with a mild thrombocytosis. By sequencing JAK2 and MPL coding exons, we identified a germline MPL R102P heterozygous mutation in the proband and his daughter. Concomitantly, we detected high TPO levels in the serum of these two patients. The mutation was not found in three other unaffected cases from the family except in another proband's daughter who did not present thrombocytosis but had a high TPO level. The MPL R102P mutation was first described in congenital amegakaryocytic thrombocytopenia in a homozygous state with a loss-of-function activity. It was previously shown that MPL R102P was blocked in the endoplasmic reticulum without being able to translocate to the plasma membrane. Thus, this case report identifies for the first time that MPL R102P mutation can differently impact megakaryopoiesis: thrombocytosis or thrombocytopenia depending on the presence of the heterozygous or homozygous state, respectively. The paradoxical effect associated with heterozygous MPL R102P may be due to subnormal cell-surface expression of wild-type MPL in platelets inducing a defective TPO clearance. As a consequence, increased TPO levels may activate megakaryocyte progenitors that express a lower, but still sufficient level of MPL for the induction of proliferation.

  7. Identification of MPL R102P Mutation in Hereditary Thrombocytosis

    Christine Bellanné-Chantelot

    2017-09-01

    Full Text Available The molecular basis of hereditary thrombocytosis is germline mutations affecting the thrombopoietin (TPO/TPO receptor (MPL/JAK2 signaling axis. Here, we report one family presenting two cases with a mild thrombocytosis. By sequencing JAK2 and MPL coding exons, we identified a germline MPL R102P heterozygous mutation in the proband and his daughter. Concomitantly, we detected high TPO levels in the serum of these two patients. The mutation was not found in three other unaffected cases from the family except in another proband’s daughter who did not present thrombocytosis but had a high TPO level. The MPL R102P mutation was first described in congenital amegakaryocytic thrombocytopenia in a homozygous state with a loss-of-function activity. It was previously shown that MPL R102P was blocked in the endoplasmic reticulum without being able to translocate to the plasma membrane. Thus, this case report identifies for the first time that MPL R102P mutation can differently impact megakaryopoiesis: thrombocytosis or thrombocytopenia depending on the presence of the heterozygous or homozygous state, respectively. The paradoxical effect associated with heterozygous MPL R102P may be due to subnormal cell-surface expression of wild-type MPL in platelets inducing a defective TPO clearance. As a consequence, increased TPO levels may activate megakaryocyte progenitors that express a lower, but still sufficient level of MPL for the induction of proliferation.

  8. Duas classes de mutação na evolução de policitemia vera para leucemia mielóide aguda Two-hit model of leukemogenesis in the evolution of polycythemia vera to acute myeloid leukemia

    Juliana C. C. Ribeiro

    2009-04-01

    case of PV with evolution to AML in which it was possible to demonstrate the two-hit model of leukemogenesis: one mutation confers proliferative advantage and another interferes with differentiation. Case: A 55-year-old female patient was diagnosed with PV in 2002 and treated with phlebotomies and hydroxyurea. In 2006, there was progression topost-polycythemic fibrosis with AML one year later. She presented the JAK2V617F mutation. The result of karyotyping performed at diagnosis was normal and at transformation, 46,XX,del(20(q13.1 was detected in 4/20 metaphases. FISH analysis of a stored sample for 20q13 showed the deletion in 20% of interphases confirming the earlier presence of a clonal abnormality that was not detected by karyotyping. The JAK2V617F mutation is sufficient to cause proliferation of hematopoietic cells and has been established as a primary pathogenetic mechanism in PV. However, the evolution of the disease is heterogeneous, suggesting the occurrence of additional phenomena contributing to leukemogenesis. This case demonstrates the two-hit model in the progression of PV to LMA, in which a class of mutation induces proliferative advantage and another blocks differentiation. Two events which contribute to proliferation and to maturation blockade were detected in this patient. Other mechanisms may be implicated and prospective studies should be encouraged in an attempt to elucidate the different steps involved in leukemogenesis.

  9. Phase 1/2 study of pacritinib, a next generation JAK2/FLT3 inhibitor, in myelofibrosis or other myeloid malignancies

    Srdan Verstovsek

    2016-12-01

    Full Text Available Abstract Background Pacritinib (SB1518 is a highly selective kinase inhibitor with specificity for JAK2, FLT3, IRAK1, and CFS1R. This multicenter phase 1/2 study evaluated the maximum tolerated dose (MTD, safety, and clinical activity of pacritinib in patients with myelofibrosis (MF and other advanced myeloid malignancies. Methods In the phase 1 dose-escalation part of the study, 43 adults with advanced myeloid malignancies received pacritinib 100 to 600 mg once daily (QD. In the phase 2 part of the study, 31 adults with refractory or intermediate- or high-risk newly diagnosed MF and any degree of cytopenia received pacritinib 400 mg QD. The primary endpoint is a ≥35% reduction in spleen volume at week 24 as determined by magnetic resonance imaging. Results Five patients (11.6% experienced a dose-limiting toxicity during cycle 1 of phase 1. The clinical benefit rate was 86.0% (13 patients achieving clinical improvement and 24 patients having stable disease. The MTD was established at 500 mg QD, and the recommended phase 2 dose was 400 mg QD. In phase 2, the primary endpoint was achieved by 23.5% of evaluable patients (4/17, with 47.4% (9/19 achieving a ≥50% spleen length reduction at week 24 as measured by physical examination. At week 24, 38.9% of evaluable patients (7/18 achieved a ≥50% decrease in MF Quality of Life and Symptom Assessment total score. Gastrointestinal toxicities were the most common adverse events and were predominantly grade 1/2 in severity. Grade 3/4 anemia was reported in 5/31 patients and grade 3/4 thrombocytopenia was reported in 3/31 patients. The most frequent AEs considered to be treatment related were diarrhea (28/31, nausea (15/31, vomiting (9/31, and fatigue (4/31. Grade 3 treatment-related AEs were reported in seven patients (22.6%, four of whom had diarrhea. No grade 4/5 treatment-related AEs were reported. No leukopenia, neutropenia, or lymphopenia were reported. Conclusions Pacritinib was well

  10. Mucuna pruriens (L.) DC chemo sensitize human breast cancer cells via downregulation of prolactin-mediated JAK2/STAT5A signaling.

    Sinha, Sonam; Sharma, Sonal; Vora, Jaykant; Shah, Heta; Srivastava, Anshu; Shrivastava, Neeta

    2018-05-10

    Mucuna pruriens (L.) DC (MP) is an ancient Indian medicinal plant traditionally used to treat Parkinson's disease. L-Dopa (LD), precursor of dopamine is abundantly found in the seeds of MP. L-dopa is a natural inhibitor of prolactin (PRL) hormone which is required to maintain lactation in women but it's over production (hyperprolactinemia) plays critical role in advancement of breast cancer. We aim to examine the pharmacological effect of LD and MP on this hyperprolactinemia associated breast cancer and related signaling for effective management of the disease. We also investigated chemo-sensitizing effect of MP on hyperprolactinemia-mediated cisplatin resistance. Methanolic seed extract of MP were prepared and analysed using HPLC. Effect of LD and MP on the cellular viability of breast cancer cells (T47D, MCF-7, MDA-MB-468 and MDA-MB-231) were evaluated using MTT assay. Further, effect of LD and MP on colony forming potential, DNA damage, cell cycle distribution and apoptosis was determined using agar/agarose method, comet assay and annexin and PI method followed by FACS analysis. To reveal the molecular mechanism involved in the anti-cancer activity of MP, transcriptional and translational level analysis of the key proteins involved in the PRL-mediated signaling, was performed using RT-PCR and western blot analysis. The effect of MP extract on PRL-mediated signaling was validated using dopaminergic agonist bromocriptine. MP extract and cisplatin was given in different combination with appropriate controls to check their effect on chemo-resistivity of breast cancer cells. Our results demonstrated that MP seed extract has the potential to inhibit cellular proliferation of PRL expressing T47D and MCF-7 breast cancer cells via induction of DNA damage, G1 phase of cell cycle arrest and apoptosis more effectively as compare to LD. Further, MP-mediated anti-cancerous effect was associated with the downregulation of PRL expression, further suppressing the JAK2/STAT5A

  11. Detection of TET2, KRAS and CBL variants by Next Generation Sequencing and analysis of their correlation with JAK2 and FLT3 in childhood AML

    Dilara Fatma Akin

    2016-04-01

    Conclusion: We found novel mutations for TET2, KRAS, and CBL. The detected variants in this article seem to be the first screening results of genes studied by NGS in childhood AML patients. Our results also showed some degree of association between FLT3-ITD and TET2, KRAS, CBL mutations.

  12. Oncogene mutational profile in nasopharyngeal carcinoma

    Zhang ZC

    2014-03-01

    Full Text Available Zi-Chen Zhang,1,* Sha Fu,1,* Fang Wang,1 Hai-Yun Wang,1 Yi-Xin Zeng,2 Jian-Yong Shao11Department of Molecular Diagnostics, 2Department of Experimental Research, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center of Cancer Medicine, Guangzhou, People's Republic of China *These authors contributed equally to this work Abstract: Nasopharyngeal carcinoma (NPC is a common tumor in Southern China, but the oncogene mutational status of NPC patients has not been clarified. Using time-of-flight mass spectrometry, 238 mutation hotspots in 19 oncogenes were examined in 123 NPC patients. The relationships between mutational status and clinical data were assessed with a χ2 or Fisher's exact test. Survival analysis was performed using the Kaplan–Meier method with the log-rank test. In 123 patients, 21 (17.1% NPC tumors were positive for mutations in eight oncogenes: six patients had PIK3CA mutations (4.9%, five NRAS mutations (4.1%, four KIT mutations (3.3%, two PDGFRA mutations (1.6%, two ABL mutations (1.6%, and one with simultaneous mutations in HRAS, EGFR, and BRAF (1%. Patients with mutations were more likely to relapse or develop metastasis than those with wild-type alleles (P=0.019. No differences or correlations were found in other clinical characteristics or in patient survival. No mutations were detected in oncogenes AKT1, AKT2, CDK, ERBB2, FGFR1, FGFR3, FLT3, JAK2, KRAS, MET, and RET. These results demonstrate an association between NPC and mutations in NRAS, KIT, PIK3CA, PDGFRA, and ABL, which are associated with patient relapse and metastasis. Keywords: NPC, oncogene, mutation

  13. Blast transformation and fibrotic progression in polycythemia vera and essential thrombocythemia: a literature review of incidence and risk factors

    Cerquozzi, S; Tefferi, A

    2015-01-01

    Polycythemia vera (PV) and essential thrombocythemia (ET) constitute two of the three BCR-ABL1-negative myeloproliferative neoplasms and are characterized by relatively long median survivals (approximately 14 and 20 years, respectively). Potentially fatal disease complications in PV and ET include disease transformation into myelofibrosis (MF) or acute myeloid leukemia (AML). The range of reported frequencies for post-PV MF were 4.9–6% at 10 years and 6–14% at 15 years and for post-ET MF were 0.8–4.9% at 10 years and 4–11% at 15 years. The corresponding figures for post-PV AML were 2.3–14.4% at 10 years and 5.5–18.7% at 15 years and for post-ET AML were 0.7–3% at 10 years and 2.1–5.3% at 15 years. Risk factors cited for post-PV MF include advanced age, leukocytosis, reticulin fibrosis, splenomegaly and JAK2V617F allele burden and for post-ET MF include advanced age, leukocytosis, anemia, reticulin fibrosis, absence of JAK2V617F, use of anagrelide and presence of ASXL1 mutation. Risk factors for post-PV AML include advanced age, leukocytosis, reticulin fibrosis, splenomegaly, abnormal karyotype, TP53 or RUNX1 mutations as well as use of pipobroman, radiophosphorus (P32) and busulfan and for post-ET AML include advanced age, leukocytosis, anemia, extreme thrombocytosis, thrombosis, reticulin fibrosis, TP53 or RUNX1 mutations. It is important to note that some of the aforementioned incidence figures and risk factor determinations are probably inaccurate and at times conflicting because of the retrospective nature of studies and the inadvertent labeling, in some studies, of patients with prefibrotic primary MF or ‘masked' PV, as ET. Ultimately, transformation of MPN leads to poor outcomes and management remains challenging. Further understanding of the molecular events leading to disease transformation is being investigated. PMID:26565403

  14. Kefir peptides prevent high-fructose corn syrup-induced non-alcoholic fatty liver disease in a murine model by modulation of inflammation and the JAK2 signaling pathway

    Chen, H L; Tsai, T C; Tsai, Y C; Liao, J W; Yen, C C; Chen, C M

    2016-01-01

    Objective: In recent years, people have changed their eating habits, and high-fructose-containing bubble tea has become very popular. High-fructose intake has been suggested to be a key factor that induces non-alcoholic fatty liver disease (NAFLD). Kefir, a fermented milk product composed of microbial symbionts, has demonstrated numerous biological activities, including antibacterial, antioxidant and immunostimulating effects. The present study aims to evaluate the effects of kefir peptides on high-fructose-induced hepatic steatosis and the possible molecular mechanism. Results: An animal model of 30% high-fructose-induced NAFLD in C57BL/6J mice was established. The experiment is divided into the following six groups: (1) normal: H2O drinking water; (2) mock: H2O+30% fructose; (3) KL: low-dose kefir peptides (50 mg kg−1)+30% fructose; (4) KM: medium-dose kefir peptides (100 mg kg−1)+30% fructose; (5) KH: high-dose kefir peptides (150 mg kg−1)+30% fructose; and (6) CFM: commercial fermented milk (100 mg kg−1)+30% fructose. The results show that kefir peptides improve fatty liver syndrome by decreasing body weight, serum alanine aminotransferase, triglycerides, insulin and hepatic triglycerides, cholesterol, and free fatty acids as well as the inflammatory cytokines (TNF-α, IL-6 and IL-1β) that had been elevated in fructose-induced NAFLD mice. In addition, kefir peptides markedly increased phosphorylation of AMPK to downregulate its targeted enzymes, ACC (acetyl-CoA carboxylase) and SREBP-1c (sterol regulatory element-binding protein 1), and inhibited de novo lipogenesis. Furthermore, kefir peptides activated JAK2 to stimulate STAT3 phosphorylation, which can translocate to the nucleus, and upregulated several genes, including the CPT1 (carnitine palmitoyltransferase-1) involved in fatty acid oxidation. Conclusion: Our data have demonstrated that kefir peptides can improve the symptoms of NAFLD, including body weight, energy intake

  15. Kefir peptides prevent high-fructose corn syrup-induced non-alcoholic fatty liver disease in a murine model by modulation of inflammation and the JAK2 signaling pathway.

    Chen, H L; Tsai, T C; Tsai, Y C; Liao, J W; Yen, C C; Chen, C M

    2016-12-12

    In recent years, people have changed their eating habits, and high-fructose-containing bubble tea has become very popular. High-fructose intake has been suggested to be a key factor that induces non-alcoholic fatty liver disease (NAFLD). Kefir, a fermented milk product composed of microbial symbionts, has demonstrated numerous biological activities, including antibacterial, antioxidant and immunostimulating effects. The present study aims to evaluate the effects of kefir peptides on high-fructose-induced hepatic steatosis and the possible molecular mechanism. An animal model of 30% high-fructose-induced NAFLD in C57BL/6J mice was established. The experiment is divided into the following six groups: (1) normal: H 2 O drinking water; (2) mock: H 2 O+30% fructose; (3) KL: low-dose kefir peptides (50 mg kg -1 )+30% fructose; (4) KM: medium-dose kefir peptides (100 mg kg -1 )+30% fructose; (5) KH: high-dose kefir peptides (150 mg kg -1 )+30% fructose; and (6) CFM: commercial fermented milk (100 mg kg -1 )+30% fructose. The results show that kefir peptides improve fatty liver syndrome by decreasing body weight, serum alanine aminotransferase, triglycerides, insulin and hepatic triglycerides, cholesterol, and free fatty acids as well as the inflammatory cytokines (TNF-α, IL-6 and IL-1β) that had been elevated in fructose-induced NAFLD mice. In addition, kefir peptides markedly increased phosphorylation of AMPK to downregulate its targeted enzymes, ACC (acetyl-CoA carboxylase) and SREBP-1c (sterol regulatory element-binding protein 1), and inhibited de novo lipogenesis. Furthermore, kefir peptides activated JAK2 to stimulate STAT3 phosphorylation, which can translocate to the nucleus, and upregulated several genes, including the CPT1 (carnitine palmitoyltransferase-1) involved in fatty acid oxidation. Our data have demonstrated that kefir peptides can improve the symptoms of NAFLD, including body weight, energy intake, inflammatory reaction and the

  16. MSM enhances GH signaling via the Jak2/STAT5b pathway in osteoblast-like cells and osteoblast differentiation through the activation of STAT5b in MSCs.

    Youn Hee Joung

    Full Text Available Methylsulfonylmethane (MSM is a naturally occurring sulfur compound with well-known anti-oxidant properties and anti-inflammatory activities. But, its effects on bone are unknown. Growth hormone (GH is regulator of bone growth and bone metabolism. GH activates several signaling pathways such as the Janus kinase (Jak/signal transducers and activators of transcription (STAT pathway, thereby regulating expression of genes including insulin-like growth factor (IGF-1. GH exerts effects both directly and via IGF-1, which signals by activating the IGF-1 receptor (IGF-1R. In this study, we investigated the effects of MSM on the GH signaling via the Jak/STAT pathway in osteoblasts and the differentiation of primary bone marrow mesenchymal stem cells (MSCs. MSM was not toxic to osteoblastic cells and MSCs. MSM increased the expression of GH-related proteins including IGF-1R, p-IGF-1R, STAT5b, p-STAT5b, and Jak2 in osteoblastic cells and MSCs. MSM increased IGF-1R and GHR mRNA expression in osteoblastic cells. The expression of MSM-induced IGF-1R and GHR was inhibited by AG490, a Jak2 kinase inhibitor. MSM induced binding of STAT5 to the IGF-1R and increased IGF-1 and IGF-1R promoter activities. Analysis of cell extracts by immunoprecipitation and Western blot showed that MSM enhanced GH-induced activation of Jak2/STAT5b. We found that MSM and GH, separately or in combination, activated GH signaling via the Jak2/STAT5b pathway in UMR-106 cells. Using siRNA analysis, we found that STAT5b plays an essential role in GH signaling activation in C3H10T1/2 cells. Osteogenic marker genes (ALP, ON, OCN, BSP, OSX, and Runx2 were activated by MSM, and siRNA-mediated STAT5b knockdown inhibited MSM-induced expression of osteogenic markers. Furthermore, MSM increased ALP activity and the mineralization of MSCs. Taken together, these results indicated that MSM can promote osteogenic differentiation of MSCs through activation of STAT5b.

  17. Bleeding complications in BCR-ABL negative myeloproliferative neoplasms: prevalence, type, and risk factors in a single-center cohort.

    Kander, Elizabeth M; Raza, Sania; Zhou, Zheng; Gao, Juehua; Zakarija, Anaadriana; McMahon, Brandon J; Stein, Brady L

    2015-11-01

    The BCR-ABL1-negative myeloproliferative neoplasms (MPN) share an increased risk of thrombotic and hemorrhagic complications. Risk factors for hemorrhage are less well defined than those for thrombosis. Because patients with CALR mutations have higher platelet counts compared to JAK2 V617F-mutated patients, bleeding rates may be increased in this group. Our aim was to retrospectively evaluate whether acquired von Willebrand disease (AvWD), thrombocytosis, mutational status, or treatment history are associated with bleeding in a cohort of MPN patients. Using an electronic database, MPN patients seen between 2005 and 2013 were retrospectively identified using ICD-9 codes and billing records. A bleeding event was defined as one that was identified in the medical record and graded based on the Common Terminology Criteria for Adverse Event (CTCAE) version 4.0. Among 351 MPN patients, 15.6 % experienced 64 bleeding event types. There was no association of bleeding with mutational status, gender, MPN subtype, aspirin use, prior thrombosis, or platelet count at presentation. There was an association between bleeding and older age at diagnosis. aVWD was identified in six patients. In this single-center retrospective study, bleeding events were identified in 15 % of patients, and associated with older age at diagnosis. aVWD was rarely tested for in this cohort.

  18. Understanding Splenomegaly in Myelofibrosis: Association with Molecular Pathogenesis

    Moo-Kon Song

    2018-03-01

    Full Text Available Myelofibrosis (MF is a clinical manifestation of chronic BCR-ABL1-negative chronic myeloproliferative neoplasms. Splenomegaly is one of the major clinical manifestations of MF and is directly linked to splenic extramedullary hematopoiesis (EMH. EMH is associated with abnormal trafficking patterns of clonal hematopoietic cells due to the dysregulated bone marrow (BM microenvironment leading to progressive splenomegaly. Several recent data have emphasized the role of several cytokines for splenic EMH. Alteration of CXCL12/CXCR4 pathway could also lead to splenic EMH by migrated clonal hematopoietic cells from BM to the spleen. Moreover, low Gata1 expression was found to be significantly associated with the EMH. Several gene mutations were found to be associated with significant splenomegaly in MF. In recent data, JAK2 V617F homozygous mutation was associated with a larger spleen size. In other data, CALR mutations in MF were signigicantly associated with longer larger splenomegaly-free survivals than others. In addition, MF patients with ≥1 mutations in AZXL1, EZH1 or IDH1/2 had significantly low spleen reduction response in ruxolitinib treatment. Developments of JAK inhibitors, such as ruxolitinib, pacritinib, momelotinib, and febratinib enabled the effective management in MF patients. Especially, significant spleen reduction responses of the drugs were demonstrated in several randomized clinical studies, although those could not eradicate allele burdens of MF.

  19. [Diagnostic molecular pathology of lymphatic and myeloid neoplasms].

    Klapper, W; Kreipe, H

    2015-03-01

    Molecular pathology has been an integral part of the diagnostics of tumors of the hematopoietic system substantially longer than for solid neoplasms. In contrast to solid tumors, the primary objective of molecular pathology in hematopoietic neoplasms is not the prediction of drug efficacy but the diagnosis itself by excluding reactive proliferation and by using molecular features for tumor classification. In the case of malignant lymphomas, the most commonly applied molecular tests are those for gene rearrangements for immunoglobulin heavy chains and T-cell receptors. However, this article puts the focus on new and diagnostically relevant assays in hematopathology. Among these are mutations of MYD88 codon 265 in lymphoplasmacytic lymphomas, B-raf V600E in hairy cell leukemia and Stat3 exon 21 in indolent T-cell lymphomas. In myeloproliferative neoplasms, MPL W515, calreticulin exon 9 and the BCR-ABL and JAK2 V617F junctions are the most frequently analyzed differentiation series. In myelodysplastic and myeloproliferative neoplasms, SRSF2, SETBP1 and CSF3R mutations provide important differential diagnostic information. Genes mutated in myelodysplastic syndromes (MDS) are particularly diverse but their analysis significantly improves the differential diagnostics between reactive conditions and MDS. The most frequent changes in MDS include mutations of TET2 and various genes encoding splicing factors.

  20. Investigation of T-cell immunoglobulin- and mucin-domain-containing molecule-3 (TIM-3) polymorphisms in essential thrombocythaemia (ET).

    Han, Fuyan; Wang, Guanghai; Li, Yuantang; Tian, Wenjun; Dong, Zhenfang; Cheng, Shiqing; Liu, Yiqing; Qu, Teng; Wang, Xiaoying; Wang, Yong; Zhang, Bingchang; Ju, Ying

    2017-07-01

    T-cell immunoglobulin- and mucin-domain-containing molecule-3 (TIM-3) is preferentially expressed on terminally differentiated Th1 cells and inhibits their IFN-γ production. It has been reported that chronic inflammation may be an important driving force for myeloproliferative neoplasms (MPNs). Therefore, we hypothesized that as an important inflammation regulator, TIM-3 may be involved in essential thrombocythaemia (ET). The goal of this study was to investigate whether the -1516G > T, -574G > T and +4259T > G single-nucleotide polymorphisms (SNPs) within the TIM-3 gene contribute to the genetic susceptibility of individuals to ET. Genotyping of the TIM-3 -1516G > T, -574G > T and + 4259T > G SNPs was performed in 175 patients with ET and in 151 controls via a polymerase chain reaction-restriction fragment length polymorphism assay. We also investigated the relationships between the genotypes of each SNP and the risk factors of ET such as routine blood indexes, age and JAK2 V617F mutation. The genotype and allele frequencies of the -1516G > T SNP (p = 0.016 and 0.019, respectively), the -574G > T SNP (p = 0.035 and 0.038, respectively) and the +4259T > G SNP (p = 0.036 and 0.038, respectively) of the ET patients and the controls were significantly different. A haplotype analysis found that the GGT and TGT haplotypes had significantly different distributions between ET and controls (p = 0.041 and 0.041, respectively). However, no significant differences were detected between the genotypes of all SNPs and routine blood indexes, age and JAK2V617F mutation. The -1516G > T, -574G > T and +4259T > G SNPs within TIM-3 gene might play an important role as a genetic risk factor in the pathogenesis of ET.

  1. Novel 1,3,4-thiadiazoles inhibit colorectal cancer via blockade of IL-6/COX-2 mediated JAK2/STAT3 signals as evidenced through data-based mathematical modeling.

    Raj, Vinit; Bhadauria, Archana S; Singh, Ashok K; Kumar, Umesh; Rai, Amit; Keshari, Amit K; Kumar, Pranesh; Kumar, Dinesh; Maity, Biswanath; Nath, Sneha; Prakash, Anand; Ansari, Kausar M; Jat, Jawahar L; Saha, Sudipta

    2018-03-23

    We attempted a preclinical study using DMH-induced CRC rat model to evaluate the antitumor potential of our recently synthesized 1,3,4-thiadiazoles. The molecular insights were confirmed through ELISA, qRT-PCR and western blot analyses. The CRC condition was produced in response to COX-2 and IL-6 induced activation of JAK2/STAT3 which, in turn, was due to the enhanced phosphorylation of JAK2 and STAT3. The treatment with 1,3,4-thiadiazole derivatives (VR24 and VR27) caused the significant blockade of this signaling pathway. The behavior of STAT3 populations in response to IL-6 and COX-2 stimulations was further confirmed through data-based mathematical modeling using the quantitative western blot data. Finally, VR24 and VR27 restored the perturbed metabolites associated to DMH-induced CRC as evidenced through 1 H NMR based serum metabolomics. The tumor protecting ability of VR24 and VR27 was found comparable or to some degree better than the marketed chemotherapeutics, 5-flurouracil. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Transcriptome analysis of bone marrow mesenchymal stromal cells from patients with primary myelofibrosis

    Christophe Martinaud

    2015-09-01

    Full Text Available Primary myelofibrosis (PMF is a clonal myeloproliferative neoplasm whose severity and treatment complexity are attributed to the presence of bone marrow (BM fibrosis and alterations of stroma impairing the production of normal blood cells. Despite the recently discovered mutations including the JAK2V617F mutation in about half of patients, the primitive event responsible for the clonal proliferation is still unknown. In the highly inflammatory context of PMF, the presence of fibrosis associated with a neoangiogenesis and an osteosclerosis concomitant to the myeloproliferation and to the increase number of circulating hematopoietic progenitors suggests that the crosstalk between hematopoietic and stromal cells is deregulated in the PMF BM microenvironmental niches. Within these niches, mesenchymal stromal cells (BM-MSC play a hematopoietic supportive role in the production of growth factors and extracellular matrix which regulate the proliferation, differentiation, adhesion and migration of hematopoietic stem/progenitor cells. A transcriptome analysis of BM-MSC in PMF patients will help to characterize their molecular alterations and to understand their involvement in the hematopoietic stem/progenitor cell deregulation that features PMF.

  3. Hb Heathrow [β103(G5)Phe→Leu], a First Report in an Asian Patient with Erythrocytosis.

    Shin, Sang Yong; Kim, Hyun Young; Kim, Hee Jin; Kim, Hoon Gu

    2017-05-01

    Congenital erythrocytosis (CE) is a rare and heterogeneous disease. The high oxygen affinity hemoglobin (Hb) variants are the most common cause of CE. Herein, we report a Korean patient with isolated erythrocytosis. A 25-year-old man was referred to our hospital for evaluation of high Hb level (Hb 20.4 g/dL, hematocrit 58%, reticulocyte count 2.90%, white blood cell count 6.83×10⁹/L, and platelet count 195×10⁹/L). Bone marrow biopsy revealed normocellular marrow without myeloproliferative features. JAK2 (V617F, exon 12), CALR (exon 9), and MPL W515K/L mutations were not detected. P₅₀ (partial pressure at which Hb is half saturated with oxygen), which is an indicator of left-shift of oxygen dissociation curve (high oxygen affinity state), was 14.3 mm Hg (reference value 22.6-29.4 mm Hg). He was suspected to have CE. Mutation analysis of the HBB gene revealed the known Hb variant, Hb Heathrow [β103(G5)Phe→Leu]. This is the first report of Hb Heathrow in Asian. © Copyright: Yonsei University College of Medicine 2017.

  4. Upregulation of Nicotinic Acetylcholine Receptor alph4+beta2 through a Ligand-Independent PI3Kbeta Mechanism That Is Enhanced by TNFalpha and the Jak2/p38Mapk Pathways.

    Rogers, Scott W; Gahring, Lorise C

    2015-01-01

    High affinity nicotine-binding sites in the mammalian brain are neuronal nicotinic acetylcholine receptors (nAChR) assembled from at least alpha4 and beta2 subunits into pentameric ion channels. When exposed to ligands such as nicotine, these receptors respond by undergoing upregulation, a correlate of nicotine addiction. Upregulation can be measured using HEK293 (293) cells that stably express alpha4 and beta2 subunits using quantification of [3H]epibatidine ([3H]Eb) binding to measure mature receptors. Treatment of these cells with choline also produces upregulation through a hemicholinium3 (HC3)-sensitive (choline kinase) and an HC3-insensitive pathway which are both independent of the mechanism used by nicotine for upregulation. In both cases, upregulation is significantly enhanced by the pro-inflammatory cytokine tumor necrosis factor alpha (TNFα) which signals through its receptor Tnfr1 to activate p38Mapk. Here we report that the inhibition of class1 phosphoinositide 3-kinases isoform PI3Kbeta using the selective antagonist PI828 is alone sufficient to produce upregulation and enhance both nicotine and choline HC3-sensitive mediated upregulation. Further, these processes are impacted upon by an AG-490 sensitive Jak2-associated pathway. Both PI3Kbeta (negative) and Jak2 (positive) modulation of upregulation converge through p38Mapk and both overlap with TNFalpha enhancement of this process. Upregulation through the PI3Kbeta pathway did not require Akt. Collectively these findings support upregulation of endogenous alpha4beta2 as a balance among cellular signaling networks that are highly responsive to multiple environmental, inflammatory and metabolic agents. The findings also suggest how illness and metabolic stress could alter the expression of this important nicotinic receptor and novel avenues to intercede in modifying its expression.

  5. The myeloproliferative neoplasms, unclassifiable: clinical and pathological considerations.

    Gianelli, Umberto; Cattaneo, Daniele; Bossi, Anna; Cortinovis, Ivan; Boiocchi, Leonardo; Liu, Yen-Chun; Augello, Claudia; Bonometti, Arturo; Fiori, Stefano; Orofino, Nicola; Guidotti, Francesca; Orazi, Attilio; Iurlo, Alessandra

    2017-02-01

    In this study, we investigate in detail the morphological, clinical and molecular features of 71 consecutive patients with a diagnosis of myeloproliferative neoplasms, unclassifiable. We performed a meticulous morphological analysis and found that most of the cases displayed a hypercellular bone marrow (70%) with normal erythropoiesis without left-shifting (59%), increased granulopoiesis with left-shifting (73%) and increased megakaryocytes with loose clustering (96%). Megakaryocytes displayed frequent giant forms with hyperlobulated or bulbous nuclei and/or other maturation defects. Interestingly, more than half of the cases displayed severe bone marrow fibrosis (59%). Median values of hemoglobin level and white blood cells count were all within the normal range; in contrast, median platelets count and lactate dehydrogenase were increased. Little less than half of the patients (44%) showed splenomegaly. JAK2V617F mutation was detected in 72% of all patients. Among the JAK2-negative cases, MPLW515L mutation was found in 17% and CALR mutations in 67% of the investigated cases, respectively. Finally, by multiple correspondence analysis of the morphological profiles, we found that all but four of the cases could be grouped in three morphological clusters with some features similar to those of the classic BCR-ABL1-negative myeloproliferative neoplasms. Analysis of the clinical parameters in these three clusters revealed discrepancies with the morphological profile in about 55% of the patients. In conclusion, we found that the category of myeloproliferative neoplasm, unclassifiable is heterogeneous but identification of different subgroups is possible and should be recommended for a better management of these patients.

  6. Myeloproliferative neoplasms and inflammation: whether to target the malignant clone or the inflammatory process or both.

    Koschmieder, S; Mughal, T I; Hasselbalch, H C; Barosi, G; Valent, P; Kiladjian, J-J; Jeryczynski, G; Gisslinger, H; Jutzi, J S; Pahl, H L; Hehlmann, R; Maria Vannucchi, A; Cervantes, F; Silver, R T; Barbui, T

    2016-05-01

    The Philadelphia-negative myeloproliferative neoplasms (MPNs) are clonal disorders involving hematopoietic stem and progenitor cells and are associated with myeloproliferation, splenomegaly and constitutional symptoms. Similar signs and symptoms can also be found in patients with chronic inflammatory diseases, and inflammatory processes have been found to play an important role in the pathogenesis and progression of MPNs. Signal transduction pathways involving JAK1, JAK2, STAT3 and STAT5 are causally involved in driving both the malignant cells and the inflammatory process. Moreover, anti-inflammatory and immune-modulating drugs have been used successfully in the treatment of MPNs. However, to date, many unresoved issues remain. These include the role of somatic mutations that are present in addition to JAK2V617F, CALR and MPL W515 mutations, the interdependency of malignant and nonmalignant cells and the means to eradicate MPN-initiating and -maintaining cells. It is imperative for successful therapeutic approaches to define whether the malignant clone or the inflammatory cells or both should be targeted. The present review will cover three aspects of the role of inflammation in MPNs: inflammatory states as important differential diagnoses in cases of suspected MPN (that is, in the absence of a clonal marker), the role of inflammation in MPN pathogenesis and progression and the use of anti-inflammatory drugs for MPNs. The findings emphasize the need to separate the inflammatory processes from the malignancy in order to improve our understanding of the pathogenesis, diagnosis and treatment of patients with Philadelphia-negative MPNs.

  7. From leeches to personalized medicine: evolving concepts in the management of polycythemia vera

    Vannucchi, Alessandro M.

    2017-01-01

    Polycythemia vera is a clonal disorder of hematopoietic stem/progenitor cells. It manifests as an expansion of red cell mass. It is the most common chronic myeloproliferative neoplasm. In virtually all cases, it is characterized by a V617F point mutation in JAK2 exon 14 or less common mutations in exon 12. The landmark discovery of the autonomously activated JAK/STAT signaling pathway paved the way for the clinical development of the first target drug, the JAK1 and JAK2 inhibitor ruxolitinib. This is now approved for patients with resistance or intolerance to hydroxyurea. Phlebotomies and hydroxyurea are still the cornerstone of treatment, and aim to prevent the first appearance or recurrence of cardiovascular events that, together with progression to post-polycythemia vera myelofibrosis and leukemia, represent the main causes of death. Interferon-α is an alternative drug and has been shown to induce molecular remissions. It is currently undergoing phase III trials that might eventually lead to its approval for clinical use. The last few years have witnessed important advances towards an accurate early diagnosis of polycythemia vera, greater understanding of its pathogenesis, and improved patient management. This review will focus on the most recent achievements and will aim to unify the different concepts involved in a personalized approach to the patient with polycythemia vera. In spite of many recent advances in the understanding of its pathogenesis and improved disease management, polycythemia vera remains a life-threatening myeloproliferative neoplasm for which there is no cure. This review will present a critical overview of evolving concepts in diagnosis and treatment of this disease. PMID:27884974

  8. Evaluation of plitidepsin in patients with primary myelofibrosis and post polycythemia vera/essential thrombocythemia myelofibrosis: results of preclinical studies and a phase II clinical trial

    Pardanani, A; Tefferi, A; Guglielmelli, P; Bogani, C; Bartalucci, N; Rodríguez, J; Extremera, S; Pérez, I; Alfaro, V; Vannucchi, A M

    2015-01-01

    Previous data established that plitidepsin, a cyclic depsipeptide, exerted activity in a mouse model of myelofibrosis (MF). New preclinical experiments reported herein found that low nanomolar plitidepsin concentrations potently inhibited the proliferation of JAK2V617F-mutated cell lines and reduced colony formation by CD34+ cells of individuals with MF, at least in part through modulation of p27 levels. Cells of MF patients had significantly reduced p27 content, that were modestly increased upon plitidepsin exposure. On these premise, an exploratory phase II trial evaluated plitidepsin 5 mg/m 2 3-h intravenous infusion administered on days 1 and 15 every 4 weeks (q4wk). Response rate (RR) according to the International Working Group for Myelofibrosis Research and Treatment consensus criteria was 9.1% (95% CI, 0.2–41.3%) in 11 evaluable patients during the first trial stage. The single responder achieved a red cell transfusion independence and stable disease was reported in nine additional patients (81.8%). Eight patients underwent a short-lasting improvement of splenomegaly. In conclusion, plitidepsin 5 mg/m 2 3-h infusion q4wk was well tolerated but had a modest activity in patients with primary, post-polycythaemia vera or post-essential thrombocythaemia MF. Therefore, this trial was prematurely terminated and we concluded that further clinical trials with plitidepsin as single agent in MF are not warranted

  9. Clinical, histopathologic, and genetic features of pediatric primary myelofibrosis--an entity different from adults.

    DeLario, Melissa R; Sheehan, Andrea M; Ataya, Ramona; Bertuch, Alison A; Vega, Carlos; Webb, C Renee; Lopez-Terrada, Dolores; Venkateswaran, Lakshmi

    2012-05-01

    Primary myelofibrosis is a chronic myeloproliferative neoplasm characterized by cytopenias, leukoerythroblastosis, extramedullary hematopoiesis, hepatosplenomegaly and bone marrow fibrosis. Primary myelofibrosis is a rare disorder in adults; children are even less commonly affected by this entity, with the largest pediatric case series reporting on three patients. Most literature suggests spontaneous resolution of myelofibrosis without long term complications in the majority of affected children. We describe the clinical, pathologic, and molecular characteristics and outcomes of nineteen children with primary myelofibrosis treated in our center from 1984 to 2011. Most patients had cytopenia significant enough to require supportive therapy. No child developed malignant transformation and only five of the 19 children (26%) had spontaneous resolution of disease. Sequence analyses for JAK2V617F and MPLW515L mutations were performed on bone marrow samples from 17 and six patients, respectively, and the results were negative. In conclusion, analysis of this large series of pediatric patients with primary myelofibrosis demonstrates distinct clinical, hematologic, bone marrow, and molecular features from adult patients. Copyright © 2012 Wiley Periodicals, Inc.

  10. The real-world outcomes of treating Polycythemia Vera: Physician adherence to treatment guidelines.

    Jackson Chornenki, Nicholas L; Chai-Adisaksopha, Chatree; Leong, Darryl P; Siegal, Deborah M; Hillis, Christopher M

    2018-06-04

    Therapy in Polycythemia Vera (PV), a myeloproliferative neoplasm, focuses on reducing cardiovascular (CV) risk without increasing bleeding or hematological progression. However, the real-world practice of treating PV in North America is understudied. We performed a retrospective cohort study of newly diagnosed PV (JAK2V617F mutation positive) patients in Hamilton, Canada to fill this knowledge gap. Out of 108 patients included, (n = 45, 41.7%) patients did not receive therapy consistent with contemporary treatment guidelines. Multivariable analysis showed increased white blood cell count at diagnosis (HR, 1.09; 95% CI, 1.04-1.14; p < 0.001), older age (HR, 1.15; 95% CI, 1.07-1.23; p < 0.001) and diabetic history (HR, 3.71; 95% CI, 1.27-10.78; p = 0.012) associated with greater mortality. Not receiving pharmacological treatment according to guidelines was also independently associated with increased mortality (HR, 3.12; 95% CI, 1.13-8.65; p = 0.029). Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. Protein kinase Cɛ inhibition restores megakaryocytic differentiation of hematopoietic progenitors from primary myelofibrosis patients.

    Masselli, E; Carubbi, C; Gobbi, G; Mirandola, P; Galli, D; Martini, S; Bonomini, S; Crugnola, M; Craviotto, L; Aversa, F; Vitale, M

    2015-11-01

    Among the three classic Philadelphia chromosome-negative myeloproliferative neoplasms, primary myelofibrosis (PMF) is the most severe in terms of disease biology, survival and quality of life. Abnormalities in the process of differentiation of PMF megakaryocytes (MKs) are a hallmark of the disease. Nevertheless, the molecular events that lead to aberrant megakaryocytopoiesis have yet to be clarified. Protein kinase Cɛ (PKCɛ) is a novel serine/threonine kinase that is overexpressed in a variety of cancers, promoting aggressive phenotype, invasiveness and drug resistance. Our previous findings on the role of PKCɛ in normal (erythroid and megakaryocytic commitment) and malignant (acute myeloid leukemia) hematopoiesis prompted us to investigate whether it could be involved in the pathogenesis of PMF MK-impaired differentiation. We demonstrate that PMF megakaryocytic cultures express higher levels of PKCɛ than healthy donors, which correlate with higher disease burden but not with JAK2V617F mutation. Inhibition of PKCɛ function (by a negative regulator of PKCɛ translocation) or translation (by target small hairpin RNA) leads to reduction in PMF cell growth, restoration of PMF MK differentiation and inhibition of PKCɛ-related anti-apoptotic signaling (Bcl-xL). Our data suggest that targeting PKCɛ directly affects the PMF neoplastic clone and represent a proof-of-concept for PKCɛ inhibition as a novel therapeutic strategy in PMF.

  12. Emerging treatments for essential thrombocythemia

    Okoli S

    2011-12-01

    Full Text Available Steven Okoli, Claire HarrisonDepartment of Haematology, Guy's and St Thomas' NHS Foundation Trust, Great Maze Pond, London, UKAbstract: In 1934, Epstein and Goedel used the term hemorrhagic thrombocythemia to describe a disorder characterized by permanent elevation of a platelet count to more than three times normal, hyperplasia of megakaryocytes, and the tendency for venous thrombosis and spontaneous hemorrhage. Over the last 75 years, and particularly in the past 6 years, major progress has been made in our understanding of essential thrombocythemia (ET and its pathogenesis with the identification of the highly prevalent JAK-2 V617F and other mutations. Current management of this condition is based upon historical data and with treatments that have not changed significantly for nearly two decades. This study discusses this and recent progress, highlighting exciting new data with old and new drugs, as well as which patients in particular should be evaluated for these new therapies.Keywords: essential thrombocythemia, interferon, JAK inhibitor

  13. Application of prognostic score IPSET-thrombosis in patients with essential thrombocythemia of a Brazilian public service

    Luana Magalhães Navarro

    Full Text Available Summary Introduction: In patients with essential thrombocythemia (ET, the vascular complications contribute to morbidity and mortality. To better predict the occurrence of thrombotic events, an International Prognostic Score for Thrombosis in Essential Thrombocythemia (IPSET-thrombosis has recently been proposed. We present the application of this score and compare its results with the usual classification system. Method: We retrospectively evaluated the characteristics and risk factors for thrombosis of 46 patients with a diagnosis of ET seen in the last 6 years at Faculdade de Medicina do ABC (FMABC. Results: Thrombosis in the arterial territory was more prevalent than in venous sites. We observed that cardiovascular risk factors (hypertension, hypercholesterolemia, diabetes mellitus, and smoking were also risk factors for thrombosis (p<0.001. Age over 60 years and presence of JAK2 V617F mutation were not associated with the occurrence of thrombotic events. No patient classified by IPSET-thrombosis as low risk had a thrombotic event. Furthermore, using the IPSET-thrombosis scale, we identified two patients who had thrombotic events during follow-up and were otherwise classified in the low-risk group of the traditional classification. Leukocytosis at diagnosis was significantly associated with arterial thrombosis (p=0.02, while splenomegaly was associated with venous thrombotic events (p=0.01. Conclusion: Cardiovascular risk factors and leukocytosis were directly associated with arterial thrombosis. IPSET-thrombosis appears to be better than the traditional classification at identifying lower risk patients who do not need specific therapy.

  14. Budd-Chiari syndrome and heparin-induced thrombocytopenia in polycythemia vera: Successful treatment with repeated TIPS and interferon alpha

    Akoum Riad

    2009-01-01

    Full Text Available Polycythemia vera (PV is a common cause of Budd-Chiari syndrome (BCS and portal vein thrombosis (PVT. The postpartum period is a precipitating cofactor. An additional heparin-induced thrombocytopenia/thrombosis (HIT/T leads to a life-threatening condition in which transjugular intrahepatic portosystemic shunting (TIPS seems to be the only life-saving procedure. We describe the case of a subacute BCS and PVT in the late postpartum period. The diagnosis was established using CT scan, MRI, and Doppler ultrasonography of abdominal vessels and the laboratory findings were compatible with PV. After a successful creation of TIPS, a HIT/T worsened the hemorrhagic and thrombotic picture. TIPS procedure was successfully repeated and heparin was replaced with Fondaparinux and then vitamin K antagonist. The treatment with interferon alpha-2A, started after the normalization of liver functions, resulted in a complete remission within 6 months. The JAK2 V617F mutation clone remained undetectable after 2 years′ follow-up.

  15. Idiopathic erythrocytosis in a patient on chronic hemodialysis

    Dong Hyun Lee

    2015-03-01

    Full Text Available A 78-year-old man on hemodialysis presented to our hospital with erythrocytosis. He had started hemodialysis 4 years previously, with a hemoglobin level of 9.8 g/dL, and was administered erythropoiesis stimulating agents and ferrous sulfate. Two years previously, his hemoglobin level increased to 14.5 g/dL and the treatment for anemia was discontinued. He continued hemodialysis thrice weekly; however, the hemoglobin level had increased to 17.0 g/dL at the time of presenting to our hospital. His serum erythropoietin level was 31.4 mIU/mL (range, 3.7–31.5 mIU/mL, carboxyhemoglobin level was 0.6% (range, 0–1.5%, and oxygen saturation in ambient air was 95.4%. The JAK2 V617F mutation was not observed and other bone marrow abnormalities were not identified. The patient was diagnosed with bladder cancer and a transurethral resection was performed. Eight months after the treatment of bladder cancer, his hemoglobin level was 15.1 g/dL, and he was diagnosed with idiopathic erythrocytosis.

  16. Age-related cancer mutations associated with clonal hematopoietic expansion

    Xie, Mingchao; Lu, Charles; Wang, Jiayin; McLellan, Michael D.; Johnson, Kimberly J.; Wendl, Michael C.; McMichael, Joshua F.; Schmidt, Heather K.; Yellapantula, Venkata; Miller, Christopher A.; Ozenberger, Bradley A.; Welch, John S.; Link, Daniel C.; Walter, Matthew J.; Mardis, Elaine R.; Dipersio, John F.; Chen, Feng; Wilson, Richard K.; Ley, Timothy J.; Ding, Li

    2015-01-01

    Several genetic alterations characteristic of leukemia and lymphoma have been detected in the blood of individuals without apparent hematological malignancies. We analyzed blood-derived sequence data from 2,728 individuals within The Cancer Genome Atlas, and discovered 77 blood-specific mutations in cancer-associated genes, the majority being associated with advanced age. Remarkably, 83% of these mutations were from 19 leukemia/lymphoma-associated genes, and nine were recurrently mutated (DNMT3A, TET2, JAK2, ASXL1, TP53, GNAS, PPM1D, BCORL1 and SF3B1). We identified 14 additional mutations in a very small fraction of blood cells, possibly representing the earliest stages of clonal expansion in hematopoietic stem cells. Comparison of these findings to mutations in hematological malignancies identified several recurrently mutated genes that may be disease initiators. Our analyses show that the blood cells of more than 2% of individuals (5–6% of people older than 70 years) contain mutations that may represent premalignant, initiating events that cause clonal hematopoietic expansion. PMID:25326804

  17. Dynamics of ASXL1 mutation and other associated genetic alterations during disease progression in patients with primary myelodysplastic syndrome

    Chen, T-C; Hou, H-A; Chou, W-C; Tang, J-L; Kuo, Y-Y; Chen, C-Y; Tseng, M-H; Huang, C-F; Lai, Y-J; Chiang, Y-C; Lee, F-Y; Liu, M-C; Liu, C-W; Liu, C-Y; Yao, M; Huang, S-Y; Ko, B-S; Hsu, S-C; Wu, S-J; Tsay, W; Chen, Y-C; Tien, H-F

    2014-01-01

    Recently, mutations of the additional sex comb-like 1 (ASXL1) gene were identified in patients with myelodysplastic syndrome (MDS), but the interaction of this mutation with other genetic alterations and its dynamic changes during disease progression remain to be determined. In this study, ASXL1 mutations were identified in 106 (22.7%) of the 466 patients with primary MDS based on the French-American-British (FAB) classification and 62 (17.1%) of the 362 patients based on the World Health Organization (WHO) classification. ASXL1 mutation was closely associated with trisomy 8 and mutations of RUNX1, EZH2, IDH, NRAS, JAK2, SETBP1 and SRSF2, but was negatively associated with SF3B1 mutation. Most ASXL1-mutated patients (85%) had concurrent other gene mutations at diagnosis. ASXL1 mutation was an independent poor prognostic factor for survival. Sequential studies showed that the original ASXL1 mutation remained unchanged at disease progression in all 32 ASXL1-mutated patients but were frequently accompanied with acquisition of mutations of other genes, including RUNX1, NRAS, KRAS, SF3B1, SETBP1 and chromosomal evolution. On the other side, among the 80 ASXL1-wild patients, only one acquired ASXL1 mutation at leukemia transformation. In conclusion, ASXL1 mutations in association with other genetic alterations may have a role in the development of MDS but contribute little to disease progression

  18. Patient characteristics and outcomes in adolescents and young adults with classical Philadelphia chromosome-negative myeloproliferative neoplasms.

    Boddu, Prajwal; Masarova, Lucia; Verstovsek, Srdan; Strati, Paolo; Kantarjian, Hagop; Cortes, Jorge; Estrov, Zeev; Pierce, Sherry; Pemmaraju, Naveen

    2018-01-01

    Little is known about the outcomes of Philadelphia-negative myeloproliferative neoplasms (MPNs) in adolescents and young adults (AYA). We reviewed all patients with essential thrombocythemia (ET), polycythemia vera (PV), and myelofibrosis (MF) treated at our institution from 1988 to 2016 who were aged 16 to 39 years (AYA) and described their outcomes in comparison to older MPN population. Of 2206 patients, 185 (8.3%) were identified as AYA: 105 (57%) ET, 43 (23%) PV, and 37 (20%) MF. The median age was 33 years [range, 16-39], and median follow-up time 3 years [range, 0.04-25]. JAK2 allele burdens were significantly lower among AYA JAK2V617F-mutated patients in both PV (p = 0.001) and MF (p = 0.005). Seven percent of MPN AYA patients were diagnosed with a thrombotic event at, or prior to, diagnosis. Over the short median follow-up, 4 thrombotic (PV = 1, MF = 3) and 3 leukemia (ET = 2, MF = 1) events occurred. In multivariate analysis, AYA did not predict for thrombotic or transformational events across three cohorts. In the MF cohort, there was a reduced frequency of negative prognostic variables of anemia (p = 0.011) and leukocytosis (p = 0.048) in AYA when compared with non-AYA. Overall survival was significantly superior in the AYA cohorts in all three MPN groups, namely MF (p < 0.001), PV (p < 0.001), and ET (p = 0.002). Our findings suggest that MPN AYA patients exhibit an indolent clinical phenotype characterized by favorable survival outcomes.

  19. Clinical and molecular response to interferon-α therapy in essential thrombocythemia patients with CALR mutations.

    Verger, Emmanuelle; Cassinat, Bruno; Chauveau, Aurélie; Dosquet, Christine; Giraudier, Stephane; Schlageter, Marie-Hélène; Ianotto, Jean-Christophe; Yassin, Mohammed A; Al-Dewik, Nader; Carillo, Serge; Legouffe, Eric; Ugo, Valerie; Chomienne, Christine; Kiladjian, Jean-Jacques

    2015-12-10

    Myeloproliferative neoplasms are clonal disorders characterized by the presence of several gene mutations associated with particular hematologic parameters, clinical evolution, and prognosis. Few therapeutic options are available, among which interferon α (IFNα) presents interesting properties like the ability to induce hematologic responses (HRs) and molecular responses (MRs) in patients with JAK2 mutation. We report on the response to IFNα therapy in a cohort of 31 essential thrombocythemia (ET) patients with CALR mutations (mean follow-up of 11.8 years). HR was achieved in all patients. Median CALR mutant allelic burden (%CALR) significantly decreased from 41% at baseline to 26% after treatment, and 2 patients even achieved complete MR. In contrast, %CALR was not significantly modified in ET patients treated with hydroxyurea or aspirin only. Next-generation sequencing identified additional mutations in 6 patients (affecting TET2, ASXL1, IDH2, and TP53 genes). The presence of additional mutations was associated with poorer MR on CALR mutant clones, with only minor or no MRs in this subset of patients. Analysis of the evolution of the different variant allele frequencies showed that the mutated clones had a differential sensitivity to IFNα in a given patient, but no new mutation emerged during treatment. In all, this study shows that IFNα induces high rates of HRs and MRs in CALR-mutated ET, and that the presence of additional nondriver mutations may influence the MR to therapy. © 2015 by The American Society of Hematology.

  20. Myeloid malignancies: mutations, models and management

    Murati, Anne; Brecqueville, Mandy; Devillier, Raynier; Mozziconacci, Marie-Joelle; Gelsi-Boyer, Véronique; Birnbaum, Daniel

    2012-01-01

    Myeloid malignant diseases comprise chronic (including myelodysplastic syndromes, myeloproliferative neoplasms and chronic myelomonocytic leukemia) and acute (acute myeloid leukemia) stages. They are clonal diseases arising in hematopoietic stem or progenitor cells. Mutations responsible for these diseases occur in several genes whose encoded proteins belong principally to five classes: signaling pathways proteins (e.g. CBL, FLT3, JAK2, RAS), transcription factors (e.g. CEBPA, ETV6, RUNX1), epigenetic regulators (e.g. ASXL1, DNMT3A, EZH2, IDH1, IDH2, SUZ12, TET2, UTX), tumor suppressors (e.g. TP53), and components of the spliceosome (e.g. SF3B1, SRSF2). Large-scale sequencing efforts will soon lead to the establishment of a comprehensive repertoire of these mutations, allowing for a better definition and classification of myeloid malignancies, the identification of new prognostic markers and therapeutic targets, and the development of novel therapies. Given the importance of epigenetic deregulation in myeloid diseases, the use of drugs targeting epigenetic regulators appears as a most promising therapeutic approach

  1. Age-related mutations associated with clonal hematopoietic expansion and malignancies.

    Xie, Mingchao; Lu, Charles; Wang, Jiayin; McLellan, Michael D; Johnson, Kimberly J; Wendl, Michael C; McMichael, Joshua F; Schmidt, Heather K; Yellapantula, Venkata; Miller, Christopher A; Ozenberger, Bradley A; Welch, John S; Link, Daniel C; Walter, Matthew J; Mardis, Elaine R; Dipersio, John F; Chen, Feng; Wilson, Richard K; Ley, Timothy J; Ding, Li

    2014-12-01

    Several genetic alterations characteristic of leukemia and lymphoma have been detected in the blood of individuals without apparent hematological malignancies. The Cancer Genome Atlas (TCGA) provides a unique resource for comprehensive discovery of mutations and genes in blood that may contribute to the clonal expansion of hematopoietic stem/progenitor cells. Here, we analyzed blood-derived sequence data from 2,728 individuals from TCGA and discovered 77 blood-specific mutations in cancer-associated genes, the majority being associated with advanced age. Remarkably, 83% of these mutations were from 19 leukemia and/or lymphoma-associated genes, and nine were recurrently mutated (DNMT3A, TET2, JAK2, ASXL1, TP53, GNAS, PPM1D, BCORL1 and SF3B1). We identified 14 additional mutations in a very small fraction of blood cells, possibly representing the earliest stages of clonal expansion in hematopoietic stem cells. Comparison of these findings to mutations in hematological malignancies identified several recurrently mutated genes that may be disease initiators. Our analyses show that the blood cells of more than 2% of individuals (5-6% of people older than 70 years) contain mutations that may represent premalignant events that cause clonal hematopoietic expansion.

  2. A remarkable hematological and molecular response pattern in a patient with polycythemia vera during combination therapy with simvastatin and alendronate

    Anders Lindholm Sørensen

    2016-01-01

    Full Text Available We report a 57-year old man with polycythemia vera, who had a remarkable hematological and molecular response during treatment with simvastatin and alendronate. The patient was treated with this combination for 56 months, and during this period the patient has been in complete hematological remission. The JAK2-V617F allele burden has dropped from 64% to sustained values below 20%, and follow-up bone marrow biopsies have revealed no change in PV features, without any regular cytoreductive treatment.

  3. Recent advances in the bcr-abl negative chronic myeloproliferative diseases

    Stroncek David F

    2006-10-01

    Full Text Available Abstract The chronic myeloproliferative disorders are clonal hematopoietic stem cell disorders of unknown etiology. In one of these (chronic myeloid leukemia, there is an associated pathognomonic chromosomal abnormality known as the Philadelphia chromosome. This leads to constitutive tyrosine kinase activity which is responsible for the disease and is used as a target for effective therapy. This review concentrates on the search in the other conditions (polycythemia vera, essential thrombocythemia and idiopathic mylofibrosis for a similar biological marker with therapeutic potential. There is no obvious chromosomal marker in these conditions and yet evidence of clonality can be obtained in females by the use of X-inactivation patterns. PRV-1mRNA over expression, raised vitamin B12 levels and raised neutrophil alkaline phosphatase scores are evidence that cells in these conditions have received excessive signals for proliferation, maturation and reduced apoptosis. The ability of erythroid colonies to grow spontaneously without added external erythropoietin in some cases, provided a useful marker and a clue to this abnormal signaling. In the past year several important discoveries have been made which go a long way in elucidating the involved pathways. The recently discovered JAK2 V617F mutation which occurs in the majority of cases of polycythemia vera and in about half of the cases with the two other conditions, enables constitutive tyrosine kinase activity without the need for ligand binding to hematopoietic receptors. This mutation has become the biological marker for these conditions and has spurred the development of a specific therapy to neutralize its effects. The realization that inherited mutations in the thrombopoietin receptor (c-Mpl can cause a phenotype of thrombocytosis such as in Mpl Baltimore (K39N and in a Japanese family with S505A, has prompted the search for acquired mutations in this receptor in chronic myeloproliferative

  4. Overcoming Bcr-Abl T315I mutation by combination of GNF-2 and ATP competitors in an Abl-independent mechanism

    Khateb, Mamduh; Ruimi, Nili; Khamisie, Hazem; Najajreh, Yousef; Mian, Afsar; Metodieva, Anna; Ruthardt, Martin; Mahajna, Jamal

    2012-01-01

    Philadelphia positive leukemias are characterized by the presence of Bcr-Abl fusion protein which exhibits an abnormal kinase activity. Selective Abl kinase inhibitors have been successfully established for the treatment of Ph (+) leukemias. Despite high rates of clinical response, Ph (+) patients can develop resistance against these kinase inhibitors mainly due to point mutations within the Abl protein. Of special interest is the ‘gatekeeper’ T315I mutation, which confers complete resistance to Abl kinase inhibitors. Recently, GNF-2, Abl allosteric kinase inhibitor, was demonstrated to possess cellular activity against Bcr-Abl transformed cells. Similarly to Abl kinase inhibitors (AKIs), GNF-2 failed to inhibit activity of mutated Bcr-Abl carrying the T315I mutation. Ba/F3 cells harboring native or T315I mutated Bcr-Abl constructs were treated with GNF-2 and AKIs. We monitored the effect of GNF-2 with AKIs on the proliferation and clonigenicity of the different Ba/F3 cells. In addition, we monitored the auto-phosphorylation activity of Bcr-Abl and JAK2 in cells treated with GNF-2 and AKIs. In this study, we report a cooperation between AKIs and GNF-2 in inhibiting proliferation and clonigenicity of Ba/F3 cells carrying T315I mutated Bcr-Abl. Interestingly, cooperation was most evident between Dasatinib and GNF-2. Furthermore, we showed that GNF-2 was moderately active in inhibiting the activity of JAK2 kinase, and presence of AKIs augmented GNF-2 activity. Our data illustrated the ability of allosteric inhibitors such as GNF-2 to cooperate with AKIs to overcome T315I mutation by Bcr-Abl-independent mechanisms, providing a possibility of enhancing AKIs efficacy and overcoming resistance in Ph+ leukemia cells

  5. Effects of clinically relevant MPL mutations in the transmembrane domain revealed at the atomic level through computational modeling.

    Lee, Tai-Sung; Kantarjian, Hagop; Ma, Wanlong; Yeh, Chen-Hsiung; Giles, Francis; Albitar, Maher

    2011-01-01

    Mutations in the thrombopoietin receptor (MPL) may activate relevant pathways and lead to chronic myeloproliferative neoplasms (MPNs). The mechanisms of MPL activation remain elusive because of a lack of experimental structures. Modern computational biology techniques were utilized to explore the mechanisms of MPL protein activation due to various mutations. Transmembrane (TM) domain predictions, homology modeling, ab initio protein structure prediction, and molecular dynamics (MD) simulations were used to build structural dynamic models of wild-type and four clinically observed mutants of MPL. The simulation results suggest that S505 and W515 are important in keeping the TM domain in its correct position within the membrane. Mutations at either of these two positions cause movement of the TM domain, altering the conformation of the nearby intracellular domain in unexpected ways, and may cause the unwanted constitutive activation of MPL's kinase partner, JAK2. Our findings represent the first full-scale molecular dynamics simulations of the wild-type and clinically observed mutants of the MPL protein, a critical element of the MPL-JAK2-STAT signaling pathway. In contrast to usual explanations for the activation mechanism that are based on the relative translational movement between rigid domains of MPL, our results suggest that mutations within the TM region could result in conformational changes including tilt and rotation (azimuthal) angles along the membrane axis. Such changes may significantly alter the conformation of the adjacent and intrinsically flexible intracellular domain. Hence, caution should be exercised when interpreting experimental evidence based on rigid models of cytokine receptors or similar systems.

  6. Spectrum of somatic mutations detected by targeted next-generation sequencing and their prognostic significance in adult patients with acute lymphoblastic leukemia

    Juan Feng

    2017-02-01

    Full Text Available Abstract Target-specific next-generation sequencing technology was used to analyze 112 genes in adult patients with acute lymphoblastic leukemia (ALL. This sequencing mainly focused on the specific mutational hotspots. Among the 121 patients, 93 patients were B-ALL (76.9%, and 28 patients (23.1% were T-ALL. Of the 121 patients, 110 (90.9% harbored at least one mutation. The five most frequently mutated genes in T-ALL are NOTCH1, JAK3, FBXW7, FAT1, and NRAS. In B-ALL, FAT1, SF1, CRLF2, TET2, and PTPN1 have higher incidence of mutations. Gene mutations are different between Ph+ALL and Ph−ALL patients. B-ALL patients with PTPN11 mutation and T-ALL patients with NOTCH1 and/or FBXW7 mutations showed better survival. But B-ALL with JAK1/JAK2 mutations showed worse survival. The results suggest that gene mutations exist in adult ALL patients universally, they are related with prognosis.

  7. Where to Turn for Second-Line Cytoreduction After Hydroxyurea in Polycythemia Vera?

    Nazha, Aziz; Gerds, Aaron T

    2016-04-01

    The goals of therapy in patients with polycythemia vera (PV) are to improve disease-related symptoms, prevent the incidence or recurrence of thrombosis, and possibly delay or prevent the transformation into myelofibrosis or acute myeloid leukemia (AML). Cytoreductive therapies have been used in older patients and those with a history of thrombosis to achieve these goals. Hydroxyurea (HU) remains the first-line cytoreductive choice; however, up to one in four patients treated with HU over time will develop resistance or intolerance to HU. More importantly, patients who fail HU have a 5.6-fold increase in mortality and a 6.8-fold increase risk of transformation to myelofibrosis or AML; therefore, alternative therapies are needed for these patients. Interferon-α has been used in PV and has shown significant activity in achieving hematologic responses and decreasing JAK2 V617F mutation allele burden. JAK inhibition has also been investigated and recently garnered regulatory approval for this indication. In this review, we will discuss the current treatment options that are available for patients after HU and the novel therapies that are currently under investigation. The outcomes of PV patients who fail or who are intolerant of hydroxyurea are poor. Although pegylated interferon can be considered in younger patients, currently, ruxolitinib is the only U.S. Food and Drug Administration-approved agent in this setting, representing a viable option, leading to hematocrit control and a reduction in spleen size and constitutional symptoms. Although a small number of patients will achieve a molecular response with continuous treatment, the implications of such response on the clinical outcomes are still unknown. Patients whose disease is not adequately controlled with ruxolitinib, or who lose their response, can be treated with low-dose busulfan or pipobroman; however, they should be encouraged to participate in trials with novel therapies. ©AlphaMed Press.

  8. Safety and efficacy of ruxolitinib in splanchnic vein thrombosis associated with myeloproliferative neoplasms.

    Pieri, Lisa; Paoli, Chiara; Arena, Umberto; Marra, Fabio; Mori, Fabio; Zucchini, Mery; Colagrande, Stefano; Castellani, Alessandro; Masciulli, Arianna; Rosti, Vittorio; De Stefano, Valerio; Betti, Silvia; Finazzi, Guido; Ferrari, Maria Luisa; Rumi, Elisa; Ruggeri, Marco; Nichele, Ilaria; Guglielmelli, Paola; Fjerza, Rajmonda; Mannarelli, Carmela; Fanelli, Tiziana; Merli, Lucia; Corbizi Fattori, Giuditta; Massa, Margherita; Cimino, Giuseppe; Rambaldi, Alessandro; Barosi, Giovanni; Cazzola, Mario; Barbui, Tiziano; Vannucchi, Alessandro M

    2017-02-01

    Splanchnic vein thrombosis (SVT) is one of the vascular complications of myeloproliferative neoplasms (MPN). We designed a phase 2 clinical trial to evaluate safety and efficacy of ruxolitinib in reducing splenomegaly and improving disease-related symptoms in patients with MPN-associated SVT. Patients diagnosed with myelofibrosis (12 cases), polycythemia vera (5 cases) and essential thrombocythemia (4 cases) received ruxolitinib for 24 weeks in the core study period. Spleen volume was assessed by magnetic resonance imaging (MRI) and splanchnic vein circulation by echo-Doppler analysis. Nineteen patients carried JAK2V617F, one had MPLW515L, and one CALRL367fs*46 mutation. Eighteen patients had spleno-portal-mesenteric thrombosis, two had Budd-Chiari syndrome, and one had both sites involved; 16 patients had esophageal varices. Ruxolitinib was well tolerated with hematological toxicities consistent with those of patients without SVT and no hemorrhagic adverse events were recorded. After 24 weeks of treatment, spleen volume reduction ≥35% by MRI was achieved by 6/21 (29%) patients, and a ≥50% spleen length reduction by palpation at any time up to week 24 was obtained by 13/21 (62%) patients. At week 72, 8 of the 13 (62%) patients maintained the spleen response by palpation. No significant effect of treatment on esophageal varices or in splanchnic circulation was observed. MPN-related symptoms, evaluated by MPN-symptom assessment form (SAF) TSS questionnaire, improved significantly during the first 4 weeks and remained stable up to week 24. In conclusion, this trial shows that ruxolitinib is safe in patients with MPN-associated SVT, and effective in reducing spleen size and disease-related symptoms. © 2016 Wiley Periodicals, Inc.

  9. Clinico-Pathological Profile and Outcomes of Patients with Polycythaemia Vera, Essential Thrombocythaemaia and Idiopathic Myelofibrosis: A Tertiary Care Center Experience from Southern Pakistan

    Shaikh, M. S.; Shaikh, M. U.; Adil, S. N.; Ahmed, Z. A.; Khurshid, M.

    2016-01-01

    Background: The P hiladelphia Negative Classic Myeloproliferative Neoplasms include polycythaemia vera (PV), essential thrombocythaemia (ET) and idiopathic myelofibrosis (IMF). These three disorders share several clinical and laboratory features including JAK2 V617F mutation. Our objectives were to determine the clinico-pathological profile and outcomes of Pakistani patients with polycythaemia vera (PV), essential thrombocythaemia (ET) and idiopathic myelofibrosis (IMF) in order to have an insight regarding behaviour of these conditions. Methods: A retrospective analysis of all the cases of PV, ET and IMF diagnosed at our institute from January 1995 to December 2013 was performed. Age, gender, clinical presentation, laboratory investigations, treatment provided and duration of follow-up were included for analysis. Appropriate statistics were utilized for calculation of data. Results: A total of 58 patients were diagnosed as PV, ET or IMF during the study period. Male to female ratio was 1.1:1. Forty five percent (n=27) patients came to medical attention due to abnormal laboratory results, 3 had cerebrovascular events, 3 had pruritus, and 1 patient each with gangrene and Budd-Chiari syndrome. Haemorrhage was not seen in any patient. Sixty percent (n=35) patients were treated with phlebotomy, hydroxyurea and aspirin alone or in combination. None of the patients transformed to myelofibrosis (MF) or myelodysplasia (MDS) during the mean (±SD) follow-up period of 57.2±50 months. One patient with ET transformed to acute myeloid leukaemia 9 years after the diagnosis. Conclusions: This study demonstrated a relatively more benign form of PV, ET and IMF with lesser frequency of symptoms, good response to treatment and less likelihood of transformation to MF, MDS or AML. (author)

  10. Quercetin inhibits the poly(dA:dT)-induced secretion of IL-18 via down-regulation of the expressions of AIM2 and pro-caspase-1 by inhibiting the JAK2/STAT1 pathway in IFN-γ-primed human keratinocytes.

    Lee, Kyung-Mi; Kang, Jung Hoon; Yun, Mihee; Lee, Seong-Beom

    2018-06-05

    Quercetin, a polyphenol, belongs to a class of flavonoids that exerts anti-inflammatory effects. Interleukin (IL)-18 is a member of the IL-1 family cytokine that regulates immune responses and is implicated in various inflammatory skin diseases. Absent in melanoma 2 (AIM2) is a cytosolic double-stranded (ds) DNA sensor that recognizes the dsDNA of a microbial or host origin. Binding of dsDNA to AIM2 simulates caspase-1-dependent inflammasome activity, which leads to the production of IL-1β and IL-18. Increased levels of AIM2 have been observed in patients with inflammatory skin diseases. In the current study, we investigated the issue of whether or how Quercetin attenuates poly (dA:dT), a synthetic analog of microbial dsDNA, -induced IL-18 secretion in IFN-γ-primed human keratinocytes. Treatment with 5 and 10 μM of Quercetin inhibited the poly (dA:dT)-induced secretion of IL-18 after IFN-γ priming and before poly (dA:dT)-induced AIM2 activation. In addition, treatment with Quercetin at 10 μM, significantly inhibited the phosphorylation of JAK2 and STAT1, and the nuclear translocation of phosphorylated STAT1 in poly (dA:dT)-treated and IFN-γ-primed keratinocytes. These results suggest that treatment with Quercetin inhibits the poly (dA:dT)-induced secretion of IL-18 via down-regulation of the expressions of AIM2 and pro-caspase-1 by inhibiting the JAK2/STAT1 pathway in IFN-γ-primed keratinocytes. Copyright © 2018 Elsevier Inc. All rights reserved.

  11. Expanding the SHOC2 mutation associated phenotype of Noonan syndrome with loose anagen hair: structural brain anomalies and myelofibrosis.

    Gripp, Karen W; Zand, Dina J; Demmer, Laurie; Anderson, Carol E; Dobyns, William B; Zackai, Elaine H; Denenberg, Elizabeth; Jenny, Kim; Stabley, Deborah L; Sol-Church, Katia

    2013-10-01

    Noonan syndrome is a heterogenous rasopathy typically presenting with short stature, characteristic facial features, cardiac abnormalities including pulmonic valve stenosis, ASD and hypertrophic cardiomyopathy (HCM), cryptorchidism, ectodermal abnormalities, and learning differences. The phenotype is variable, and limited genotype phenotype correlation exists with SOS1 mutations often associated with normal cognition and stature, RAF1 mutations entailing a high HCM risk, and certain PTPN11 mutations predisposing to juvenile myelomonocytic leukemia. The recently identified SHOC2 mutation (p.Ser2Gly) causes Noonan syndrome with loose anagen hair. We report five patients with this mutation. All had skin hyperpigmentation, sparse light colored hair, increased fine wrinkles, ligamentous laxity, developmental delay, and 4/4 had a structural cardiac anomaly. Hypotonia and macrocephaly occurred in 4/5 (80%); 3/5 (60%) had polyhydramnios, increased birth weight or required use of a feeding tube. Distinctive brain abnormalities included relative megalencephaly and enlarged subarachnoid spaces suggestive of benign external hydrocephalus, and a relatively small posterior fossa as indicated by a vertical tentorium. The combination of a large brain with a small posterior fossa likely resulted in the high rate of cerebellar tonsillar ectopia (3/4; 75%). Periventricular nodular heterotopia was seen in one patient with a thick and dysplastic corpus callosum. We report on the first hematologic neoplasm, myelofibrosis, in a 2-year-old patient with SHOC2 mutation. Myelofibrosis is exceedingly rare in children and young adults. The absence of a somatic JAK2 mutation, seen in the majority of patients with myelofibrosis, is noteworthy as it suggests that germline or somatic SHOC2 mutations are causally involved in myelofibrosis. Copyright © 2013 Wiley Periodicals, Inc.

  12. Clonal composition of human ovarian cancer based on copy number analysis reveals a reciprocal relation with oncogenic mutation status.

    Sakai, Kazuko; Ukita, Masayo; Schmidt, Jeanette; Wu, Longyang; De Velasco, Marco A; Roter, Alan; Jevons, Luis; Nishio, Kazuto; Mandai, Masaki

    2017-10-01

    Intratumoral heterogeneity of cancer cells remains largely unexplored. Here we investigated the composition of ovarian cancer and its biological relevance. A whole-genome single nucleotide polymorphism array was applied to detect the clonal composition of 24 formalin-fixed, paraffin-embedded samples of human ovarian cancer. Genome-wide segmentation data consisting of the log2 ratio (log2R) and B allele frequency (BAF) were used to calculate an estimate of the clonal composition number (CC number) for each tumor. Somatic mutation profiles of cancer-related genes were also determined for the same 24 samples by next-generation sequencing. The CC number was estimated successfully for 23 of the 24 cancer samples. The mean ± SD value for the CC number was 1.7 ± 1.1 (range of 0-4). A somatic mutation in at least one gene was identified in 22 of the 24 ovarian cancer samples, with the mutations including those in the oncogenes KRAS (29.2%), PIK3CA (12.5%), BRAF (8.3%), FGFR2 (4.2%), and JAK2 (4.2%) as well as those in the tumor suppressor genes TP53 (54.2%), FBXW7 (8.3%), PTEN (4.2%), and RB1 (4.2%). Tumors with one or more oncogenic mutations had a significantly lower CC number than did those without such a mutation (1.0 ± 0.8 versus 2.3 ± 0.9, P = 0.0027), suggesting that cancers with driver oncogene mutations are less heterogeneous than those with other mutations. Our results thus reveal a reciprocal relation between oncogenic mutation status and clonal composition in ovarian cancer using the established method for the estimation of the CC number. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

  13. Antecedent cardiovascular disease and autoimmunity in Philadelphia-negative chronic myeloproliferative neoplasms

    Sørensen, Anders Lindholm; Hasselbalch, Hans K

    2016-01-01

    leukemia (CLL) patients. Odds ratios (ORs) and p-values using Fischer's exact tests were calculated. The data was adjusted for confounding effects by logistic regression. Results: A significantly increased risk of MPNs compared to CLL was observed in subjects with a prior history of any autoimmune disease...... (OR = 1.86, 95%CI 1.16-2.98). A positive association between JAK2-V617F positive MPN and any autoimmune disease was observed at follow-up (OR = 2.62, 95% CI 1.21-5.67). A significantly increased risk of MPN compared to CLL was also observed in subjects with prior thromboembolic events (TE-events) (OR...... in the hematopoietic stem cell resulting in MPNs, or whether this association actually reflects a long-lasting pre-MPN-diagnosis phase, in which the MPN-disease per se contributes to a chronic inflammatory state and immune deregulation....

  14. The phenotype of polycythemia due to Croatian homozygous VHL (571C>G:H191D) mutation is different from that of Chuvash polycythemia (VHL 598C>T:R200W).

    Tomasic, Nikica Ljubas; Piterkova, Lucie; Huff, Chad; Bilic, Ernest; Yoon, Donghoon; Miasnikova, Galina Y; Sergueeva, Adelina I; Niu, Xiaomei; Nekhai, Sergei; Gordeuk, Victor; Prchal, Josef T

    2013-04-01

    Mutations of VHL (a negative regulator of hypoxia-inducible factors) have position-dependent distinct cancer phenotypes. Only two known inherited homozygous VHL mutations exist and they cause polycythemia: Chuvash R200W and Croatian H191D. We report a second polycythemic Croatian H191D homozygote distantly related to the first propositus. Three generations of both families were genotyped for analysis of shared ancestry. Biochemical and molecular tests were performed to better define their phenotypes, with an emphasis on a comparison with Chuvash polycythemia. The VHL H191D mutation did not segregate in the family defined by the known common ancestors of the two subjects, suggesting a high prevalence in Croatians, but haplotype analysis indicated an undocumented common ancestor ∼six generations ago as the founder of this mutation. We show that erythropoietin levels in homozygous VHL H191D individuals are higher than in VHL R200W patients of similar ages, and their native erythroid progenitors, unlike Chuvash R200W, are not hypersensitive to erythropoietin. This observation contrasts with a report suggesting that polycythemia in VHL R200W and H191D homozygotes is due to the loss of JAK2 regulation from VHL R200W and H191D binding to SOCS1. In conclusion, our studies further define the hematologic phenotype of VHL H191D and provide additional evidence for phenotypic heterogeneity associated with the positional effects of VHL mutations.

  15. Polycythemia is associated with bone loss and reduced osteoblast activity in mice.

    Oikonomidou, P R; Casu, C; Yang, Z; Crielaard, B; Shim, J H; Rivella, S; Vogiatzi, M G

    2016-04-01

    Increased fragility has been described in humans with polycythemia vera (PV). Herein, we describe an osteoporotic phenotype associated with decreased osteoblast activity in a mouse model of PV and another mouse of polycythemia and elevated circulating erythropoietin (EPO). Our results are important for patients with PV or those treated with recombinant EPO (rEPO). PV and other myeloproliferative syndromes have been recently associated with an increased risk for fractures. However, the presence of osteoporosis in these patients has not been well documented. EPO, a hormone primarily known to stimulate erythropoiesis, has been shown recently to regulate bone homeostasis in mice. The aim of this study was to examine the bone phenotype of a mouse model of PV and compare it to that of animals with polycythemia caused by elevated circulating EPO. Bone mass and remodeling were evaluated by micro-computed tomography and histomorphometry. The JAK2(V617F) knock-in mouse, a model of human PV, manifests polycythemia and low circulating EPO levels. Results from this mouse were compared to wild type (wt) controls and the tg6 transgenic mouse that shows polycythemia caused by increased constitutive expression of EPO. Compared to wt, both JAK2(V617F) and tg6 mice had a decrease in trabecular bone mass. Tg6 mice showed an additional modest decrease in cortical thickness and cortical bone volume per tissue volume (P Polycythemia caused by chronically elevated circulating EPO also results in bone loss, and implications on patients treated with rEPO should be evaluated.

  16. Deletion mutations of bacteriophage

    Ryo, Yeikou

    1975-01-01

    Resolution of mutation mechanism with structural changes of DNA was discussed through the studies using bacteriophage lambda. One of deletion mutations inductions of phage lambda is the irradiation of ultraviolet ray. It is not clear if the inductions are caused by errors in reparation of ultraviolet-induced damage or by the activation of int gene. Because the effective site of int gene lies within the regions unnecessary for existing, it is considered that int gene is connected to deletion mutations induction. A certain system using prophage complementarity enables to detect deletion mutations at essential hereditary sites and to solve the relations of deletion mutations with other recombination system, DNA reproduction and repairment system. Duplication and multiplication of hereditary elements were discussed. If lambda deletion mutations of the system, which can control recombination, reproduction and repairment of added DNA, are constructed, mutations mechanism with great changes of DNA structure can be solved by phage lambda. (Ichikawa, K.)

  17. Better plants through mutations

    1988-01-01

    This is a public relations film describing problems associated with the genetic improvement of crop plants through induced mutations. Mutations are the ultimate source of genetic variation in plants. Mutation induction is now established as a practical tool in plant breeding. The Joint FAO/IAEA Division and the IAEA's laboratory at Seibersdorf have supported research and practical implementation of mutation breeding of both seed propagated and vegetatively propagated plants. Plant biotechnology based on in vitro culture and recombinant DNA technology will make a further significant contribution to plant breeding

  18. Mutation and premating isolation

    Woodruff, R. C.; Thompson, J. N. Jr

    2002-01-01

    While premating isolation might be traceable to different genetic mechanisms in different species, evidence supports the idea that as few as one or two genes may often be sufficient to initiate isolation. Thus, new mutation can theoretically play a key role in the process. But it has long been thought that a new isolation mutation would fail, because there would be no other individuals for the isolation-mutation-carrier to mate with. We now realize that premeiotic mutations are very common and will yield a cluster of progeny carrying the same new mutant allele. In this paper, we discuss the evidence for genetically simple premating isolation barriers and the role that clusters of an isolation mutation may play in initiating allopatric, and even sympatric, species divisions.

  19. Genetic Mutations in Cancer

    Many different types of genetic mutations are found in cancer cells. This infographic outlines certain types of alterations that are present in cancer, such as missense, nonsense, frameshift, and chromosome rearrangements.

  20. AIP mutations and gigantism.

    Rostomyan, Liliya; Potorac, Iulia; Beckers, Pablo; Daly, Adrian F; Beckers, Albert

    2017-06-01

    AIP mutations are rare in sporadic acromegaly but they are seen at a higher frequency among certain specific populations of pituitary adenoma patients (pituitary gigantism cases, familial isolated pituitary adenoma (FIPA) kindreds, and patients with macroadenomas who are diagnosed ≤30 years). AIP mutations are most prevalent in patients with pituitary gigantism (29% of this group were found to have mutations in AIP gene). These data support targeted genetic screening for AIP mutations/deletions in these groups of pituitary adenoma patients. Earlier diagnosis of AIP-related acromegaly-gigantism cases enables timely clinical evaluation and treatment, thereby improving outcomes in terms of excessive linear growth and acromegaly comorbidities. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  1. Mutation breeding in peas

    Jaranowski, J [Institute of Genetics and Plant Breeding, Academy of Agriculture, Poznan (Poland); Micke, A [Joint FAO/IAEA Division of Isotope and Radiation Applications of Atomic Energy for Food and Agricultural Development, International Atomic Energy Agency, Vienna (Austria)

    1985-02-01

    The pea as an ancient crop plant still today has wide uses and is an import source of food protein. It is also an important object for genetic studies and as such has been widely used in mutation induction experiments. However, in comparison with cereals this ancient crop plant (like several other grain legumes) has gained relatively little from advances in breeding. The review focuses on the prospects of genetic improvement of pea by induced mutations, discusses principles and gives methodological information. (author)

  2. Mutation breeding in peas

    Jaranowski, J.; Micke, A.

    1985-01-01

    The pea as an ancient crop plant still today has wide uses and is an import source of food protein. It is also an important object for genetic studies and as such has been widely used in mutation induction experiments. However, in comparison with cereals this ancient crop plant (like several other grain legumes) has gained relatively little from advances in breeding. The review focuses on the prospects of genetic improvement of pea by induced mutations, discusses principles and gives methodological information. (author)

  3. Mutator activity in Schizophyllum commune

    Shneyour, Y.; Koltin, Y. (Tel Aviv Univ. (Israel). Dept. of Microbiology)

    1983-01-01

    A strain with an elevated level of spontaneous mutations and an especially high rate of reversion at a specific locus (pab/sup -/) was identified. The mutator trait is recessive. UV sensitivity and the absence of a UV-specific endonucleolytic activity were associated with the enhancement of the mutation rate in mutator strains. The endonuclease associated with the regulation of the mutation rate also acted on single-stranded DNA. The molecular weight of this enzyme is about 38,000 daltons.

  4. Germline mutations in candidate predisposition genes in individuals with cutaneous melanoma and at least two independent additional primary cancers.

    Pritchard, Antonia L; Johansson, Peter A; Nathan, Vaishnavi; Howlie, Madeleine; Symmons, Judith; Palmer, Jane M; Hayward, Nicholas K

    2018-01-01

    While a number of autosomal dominant and autosomal recessive cancer syndromes have an associated spectrum of cancers, the prevalence and variety of cancer predisposition mutations in patients with multiple primary cancers have not been extensively investigated. An understanding of the variants predisposing to more than one cancer type could improve patient care, including screening and genetic counselling, as well as advancing the understanding of tumour development. A cohort of 57 patients ascertained due to their cutaneous melanoma (CM) diagnosis and with a history of two or more additional non-cutaneous independent primary cancer types were recruited for this study. Patient blood samples were assessed by whole exome or whole genome sequencing. We focussed on variants in 525 pre-selected genes, including 65 autosomal dominant and 31 autosomal recessive cancer predisposition genes, 116 genes involved in the DNA repair pathway, and 313 commonly somatically mutated in cancer. The same genes were analysed in exome sequence data from 1358 control individuals collected as part of non-cancer studies (UK10K). The identified variants were classified for pathogenicity using online databases, literature and in silico prediction tools. No known pathogenic autosomal dominant or previously described compound heterozygous mutations in autosomal recessive genes were observed in the multiple cancer cohort. Variants typically found somatically in haematological malignancies (in JAK1, JAK2, SF3B1, SRSF2, TET2 and TYK2) were present in lymphocyte DNA of patients with multiple primary cancers, all of whom had a history of haematological malignancy and cutaneous melanoma, as well as colorectal cancer and/or prostate cancer. Other potentially pathogenic variants were discovered in BUB1B, POLE2, ROS1 and DNMT3A. Compared to controls, multiple cancer cases had significantly more likely damaging mutations (nonsense, frameshift ins/del) in tumour suppressor and tyrosine kinase genes and

  5. Are There Mutator Polymerases?

    Miguel Garcia-Diaz

    2003-01-01

    Full Text Available DNA polymerases are involved in different cellular events, including genome replication and DNA repair. In the last few years, a large number of novel DNA polymerases have been discovered, and the biochemical analysis of their properties has revealed a long list of intriguing features. Some of these polymerases have a very low fidelity and have been suggested to play mutator roles in different processes, like translesion synthesis or somatic hypermutation. The current view of these processes is reviewed, and the current understanding of DNA polymerases and their role as mutator enzymes is discussed.

  6. MUTATIONS IN CALMODULIN GENES

    2013-01-01

    The present invention relates to an isolated polynucleotide encoding at least a part of calmodulin and an isolated polypeptide comprising at least a part of a calmodulin protein, wherein the polynucleotide and the polypeptide comprise at least one mutation associated with a cardiac disorder. The ...... the binding of calmodulin to ryanodine receptor 2 and use of such compound in a treatment of an individual having a cardiac disorder. The invention further provides a kit that can be used to detect specific mutations in calmodulin encoding genes....

  7. Mutation, somatic mutation and diseases of man

    Burnet, F.M.

    1976-01-01

    The relevance of the intrinsic mutagenesis for the evolution process, genetic diseases and the process of aging is exemplified. The fundamental reaction is the function of the DNA and the DNA-enzymes like the DNA-polymerases in replication, repair, and transcription. These defects are responsible for the mutation frequency and the genetic drift in the evolution process. They cause genetic diseases like Xeroderma pigmentosum which is described here in detail. The accumulation of structural and functional mistakes leads to diseases of old age, for example to autoimmune diseases and immune suppression. There is a proportionality between the duration of life and the frequency of mistakes in the enzymatic repair system. No possibility of prophylaxis or therapy is seen. Methods for prognosis could be developed. (AJ) [de

  8. Mutations and chromosomal aberrations

    Kihlman, B.A.

    1977-01-01

    The genetic changes of mutations and chromosomal aberrations are discussed. The consequences of both depend not only on the type of genetic change produced but also on the type of cell that is affected and on the development stage of the organism. (C.F.)

  9. Mutations in GABRB3

    Møller, Rikke S; Wuttke, Thomas V; Helbig, Ingo

    2017-01-01

    OBJECTIVE: To examine the role of mutations in GABRB3 encoding the β3 subunit of the GABAA receptor in individual patients with epilepsy with regard to causality, the spectrum of genetic variants, their pathophysiology, and associated phenotypes. METHODS: We performed massive parallel sequencing ...

  10. Kin Selection - Mutation Balance

    Dyken, J. David Van; Linksvayer, Timothy Arnold; Wade, Michael J.

    2011-01-01

    selection-mutation balance, which provides an evolutionary null hypothesis for the statics and dynamics of cheating. When social interactions have linear fitness effects and Hamilton´s rule is satisfied, selection is never strong enough to eliminate recurrent cheater mutants from a population, but cheater...

  11. Mutations in galactosemia

    Reichardt, J.K.V. [Univ. of Southern California School of Medicine, Los Angeles, CA (United States)

    1995-10-01

    This Letter raises four issues concerning two papers on galactosemia published in the March 1995 of the Journal. First, table 2 in the paper by Elsas et al. incorrectly attributes seven galactose-l-phosphate uridyl transferase (GALT) mutations (S135L, L195P, K285N, N314D, R333W, R333G, and K334R). The table also fails to mention that others have reported the same two findings attributed to {open_quotes}Leslie et al.; Elsas et al. and in press{close_quotes} and {open_quotes}Leslie et al.; Elsas et al.{close_quotes} The first finding on the prevalence of the Q188R galactosemia mutation in the G/G Caucasian population has also been described by Ng et al., and the second finding on the correlation of the N314D GALT mutation with the Duarte variant was reported by Lin et al. Second, Elsas et al. suggest that the E203K and N314D mutations may {open_quotes}produce intra-allelic complementation when in cis{close_quotes}. This speculation is supported by the activity data of individual III-2 but is inconsistent with the activities of three other individuals I-1, II-1, and III-1 of the same pedigree. The GALT activity measured in these three individuals suggests a dominant negative effect of E203K in E203K-N314D chromosomes, since they all have less than normal activity. Thus, the preponderance of the data in this paper is at odds with the authors speculation. It is worth recalling that Lin et al. also identified four N314D GALT mutations on 95 galactosemic chromosomes examined. A similar situation also appears to be the case in proband III-1 (with genotype E203K-N314D/IVSC) in the Elsas et al. paper. 9 refs.

  12. Mutation breeding newsletter. No. 45

    2001-07-01

    This issue of the Mutation Breeding newsletter contains 39 articles dealing with radiation induced mutations and chemical mutagenesis techniques in plant breeding programs with the aims of improving crop productivity and disease resistance as well as exploring genetic variabilities

  13. Mutation breeding newsletter. No. 33

    NONE

    1989-01-01

    This issue of the newsletter reports a number of research news and research abstracts on application of radiation induced mutation techniques to increase mutagenesis and mutation frequency in plant breeding projects.

  14. Mutation breeding newsletter. No. 33

    1989-01-01

    This issue of the newsletter reports a number of research news and research abstracts on application of radiation induced mutation techniques to increase mutagenesis and mutation frequency in plant breeding projects

  15. Mutation breeding in pepper

    Daskalov, S [Plant Breeding Unit, Joint FAO/IAEA Division of Isotope and Radiation Applications of Atomic Energy for Food and Agricultural Development, Seibersdorf Laboratory, International Atomic Energy Agency, Vienna (Austria)

    1986-03-01

    Pepper (Capsicum sp.) is an important vegetable and spice crop widely grown in tropical as well as in temperate regions. Until recently the improvement programmes were based mainly on using natural sources of germ plasma, crossbreeding and exploiting the heterosis of F{sub 1} hybrids. However, interest in using induced mutations is growing. A great number of agronomically useful mutants as well as mutants valuable for genetic, cytological and physiological studies have been induced and described. In this review information is presented about suitable mutagen treatment procedures with radiation as well as chemicals, M{sub 1} effects, handling the treated material in M{sub 1}, M{sub 2} and subsequent generations, and mutant screening procedures. This is supplemented by a description of reported useful mutants and released cultivars. Finally, general advice is given on when and how to incorporate mutation induction in Capsicum improvement programmes. (author)

  16. Mutation breeding in pepper

    Daskalov, S.

    1986-01-01

    Pepper (Capsicum sp.) is an important vegetable and spice crop widely grown in tropical as well as in temperate regions. Until recently the improvement programmes were based mainly on using natural sources of germ plasma, crossbreeding and exploiting the heterosis of F 1 hybrids. However, interest in using induced mutations is growing. A great number of agronomically useful mutants as well as mutants valuable for genetic, cytological and physiological studies have been induced and described. In this review information is presented about suitable mutagen treatment procedures with radiation as well as chemicals, M 1 effects, handling the treated material in M 1 , M 2 and subsequent generations, and mutant screening procedures. This is supplemented by a description of reported useful mutants and released cultivars. Finally, general advice is given on when and how to incorporate mutation induction in Capsicum improvement programmes. (author)

  17. Mutated hilltop inflation revisited

    Pal, Barun Kumar

    2018-05-01

    In this work we re-investigate pros and cons of mutated hilltop inflation. Applying Hamilton-Jacobi formalism we solve inflationary dynamics and find that inflation goes on along the {W}_{-1} branch of the Lambert function. Depending on the model parameter mutated hilltop model renders two types of inflationary solutions: one corresponds to small inflaton excursion during observable inflation and the other describes large field inflation. The inflationary observables from curvature perturbation are in tune with the current data for a wide range of the model parameter. The small field branch predicts negligible amount of tensor to scalar ratio r˜ O(10^{-4}), while the large field sector is capable of generating high amplitude for tensor perturbations, r˜ O(10^{-1}). Also, the spectral index is almost independent of the model parameter along with a very small negative amount of scalar running. Finally we find that the mutated hilltop inflation closely resembles the α -attractor class of inflationary models in the limit of α φ ≫ 1.

  18. Mutation breeding in jute

    Joshua, D.C.

    1980-01-01

    Mutagenic studies in jute in general dealt with the morphological abnormalities of the M 1 generation in great detail. Of late, induction of a wide spectrum of viable mutations have been reported in different varieties of both the species. Mutations affecting several traits of agronomic importance such as, plant height, time of flowering, fibre yield and quality, resistance to pests and diseases are also available. Cytological analysis of a large collection of induced mutants resulted in the isolation of seven trisomics in an olitorius variety. Several anatomical parameters which are the components of fibre yield, have also received attention. Some mutants with completely altered morphology were used for interpreting the evolution of leaf shape in Tiliaceas and related families. A capsularis variety developed using mutation breeding technique has been released for cultivation. Several others, including derivatives of inter-mutant hybridization have been found to perform well at different locations in the All India Coordinated Trials. Presently, chemical mutagenesis and induction of mutants of physiological significance are receiving considerable attention. The induced variability is being used in genetic and linkage studies. (author)

  19. Platelet indices in Philadelphia-negative chronic myeloproliferative neoplasms / Indicii plachetari de volum în neoplasmele mieloproliferative cronice Philadelphia-negative

    Olteanu Ariela-Ligia

    2015-06-01

    Full Text Available Introducere: Neoplasmele mieloproliferative cronice cromozom Philadelphia negative (Ph-MPN -policitemia vera (PV, trombocitemia esenţială (TE şi mielofibroza primară (MP - sunt caracterizate de o rată mare de complicaţii trombotice, parţial date de activarea trombocitară. Trombocitele mari sunt mai active, cu o funcţie procoagulantă crescută şi au rol patogenic demonstrat în tromboza arterială şi venoasă. În studiul nostru am încercat să stabilim dacă indicii trombocitari (MPV, PDW, P-LCR, furnizaţi de analizoarele de hematologie în hemoleucograma completă, sunt modificaţi la pacienţii diagnosticaţi cu Ph-MPN comparativ cu subiecţii sănătoşi. Material şi metodă: Hemoleucograma, ce a inclus şi indicii trombocitari, a fost determinată la 102 pacienţi Ph- MPN şi la 102 subiecţi sănătoşi cu ajutorul analizorului de hematologie Sysmex XS 1000i (metoda impedanţei, iar testele biochimice (glucoza şi parametrii metabolismului lipidic, pe analizorul Architect c8000. Prezenţa mutaţiei JAK2 V617F, la pacienţii cu Ph-MPN, a fost evidenţiată prin tehnica ARMS-PCR. Rezultate: Indicii de volum plachetari (IVP măsuraţi prin metoda impedanţei, nu au fost semnificativ modificaţi la pacienţii cu Ph-MPN comparativ cu cei ai subiecţilor sănătoşi. Totuşi, am observat o moderată corelaţie între valoarea acestor indici şi prezenţa mutaţiei JAK2V617F, fără însă a se atinge o diferenţă semnificativă din punct de vedere statistic. IVP au fost crescuţi la micul subgrup de pacienţi trataţi cu anagrelide şi scăzuţi la cei trataţi cu simvastatin, comparativ cu pacienţii care nu au primit aceste terapii. Concluzii: Folosind metoda impedanţei în determinarea indicilor trombocitari, în studiul nostru nu am demonstrat o diferenţă semnificativă între valorile indicilor trombocitari la pacienţii cu Ph- MPN comparativ cu subiecţii sănătoşi. Sunt necesare studii ulterioare pentru a demonstra o

  20. Mutation breeding in chickpea

    2009-01-01

    Chickpea is an important food legume in Turkey. Turkey is one of the most important gene centers in the world for legumes. The most widely known characteristic of chickpea is that it is an important vegetable protein source used in human and animal nutrition. However, the dry grains of chickpea, has 2-3 times more protein than our traditional food of wheat. In addition, cheakpea is also energy source because of its high carbohydrate content. It is very rich in some vitamin and mineral basis. In the plant breeding, mutation induction has become an effective way of supplementing existing germplasm and improving cultivars. Many successful examples of mutation induction have proved that mutation breeding is an effective and important approach to food legume improvement. The induced mutation technique in chickpea has proved successful and good results have been attained. Realizing the potential of induced mutations, a mutation breeding programme was initiated at the Nuclear Agriculture Section of the Saraykoey Nuclear Research and Training Center in 1994. The purpose of the study was to obtain high yielding chickpea mutants with large seeds, good cooking quality and high protein content. Beside this some characters such as higher adaptation ability, tolerant to cold and drought, increased machinery harvest type, higher yield, resistant to diseases especially to antracnose and pest were investigated too. Parents varieties were ILC-482, AK-7114 and AKCIN-91 (9 % seed moisture content and germination percentage 98 %) in these experiments. The irradiation doses were 0 (control), 50, 100, 150, 200, 250, 300, 350, 400, 500 ve 600 Gy for greenhouse experiments and 0 (control), 50, 100, 150, 200, 250, 300, 350 ve 400 Gy for field experiments, respectively. One thousand seeds for per treatment were sown in the field for the M 1 . At maturity, 3500 single plants were harvested and 20 seeds were taken from each M 1 plant and planted in the following season. During plant growth

  1. Induced mutations in citrus

    Spiegel-Roy, P.; Vardi, Aliza

    1990-01-01

    Full text: Parthenocarpic tendency is an important prerequisite for successful induction of seedlessness in breeding and especially in mutation breeding. A gene for asynapsis and accompanying seedless fruit has been found by us in inbred progeny of cv. 'Wilking'. Using budwood irradiation by gamma rays, seedless mutants of 'Eureka' and 'Villafranca' lemon (original clone of the latter has 25 seeds) and 'Minneola' tangelo have been obtained. Ovule sterility of the three mutants is nearly complete, with some pollen fertility still remaining. A semi-compact mutant of Shamouti orange has been obtained by irradiation. A programme for inducing seedlessness in easy peeling citrus varieties and selections has been initiated. (author)

  2. Induced skeletal mutations

    Selby, P.B.

    1979-01-01

    This paper describes a large-scale experiment that, by means of breeding tests, confirmed that many dominant skeletal mutations are induced by large-dose radiation exposure. The author also discusses: (1) the major advantages and disadvantages of the skeletal method in improving estimates of genetic hazard to man; (2) future uses of the skeletal method; (3) direct estimation of risk beyond the first generation using the skeletal method; and (4) the possibility of using the skeletal method as a quick and easy screen for chemical mutagens

  3. Mutation Breeding Newsletter. No. 39

    1992-01-01

    This newsletter contains brief articles on the use of radiation to induce mutations in plants; radiation-induced mutants in Chrysanthemum; disrupting the association between oil and protein content in soybean seeds; mutation studies on bougainvillea; a new pepper cultivar; and the use of mutation induction to improve the quality of yam beans. A short review of the seminar on the use of mutation and related biotechnology for crop improvement in the Middle East and Mediterranean regions, and a description of a Co-ordinated Research Programme on the application of DNA-based marker mutations for the improvement of cereals and other sexually reproduced crop species are also included. Two tables are given: these are based on the ''FAO/IAEA Mutant Varieties Database'' and show the number of mutated varieties and the number of officially released mutant varieties in particular crops/species. Refs and tabs

  4. Mutations induced in plant breeding

    Barriga B, P.

    1984-01-01

    The most significant aspects of the use of ionizing radiations in plant breeding are reviewed. Aspects such as basic principles of mutation, expression and selection in obtention of mutants, methods for using induced mutations and sucess achieved with this methodology in plant breeding are reviewed. Results obtained in a program of induced mutation on wheat for high content of protein and lysine at the Universidad Austral de Chile are presented. (Author)

  5. Mutations induced in plant breeding

    Barriga B, P. (Universidad Austral de Chile, Valdivia. Inst. de Produccion y Sanidad Vegetal)

    1984-10-01

    The most significant aspects of the use of ionizing radiations in plant breeding are reviewed. Aspects such as basic principles of mutation, expression and selection in obtention of mutants, methods for using induced mutations and sucess achieved with this methodology in plant breeding are reviewed. Results obtained in a program of induced mutation on wheat for high content of protein and lysine at the Universidad Austral de Chile are presented.

  6. Mutation breeding newsletter. No. 43

    1997-10-01

    This issue of the Newsletter includes articles dealing with radiation induced mutation based plant breeding research findings aimed at improving productivity, disease resistance and tolerance of stress conditions

  7. Mutation breeding in mangosteen

    Mohd Khalid Mohd Zain

    2002-01-01

    Mangosteen the queen of the tropical fruits is apomitic and only a cultivar is reported and it reproduces asexually. Conventional breeding is not possible and the other methods to create variabilities are through genetic engineering and mutation breeding. The former technique is still in the infantry stage in mangosteen research while the latter has been an established tool in breeding to improve cultivars. In this mutation breeding seeds of mangosteen were irradiated using gamma rays and the LD 50 for mangosteen was determined and noted to be very low at 10 Gy. After sowing in the seedbed, the seedlings were transplanted in polybags and observed in the nursery bed for about one year before planted in the field under old oil palm trees in Station MARDI, Kluang. After evaluation and screening, about 120 mutant mangosteen plants were selected and planted in Kluang. The plants were observed and some growth data taken. There were some mutant plants that have good growth vigour and more vigorous that the control plants. The trial are now in the fourth year and the plants are still in the juvenile stage. (Author)

  8. Mutation breeding in chickpea

    Sagel, Z.; Tutluer, M. I.; Peskircioglu, H.; Kantoglu, Y.; Kunter, B.

    2009-01-01

    Chickpea is an important food legume in Turkey. Turkey is one of the most important gene centers in the world for legumes. Realizing the potential of induced mutations, a mutation breeding programme was initiated at the Nuclear Agriculture Section of the Saraykoy Nuclear Research and Training Center in 1994. The purpose of the study was to obtain high yielding chickpea mutants with large seeds, good cooking quality and high protein content. Beside this some characters such as higher adaptation ability, tolerant to cold and drought, increased machinery harvest type, higher yield, resistant to diseases especially to antracnose and pest were investigated too. Parent varieties were ILC-482, AK-7114 and AKCIN-91 had been used in these experiments. The irradiation doses were 0 (control), 50, 100, 150, 200, 250, 300, 350 and 400 Gy for field experiments, respectively. As a result of these experiments, two promising mutant lines were chosen and given to the Seed Registration and Certification Center for official registration These two promising mutants were tested at five different locations of Turkey, in 2004 and 2005 years. After 2 years of registration experiments one of outstanding mutants was officially released as mutant chickpea variety under the name TAEK-SAGEL, in 2006. Some basic characteristics of this mutant are; earliness (95-100 day), high yield capacity (180-220 kg/da), high seed protein (22-25 %), first pot height (20-25 cm), 100 seeds weight (42-48 g), cooking time (35-40 min) and resistance to Ascochyta blight.

  9. Studies on mutation techniques in rice breeding

    Wang Cailian; Chen Qiufang; Jin Wei

    2001-01-01

    Synthetical techniques for improving rice mutation breeding efficiency were studied. The techniques consist of corresponding relationship between radiosensitivity and mutation frequency, choosing appropriate materials, combination of physical and chemical mutagens, mutagenic effects of the new mutagenic agents as proton, ions, synchronous irradiation and space mutation. These techniques and methods for inducing mutations are very valuable to increase inducing mutation efficiency and breeding level

  10. Mutation breeding in soybean

    Baradjanegara, A.A.

    1983-01-01

    In Indonesia, soybean is one of the important crop after rice. It is generally cultivated in the lowlands and rarely in the highlands. Seeds of soybean variety ORBA were treated with various doses of fast neutrons, gamma rays, EMS and NaN 3 with the aims of studying the mutagen effects in M-1 and M-2 generations and also to select mutants adapted to highland conditions. D-50 doses for gamma rays, fast neutrons and EMS were around 23 krad, 2,300 rad, 0.3%, respectively. Much higher chlorophyll mutation frequency was observed in EMS treatment of 0.3%. Seven mutants were shorter and four early mutants matured from 4 to 20 days earlier than the control plants. Two early mutants were quite adaptable in both the low and highlands and produced better yields than the parental material. (author)

  11. Founder Mutations in Xeroderma Pigmentosum

    Tamura, Deborah; DiGiovanna, John J.; Kraemer, Kenneth H.

    2012-01-01

    In this issue, Soufir et al. report a founder mutation in the XPC DNA repair gene in 74% of families with xeroderma pigmentosum (XP) in the Maghreb region (Algeria, Morocco, and Tunisia) of northern Africa. These patients have a high frequency of skin cancer. The presence of this founder mutation provides an opportunity for genetic counseling and early diagnosis of XP. PMID:20463673

  12. Mutations causative of familial hypercholesterolaemia

    Benn, Marianne; Watts, Gerald F; Tybjærg-Hansen, Anne

    2016-01-01

    causing mutations in 98 098 participants from the general population, the Copenhagen General Population Study. METHODS AND RESULTS: We genotyped for LDLR[W23X;W66G;W556S] and APOB[R3500Q] accounting for 38.7% of pathogenic FH mutations in Copenhagen. Clinical FH assessment excluded mutation information......-cholesterol concentration to discriminate between mutation carriers and non-carriers was 4.4 mmol/L. CONCLUSION: Familial hypercholesterolaemia-causing mutations are estimated to occur in 1:217 in the general population and are best identified by a definite or probable phenotypic diagnosis of FH based on the DLCN criteria....... The prevalence of the four FH mutations was 0.18% (1:565), suggesting a total prevalence of FH mutations of 0.46% (1:217). Using the Dutch Lipid Clinic Network (DLCN) criteria, odds ratios for an FH mutation were 439 (95% CI: 170-1 138) for definite FH, 90 (53-152) for probable FH, and 18 (13-25) for possible FH...

  13. Mutation induction by heavy ions

    Kiefer, J.; Stoll, U.; Schneider, E.

    1994-10-01

    Mutation induction by heavy ions is compared in yeast and mammalian cells. Since mutants can only be recovered in survivors the influence of inactivation cross sections has to be taken into account. It is shown that both the size of the sensitive cellular site as well as track structure play an important role. Another parameter which influences the probability of mutation induction is repair: Contrary to naive assumptions primary radiation damage does not directly lead to mutations but requires modification to reconstitute the genetic machinery so that mutants can survive. The molecular structure of mutations was analyzed after exposure to deuterons by amplification with the aid of polymerase chain reaction. The results-although preliminary-demonstrate that even with densely ionizing particles a large fraction does not carry big deletions which suggests that point mutations may also be induced by heavy ions.

  14. Mutation breeding in ornamental plants

    Datta, S.K.

    1990-01-01

    Full text: Mutation induction produced a large number of new promising varieties in ornamental species. 37 new mutants of Chrysanthemum and 14 of rose have been developed by mutations and released for commercialisation. The mutations in flower colour/shape were detected as chimeras in M 1 V 1 , M 1 V 2 , M 1 V 3 generations. The mutation frequency varied with the cultivar and exposure to gamma rays. Comparative analysis of original cultivars and their respective induced mutants on cytomorphological, anatomical and biochemical characters are being carried out for better understanding of the mechanism involved in the origin and evolution of somatic flower colour/shape mutations. Cytological analysis with reference to chromosomal aberrations, chromosome number, ICV, INV and DNA content gave no differences between the original and mutant cultivars. Analysis of florets/petal pigments by TLC and spectrophotometric methods indicated both qualitative and quantitative changes. (author)

  15. Mutational meltdown in laboratory yeast populations

    Zeyl, C.; Mizesko, M.; Visser, de J.A.G.M.

    2001-01-01

    In small or repeatedly bottlenecked populations, mutations are expected to accumulate by genetic drift, causing fitness declines. In mutational meltdown models, such fitness declines further reduce population size, thus accelerating additional mutation accumulation and leading to extinction. Because

  16. Minisequencing mitochondrial DNA pathogenic mutations

    Carracedo Ángel

    2008-04-01

    Full Text Available Abstract Background There are a number of well-known mutations responsible of common mitochondrial DNA (mtDNA diseases. In order to overcome technical problems related to the analysis of complete mtDNA genomes, a variety of different techniques have been proposed that allow the screening of coding region pathogenic mutations. Methods We here propose a minisequencing assay for the analysis of mtDNA mutations. In a single reaction, we interrogate a total of 25 pathogenic mutations distributed all around the whole mtDNA genome in a sample of patients suspected for mtDNA disease. Results We have detected 11 causal homoplasmic mutations in patients suspected for Leber disease, which were further confirmed by standard automatic sequencing. Mutations m.11778G>A and m.14484T>C occur at higher frequency than expected by change in the Galician (northwest Spain patients carrying haplogroup J lineages (Fisher's Exact test, P-value Conclusion We here developed a minisequencing genotyping method for the screening of the most common pathogenic mtDNA mutations which is simple, fast, and low-cost. The technique is robust and reproducible and can easily be implemented in standard clinical laboratories.

  17. Mutation breeding in malting barley

    Hiraki, Makoto; Sanada, Matsuyoshi

    1984-03-01

    The released varieties of malting barley through mutation breeding is more than ten in number, including foreign varieties. In Japan four varieties has been released so far. We started mutation breeding in 1956 together with cross breeding that we employed before. Until now, Gamma 4, Amagi Nijo 1 and Fuji Nijo 2 have been produced from the direct use of induced mutations and Nirasaki Nijo 8 from the indirect use of them. Mutation breeding has been used mainly in the partial improvement of agronomic characteristics since the selection for malting quality was very complicated. As the variety bred by induced mutation is usually equivalent to the original variety in malting quality, both this new variety and the original one could be cultivated in the same area without any problem on later malt production. Particularly when one farmer cultivates barley in an extensive acreage, he can harvest at the best time according to the different maturing time of each variety. From these points of view, mutation breeding is an efficient tool in malting barley breeding. Mutagens we have used so far are X-rays, ..gamma..-rays, neutron and chemicals such as dES. From our experience in selection, the low dose of radiation and chemical mutagens are more effective in selection of point mutation than the high dose of radiation which tends to produce many abnormal but few practical mutants. (author).

  18. HNPCC: Six new pathogenic mutations

    Epplen Joerg T

    2004-06-01

    Full Text Available Abstract Background Hereditary non-polyposis colorectal cancer (HNPCC is an autosomal dominant disease with a high risk for colorectal and endometrial cancer caused by germline mutations in DNA mismatch-repair genes (MMR. HNPCC accounts for approximately 2 to 5% of all colorectal cancers. Here we present 6 novel mutations in the DNA mismatch-repair genes MLH1, MSH2 and MSH6. Methods Patients with clinical diagnosis of HNPCC were counselled. Tumor specimen were analysed for microsatellite instability and immunohistochemistry for MLH1, MSH2 and MSH6 protein was performed. If one of these proteins was not detectable in the tumor mutation analysis of the corresponding gene was carried out. Results We identified 6 frameshift mutations (2 in MLH1, 3 in MSH2, 1 in MSH6 resulting in a premature stop: two mutations in MLH1 (c.2198_2199insAACA [p.N733fsX745], c.2076_2077delTG [p.G693fsX702], three mutations in MSH2 (c.810_811delGT [p.C271fsX282], c.763_766delAGTGinsTT [p.F255fsX282], c.873_876delGACT [p.L292fsX298] and one mutation in MSH6 (c.1421_1422dupTG [p.C475fsX480]. All six tumors tested for microsatellite instability showed high levels of microsatellite instability (MSI-H. Conclusions HNPCC in families with MSH6 germline mutations may show an age of onset that is comparable to this of patients with MLH1 and MSH2 mutations.

  19. Factor V Leiden Mutation and PT 20210 Mutation Test

    ... Disorders Fibromyalgia Food and Waterborne Illness Fungal Infections Gout Graves Disease Guillain-Barré Syndrome Hashimoto Thyroiditis Heart ... Tested? To determine whether you have an inherited gene mutation that increases your risk of developing a ...

  20. Mutations induced by ultraviolet light

    Pfeifer, Gerd P.; You, Young-Hyun; Besaratinia, Ahmad

    2005-01-01

    The different ultraviolet (UV) wavelength components, UVA (320-400 nm), UVB (280-320 nm), and UVC (200-280 nm), have distinct mutagenic properties. A hallmark of UVC and UVB mutagenesis is the high frequency of transition mutations at dipyrimidine sequences containing cytosine. In human skin cancers, about 35% of all mutations in the p53 gene are transitions at dipyrimidines within the sequence 5'-TCG and 5'-CCG, and these are localized at several mutational hotspots. Since 5'-CG sequences are methylated along the p53 coding sequence in human cells, these mutations may be derived from sunlight-induced pyrimidine dimers forming at sequences that contain 5-methylcytosine. Cyclobutane pyrimidine dimers (CPDs) form preferentially at dipyrimidines containing 5-methylcytosine when cells are irradiated with UVB or sunlight. In order to define the contribution of 5-methylcytosine to sunlight-induced mutations, the lacI and cII transgenes in mouse fibroblasts were used as mutational targets. After 254 nm UVC irradiation, only 6-9% of the base substitutions were at dipyrimidines containing 5-methylcytosine. However, 24-32% of the solar light-induced mutations were at dipyrimidines that contain 5-methylcytosine and most of these mutations were transitions. Thus, CPDs forming preferentially at dipyrimidines with 5-methylcytosine are responsible for a considerable fraction of the mutations induced by sunlight in mammalian cells. Using mouse cell lines harboring photoproduct-specific photolyases and mutational reporter genes, we showed that CPDs (rather than 6-4 photoproducts or other lesions) are responsible for the great majority of UVB-induced mutations. An important component of UVB mutagenesis is the deamination of cytosine and 5-methylcytosine within CPDs. The mutational specificity of long-wave UVA (340-400 nm) is distinct from that of the shorter wavelength UV and is characterized mainly by G to T transversions presumably arising through mechanisms involving oxidized DNA

  1. Radiation mutation breeding

    Song, Hi Sup; Kim, Jae Sung; Kim, Jin Kyu; Shin, In Chul; Lim, Young Taek

    1998-04-01

    In order to develop an advanced technical knowledge for the selection of better mutants, some of the crops were irradiated and the mutation rate, the survival rate and the method for selction of a mutant were studied. Furthermore, this study aimed to obtain basic data applicable to the development of genetic resources by evaluation and analysis the specific character for selection of the superior mutant and its plant breeding. 1. selection of the mutant with a superior resistance against environment in the principal crops 1) New varieties of mutant rices such as Wonpyeongbyeo, Wongwangbyeo, Winmibyeo, and heogseon chalbeyeo (sticky forma) were registered in the national variety list and made an application to crop variety protection right. They are under review now. 2) We also keep on studying on the number of a grain of 8 lines of excellent mutant rice for the purpose of improvement of breeding . 3) We selected 3 lines which have a resistance to pod and stem blight in large soybean, 31 lines with small grain size and higher yield, 112 lines of soybean of cooking, 7 lines of low lipoxygenase content, and 12 lines with decreased phytic acid content by 20 % compared to the previous level. 2. Selection of advanced Mugunwha (Rose of Sharon) mutant 1) Bagseul, a new variety of mutant, was developed and 30 plantlets of it are being proliferated. 2) Fifty-three lines of a mutant having a various morphologies were selected

  2. Radiation mutation breeding

    Song, Hi Sup; Kim, Jae Sung; Kim, Jin Kyu; Shin, In Chul; Lim, Young Taek

    1998-04-01

    In order to develop an advanced technical knowledge for the selection of better mutants, some of the crops were irradiated and the mutation rate, the survival rate and the method for selction of a mutant were studied. Furthermore, this study aimed to obtain basic data applicable to the development of genetic resources by evaluation and analysis the specific character for selection of the superior mutant and its plant breeding. 1. selection of the mutant with a superior resistance against environment in the principal crops 1) New varieties of mutant rices such as Wonpyeongbyeo, Wongwangbyeo, Winmibyeo, and heogseon chalbeyeo (sticky forma) were registered in the national variety list and made an application to crop variety protection right. They are under review now. 2) We also keep on studying on the number of a grain of 8 lines of excellent mutant rice for the purpose of improvement of breeding . 3) We selected 3 lines which have a resistance to pod and stem blight in large soybean, 31 lines with small grain size and higher yield, 112 lines of soybean of cooking, 7 lines of low lipoxygenase content, and 12 lines with decreased phytic acid content by 20 % compared to the previous level. 2. Selection of advanced Mugunwha (Rose of Sharon) mutant 1) Bagseul, a new variety of mutant, was developed and 30 plantlets of it are being proliferated. 2) Fifty-three lines of a mutant having a various morphologies were selected.

  3. Mutation breeding in wheat

    Amer, I.M.

    2002-01-01

    The study aims to improve the productivity of wheat by using gamma ray (100 - 600 Gy) in mutation breading. Five local varieties were used and the program continued for the Sakha 69 for seven generations. Seeds irradiated with 600 Gy were not germinated in the field, while low doses (100-150 Gy) stimulated the root growth and spike length. The higher doses caused gradual decrease of growth with differences in varieties response. in the second generation, a genetic differences were noticed in most varieties using doses of 100-300 Gy, and the dispike was disappeared when 250 Gy was used. 79 plants from irradiated Sakha 69 were selected according to spike length and the number of grains and planted with the control to test the third generation. differences between the varieties were noticed and 8 mutants with high productivity were selected and evaluated in the fourth and fifth generations with the local variety. The mutants improve the productivity and in particular the mutants Nos.. (19-1), (14-3), and (30-2). The experiment showed the relation between the planting sites and the mutants in the sixth and seven generations

  4. Induced mutations in castor

    Ganesan, K.; Javad Hussain, H.S.; Vindhiyavarman, P.

    2001-01-01

    Castor (Ricinus communis L.) is an important oilseed crop in India. To create variability mutations were induced in two cultivars 'TMV5' (maturing in 130-140 days) and 'CO1' (perennial type). Gamma rays and diethyl sulphate and ethidium bromide were used for seed treatment. Ten doses, from 100 to 1000 Gy were employed. For chemical mutagenesis five concentrations of mutagenes from 10 to 50 mM were tried. No economic mutants could be isolated after treatment with the chemical mutagens. The following economic mutants were identified in the dose 300 Gy of gamma rays. Annual types from perennial CO 1 castor CO 1 is a perennial variety (8-10 years) with bold seeds (100 seed weight 90 g) and high oil content (57%). Twenty-one lines were isolated with annual types (160-180 days) with high yield potential as well as bold seeds and high oil content. These mutants, identified in M 3 generation were bred true in subsequent generations up to M 8 generation. Critical evaluation of the mutants in yield evaluation trials is in progress

  5. Methylmalonic Acid Test

    ... Factor Antibody Iron Iron Tests JAK2 Mutation Kidney Stone Analysis Kidney Stone Risk Panel KRAS Mutation Lactate Lactate Dehydrogenase (LD) ... in Previous Reviews Clarke, W. and Dufour, D. R., Editors (2006). Contemporary Practice in Clinical Chemistry, AACC ...

  6. Mutation breeding newsletter. No. 22

    NONE

    1983-07-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

  7. Mutation breeding newsletter. No. 34

    NONE

    1989-07-01

    This issue of the Newsletter presents abstracts and short communications of research results on radiation and chemical induced mutation breeding projects. Positive traits such as disease resistance and increased productivity are highlighted.

  8. Mutation breeding newsletter. No. 29

    NONE

    1987-02-01

    This issue of the Newsletter presents reports and rea search abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

  9. Mutation breeding newsletter. No. 15

    NONE

    1980-02-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

  10. Mutation breeding newsletter. No. 5

    1975-02-01

    This issue of the Newsletter presents reports and rea search abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  11. Mutation breeding newsletter. No. 15

    1980-02-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  12. Mutation breeding newsletter. No. 14

    1979-07-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  13. Mutation breeding newsletter. No. 16

    1980-07-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  14. Mutation breeding newsletter. No. 12

    1978-07-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  15. Mutation breeding newsletter. No. 28

    NONE

    1986-09-01

    This issue of the Newsletter presents reports and research abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

  16. Mutation breeding newsletter. No. 29

    1987-02-01

    This issue of the Newsletter presents reports and rea search abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  17. Mutation breeding newsletter. No. 9

    1977-01-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  18. Mutation breeding newsletter. No. 7

    NONE

    1976-01-01

    This issue of the Newsletter presents reports and rea search abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

  19. Mutation Breeding Newsletter. No. 37

    1991-01-01

    This newsletter contains a brief account of FAO/IAEA meetings held in 1990 on plant breeding involving the use of induced mutations. It also features a list of commercially available plant cultivars produced by such techniques. Refs and tabs

  20. Mutation breeding newsletter. No. 4

    1974-08-01

    This issue of the Newsletter presents reports and rea search abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  1. Mutation breeding newsletter. No. 18

    NONE

    1981-07-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

  2. Mutation breeding newsletter. No. 9

    NONE

    1977-01-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

  3. Mutation breeding newsletter. No. 34

    1989-07-01

    This issue of the Newsletter presents abstracts and short communications of research results on radiation and chemical induced mutation breeding projects. Positive traits such as disease resistance and increased productivity are highlighted

  4. Mutation breeding newsletter. No. 24

    NONE

    1984-07-01

    This issue of the Newsletter presents reports and research abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

  5. Mutation breeding newsletter. No. 32

    NONE

    1988-07-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

  6. Mutation breeding newsletter. No. 36

    NONE

    1990-07-01

    This issue of the Newsletter presents abstracts and short communications of research results on radiation and chemical induced mutation breeding projects. Positive traits such as disease resistance and increased productivity are highlighted.

  7. Mutation breeding newsletter. No. 3

    NONE

    1974-01-01

    This issue of the Newsletter presents reports and rea search abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

  8. Mutation breeding newsletter. No. 3

    1974-01-01

    This issue of the Newsletter presents reports and rea search abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  9. Mutation breeding newsletter. No. 11

    1978-02-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  10. Mutation breeding newsletter. No. 6

    1975-08-01

    This issue of the Newsletter presents reports and rea search abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  11. Mutation breeding newsletter. No. 1

    1972-05-01

    This issue of the Newsletter presents reports and rea search abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  12. Mutation breeding newsletter. No. 31

    1988-03-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  13. Mutation breeding newsletter. No. 44

    1999-04-01

    This issue of the Newsletter presents research reports on the role of radiation induced mutation and chemical mutagens in improving productivity, disease resistance; cold and salinity tolerance of various crops and ornamental plants

  14. Mutation breeding newsletter. No. 1

    NONE

    1972-05-01

    This issue of the Newsletter presents reports and rea search abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

  15. Mutation breeding newsletter. No. 25

    1985-01-01

    This issue of the Newsletter presents reports and research abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  16. Mutation breeding newsletter. No. 32

    1988-07-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  17. Mutation breeding newsletter. No. 5

    NONE

    1975-02-01

    This issue of the Newsletter presents reports and rea search abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

  18. Mutation breeding newsletter. No. 20

    NONE

    1982-07-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

  19. Mutation breeding newsletter. No. 28

    1986-09-01

    This issue of the Newsletter presents reports and research abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  20. Mutation breeding newsletter. No. 17

    NONE

    1981-03-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

  1. Mutation breeding newsletter. No. 16

    NONE

    1980-07-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

  2. Mutation breeding newsletter. No. 8

    NONE

    1976-09-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

  3. Mutation breeding newsletter. No. 4

    NONE

    1974-08-01

    This issue of the Newsletter presents reports and rea search abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

  4. Mutation breeding newsletter. No. 12

    NONE

    1978-07-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

  5. Mutation breeding newsletter. No. 6

    NONE

    1975-08-01

    This issue of the Newsletter presents reports and rea search abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

  6. Mutation breeding newsletter. No. 10

    NONE

    1977-07-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

  7. Mutation breeding newsletter. No. 14

    NONE

    1979-07-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

  8. Mutation breeding newsletter. No. 36

    1990-07-01

    This issue of the Newsletter presents abstracts and short communications of research results on radiation and chemical induced mutation breeding projects. Positive traits such as disease resistance and increased productivity are highlighted

  9. CHRNE Mutation and Congenital Myasthenia

    J Gordon Millichap

    2009-01-01

    Full Text Available The CHRNE e1293insG mutation was identified in 14 (60% of 23 North African families with an early onset form of congenital myasthenic syndrome studied at centers in France, Tunisia, Algeria, and UK.

  10. Mutation breeding newsletter. No. 19

    1982-01-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  11. Mutation breeding newsletter. No. 7

    1976-01-01

    This issue of the Newsletter presents reports and rea search abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  12. Mutation breeding newsletter. No. 24

    1984-07-01

    This issue of the Newsletter presents reports and research abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  13. Mutation breeding newsletter. No. 20

    1982-07-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  14. Mutation breeding newsletter. No. 18

    1981-07-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  15. Mutation breeding newsletter. No. 31

    NONE

    1988-03-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

  16. Mutation breeding newsletter. No. 27

    1986-02-01

    This issue of the Newsletter presents reports and research abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  17. Mutation breeding newsletter. No. 26

    1985-10-01

    This issue of the Newsletter presents reports and research abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  18. Mutation breeding newsletter. No. 17

    1981-03-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  19. Mutation breeding newsletter. No. 30

    1987-07-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  20. Mutation breeding newsletter. No. 13

    NONE

    1979-02-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

  1. Mutation breeding newsletter. No. 30

    NONE

    1987-07-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

  2. Mutation breeding newsletter. No. 19

    NONE

    1982-01-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

  3. Mutation breeding newsletter. No. 26

    NONE

    1985-10-01

    This issue of the Newsletter presents reports and research abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

  4. Mutation breeding newsletter. No. 25

    NONE

    1985-01-01

    This issue of the Newsletter presents reports and research abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

  5. Mutation breeding newsletter. No. 23

    NONE

    1983-01-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

  6. Mutation breeding newsletter. No. 27

    NONE

    1986-02-01

    This issue of the Newsletter presents reports and research abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

  7. Mutation breeding newsletter. No. 2

    NONE

    1973-02-01

    This issue of the Newsletter presents reports and rea search abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

  8. Mutation breeding newsletter. No. 11

    NONE

    1978-02-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants.

  9. Mutation breeding newsletter. No. 23

    1983-01-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  10. Mutation breeding newsletter. No. 2

    1973-02-01

    This issue of the Newsletter presents reports and rea search abstracts on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  11. Mutation breeding newsletter. No. 10

    1977-07-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  12. Mutation breeding newsletter. No. 8

    1976-09-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  13. Mutation breeding newsletter. No. 13

    1979-02-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  14. BRAF mutations in conjunctival melanoma

    Larsen, Ann-Cathrine; Dahl, Christina; Dahmcke, Christina M.

    2016-01-01

    with atypia. BRAF mutations were identified in 39 of 111 (35%) cases. The rate ratio of BRAF-mutated versus BRAF-wild-type melanoma did not change over time. BRAF mutations were associated with T1 stage (p = 0.007), young age (p = 0.001), male gender (p = 0.02), sun-exposed location (p = 0.01), mixed....../non-pigmented tumour colour (p = 0.02) and nevus origin (p = 0.005), but did not associate with prognosis. BRAF status in conjunctival melanoma and paired premalignant lesions corresponded in 19 of 20 cases. Immunohistochemistry detected BRAF V600E mutations with a sensitivity of 0.94 and a specificity of 1...

  15. Mutation breeding newsletter. No. 22

    1983-07-01

    This issue of the Newsletter presents new reports on mutation breeding programs using radiation or chemical mutagenesis to improve productivity, introduce disease resistance or induce morphological changes in crop plants

  16. Drie nuwe verklaringsopsies in die Jakobusbrief (Jak 2:1, 4: 5; 5: 6)

    van die bogenoemde drie verse in Jakobus het daar in die onlangse navorsing wel ..... schengeist — das ist der Sinn des Zitats' (1921: 268, 1976: 224). Calvyn ... liefde van God (vgl Eks 20: 5, 34: 14; Deut 4: 24; Jos 24: 19; Jes 26: 11) word in die ... word, waarop nie 'n direkte Skrifaanhaling hoef te volg nie. Davids.

  17. Tamoxifen inhibits astrocytic JAK2/STAT3 pathway in rats with ...

    LDL-C levels was influenced by factors, such as age, BMI, exercise, diet, and smoking habits. In MCC group, the ... International Pharmaceutical Abstract, Chemical Abstracts, Embase, Index Copernicus, EBSCO, African ... for several years in an attempt to resolve this issue. ... a temperature-controlled environment (22 – 25.

  18. Drie nuwe verklaringsopsies in die Jakobusbrief (Jak 2:1; 4:5; 5:6 ...

    New options in the understanding of the Epistle of James (Js 2:1; 4:5; 5:6) New methods of interpretation occasionally lead to new options in the understanding of texts. In the case of the Epistle of James, the interpretation has until recently stood under the spell of the 'comparative' method of Dibelius. Greater emphasis on ...

  19. Mutation breeding in Brazil

    Neto, A T; Menten, J O.M. [Centro de Energia Nuclear na Agricultura, Piracicaba (Brazil); Ando, A

    1980-03-01

    How mutation induction is used for plant breeding in Brazil is reported. For upland rice, the combined treatment with gamma-ray and mutagens (ethylene imine or ethylmethane sulfonate) has been used on the variety, Dourado Precoce, and some mutants with shortculm length and/or earliness without altering the productivity have been obtained. A project on the quantitative and qualitative protein improvement in upland rice was also started in 1979. In corn, the effect of gamma-irradiation on heterosis has been analyzed, and it was found that the single hybrids from two parental lines derived from irradiated seeds had increased ear productivity. For beans (Phaseolus yulgaris), gamma-irradiation and chemical mutagens have been used to induce the mutants with different seed color, disease resistance to golden mosaic virus and Xanthomonas phaseoli, earliness, high productivity and high protein content. Some mutants with partly improved characters have been obtained in these experiments. Two varieties of wheat tolerant to aluminum toxicity have been obtained, but the one showed high lodging due to its unfavorable plant height, and the other was highly susceptible to culm rust. Therefore, irradiation experiments have been started to improve these characters. The projects involving the use of gamma-irradiation have been tested to obtain the mutant lines insensitive to photoperiod and resistant to bud-blight in soybean, the mutant lines resistant to mosaic virus in papaya, the photoperiod-insensitive mutants in sorghum, the mosaic virus resistant and non-flowering mutants in sugar cane, and the Fusarium and nematode-resistant mutants in black pepper.

  20. Screening of three Mediterranean phenylketonuria mutations in ...

    as the most frequent mutation (Dahri et al. 2010). The. E280K mutation was also reported in Mediterranean popu- lations (Guldberg et al. 1993). Since Tunisia is a Mediter- ranean country, patients with PKU are presumed to have these mutations. The aim of this study was to assess prevalence of the three above mutations ...

  1. Signatures of mutational processes in human cancer

    Alexandrov, L.B.; Nik-Zainal, S.; Wedge, D.C.; Aparicio, S.A.; Behjati, S.; Biankin, A.V.; Bignell, G.R.; Bolli, N.; Borg, A.; Borresen-Dale, A.L.; Boyault, S.; Burkhardt, B.; Butler, A.P.; Caldas, C.; Davies, H.R.; Desmedt, C.; Eils, R.; Eyfjord, J.E.; Foekens, J.A.; Greaves, M.; Hosoda, F.; Hutter, B.; Ilicic, T.; Imbeaud, S.; Imielinsk, M.; Jager, N.; Jones, D.T.; Knappskog, S.; Kool, M.; Lakhani, S.R.; Lopez-Otin, C.; Martin, S.; Munshi, N.C.; Nakamura, H.; Northcott, P.A.; Pajic, M.; Papaemmanuil, E.; Paradiso, A.; Pearson, J.V.; Puente, X.S.; Raine, K.; Ramakrishna, M.; Richardson, A.L.; Richter, J.; Rosenstiel, P.; Schlesner, M.; Schumacher, T.N.; Span, P.N.; Teague, J.W.; Totoki, Y.; Tutt, A.N.; Valdes-Mas, R.; Buuren, M.M. van; Veer, L. van 't; Vincent-Salomon, A.; Waddell, N.; Yates, L.R.; Zucman-Rossi, J.; Futreal, P.A.; McDermott, U.; Lichter, P.; Meyerson, M.; Grimmond, S.M.; Siebert, R.; Campo, E.; Shibata, T.; Pfister, S.M.; Campbell, P.J.; Stratton, M.R.; Schlooz-Vries, M.S.; Tol, J.J. van; Laarhoven, H.W. van; Sweep, F.C.; Bult, P.; et al.,

    2013-01-01

    All cancers are caused by somatic mutations; however, understanding of the biological processes generating these mutations is limited. The catalogue of somatic mutations from a cancer genome bears the signatures of the mutational processes that have been operative. Here we analysed 4,938,362

  2. Common Β- Thalassaemia Mutations in

    P Azarfam

    2005-01-01

    Full Text Available Introduction: β –Thalassaemia was first explained by Thomas Cooly as Cooly’s anaemia in 1925. The β- thalassaemias are hereditary autosomal disorders with decreased or absent β-globin chain synthesis. The most common genetic defects in β-thalassaemias are caused by point mutations, micro deletions or insertions within the β-globin gene. Material and Methods: In this research , 142 blood samples (64 from childrens hospital of Tabriz , 15 samples from Shahid Gazi hospital of Tabriz , 18 from Urumia and 45 samples from Aliasghar hospital of Ardebil were taken from thalassaemic patients (who were previously diagnosed .Then 117 non-familial samples were selected . The DNA of the lymphocytes of blood samples was extracted by boiling and Proteinase K- SDS procedure, and mutations were detected by ARMS-PCR methods. Results: From the results obtained, eleven most common mutations,most of which were Mediterranean mutations were detected as follows; IVS-I-110(G-A, IVS-I-1(G-A ،IVS-I-5(G-C ,Frameshift Codon 44 (-C,( codon5(-CT,IVS-1-6(T-C, IVS-I-25(-25bp del ,Frameshift 8.9 (+G ,IVS-II-1(G-A ,Codon 39(C-T, Codon 30(G-C the mutations of the samples were defined. The results showed that Frameshift 8.9 (+G, IVS-I-110 (G-A ,IVS-II-I(G-A, IVS-I-5(G-C, IVS-I-1(G-A , Frameshift Codon 44(-C , codon5(-CT , IVS-1-6(T-C , IVS-I-25(-25bp del with a frequency of 29.9%, 25.47%,17.83%, 7.00%, 6.36% , 6.63% , 3.8% , 2.5% , 0.63% represented the most common mutations in North - west Iran. No mutations in Codon 39(C-T and Codon 30(G-C were detected. Cunclusion: The frequency of the same mutations in patients from North - West of Iran seems to be different as compared to other regions like Turkey, Pakistan, Lebanon and Fars province of Iran. The pattern of mutations in this region is more or less the same as in the Mediterranean region, but different from South west Asia and East Asia.

  3. SQSTM1 Mutations and Glaucoma.

    Todd E Scheetz

    Full Text Available Glaucoma is the most common cause of irreversible blindness worldwide. One subset of glaucoma, normal tension glaucoma (NTG occurs in the absence of high intraocular pressure. Mutations in two genes, optineurin (OPTN and TANK binding kinase 1 (TBK1, cause familial NTG and have known roles in the catabolic cellular process autophagy. TKB1 encodes a kinase that phosphorylates OPTN, an autophagy receptor, which ultimately activates autophagy. The sequestosome (SQSTM1 gene also encodes an autophagy receptor and also is a target of TBK1 phosphorylation. Consequently, we hypothesized that mutations in SQSTM1 may also cause NTG. We tested this hypothesis by searching for glaucoma-causing mutations in a cohort of NTG patients (n = 308 and matched controls (n = 157 using Sanger sequencing. An additional 1098 population control samples were also analyzed using whole exome sequencing. A total of 17 non-synonymous mutations were detected which were not significantly skewed between cases and controls when analyzed separately, or as a group (p > 0.05. These data suggest that SQSTM1 mutations are not a common cause of NTG.

  4. Mutation breeding in Philippine fruits

    Espino, R.R.C.

    1987-09-01

    Studies were made to establish standard conditions for mutation induction by gamma-irradiation to be performed in combination with in-vitro culture for banana and citrus spp. Besides this, radio-sensitivity of seeds and/or plantlets of mango, sugar apple, soursop, lanzones and Jack fruit was investigated and primary observation on the occurrence of mutation was made. For the mutagenesis of banana shoot tip cultures, radio-sensitivity of plantlets derived from the culture as well as fresh-cultured shoots was examined and phenotypes indicative of mutation, such as chlorophyl streaking, slow growth, pigmentation and varied bunch orientation were recorded. Isozyme analysis for mutated protein structure was not conclusive. In the in-vitro culture of Citrus spp., seeds placed on fresh media as well as germinating seeds and two-leaf stage seedlings in test tubes were examined for their radio-sensitivity. Irradiated materials were propagated for further observation. In these two crops, basic methodology for mutation induction with combined use of in-vitro culture and gamma-irradiation was established. In mango, sugar apple, soursop, lanzones and Jack fruit, basic data on radiosensitivity were obtained. In mango, leaf abnormalities were observed after the treatment of scions

  5. A novel STAT inhibitor, OPB-31121, has a significant antitumor effect on leukemia with STAT-addictive oncokinases

    Hayakawa, F; Sugimoto, K; Harada, Y; Hashimoto, N; Ohi, N; Kurahashi, S; Naoe, T

    2013-01-01

    Signal transduction and activator of transcription (STAT) proteins are extracellular ligand-responsive transcription factors that mediate cell proliferation, apoptosis, differentiation, development and the immune response. Aberrant signals of STAT induce uncontrolled cell proliferation and apoptosis resistance and are strongly involved in cancer. STAT has been identified as a promising target for antitumor drugs, but to date most trials have not been successful. Here, we demonstrated that a novel STAT inhibitor, OPB-31121, strongly inhibited STAT3 and STAT5 phosphorylation without upstream kinase inhibition, and induced significant growth inhibition in various hematopoietic malignant cells. Investigation of various cell lines suggested that OPB-31121 is particularly effective against multiple myeloma, Burkitt lymphoma and leukemia harboring BCR–ABL, FLT3/ITD and JAK2 V617F, oncokinases with their oncogenicities dependent on STAT3/5. Using an immunodeficient mouse transplantation system, we showed the significant antitumor effect of OPB-31121 against primary human leukemia cells harboring these aberrant kinases and its safety for normal human cord blood cells. Finally, we demonstrated a model to overcome drug resistance to upstream kinase inhibitors with a STAT inhibitor. These results suggested that OPB-31121 is a promising antitumor drug. Phase I trials have been performed in Korea and Hong Kong, and a phase I/II trial is underway in Japan

  6. Mutation in cultured mammalian cells

    Nakamura, N.; Okada, S.

    1982-01-01

    Mammalian cell cultures were exposed to gamma-rays at various dose rates. Dose-rate effects were observed in cultured somatic cells of the mouse for cell killing and mutations resistant to 6-thioguanine (TGsup(r)) and to methotrexate (MTXsup(r)). Linear quadratic model may be applied to cell killing and TGsup(r) mutations in some cases but can not explain the whole data. Results at low doses with far low dose-rate were not predictable from data at high doses with acute or chronic irradiation. Radioprotective effects of dimethyl sulfoxide were seen only after acute exposure but not after chronic one, suggesting that damages by indirect action of radiations may be potentially reparable by cells. TGsup(r) mutations seem to contain gross structural changes whereas MTXsup(r) ones may have smaller alterations. (Namekawa, K.)

  7. Thalassemia mutations in Gaziantep, Turkey

    STORAGESEVER

    2010-02-22

    Feb 22, 2010 ... Table 3. Frequency of β-thalassemia mutations in the Eastern Mediterranean. Mutation. This study Turkey Cyprus Greece Syria Palestine Bulgaria Azerbaijan Iran Iraq. IVS 1.110 (G>A). 29.1. 39.3. 79.7. 42.1. 24.1. 17.6. 24.2. 20.2. 4.8 1.9. IVS 2.1 (G>A). 12.3. 4.7. -. 3.3. 4.2. 2.9. -. -. 33.9 18.3. IVS 1.1 (G>A).

  8. Energy parasites trigger oncogene mutation

    Pokorný, Jiří; Pokorný, Jan; Jandová, Anna; Kobilková, J.; Vrba, J.; Vrba, J. jr.

    2016-01-01

    Roč. 92, č. 10 (2016), s. 577-582 ISSN 0955-3002 R&D Projects: GA ČR GA16-12757S Institutional support: RVO:68378271 ; RVO:67985882 Keywords : cancer initiation * cell-mediated immunity * coherent electromagnetic states * genome somatic mutation * LDH virus * parasitic energy consumption Subject RIV: BO - Biophysics Impact factor: 1.992, year: 2016

  9. Induced mutation of Dendrobium orchid

    Sakinah Ariffin; Mohd Nazir Basiran

    2000-01-01

    Dendrobiiim orchids serve as the main orchid cut flower export of Malaysia. The wide range of colour and forms presently available in the market are obtained through hybridisation. Induced mutation breeding program was initiated on a commercial variety Dendrobium 'Sonia Kai' to explore the possibilities of obtaining new colour and forms. Matured seeds from self pollination were cultured and irradiated at 35 Gy at the protocorm-like bodies (PLBS) stage. Selection of induced mutations was done after the first flowering of the plants regenerated from the irradiated protocorms. Results showed changes in flower colour, shape and size. Most of these chances are expressed in different combinations in the petals, sepals and lip of the flowers. Thus, resulting. in a very wide spectrum of mutations. Some of these chances are not stable. To date, mutants that showed stable characteristics changes are grouped into 11 categories based on flower colour and form. These results show that the combination of its vitro technique and induced mutation can be applied in orchid breeding to produce new interesting and attractive variety for the market

  10. Mutational specificity of SOS mutagenesis

    Kato, Takeshi

    1986-01-01

    In an approach to the isolation of mutants of E. coli unable to produce mutations by ultraviolet light, the author has found new umuC-mutants. Their properties could be explained by ''SOS hypothesis of Radman and Witkin'', which has now been justified by many investigators. Analysis of the umuC region of E. coli chromosome cloned in pSK 100 has led to the conclusion that two genes, umuD and umuC, having the capacity of mutation induction express in the same mechanism as that of SOS genes, which is known to be inhibited by LexA protein bonding to ''SOS box'' found at promotor region. Suppressor analysis for mutational specificity has revealed: (i) umuDC-independent mutagens, such as EMS and (oh) 4 Cy, induce selected base substitution alone; and (ii) umuDC-dependent mutagens, such as X-rays and gamma-rays, induce various types of base substitution simultaneously, although they have mutational specificity. In the umuDC-dependent processes of basechange mutagenesis, the spectra of base substitution were a mixture of base substitution reflecting the specific base damages induced by individual mutagens and nonspecific base substitution. In conclusion, base substitution plays the most important role in umuDC-dependent mutagenesis, although mutagenesis of umuDC proteins remains uncertain. (Namekawa, K.)

  11. Mutated genes as research tool

    1981-01-01

    Green plants are the ultimate source of all resources required for man's life, his food, his clothes, and almost all his energy requirements. Primitive prehistoric man could live from the abundance of nature surrounding him. Man today, dominating nature in terms of numbers and exploiting its limited resources, cannot exist without employing his intelligence to direct natural evolution. Plant sciences, therefore, are not a matter of curiosity but an essential requirement. From such considerations, the IAEA and FAO jointly organized a symposium to assess the value of mutation research for various kinds of plant science, which directly or indirectly might contribute to sustaining and improving crop production. The benefit through developing better cultivars that plant breeders can derive from using the additional genetic resources resulting from mutation induction has been assessed before at other FAO/IAEA meetings (Rome 1964, Pullman 1969, Ban 1974, Ibadan 1978) and is also monitored in the Mutation Breeding Newsletter, published by IAEA twice a year. Several hundred plant cultivars which carry economically important characters because their genes have been altered by ionizing radiation or other mutagens, are grown by farmers and horticulturists in many parts of the world. But the benefit derived from such mutant varieties is without any doubt surpassed by the contribution which mutation research has made towards the advancement of genetics. For this reason, a major part of the papers and discussions at the symposium dealt with the role induced-mutation research played in providing insight into gene action and gene interaction, the organization of genes in plant chromosomes in view of homology and homoeology, the evolutionary role of gene duplication and polyploidy, the relevance of gene blocks, the possibilities for chromosome engineering, the functioning of cytroplasmic inheritance and the genetic dynamics of populations. In discussing the evolutionary role of

  12. Radiation-induced mutation at minisatellite loci

    Dubrova, Y.E.; Nesterov, V.N.; Krouchinsky, N.G.

    1997-01-01

    We are studying the radiation-induced increase of mutation rate in minisatellite loci in mice and humans. Minisatellite mutations were scored by multilocus DNA fingerprint analysis in the progeny of γ-irradiated and non-irradiated mice. The frequency of mutation in offspring of irradiated males was 1.7 higher that in the control group. Germline mutation at human minisatellite loci was studied among children born in heavily polluted areas of the Mogilev district of Belarus after the Chernobyl accident and in a control population. The frequency of mutation assayed both by DNA fingerprinting and by eight single locus probes was found to be two times higher in the exposed families than in the control group. Furthermore, mutation rate was correlated with the parental radiation dose for chronic exposure 137 Cs, consistent with radiation-induction of germline mutation. The potential use of minisatellites in monitoring germline mutation in humans will be discussed

  13. Recurrent LDL-receptor mutation causes familial ...

    1995-05-05

    May 5, 1995 ... 3. eaudet . New. Recurrent LDL-receptor mutation causes familial hypercholesterolaemia in ... amplification refractory mutation system (ARMS)" and single- strand conformation .... Location. Afrikaner. Mixed race. ApaLl.

  14. Manual on mutation breeding. 2. ed.

    1977-01-01

    The manual is a compilation of work done on the use of induced mutations in plant breeding, and presents general methods and techniques in this field. The use of chemical mutagens and ionizing radiations (X-rays, gamma rays, α- and β-particles, protons, neutrons) are described as well as the effects of these mutagens. The different types of mutations achieved can be divided into genome mutations, chromosome mutations and extra nuclear mutations. Separate chapters deal with mutation techniques in breeding seed-propagated species and asexually propagated plants (examples of development of cultivars given). Plant characters which can be improved by mutation breeding include yield, ripening time, growth habit, disease resistance and tolerance to environmental factors (temperature, salinity etc.). The use of mutagens for some specific plant breeding problems is discussed and attention is also paid to somatic cell genetics in connection with induced mutations. The manual contains a comprehensive bibliography (60 p. references) and a subject index

  15. Adaptive mutation: has the unicorn landed?

    Foster, P L

    1998-01-01

    Reversion of an episomal Lac- allele during lactose selection has been studied as a model for adaptive mutation. Although recent results show that the mutations that arise during selection are not "adaptive" in the original sense, the mutagenic mechanism that produces these mutations may nonetheless be of evolutionary significance. In addition, a transient mutational state induced in a subpopulation of starving cells could provide a species with a mechanism for adaptive evolution. PMID:9560365

  16. Adaptive mutation: has the unicorn landed?

    Foster, P L

    1998-04-01

    Reversion of an episomal Lac- allele during lactose selection has been studied as a model for adaptive mutation. Although recent results show that the mutations that arise during selection are not "adaptive" in the original sense, the mutagenic mechanism that produces these mutations may nonetheless be of evolutionary significance. In addition, a transient mutational state induced in a subpopulation of starving cells could provide a species with a mechanism for adaptive evolution.

  17. Urinary Tract Effects of HPSE2 Mutations

    Stuart, H; Roberts, N; Hilton, E; McKenzie, E; Daly, S; Hadfield, K; Rahal, J; Gardiner, N; Tanley, S; Lewis, M; Sites, E; Angle, B; Alves, C; Lourenço, T; Rodrigues, M

    2015-01-01

    Urofacial syndrome (UFS) is an autosomal recessive congenital disease featuring grimacing and incomplete bladder emptying. Mutations of HPSE2, encoding heparanase 2, a heparanase 1 inhibitor, occur in UFS, but knowledge about the HPSE2 mutation spectrum is limited. Here, seven UFS kindreds with HPSE2 mutations are presented, including one with deleted asparagine 254, suggesting a role for this amino acid, which is conserved in vertebrate orthologs. HPSE2 mutations were absent in 23 non-neurog...

  18. Haploid rice plants in mutation studies

    Tanaka, S [Institute of Radiation Breeding, Ministry of Agriculture and Forestry, Ohmiya, Ibaraki-ken (Japan)

    1970-03-01

    Studies were made on chlorophyll-deficient sectors and diploid-like sectors in haploid rice plants exposed to chronic gamma irradiation, and on germinal mutations in diploid strains derived from the haploid plants. The induction and elimination of somatic mutations in haploid plants and the occurrence of drastic germinal mutations in diploid strains from haploid plants are discussed. (author)

  19. Studies of human mutation rates: Progress report

    Neel, J.V.

    1988-01-01

    Progress was recorded between January 1 and July 1, 1987 on a project entitled ''Studies of Human Mutation Rates''. Studies underway include methodology for studying mutation at the DNA level, algorithms for automated analyses of two-dimensional polyacrylamide DNA gels, theoretical and applied population genetics, and studies of mutation frequency in A-bomb survivors

  20. Mitochondrial mutations drive prostate cancer aggression

    Hopkins, Julia F.; Sabelnykova, Veronica Y.; Weischenfeldt, Joachim

    2017-01-01

    Nuclear mutations are well known to drive tumor incidence, aggression and response to therapy. By contrast, the frequency and roles of mutations in the maternally inherited mitochondrial genome are poorly understood. Here we sequence the mitochondrial genomes of 384 localized prostate cancer...... in prostate cancer, and suggest interplay between nuclear and mitochondrial mutational profiles in prostate cancer....

  1. Radiation induced chlorophyll mutations in rice

    Bari, G.; Mustafa, G.; Soomro, A.M.; Baloch, A.W.

    1985-01-01

    Air dried grains of four local varieties of rice were treated with gamma-rays and fast neutrons for determining their mutagenic effectiveness through the occurence of chlorophyll mutations. Fast neutrons were more effective in inducing chlorophyll mutations and the rice variety Basmati 370 produced maximum number of mutations followed by varieties Sonahri Sugdasi, Jajai 77 and Sada Gulab. The highest frequency of chlorophyll mutations was that of albina types followed by striata types. The xantha, viridis and tigrina types of mutations were less frequent. (authors)

  2. Mutation Clusters from Cancer Exome.

    Kakushadze, Zura; Yu, Willie

    2017-08-15

    We apply our statistically deterministic machine learning/clustering algorithm *K-means (recently developed in https://ssrn.com/abstract=2908286) to 10,656 published exome samples for 32 cancer types. A majority of cancer types exhibit a mutation clustering structure. Our results are in-sample stable. They are also out-of-sample stable when applied to 1389 published genome samples across 14 cancer types. In contrast, we find in- and out-of-sample instabilities in cancer signatures extracted from exome samples via nonnegative matrix factorization (NMF), a computationally-costly and non-deterministic method. Extracting stable mutation structures from exome data could have important implications for speed and cost, which are critical for early-stage cancer diagnostics, such as novel blood-test methods currently in development.

  3. Gene mutations in hepatocellular adenomas

    Raft, Marie B; Jørgensen, Ernö N; Vainer, Ben

    2015-01-01

    is associated with bi-allelic mutations in the TCF1 gene and morphologically has marked steatosis. β-catenin activating HCA has increased activity of the Wnt/β-catenin pathway and is associated with possible malignant transformation. Inflammatory HCA is characterized by an oncogene-induced inflammation due...... to alterations in the Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway. In the diagnostic setting, sub classification of HCA is based primarily on immunohistochemical analyzes, and has had an increasing impact on choice of treatment and individual prognostic assessment....... This review offers an overview of the reported gene mutations associated with hepatocellular adenomas together with a discussion of the diagnostic and prognostic value....

  4. Mutation breeding newsletter. No. 41

    1994-07-01

    This newsletter contains short descriptions of research methods for the use of radiation to induce mutations and facilitate plant breeding. This method is used to develop species of plants that can survive in harsh climates and thus provide a food supply for humans and animals. Some of the mutants discussed include a salt tolerant barley, a disease resistant shrub, a cold tolerant chickpea, a highly productive Canavalia virosa and productive tomato. Refs, figs and tabs

  5. The condensed mutation in sunflower

    Leclercq, P.

    1978-01-01

    Three inbred lines of sunflower were treated with gamma rays. In the progeny of one of these lines, the desired dwarf mutation appeared with a high frequency (23%). The dwarfing was accompanied by various undesirable characteristics (lateness, poor seed production, etc.), for which correction through genetic diversification and selection is in progress. The ratio capitulum diameter/stem height has increased from 1/8 up to 1/3 [fr

  6. Rare beneficial mutations can halt Muller's ratchet

    Balick, Daniel; Goyal, Sidhartha; Jerison, Elizabeth; Neher, Richard; Shraiman, Boris; Desai, Michael

    2012-02-01

    In viral, bacterial, and other asexual populations, the vast majority of non-neutral mutations are deleterious. This motivates the application of models without beneficial mutations. Here we show that the presence of surprisingly few compensatory mutations halts fitness decay in these models. Production of deleterious mutations is balanced by purifying selection, stabilizing the fitness distribution. However, stochastic vanishing of fitness classes can lead to slow fitness decay (i.e. Muller's ratchet). For weakly deleterious mutations, production overwhelms purification, rapidly decreasing population fitness. We show that when beneficial mutations are introduced, a stable steady state emerges in the form of a dynamic mutation-selection balance. We argue this state is generic for all mutation rates and population sizes, and is reached as an end state as genomes become saturated by either beneficial or deleterious mutations. Assuming all mutations have the same magnitude selective effect, we calculate the fraction of beneficial mutations necessary to maintain the dynamic balance. This may explain the unexpected maintenance of asexual genomes, as in mitochondria, in the presence of selection. This will affect in the statistics of genetic diversity in these populations.

  7. Rare and unexpected beta thalassemic mutations in Qazvin ...

    About 13 beta-globin mutations encompass 70 - 90% of mutation spectrum in Iran. These mutations are called common beta-globin mutations. The rest are rare or unknown mutations. The objective of this study was to identify and describe rare or unknown beta-globin mutations in Qazvin province. EDTAcontaining venous ...

  8. Rare and unexpected beta thalassemic mutations in Qazvin ...

    STORAGESEVER

    2010-01-04

    Jan 4, 2010 ... About 13 beta-globin mutations encompass 70 - 90% of mutation spectrum in Iran. These mutations are called common beta-globin mutations. The rest are rare or unknown mutations. The objective of this study was to identify and describe rare or unknown beta-globin mutations in Qazvin province. EDTA-.

  9. Mutation breeding in vegetable crops

    Yamaguchi, Takashi

    1984-01-01

    Vegetables breed by seeds and vegetative organs. In main vegetables, the differentiation of clopping types, the adoption of monoculture and year-round production and shipment are carried out, adapting to various socio-economic and cultivation conditions. Protected agriculture has advanced mainly for fruit vegetables, and the seeds for sale have become almost hybrid varieties. Reflecting the situation like this, the demand for breeding is diversified and characteristic, and the case of applying mutation breeding seems to be many. The present status of the mutation breeding of vegetables is not yet well under way, but about 40 raised varieties have been published in the world. The characters introduced by induced mutation and irradiation were compact form, harvesting aptitude, the forms and properties of stems and leaves, anti-lodging property, the size, form and uniformity of fruits, male sterility and so on. The radiation sources used were mostly gamma ray or X-ray, but sometimes, combined irradiation was used. As the results obtained in Japan, burdocks as an example of gamma ray irradiation to seeds, tomatoes as an example of inducing the compound resistance against disease injury and lettuces as an example of internal beta irradiation are reported. (Kako, I.)

  10. Mutation Breeding for Crop Improvement

    Rajbir, S. Sangwan

    2017-01-01

    Chromosomes contain genes responsible of different traits of any organism. Induced mutation using chemical mutagens and radiation to modify molecular structure of plants played a major role in the development of high genetic variability and help develop new superior crop varieties. The Mutation Breeding is applicable to all plants and has generated lot of agronomically interesting mutants, both in vegetatively and seed propagated plants. The technique is easy but long and challenging to detect, isolate and characterize the mutant and gene. A sp