Sample records for jak2 v617f mutation

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

    PubMed

    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 (P< 0.001). Higher percentage of patients had JAK2V617F allele burden over 20% in PV than in ET (68.5% VS 26.7%) (P< 0.001). In PV patients, higher JAK2V617F allele burden was observed in female (P< 0.05) and leukocytosis patients (WBC above 10 × 10(9)/L) (P< 0.001). Meanwhile, ET patients showed increased JAK2V617F allele burden in the group with higher hemoglobin (HGB above 150 g/L) (P< 0.05), leukocytosis (WBC above 10 × 10(9)/L) (P< 0.001), splenomegaly (P< 0.05) and thrombosis (P< 0.05). In conclusion, the JAK2V617F mutation allele burden is higher in Chinese patients with PV than ET. 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 (P< 0.05) for ET patients by Logistic Regression.

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

    PubMed

    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.

  3. JAK2 (V617F) mutation is not associated with thrombosis in Behcet syndrome.

    PubMed

    Ar, M Cem; Hatemi, Gülen; Ekizoğlu, Seda; Bilgen, Hülya; Saçli, Sevgi; Buyru, A Nur; Soysal, Teoman; Ülkü, Birsen; Yazici, Hasan

    2012-07-01

    The Janus kinase 2(V617F) (JAK2 (V617F)) mutation is an acquired genetic defect that is considered to enhance thrombosis in Philadelphia chromosome-negative myeloproliferative neoplasms (MPNs). Thrombosis is also a well-defined component of Behcet syndrome (BS). The aim of this study was to determine the frequency of JAK2 ( V617F ) mutation in BS-associated thrombosis. A total of 152 patients with BS (62 with thrombosis and 90 without thrombosis) were enrolled. An additional 186 patients with MPNs and 107 healthy blood donors were included to serve as diseased and healthy controls, respectively. None of the patients with BS and healthy controls carried the JAK2 (V617F) mutation, whereas 67% of patients with MPNs were positive for JAK2 ( V617F ). The frequency of thrombosis in patients with MPNs was not statistically different between carriers and non-carriers of JAK2 ( V617F ) mutation. Our data suggest that JAK2 (V617F) is not directly related to thrombosis in MPNs and in other thrombotic entities, such as BS.

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

    PubMed

    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.

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

    PubMed

    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 < 12% JAK2(V617F) allelic burden. Current WHO guidelines do not recommend further testing once JAK2(V617F) mutation is detected in MPNs. The findings, however, indicate that quantification of JAK2(V617F) allele burden may be clinically relevant in MPNs and in those with low allelic burden additional testing for JAK2 exon-12 and MPL exon-10 mutation should be pursued.

  6. Relationship between JAK2V617F mutation, allele burden and coagulation function in Ph-negative myeloproliferative neoplasms.

    PubMed

    Hu, Linhui; Pu, Lianfang; Ding, Yangyang; Li, Manman; Cabanero, Michael; Xie, Jingxin; Zhou, Dejun; Yang, Dongdong; Zhang, Cui; Wang, Huiping; Zhai, Zhimin; Ru, Xiang; Li, Jingrong; Xiong, Shudao

    2017-07-01

    Our aim was to explore the relationship between JAK2V617F mutation allele burden and hematological parameters especially in coagulation function in Chinese population. This study included 133 Ph-negative myeloproliferative neoplasms (MPNs) patients between 2013 and 2016. All the clinical and experimental data of patients were collected at the time of the diagnosis without any prior treatment, including blood parameters, coagulation function, splenomegaly, vascular events and chromosome karyotype. PCR and qPCR were used to detect JAK2V617F mutation and JAK2V617F mutation allele burden. In polycythemia vera patients, a positive correlation between the allele burden of JAK2V617F mutation and PLT counts was found; in essential thrombocythemia (ET) patients, WBC counts, RBC counts, HB, and HCT were higher in mutated patients than in wild-type patients. Furthermore, PT-INR was higher in ET and PMF mutated patients. In addition, a positive correlation between the allele burden of JAK2V617F mutation and activated partial thromboplastin time (APTT) was observed in JAK2V617F mutated ET patients. Higher hematologic parameters including counts of WBC, RBC, and PLT are closely associated with JAK2V617F mutation and its burden in Ph-negative MPNs; importantly, PT-INR, APTT are also related to JAK2V617F mutation and allele burden. Thus, our data indicate that JAK2V617F mutation allele burden might not only represent the burden of MPN but also alter the coagulation function.

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

    PubMed

    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.

  8. JAK2V617F somatic mutation in the general population: myeloproliferative neoplasm development and progression rate

    PubMed Central

    Nielsen, Camilla; Bojesen, Stig E.; Nordestgaard, Børge G.; Kofoed, Klaus F.; Birgens, Henrik S.

    2014-01-01

    Clinical significance of the JAK2V617F mutation in patients with a myeloproliferative neoplasm has been the target of intensive research in recent years. However, there is considerably uncertainty about prognosis in JAK2V617F positive individuals without overt signs of myeloproliferative disease. In this study, we tested the hypothesis that increased JAK2V617F somatic mutation burden is associated with myeloproliferative neoplasm progression rate in the general population. Among 49,488 individuals from the Copenhagen General Population Study, 63 (0.1%) tested positive for the JAK2V617F mutation in the time period 2003–2008. Of these, 48 were available for re-examination in 2012. Level of JAK2V617F mutation burden was associated with myeloproliferative neoplasm progression rate, consistent with a biological continuum of increasing JAK2V617F mutation burden across increasing severity 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 by 0.55% per year, erythrocyte volume fraction increased by 1.19% per year, and erythrocyte mean corpuscular volume increased by 1.25% per year, while there was no change in platelet count or erythropoietin levels. Furthermore, we established a JAK2V617F mutation burden cut-off point of 2% indicative of disease versus no disease; however, individuals with a mutation burden below 2% may suffer from a latent form of myeloproliferative disease revealed by a slightly larger spleen and/or slightly higher lactic acid dehydrogenase concentration compared to controls. Of all 63 JAK2V617F positive individuals, 48 were eventually diagnosed with a myeloproliferative neoplasm. PMID:24907356

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

    PubMed

    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.

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

    PubMed Central

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

    2014-01-01

    Background and Objective: 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. Methods: 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. Results: 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. Conclusion: It is concluded that the co-existence of Ph +CML and JAK2 V617F mutation is possible. PMID:24639858

  11. JAK2V617F influences epigenomic changes in myeloproliferative neoplasms.

    PubMed

    Chen, Chih-Cheng; Chiu, Chia-Chen; Lee, Kuan-Der; Hsu, Chia-Chen; Chen, Hong-Chi; Huang, Tim H-M; Hsiao, Shu-Huei; Leu, Yu-Wei

    2017-12-16

    Negative valine (V) to phenylalanine (F) switch at the Janus kinase (JAK2) 617 codon (V617F) is the dominant driver mutation in patients with myeloproliferative neoplasms (MPNs). JAK2V617F was proved to be sufficient for cell transformation; however, independent mutations might influence the following epigenomic modifications. To assess the JAK2V617F-induced downstream epigenomic changes without interferences, we profiled the epigenomic changes in ectopically expressed JAK2V617F in Ba/F3 cells. Antibodies against phosphorylated signal transducer and activator of transcription 3 (pSTAT3) and enhancer of zeste homolog 2 (EZH2) were used for chromatin-immunoprecipitation sequencing (ChIP-seq) to detect the downstream epigenomic targets in the JAK2-STAT3 signaling pathway. To confirm the JAK2V617F-induced epigenetic changes in vivo, DNA methylation changes in the target loci in patients with MPNs were detected through methylation-specific polymerase chain reaction and were clustered against the changes within controls. We found that ectopically expressed JAK2V617F in Ba/F3 cells reduced the binding specificity; it was associated with cis-regulatory elements and recognized DNA motifs in both pSTAT3-downstream and EZH2-associated targets. Overlapping target loci between the control and JAK2V617F were <3% and 0.4%, respectively, as identified through pSTAT3 and EZH2 ChIP-seq. Furthermore, the methylation changes in the direct target loci (FOXH1, HOXC9, and SRF) were clustered independently from the control locus (L1TD1) and other mutation genes (HMGA2 and Lin28A) in the analyzed MPN samples. Therefore, JAK2V617F influences target binding in both pSTAT3 and EZH2. Without mutations in epigenetic regulators, JAK2V617F can induce downstream epigenomic modifications. Thus, epigenetic changes in JAK2 downstream targets might be trackable in vivo. Copyright © 2017 Elsevier Inc. All rights reserved.

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

    PubMed

    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.

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

    PubMed

    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

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

    PubMed Central

    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 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 mutations in 100 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 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. PMID:27892678

  15. Detection of JAK2 V617F mutation increases the diagnosis of myeloproliferative neoplasms

    PubMed Central

    ZHANG, SHU-PENG; LI, HUI; LAI, REN-SHENG

    2015-01-01

    The Janus kinase (JAK)2 gene, which is located on chromosome 9p24, is involved in the signaling transduction pathways of the hematopoietic and immune system. Mutations in the JAK2 gene have served as disease markers for myeloproliferative neoplasms (MPNs). The aim of the present study was to investigate the occurrence of the JAK2 gene mutation in 140 clinical samples, and to evaluate its clinical significance in MPNs and other hematological diseases. Genomic DNA was extracted from the peripheral blood leukocytes or bone marrow karyocytes of 140 clinical samples, which included 130 patients with various types of hematological disease and 10 control patients. In addition, exons 12 and 14 of the JAK2 gene were analyzed by direct sequencing and the mutation rates of various MPN subtypes were evaluated. Of the 140 samples, exons 12 and 14 were tested in 74 samples, however, exon 14 only was tested in 66 samples. No mutations were identified in exon 12. The V617F mutation rate in polycythemia vera was 82.1% (23/28), and the mutation rates in essential thrombocythemia histiocytosis, primary myelofibrosis and other MPNs were 53.1% (17/32), 40.0% (4/10) and 60.0% (6/10), respectively. Therefore, the total mutation rate of the JAK2 gene in MPN was 62.5% (50/80). For non-MPN hematological diseases, four V617F mutations were detected in samples of leukocytosis of unknown origin (4/12), however, no JAK2 V617F mutations were identified in the 10 controls. Therefore, JAK2 V617F mutations may present a novel marker for diagnosis of MPNs. Furthermore, the direct sequencing method appeared to be satisfactory for the clinical gene testing of hematological samples. PMID:25624900

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

    PubMed

    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 <4% and a significantly higher platelet count compared with JAK2 V617F (P < 0.001) and CALR (P = 0.001) single-mutation patients. The findings from this study support the possibility of coexisting mutations of the JAK2, CALR, and 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.

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

    PubMed

    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.

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

    PubMed

    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.

  19. Inferior vena cava thrombosis and its relationship with the JAK2V617F mutation and chronic myeloproliferative disease.

    PubMed

    Linnemann, Birgit; Kraft, Christiane; Roskos, Martin; Zgouras, Dimitrios; Lindhoff-Last, Edelgard

    2012-06-01

    Splanchnic vein thrombosis (SVT) is a typical manifestation of polycythaemia vera (PV) or essential thrombocythaemia (ET). The recently discovered JAK2V617F somatic mutation is closely associated with chronic myeloproliferative disease (CMD). We investigated whether thrombosis involving the inferior vena cava (IVC) is also related to the JAK2V617F mutation or CMD. Blood samples were obtained from 40 IVC thrombosis patients. Fifty-three patients with isolated lower extremity deep vein thrombosis (LE-DVT) and 20 SVT patients served as controls. The presence of the JAK2V617F mutation was assessed by real-time polymerase chain reaction (RT-PCR). The JAK2V617F allele was not detected in any of the IVC thrombosis patients but was detected in one patient (2%) with isolated LE-DVT. However, the mutation-carrying patient did not exhibit symptoms of CMD. Even after an observation period of 30months, the patient's complete blood cell count did not exhibit any pathology. In contrast, the JAK2V617F allele was detected in four patients with SVT (20%) and CMD. According to our data, there is no evidence that IVC thrombosis is associated with the JAK2V617F mutation or the presence of chronic myeloproliferative disease. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Structural effects of clinically observed mutations in JAK2 exons 13-15: comparison with V617F and exon 12 mutations

    PubMed Central

    Lee, Tai-Sung; Ma, Wanlong; Zhang, Xi; Kantarjian, Hagop; Albitar, Maher

    2009-01-01

    Background The functional relevance of many of the recently detected JAK2 mutations, except V617F and exon 12 mutants, in patients with chronic myeloproliferative neoplasia (MPN) has been significantly overlooked. To explore atomic-level explanations of the possible mutational effects from those overlooked mutants, we performed a set of molecular dynamics simulations on clinically observed mutants, including newly discovered mutations (K539L, R564L, L579F, H587N, S591L, H606Q, V617I, V617F, C618R, L624P, whole exon 14-deletion) and control mutants (V617C, V617Y, K603Q/N667K). Results Simulation results are consistent with all currently available clinical/experimental evidence. The simulation-derived putative interface, not possibly obtained from static models, between the kinase (JH1) and pseudokinase (JH2) domains of JAK2 provides a platform able to explain the mutational effect for all mutants, including presumably benign control mutants, at the atomic level. Conclusion The results and analysis provide structural bases for mutational mechanisms of JAK2, may advance the understanding of JAK2 auto-regulation, and have the potential to lead to therapeutic approaches. Together with recent mutation profiling results demonstrating the breadth of clinically observed JAK2 mutations, our findings suggest that molecular testing/diagnostics of JAK2 should extend beyond V617F and exon 12 mutations, and perhaps should encompass most of the pseudo-kinase domain-coding region. PMID:19744331

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

    PubMed

    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.

  2. JAK2-V617F-induced MAPK activity is regulated by PI3K and acts synergistically with PI3K on the proliferation of JAK2-V617F-positive cells

    PubMed Central

    Wolf, Alexandra; Eulenfeld, René; Gäbler, Karoline; Rolvering, Catherine; Haan, Serge; Behrmann, Iris; Denecke, Bernd; Haan, Claude; Schaper, Fred

    2013-01-01

    The identification of a constitutively active JAK2 mutant, namely JAK2-V617F, was a milestone in the understanding of Philadelphia chromosome-negative myeloproliferative neoplasms. The JAK2-V617F mutation confers cytokine hypersensitivity, constitutive activation of the JAK-STAT pathway, and cytokine-independent growth. In this study we investigated the mechanism of JAK2-V617F-dependent signaling with a special focus on the activation of the MAPK pathway. We observed JAK2-V617F-dependent deregulated activation of the multi-site docking protein Gab1 as indicated by constitutive, PI3K-dependent membrane localization and tyrosine phosphorylation of Gab1. Furthermore, we demonstrate that PI3K signaling regulates MAPK activation in JAK2-V617F-positve cells. This cross-regulation of the MAPK pathway by PI3K affects JAK2-V617F-specific target gene induction, erythroid colony formation, and regulates proliferation of JAK2-V617F-positive patient cells in a synergistically manner. PMID:24069558

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

    PubMed

    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. Increased risk of recurrent thrombosis in patients with essential thrombocythemia carrying the homozygous JAK2 V617F mutation.

    PubMed

    De Stefano, Valerio; Za, Tommaso; Rossi, Elena; Vannucchi, Alessandro M; Ruggeri, Marco; Elli, Elena; Micò, Caterina; Tieghi, Alessia; Cacciola, Rossella R; Santoro, Cristina; Vianelli, Nicola; Guglielmelli, Paola; Pieri, Lisa; Scognamiglio, Francesca; Cacciola, Emma; Rodeghiero, Francesco; Pogliani, Enrico M; Finazzi, Guido; Gugliotta, Luigi; Leone, Giuseppe; Barbui, Tiziano

    2010-02-01

    Evidence suggests that the JAK2 V617F mutation is associated with an increased risk of first thrombosis in patients with essential thrombocythemia (ET). Whether this mutation is also a risk factor for recurrent thrombosis is currently unknown. To investigate the impact of the JAK2 V617F mutation on the risk of recurrent thrombosis in patients with ET, we carried out a multicentre retrospective cohort study. We recruited 143 patients with previous arterial (64.4%) or venous major thrombosis (34.8%) or both (0.8%); 98 of them (68.5%) carried the mutation. Thrombosis recurred in 43 of the patients (30%); overall, after adjustment for sex, age, presence of vascular risk factors, and treatment after the first thrombosis, the presence of the JAK2 mutation did not predict recurrence (multivariable hazard ratio, HR, 0.88, 95% CI 0.46-1.68). Indeed, the individuals homozygous for the JAK2 V617F (allele burden >50%) mutation had an increased risk of recurrence in comparison with wild-type patients (HR 6.15, 95% CI 1.51-24.92). In conclusion, a homozygous JAK2 V617F mutation is an independent risk factor for recurrent thrombosis in patients with ET.

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

    PubMed

    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.

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

    PubMed Central

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

    2017-01-01

    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 (≥300×109/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. PMID:28450924

  7. Estimation of diagnosis and prognosis in ET by assessment of CALR and JAK2V617F mutations and laboratory findings: a meta-analysis.

    PubMed

    Saki, N; Shirzad, R; Rahim, F; Saki Malehi, A

    2017-07-01

    Essential thrombocythemia (ET) is a benign disease with slow progress in which thrombosis is a cause of mortality. JAK2 V617F and calreticulin (CALR) are the most frequent mutations in this disease. In this systematic review and meta-analysis, we compared the prevalence of JAK2 V617F and CALR mutations in ET and examined the incidence of thrombosis and other hematologic indices. After choosing MeSH keywords, including essential thrombocythemia, JAK2 V617F , calreticulin, prognosis, and diagnosis, as well as searching Medline/PubMed and Scopus, 12 papers were selected. Data were pooled, and summary prevalence and OR were estimated using either a random-effects model or a fixed-effects model. The frequency of JAK2 V617F and CALR shows heterogeneity in Caucasian population [JAK2 V617 I 2 % = 84.3, P < 0.001, 95% CI 0.56 (0.51-0.61)], [CALR I 2 % = 96.1, P < 0.001, 95% CI 0.23 (0.15-0.31)]. The prevalence of JAK2 V617F and CALR was 0.57 (95% CI 0.53-0.61), I 2 % = 79.3 and 0.22 (95% CI 0.16-0.27), I 2 % = 94, respectively. JAK2 V617F positive ET was associated with increasing odds of thrombosis [OR 2.35 (95% CI 1.83-3.02), P < 0.001]. The incidence of splenomegaly was not statistically different between these two mutations. Hemoglobin, platelet, and WBC count did not affect the risk of thrombosis. Detection of CALR mutation is helpful for molecular diagnosis of ET patients as well as JAK2 V617F . Due to reduction of thrombosis in CALR-positive patients, it can be stated that such patients have less thrombotic disorders and better prognosis relative to patients bearing JAK2 V617F mutation. Therefore, detection of mutation in CALR and JAK2 V617F may contribute to diagnosis and prognosis of ET patients.

  8. [High resolution melting analysis for detecting of JAK2V617F mutation in patients with myeloproliferative neoplasms].

    PubMed

    Chen, Hai-Hua; Yang, Ji-Long; Lu, Hui-Fang; Zhou, Wei-Jun; Yao, Fei; Deng, Lan

    2014-02-01

    This study was purposed to investigate the feasibility of high resolution melting (HRM) in the detection of JAK2V617F mutation in patients with myeloproliferative neoplasm (MPN). The 29 marrow samples randomly selected from patients with clinically diagnosed MPN from January 2008 to January 2011 were detected by HRM method. The results of HRM analysis were compared with that detected by allele specific polymerase chain reaction (AS-PCR) and DNA direct sequencing. The results showed that the JAK2V617F mutations were detected in 11 (37.9%, 11/29) cases by HRM, and its comparability with the direct sequencing result was 100%. While the consistency of AS-PCR with the direct sequencing was moderate (Kappa = 0.179, P = 0.316). It is concluded that the HRM analysis may be an optimal method for clinical screening of JAK2V617F mutation due to its simplicity and promptness with a high specificity.

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

    PubMed

    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.

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

    PubMed

    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.

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

    PubMed

    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.

  12. Influence of the JAK2 V617F mutation and inherited thrombophilia on the thrombotic risk among patients with essential thrombocythemia

    PubMed Central

    De Stefano, Valerio; Za, Tommaso; Rossi, Elena; Fiorini, Alessia; Ciminello, Angela; Luzzi, Claudia; Chiusolo, Patrizia; Sica, Simona; Leone, Giuseppe

    2009-01-01

    It is uncertain whether the JAK2 V617F mutation increases the thrombotic risk in patients with essential thrombocythemia, and it is unknown whether inherited thrombophilia is an additive risk factor in mutated subjects. We studied 132 patients with essential thrombocythemia, 38 of them (29%) with a history of thrombosis. The JAK2 mutation was present in 83 (63%), and inherited thrombophilia in 7. The mutated patients <60 years had a relative risk (RR) for thrombosis at any time of 3.83 (95%CI 1.27–11.49) in comparison with wild-type patients; in those with both the mutation and thrombophilia the RR was 2.23 (95%CI 1.57–3.18) and 7.66 (95%CI 2.66–22.03) in comparison with mutated or wild-type patients without thrombophilia, respectively. During the follow-up, only the homozygotes for JAK2 V617F were more prone to thrombosis (RR 17.25, 95%CI 2.33–127.4). Among the patients >60 years, no increase in RR was associated with the JAK2 mutation. In conclusion, in the younger patients with ET the thrombotic risk is higher in the JAK2 V617F-mutated and is further increased by the presence of inherited thrombophilia. PMID:19336736

  13. Assessment of the interlaboratory variability and robustness of JAK2V617F mutation assays: A study involving a consortium of 19 Italian laboratories

    PubMed Central

    Perricone, Margherita; Palandri, Francesca; Ottaviani, Emanuela; Angelini, Mario; Bagli, Laura; Bellesia, Enrica; Donati, Meris; Gemmati, Donato; Zucchini, Patrizia; Mancini, Stefania; Marchica, Valentina; Trubini, Serena; Matteis, Giovanna De; Zacomo, Silvia Di; Favarato, Mosè; Fioroni, Annamaria; Bolzonella, Caterina; Maccari, Giorgia; Navaglia, Filippo; Gatti, Daniela; Toffolatti, Luisa; Orlandi, Linda; Laloux, Vèronique; Manfrini, Marco; Galieni, Piero; Giannini, Barbara; Tieghi, Alessia; Barulli, Sara; Serino, Maria Luisa; Maccaferri, Monica; Scortechini, Anna Rita; Giuliani, Nicola; Vallisa, Daniele; Bonifacio, Massimiliano; Accorsi, Patrizia; Salbe, Cristina; Fazio, Vinicio; Gusella, Milena; Toffoletti, Eleonora; Salvucci, Marzia; Svaldi, Mirija; Gherlinzoni, Filippo; Cassavia, Francesca; Orsini, Francesco; Martinelli, Giovanni

    2017-01-01

    To date, a plenty of techniques for the detection of JAK2V617F is used over different laboratories, with substantial differences in specificity and sensitivity. Therefore, to provide reliable and comparable results, the standardization of molecular techniques is mandatory. A network of 19 centers was established to 1) evaluate the inter- and intra-laboratory variability in JAK2V617F quantification, 2) identify the most robust assay for the standardization of the molecular test and 3) allow consistent interpretation of individual patient analysis results. The study was conceived in 3 different rounds, in which all centers had to blindly test DNA samples with different JAK2V617F allele burden (AB) using both quantitative and qualitative assays. The positivity of samples with an AB < 1% was not detected by qualitative assays. Conversely, laboratories performing the quantitative approach were able to determine the expected JAK2V617F AB. Quantitative results were reliable across all mutation loads with moderate variability at low AB (0.1 and 1%; CV = 0.46 and 0.77, respectively). Remarkably, all laboratories clearly distinguished between the 0.1 and 1% mutated samples. In conclusion, a qualitative approach is not sensitive enough to detect the JAK2V617F mutation, especially at low AB. On the contrary, the ipsogen JAK2 MutaQuant CE-IVD kit resulted in a high, efficient and sensitive quantification detection of all mutation loads. This study sets the basis for the standardization of molecular techniques for JAK2V617F determination, which will require the employment of approved operating procedures and the use of certificated standards, such as the recent WHO 1st International Reference Panel for Genomic JAK2V617F. PMID:28427233

  14. Assessment of the interlaboratory variability and robustness of JAK2V617F mutation assays: A study involving a consortium of 19 Italian laboratories.

    PubMed

    Perricone, Margherita; Palandri, Francesca; Ottaviani, Emanuela; Angelini, Mario; Bagli, Laura; Bellesia, Enrica; Donati, Meris; Gemmati, Donato; Zucchini, Patrizia; Mancini, Stefania; Marchica, Valentina; Trubini, Serena; De Matteis, Giovanna; Di Zacomo, Silvia; Favarato, Mosè; Fioroni, Annamaria; Bolzonella, Caterina; Maccari, Giorgia; Navaglia, Filippo; Gatti, Daniela; Toffolatti, Luisa; Orlandi, Linda; Laloux, Vèronique; Manfrini, Marco; Galieni, Piero; Giannini, Barbara; Tieghi, Alessia; Barulli, Sara; Serino, Maria Luisa; Maccaferri, Monica; Scortechini, Anna Rita; Giuliani, Nicola; Vallisa, Daniele; Bonifacio, Massimiliano; Accorsi, Patrizia; Salbe, Cristina; Fazio, Vinicio; Gusella, Milena; Toffoletti, Eleonora; Salvucci, Marzia; Svaldi, Mirija; Gherlinzoni, Filippo; Cassavia, Francesca; Orsini, Francesco; Martinelli, Giovanni

    2017-05-16

    To date, a plenty of techniques for the detection of JAK2V617F is used over different laboratories, with substantial differences in specificity and sensitivity. Therefore, to provide reliable and comparable results, the standardization of molecular techniques is mandatory.A network of 19 centers was established to 1) evaluate the inter- and intra-laboratory variability in JAK2V617F quantification, 2) identify the most robust assay for the standardization of the molecular test and 3) allow consistent interpretation of individual patient analysis results. The study was conceived in 3 different rounds, in which all centers had to blindly test DNA samples with different JAK2V617F allele burden (AB) using both quantitative and qualitative assays.The positivity of samples with an AB < 1% was not detected by qualitative assays. Conversely, laboratories performing the quantitative approach were able to determine the expected JAK2V617F AB. Quantitative results were reliable across all mutation loads with moderate variability at low AB (0.1 and 1%; CV = 0.46 and 0.77, respectively). Remarkably, all laboratories clearly distinguished between the 0.1 and 1% mutated samples.In conclusion, a qualitative approach is not sensitive enough to detect the JAK2V617F mutation, especially at low AB. On the contrary, the ipsogen JAK2 MutaQuant CE-IVD kit resulted in a high, efficient and sensitive quantification detection of all mutation loads. This study sets the basis for the standardization of molecular techniques for JAK2V617F determination, which will require the employment of approved operating procedures and the use of certificated standards, such as the recent WHO 1st International Reference Panel for Genomic JAK2V617F.

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

    PubMed Central

    Sangkhae, Veena; Etheridge, S. Leah; Kaushansky, Kenneth

    2014-01-01

    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. PMID:25339357

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

    PubMed

    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.

  17. IRS2 silencing increases apoptosis and potentiates the effects of ruxolitinib in JAK2V617F-positive myeloproliferative neoplasms

    PubMed Central

    de Melo Campos, Paula; Machado-Neto, João A.; Eide, Christopher A.; Savage, Samantha L.; Scopim-Ribeiro, Renata; da Silva Souza Duarte, Adriana; Favaro, Patricia; Lorand-Metze, Irene; Costa, Fernando F.; Tognon, Cristina E.; Druker, Brian J.; Saad, Sara T. Olalla; Traina, Fabiola

    2016-01-01

    The recurrent V617F mutation in JAK2 (JAK2V617F) has emerged as the primary contributor to the pathogenesis of myeloproliferative neoplasms (MPN). However, the lack of complete response in most patients treated with the JAK1/2 inhibitor, ruxolitinib, indicates the need for identifying pathways that cooperate with JAK2. Activated JAK2 was found to be associated with the insulin receptor substrate 2 (IRS2) in non-hematological cells. We identified JAK2/IRS2 binding in JAK2V617F HEL cells, but not in the JAK2WT U937 cell line. In HEL cells, IRS2 silencing decreased STAT5 phosphorylation, reduced cell viability and increased apoptosis; these effects were enhanced when IRS2 silencing was combined with ruxolitinib. In U937 cells, IRS2 silencing neither reduced cell viability nor induced apoptosis. IRS1/2 pharmacological inhibition in primary MPN samples reduced cell viability in JAK2V617F-positive but not JAK2WT specimens; combination with ruxolitinib had additive effects. IRS2 expression was significantly higher in CD34+ cells from essential thrombocythemia patients compared to healthy donors, and in JAK2V617F MPN patients when compared to JAK2WT. Our data indicate that IRS2 is a binding partner of JAK2V617F in MPN. IRS2 contributes to increased cell viability and reduced apoptosis in JAK2-mutated cells. Combined pharmacological inhibition of IRS2 and JAK2 may have a potential clinical application in MPN. PMID:26755644

  18. The development of gastric cancer in a patient with polycythemia Vera, 3P deletion, and JAK2 V617F mutation.

    PubMed

    Ayvaz, Ozlem; Yavasoglu, Irfan; Kadikoylu, Gurhan; Meydan, Nezih; Barutca, Sabri; Bolaman, Zahit

    2010-12-01

    3p deletion which is frequently associated with solitary tumors and hematological malignancies is a chromosomal abnormality. Recently, Janus kinase-2 (JAK2) V617F mutation has an important role in the diagnosis of myeloproliferative disorders, especially in polycythemia vera (PV). We reported the development of gastric cancer in a 75-year-old patient with PV, 3p 12-14 deletion and JAK2 V617F mutation. PV was diagnosed according to the classification of World Health Organization. JAK2 V617F mutation with polymerase chain reaction and 3p12-14 deletion with cytogenetic examination of the bone marrow were detected. We investigated solitary tumors in the patient using computed tomographies of thorax, neck, ear, nose, and throat. However, they were normal. After 2 years, gastric cancer appeared in the patient. In conclusion, cytogenetic examination may be important in both the development and the diagnosis of hematological malignancies and solitary tumors. So the patients should be followed closely.

  19. Clinical Implications of Quantitative JAK2 V617F Analysis using Droplet Digital PCR in Myeloproliferative Neoplasms

    PubMed Central

    Lee, Eunyoung; Lee, Kyoung Joo; Park, Hyein; Chung, Jin Young; Lee, Mi-Na; Chang, Myung Hee; Yoo, Jongha; Lee, Hyewon

    2018-01-01

    Background JAK2 V617F is the most common mutation in myeloproliferative neoplasms (MPNs) and is a major diagnostic criterion. Mutation quantification is useful for classifying patients with MPN into subgroups and for prognostic prediction. Droplet digital PCR (ddPCR) can provide accurate and reproducible quantitative analysis of DNA. This study was designed to verify the correlation of ddPCR with pyrosequencing results in the diagnosis of MPN and to investigate clinical implications of the mutational burden. Methods Peripheral blood or bone marrow samples were obtained from 56 patients newly diagnosed with MPN or previously diagnosed with MPN but not yet indicated for JAK2 inhibitor treatment between 2012 and 2016. The JAK2 V617F mutation was detected by pyrosequencing as a diagnostic work-up. The same samples were used for ddPCR to determine the correlation between assays and establish a detection sensitivity cut-off. Clinical and hematologic aspects were reviewed. Results Forty-two (75%) and 46 (82.1%) patients were positive for JAK2 V617F by pyrosequencing and ddPCR, respectively. The mean mutated allele frequency at diagnosis was 37.5±30.1% and was 40.7±31.2% with ddPCR, representing a strong correlation (r=0.9712, P<0.001). Follow-up samples were available for 12 patients, including eight that were JAK2 V617F-positive. Of these, mutational burden reduction after treatment was observed in six patients (75%), consistent with trends of hematologic improvement. Conclusions Quantitative analysis of the JAK2 V617F mutation using ddPCR was highly correlated with pyrosequencing data and may reflect the clinical response to treatment. PMID:29214759

  20. Oncogenic JAK2V617F requires an intact SH2-like domain for constitutive activation and induction of a myeloproliferative disease in mice.

    PubMed

    Gorantla, Sivahari P; Dechow, Tobias N; Grundler, Rebekka; Illert, Anna Lena; Zum Büschenfelde, Christian Meyer; Kremer, Marcus; Peschel, Christian; Duyster, Justus

    2010-11-25

    The oncogenic JAK2V617F mutation is found in myeloproliferative neoplasms (MPNs) and is believed to be critical for leukemogenesis. Here we show that JAK2V617F requires an intact SH2 domain for constitutive activation of downstream signaling pathways. In addition, there is a strict requirement of cytokine receptor expression for the activation of this oncogene. Further analysis showed that the SH2 domain mutation did not interfere with JAK2 membrane distribution. However, coimmunoprecipitated experiments revealed a role for the SH2 domain in the aggregation and cross-phosphorylation of JAK2V617F at the cell membrane. Forced overexpression of cytokine receptors could rescue the JAK2V617F SH2 mutant supporting a critical role of JAK2V617F abundance for constitutive activation. However, under physiologic cytokine receptor expression the SH2 domain is absolutely necessary for oncogenic JAK2V617F activation. This is demonstrated in a bone marrow transplantation model, in which an intact SH2 domain in JAK2V617F is required for the induction of an MPN-like disease. Thus, our results points to an indispensable role of the SH2 domain in JAK2V617F-induced MPNs.

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

    PubMed

    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.

  2. The role of serum erythropoietin level and JAK2 V617F allele burden in the diagnosis of polycythaemia vera.

    PubMed

    Ancochea, Agueda; Alvarez-Larrán, Alberto; Morales-Indiano, Cristian; García-Pallarols, Francesc; Martínez-Avilés, Luz; Angona, Anna; Senín, Alicia; Bellosillo, Beatriz; Besses, Carles

    2014-11-01

    Low serum erythropoietin (EPO) is a minor criterion of Polycythaemia Vera (PV) but its diagnostic usefulness relies on studies performed before the discovery of JAK2 V617F mutation. The objective of the present study was to evaluate the diagnostic accuracy of serum EPO and JAK2 V617F allele burden as markers of PV as well as the combination of different diagnostic criteria in 287 patients (99 with PV, 137 with Essential Thrombocythaemia and 51 with non-clonal erythrocytosis). Low EPO showed good diagnostic accuracy as a marker for PV, with the area under the curve (AUC) of the chemiluminescent-enhanced enzyme immunoassay (CEIA) being better than that of radioimmunoassay (RIA) (0·87 and 0·76 for CEIA and RIA, respectively). JAK2 V617F quantification displayed an excellent diagnostic accuracy, with an AUC of 0·95. A haematocrit >52% (males) or >48% (females) plus the presence of the JAK2 V617F mutation had a sensitivity and specificity of 79% and 97%, respectively. Adding low EPO or the JAK2 V617F allele burden did not improve the diagnostic accuracy for PV whereas the inclusion of both improved the sensitivity up to 83% and maintaining 96% specificity. Haematocrit and qualitative JAK2 V617F mutation allow a reliable diagnosis of PV. Incorporation of EPO and/or JAK2 V617F mutant load does not improve the diagnostic accuracy. © 2014 John Wiley & Sons Ltd.

  3. Acute Myeloid Leukemia with MYC Rearrangement and JAK2 V617F Mutation

    PubMed Central

    Ohanian, Maro; Bueso-Ramos, Carlos; Ok, Chi Young; Lin, Pei; Patel, Keyur; Alattar, Mona Lisa; Khoury, Joseph D.; Rozovski, Uri; Estrov, Zeev; Huh, Yang O.; Cortes, Jorge; Abruzzo, Lynne V.

    2016-01-01

    Little is known about MYC dysregulation in myeloid malignancies, and we can find no published studies that have evaluated MYC protein expression in primary cases of myelodysplastic syndromes (MDS) or acute myeloid leukemias (AML). We describe the clinical, morphologic, immunophenotypic, cytogenetic, and molecular genetic findings in two MDS/AML cases that contained both MYC rearrangement and JAK2-V617F mutation. We demonstrate MYC protein expression by immunohistochemistry in both patients. PMID:26382622

  4. Loss of Ezh2 synergizes with JAK2-V617F in initiating myeloproliferative neoplasms and promoting myelofibrosis

    PubMed Central

    Nienhold, Ronny; Zmajkovic, Jakub; Hao-Shen, Hui; Geier, Florian; Dirnhofer, Stephan; Feenstra, Jelena D. Milosevic

    2016-01-01

    Myeloproliferative neoplasm (MPN) patients frequently show co-occurrence of JAK2-V617F and mutations in epigenetic regulator genes, including EZH2. In this study, we show that JAK2-V617F and loss of Ezh2 in hematopoietic cells contribute synergistically to the development of MPN. The MPN phenotype induced by JAK2-V617F was accentuated in JAK2-V617F;Ezh2−/− mice, resulting in very high platelet and neutrophil counts, more advanced myelofibrosis, and reduced survival. These mice also displayed expansion of the stem cell and progenitor cell compartments and a shift of differentiation toward megakaryopoiesis at the expense of erythropoiesis. Single cell limiting dilution transplantation with bone marrow from JAK2-V617F;Ezh2+/− mice showed increased reconstitution and MPN disease initiation potential compared with JAK2-V617F alone. RNA sequencing in Ezh2-deficient hematopoietic stem cells (HSCs) and megakaryocytic erythroid progenitors identified highly up-regulated genes, including Lin28b and Hmga2, and chromatin immunoprecipitation (ChIP)–quantitative PCR (qPCR) analysis of their promoters revealed decreased H3K27me3 deposition. Forced expression of Hmga2 resulted in increased chimerism and platelet counts in recipients of retrovirally transduced HSCs. JAK2-V617F–expressing mice treated with an Ezh2 inhibitor showed higher platelet counts than vehicle controls. Our data support the proposed tumor suppressor function of EZH2 in patients with MPN and call for caution when considering using Ezh2 inhibitors in MPN. PMID:27401344

  5. Low frequency of V617F mutation in JAK2 gene in Indian patients with hepatic venous outflow obstruction and extrahepatic portal venous obstruction.

    PubMed

    Rai, Praveer; Kumar, Pankaj; Mishra, Swapnil; Aggarwal, Rakesh

    2016-09-01

    Hepatic venous outflow tract obstruction (HVOTO) and extrahepatic portal venous obstruction (EHPVO) are important causes of portal hypertension and related complications in India. Both these conditions result from splanchnic venous thrombosis. In recent years, a V617F somatic mutation in Janus kinase 2 (JAK2) gene which is highly specific for myeloproliferative disorders has been detected in 40 % to 50 % and 30 % to 35 % of Western patients with HVOTO and EHPVO, respectively. However, data on this mutation in these conditions from Asian countries are limited. We looked for JAK2 V617F mutation in Indian patients with HVOTO (n = 40, median age 31 [range 17-51] years, 21 female) and EHPVO (n = 50, median age 23 [15-70] years, 25 female) by using two separate methods. Both the methods involved polymerase chain reaction using allele-specific primers. Positive results on one or both of these techniques were confirmed using DNA sequencing. None of the 40 patients with HVOTO and only 1 of 50 patients with EHPVO was found to have JAK2 V617F mutation. In the one patient who was found to have this mutation, both the PCR methods and DNA sequencing showed positive results. Hypercoagulability associated with JAK2 V617F mutation and associated chronic myeloproliferative disorders was not a major cause of HVOTO and EHPVO in this population.

  6. Telomere length is severely and similarly reduced in JAK2V617F-positive and -negative myeloproliferative neoplasms

    PubMed Central

    Bernard, L; Belisle, C; Mollica, L; Provost, S; Roy, D-C; Gilliland, DG; Levine, RL; Busque, L

    2015-01-01

    Myeloproliferative neoplasms (MPNs) are clonal stem cell disorders characterized by chronic proliferation of hematopoietic progenitors. We studied the telomere length (TL) of 335 MPN patients and 93 gender- and age-matched controls using a quantitative PCR method (relative TL calculated as the ratio of the amount of telomere DNA vs single-copy DNA: T/S ratio). TL was markedly reduced in MPN patients compared with controls (T/S 0.561 vs 0.990, P<0.001). In JAK2V617F MPN patients, TL correlated inversely with allelic burden (P<0.001). Patients homozygous for the mutation (allelic burden 90–100%) had the shortest TL, even when compared with patients with lower allele burdens consistent with a dominant heterozygous population (allelic burden 55–65%) (T/S 0.367 vs 0.497, P = 0.037). This suggests that the high degree of proliferation of the MPN clone reduces TL and suggests the possibility that TL shortening may be indicative of progressive genomic instability during MPN progression. The TL of JAK2V617F-negative MPN patients was similar to JAK2V617F-positive counterparts (T/S 0.527 vs 0.507, P = 0.603), suggesting that the yet-to-be-discovered causative mutation(s) impact the mutated stem cell similarly to JAK2V617F, and that TL measurement may prove useful in the diagnostic workup of JAK2V617F-negative MPN. PMID:19005480

  7. Renovascular hypertension associated with JAK2 V617F positive myeloproliferative neoplasms treated with angioplasty: 2 cases and literature review.

    PubMed

    Mishima, Eikan; Suzuki, Takehiro; Takeuchi, Yoichi; Seiji, Kazumasa; Fukuhara, Noriko; Takase, Kei; Harigae, Hideo; Abe, Takaaki; Ito, Sadayoshi

    2018-04-01

    Myeloproliferative neoplasms (MPNs) with Janus kinase 2 (JAK2) mutation are associated with a high risk for occlusive vascular diseases. We report 2 cases of renovascular hypertension associated with JAK2 V617F mutation-positive MPNs and provide a literature review. In Case 1, a 63-year-old woman had resistant hypertension, massive proteinuria, and erythrocytosis. Evaluations revealed right renal artery stenosis causing renovascular hypertension and polycythemia vera with JAK2 V617F mutation. Renin-angiotensin system inhibitors and subsequent angioplasty controlled the blood pressure and the proteinuria resolved. In Case 2, a 74-year-old woman had resistant hypertension and thrombocytosis. Evaluations confirmed left renal artery stenosis and essential thrombocythemia with JAK2 V617F. Angioplasty cured the hypertension. A literature review of 18 cases revealed the following as the most common characteristics of MPN-associated renovascular hypertension: manifests primarily in women; is associated with untreated polycythemia vera and essential thrombocythemia, concomitant leukocytosis, and JAK2 mutation positivity; and is responsive to angioplasty. This report demonstrates that JAK2 mutation-positive MPNs are a less common but important underlying cause of adult renovascular hypertension. ©2018 Wiley Periodicals, Inc.

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

    PubMed

    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.

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

    PubMed

    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.

  10. Hmga2 promotes the development of myelofibrosis in Jak2V617F knockin mice by enhancing TGF-β1 and Cxcl12 pathways.

    PubMed

    Dutta, Avik; Hutchison, Robert E; Mohi, Golam

    2017-08-17

    Myelofibrosis (MF) is a devastating blood disorder. The JAK2V617F mutation has been detected in ∼50% cases of MF. Elevated expression of high-mobility group AT hook 2 (HMGA2) has also been frequently observed in patients with MF. Interestingly, upregulation of HMGA2 expression has been found in association with the JAK2V617F mutation in significant cases of MF. However, the contribution of HMGA2 in the pathogenesis of MF remains elusive. To determine the effects of concurrent expression of HMGA2 and JAK2V617F mutation in hematopoiesis, we transduced bone marrow cells from Jak2 V617F knockin mice with lentivirus expressing Hmga2 and performed bone marrow transplantation. Expression of Hmga2 enhanced megakaryopoiesis, increased extramedullary hematopoiesis, and accelerated the development of MF in mice expressing Jak2 V617F Mechanistically, the data show that expression of Hmga2 enhances the activation of transforming growth factor-β1 (TGF-β1) and Cxcl12 pathways in mice expressing Jak2 V617F In addition, expression of Hmga2 causes upregulation of Fzd2, Ifi27l2a, and TGF-β receptor 2. Forced expression of Cxcl12, Fzd2, or Ifi27l2a increases megakaryocytic differentiation and proliferation in the bone marrow of Jak2 V617F mice, whereas TGF-β1 or Cxcl12 stimulation induces collagen deposition in the bone marrow mesenchymal stromal cells. Together, these findings demonstrate that expression of Hmga2 cooperates with Jak2 V617F in the pathogenesis of MF. © 2017 by The American Society of Hematology.

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

    PubMed Central

    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

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

    PubMed

    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.

  13. Phenotypic variability within the JAK2 V617F-positive MPD: The roles of progenitor cell and neutrophil allele burdens

    PubMed Central

    Moliterno, Alison R.; Williams, Donna M.; Rogers, Ophelia; Isaacs, Mary Ann; Spivak, Jerry L.

    2008-01-01

    (1) Objective The myeloproliferative disorders (MPD), polycythemia vera (PV), essential thrombocytosis (ET) and primary myelofibrosis (PMF) differ phenotypically but share the same JAK2V617F mutation. We examined the relationship of the quantitative JAK2V617F allele burden to MPD disease phenotype among the three MPD classes and within PV. (2) Methods We measured the JAK2V617F allele percentage in genomic DNA from neutrophils, CD34+ cells, and cloned progenitors in 212 JAK2V617F –positive MPD patients and correlated the allele burdens to both disease class and disease features. (3) Results In ET and PV, the mean CD34+ cell JAK2V617F allele burdens were lower than the corresponding neutrophil allele burdens, but these were equivalent in PMF. JAK2WT progenitors were present in ET and PV when the CD34+ JAK2V617F allele burden was lower than the neutrophil allele burden, but not in PV and PMF subjects in whom the CD34+ cell and neutrophil allele burdens were similar. CD34+ cell JAK2V617F clonal dominance, defined as coherence between the CD34+ cell and neutrophil JAK2V617F allele burdens, was present in 24% of ET, 56% of PV and 93% of PMF patients, and was independent of the CD34+ cell JAK2V617F genotype. Clonally-dominant PV patients had significantly longer disease durations, higher white cell counts and larger spleens than nondominant PV patients. (4) Conclusions We conclude that the extent of JAK2V617F CD34+ cell clonal dominance is associated with disease phenotype within the MPD, and in PV, is associated with extramedullary disease, leukocytosis and disease duration. PMID:18723264

  14. A germline JAK2 SNP is associated with predisposition to the development of JAK2V617F-positive myeloproliferative neoplasms

    PubMed Central

    Kilpivaara, Outi; Mukherjee, Semanti; Schram, Alison M; Wadleigh, Martha; Mullally, Ann; Ebert, Benjamin L; Bass, Adam; Marubayashi, Sachie; Heguy, Adriana; Garcia-Manero, Guillermo; Kantarjian, Hagop; Offit, Kenneth; Stone, Richard M; Gilliland, D Gary; Klein, Robert J; Levine, Ross L

    2013-01-01

    Polycythemia vera, essential thrombocythemia and primary myelofibrosis are myeloproliferative neoplasms (MPN) characterized by multilineage clonal hematopoiesis1–5. Given that the identical somatic activating mutation in the JAK2 tyrosine kinase gene (JAK2V617F) is observed in most individuals with polycythemia vera, essential thrombocythemia and primary myelofibrosis6–10, there likely are additional genetic events that contribute to the pathogenesis of these phenotypically distinct disorders. Moreover, family members of individuals with MPN are at higher risk for the development of MPN, consistent with the existence of MPN predisposition loci11. We hypothesized that germline variation contributes to MPN predisposition and phenotypic pleiotropy. Genome-wide analysis identified an allele in the JAK2 locus (rs10974944) that predisposes to the development of JAK2V617F-positive MPN, as well as three previously unknown MPN modifier loci. We found that JAK2V617F is preferentially acquired in cis with the predisposition allele. These data suggest that germline variation is an important contributor to MPN phenotype and predisposition. PMID:19287384

  15. After 10years of JAK2V617F: Disease biology and current management strategies in polycythaemia vera.

    PubMed

    Grinfeld, Jacob; Godfrey, Anna L

    2017-05-01

    The JAK2V617F mutation accounts for the vast majority of patients with polycythaemia vera (PV) and around half of those with other Philadelphia-negative myeloproliferative neoplasms. Since its discovery in 2005, numerous insights have been gained into the pathways by which JAK2V617F causes myeloproliferation, including activation of JAK-STAT signalling but also through other canonical and non-canonical pathways. A variety of mechanisms explain how this one mutation can be associated with distinct clinical disorders, demonstrating how constitutional and acquired factors may interact in the presence of a single mutation to determine disease phenotype. Important biological questions remain unanswered in PV, in particular how JAK2V617F affects stem cell function and what mechanisms drive myelofibrotic and leukaemic transformation. Whilst current management is largely centred on prevention of cardiovascular events, future therapies must aim to target the JAK2-mutant clone, to reverse the underlying marrow pathology and to address the risk of transformation events. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Germ line variants predispose to both JAK2 V617F clonal hematopoiesis and myeloproliferative neoplasms

    PubMed Central

    Hinds, David A.; Barnholt, Kimberly E.; Mesa, Ruben A.; Kiefer, Amy K.; Do, Chuong B.; Eriksson, Nicholas; Mountain, Joanna L.; Francke, Uta; Tung, Joyce Y.; Nguyen, Huong (Marie); Zhang, Haiyu; Gojenola, Linda; Zehnder, James L.

    2016-01-01

    We conducted a genome-wide association study (GWAS) to identify novel predisposition alleles associated with Philadelphia chromosome-negative myeloproliferative neoplasms (MPNs) and JAK2 V617F clonal hematopoiesis in the general population. We recruited a web-based cohort of 726 individuals with polycythemia vera, essential thrombocythemia, and myelofibrosis and 252 637 population controls unselected for hematologic phenotypes. Using a single-nucleotide polymorphism (SNP) array platform with custom probes for the JAK2 V617F mutation (V617F), we identified 497 individuals (0.2%) among the population controls who were V617F carriers. We performed a combined GWAS of the MPN cases plus V617F carriers in the control population (n = 1223) vs the remaining controls who were noncarriers for V617F (n = 252 140). For these MPN cases plus V617F carriers, we replicated the germ line JAK2 46/1 haplotype (rs59384377: odds ratio [OR] = 2.4, P = 6.6 × 10−89), previously associated with V617F-positive MPN. We also identified genome-wide significant associations in the TERT gene (rs7705526: OR = 1.8, P = 1.1 × 10−32), in SH2B3 (rs7310615: OR = 1.4, P = 3.1 × 10−14), and upstream of TET2 (rs1548483: OR = 2.0, P = 2.0 × 10−9). These associations were confirmed in a separate replication cohort of 446 V617F carriers vs 169 021 noncarriers. In a joint analysis of the combined GWAS and replication results, we identified additional genome-wide significant predisposition alleles associated with CHEK2, ATM, PINT, and GFI1B. All SNP ORs were similar for MPN patients and controls who were V617F carriers. These data indicate that the same germ line variants endow individuals with a predisposition not only to MPN, but also to JAK2 V617F clonal hematopoiesis, a more common phenomenon that may foreshadow the development of an overt neoplasm. PMID:27365426

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

    PubMed

    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.

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

    PubMed

    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.

  19. 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.

    PubMed

    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.

  20. 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

    PubMed Central

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

    2014-01-01

    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. PMID:23986553

  1. Self-Renewal of Single Mouse Hematopoietic Stem Cells Is Reduced by JAK2V617F Without Compromising Progenitor Cell Expansion

    PubMed Central

    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

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

    PubMed

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

    PubMed

    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.

  4. Concomitant presence of JAK2V617F mutation and BCR‑ABL translocation in two patients: A new entity or a variant of myeloproliferative neoplasms (Case report).

    PubMed

    Mousinho, Filipa; Azevedo, Ana P; Mendes, Tatiana; Santos, Paula Sousa E; Cerqueira, Rita; Matos, Sónia; Santos, Sónia; Ramos, Sância; Viana, João Faro; Lima, Fernando

    2018-05-17

    Myeloproliferative neoplasms (MPNs) are classically divided into BCR RhoGEF and GTPase activating protein (BCR)-ABL proto‑oncogene 1 non‑receptor tyrosine kinase (ABL) positive chronic myeloid leukemia (CML) and BCR‑ABL negative MPNs, including essential thrombocythemia (ET). One of the major diagnostic criteria for ET is the absence of the philadelphia chromosome, thus when present it is almost indicative of CML. ET and CML are considered to be mutually exclusive; however, there are rare situations in which patients with ET present positive BCR‑ABL without the features of CML. Although from the literature review, the frequency of JAK2V617F mutation and BCR‑ABL translocation coexistence in MPNs is low, it may be higher than expected. The current study reported cases of two patients with an initial diagnosis of ET in the presence of JAK2V617F mutation and BCR‑ABL translocation by fluorescent in situ hybridization. Both patients presented with a heterozygous BCR‑ABL translocation, and absence of p190 and p210 transcripts, seemingly a der(9) in the background of an ET JAK2V617F mutation.

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

    PubMed Central

    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

  6. JAK2V617F-mutant megakaryocytes contribute to hematopoietic stem/progenitor cell expansion in a model of murine myeloproliferation

    PubMed Central

    Zhan, H; Ma, Y; Lin, CHS; Kaushansky, K

    2016-01-01

    The myeloproliferative neoplasms (MPNs) are characterized by hematopoietic stem/progenitor cell (HSPC) expansion and overproduction of mature blood cells. The JAK2V617F mutation is present in hematopoietic cells in a majority of patients with MPNs, but the mechanism(s) responsible for MPN stem cell expansion remain incomplete. One hallmark feature of the marrow in patients with MPNs is megakaryocyte (MK) hyperplasia. We report here that mice bearing a human JAK2V617F gene restricted exclusively to the MK lineage develop many of the features of a MPN. Specifically, these mice exhibit thrombocytosis, splenomegaly, increased numbers of marrow and splenic hematopoietic progenitors and a substantial expansion of HSPCs. In addition, wild-type mice transplanted with cells from JAK2V617F-bearing MK marrow develop a myeloproliferative syndrome with thrombocytosis and erythrocytosis as well as pan-hematopoietic progenitor and stem cell expansion. As marrow histology in this murine model of myeloproliferation reveals a preferentially perivascular localization of JAK2V617F-mutant MKs and an increased marrow sinusoid vascular density, it adds to accumulating data that MKs are an important component of the marrow HSPC niche, and that MK expansion might indirectly contribute to the critical role of the thrombopoietin/c-Mpl signaling pathway in HSPC maintenance and expansion. PMID:27133820

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

    PubMed

    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.

  8. AML1 is overexpressed in patients with myeloproliferative neoplasms and mediates JAK2V617F-independent overexpression of NF-E2

    PubMed Central

    Wang, Wei; Schwemmers, Sven; Hexner, Elizabeth O.

    2010-01-01

    The transcription factor NF-E2 is overexpressed in the majority of patients with polycythemia vera (PV). Concomitantly, 95% of these patients carry the JAK2V617F mutation. Although NF-E2 levels correlate with JAK2V671F allele burden in some PV cohorts, the molecular mechanism causing aberrant NF-E2 expression has not been described. Here we show that NF-E2 expression is also increased in patients with essential thrombocythemia and primary myelofibrosis independent of the presence of the JAK2V617F mutation. Characterization of the NF-E2 promoter revealed multiple functional binding sites for AML1/RUNX-1. Chromatin immunoprecipitation demonstrated AML1 binding to the NF-E2 promoter in vivo. Moreover, AML1 binding to the NF-E2 promoter was significantly increased in granulocytes from PV patients compared with healthy controls. AML1 mRNA expression was elevated in patients with PV, essential thrombocythemia, and primary myelofibrosis both in the presence and absence of JAK2V617F. In addition, AML1 and NF-E2 expression were highly correlated. RNAi-mediated suppression of either AML1 or of its binding partner CBF-β significantly decreased NF-E2 expression. Moreover, expression of the leukemic fusion protein AML/ETO drastically decreased NF-E2 protein levels. Our data identify NF-E2 as a novel AML1 target gene and delineate a role for aberrant AML1 expression in mediating elevated NF-E2 expression in MPN patients. PMID:20339092

  9. The Jak2 Inhibitor, G6, Alleviates Jak2-V617F-Mediated Myeloproliferative Neoplasia by Providing Significant Therapeutic Efficacy to the Bone Marrow1

    PubMed Central

    Kirabo, Annet; Park, Sung O; Majumder, Anurima; Gali, Meghanath; Reinhard, Mary K; Wamsley, Heather L; Zhao, Zhizhuang Joe; Cogle, Christopher R; Bisht, Kirpal S; Keserü, György M; Sayeski, Peter P

    2011-01-01

    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 splenomegaly 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. PMID:22131881

  10. Roles of germline JAK2 activation mutation JAK2 V625F in the pathology of myeloproliferative neoplasms.

    PubMed

    Wu, Qing-Yun; Ma, Meng-Meng; Fu, Lin; Zhu, Yuan-Yuan; Liu, Yang; Cao, Jiang; Zhou, Ping; Li, Zhen-Yu; Zeng, Ling-Yu; Li, Feng; Wang, Xiao-Yun; Xu, Kai-Lin

    2018-05-18

    Janus tyrosine kinase 2 (JAK2) mediates downstream signaling of cytokine receptors in all hematological lineages, constitutively active somatic JAK2 mutations play key roles in the pathology of myeloproliferative neoplasms (MPNs). Recently, germline JAK2 mutations are also associated with triple-negative MPNs. A novel germline mutation JAK2 V625F is reported to be involved in a subset of MPNs patients. However, the pathogenesis of this mutation caused MPN is still unclear. In this study, the homology models of JAK2 V625F showed that the newly formed interaction between F625 and Y613 disrupted the JAK2 JH1-JH2 domain interactions was responsible for its activation, when F625 and Y613 interaction was disrupted, its activity significantly decreased. While, when this interaction was repaired whether by forming hydrogen bond or salt bond, it would cause JAK2 activation. Biochemical studies also demonstrated that JAK2 V625F mutation led to JAK2-STAT5 pathway activation and promoted the proliferation of BaF3 cells. Thus, our results herein provide clues to understand the mechanism JAK2 V625F mutation caused MPNs and give information for the development of JAK2 mutation specific inhibitors. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Myeloproliferative neoplasms with concurrent BCR-ABL1 translocation and JAK2 V617F mutation: a multi-institutional study from the bone marrow pathology group.

    PubMed

    Soderquist, Craig R; Ewalt, Mark D; Czuchlewski, David R; Geyer, Julia T; Rogers, Heesun J; Hsi, Eric D; Wang, Sa A; Bueso-Ramos, Carlos E; Orazi, Attilio; Arber, Daniel A; Hexner, Elizabeth O; Babushok, Daria V; Bagg, Adam

    2018-05-01

    Myeloproliferative neoplasms arise from hematopoietic stem cells with somatically altered tyrosine kinase signaling. Classification of myeloproliferative neoplasms is based on hematologic, histopathologic and molecular characteristics including the presence of the BCR-ABL1 and JAK2 V617F. Although thought to be mutually exclusive, a number of cases with co-occurring BCR-ABL1 and JAK2 V617F have been identified. To characterize the clinicopathologic features of myeloproliferative neoplasms with concomitant BCR-ABL1 and JAK2 V617F, and define the frequency of co-occurrence, we conducted a retrospective multi-institutional study. Cases were identified using a search of electronic databases over a decade at six major institutions. Of 1570 patients who were tested for both BCR-ABL1 and JAK2 V617F, six were positive for both. An additional five patients were identified via clinical records providing a total of 11 cases for detailed evaluation. For each case, clinical variables, hematologic and genetic data, and bone marrow histomorphologic features were analyzed. The sequence of identification of the genetic abnormalities varied: five patients were initially diagnosed with a JAK2 V617F+ myeloproliferative neoplasm, one patient initially had BCR-ABL1+ chronic myeloid leukemia, while both alterations were identified simultaneously in five patients. Classification of the BCR-ABL1-negative myeloproliferative neoplasms varied, and in some cases, features only became apparent following tyrosine kinase inhibitor therapy. Seven of the 11 patients showed myelofibrosis, in some cases before identification of the second genetic alteration. Our data, reflecting the largest reported study comprehensively detailing clinicopathologic features and response to therapy, show that the co-occurrence of BCR-ABL1 and JAK2 V617F is rare, with an estimated frequency of 0.4%, and most often reflects two distinct ('composite') myeloproliferative neoplasms. Although uncommon, it is important to be

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

    PubMed

    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.

  13. Ruxolitinib reduces JAK2 p.V617F allele burden in patients with polycythemia vera enrolled in the RESPONSE study.

    PubMed

    Vannucchi, Alessandro Maria; Verstovsek, Srdan; Guglielmelli, Paola; Griesshammer, Martin; Burn, Timothy C; Naim, Ahmad; Paranagama, Dilan; Marker, Mahtab; Gadbaw, Brian; Kiladjian, Jean-Jacques

    2017-07-01

    In patients with polycythemia vera (PV), an elevated JAK2 p.V617F allele burden is associated with indicators of more severe disease (e.g., leukocytosis, splenomegaly, and increased thrombosis risk); however, correlations between allele burden reductions and clinical benefit in patients with PV have not been extensively evaluated in a randomized trial. This exploratory analysis from the multicenter, open-label, phase 3 Randomized Study of Efficacy and Safety in Polycythemia Vera With JAK Inhibitor INCB018424 Versus Best Supportive Care trial evaluated the long-term effect of ruxolitinib treatment on JAK2 p.V617F allele burden in patients with PV. Evaluable JAK2 p.V617F-positive patients randomized to ruxolitinib (n = 107) or best available therapy (BAT) who crossed over to ruxolitinib at week 32 (n = 97) had consistent JAK2 p.V617F allele burden reductions throughout the study. At all time points measured (up to weeks 208 [ruxolitinib-randomized] and 176 [ruxolitinib crossover]), mean changes from baseline over time in JAK2 p.V617F allele burden ranged from -12.2 to -40.0% (ruxolitinib-randomized) and -6.3 to -17.8% (ruxolitinib crossover). Complete or partial molecular response was observed in 3 patients (ruxolitinib-randomized, n = 2; ruxolitinib crossover, n = 1) and 54 patients (ruxolitinib-randomized, n = 33; ruxolitinib crossover, n = 20; BAT, n = 1), respectively. Among patients treated with interferon as BAT (n = 13), the mean maximal reduction in allele burden from baseline was 25.6% after crossover to ruxolitinib versus 6.6% before crossover. Collectively, the data from this exploratory analysis suggest that ruxolitinib treatment for up to 4 years provides progressive reductions in JAK2 p.V617F allele burden in patients with PV who are resistant to or intolerant of hydroxyurea. The relationship between allele burden changes and clinical outcomes in patients with PV remains unclear.

  14. The JAK2 46/1 haplotype predisposes to MPL-mutated myeloproliferative neoplasms

    PubMed Central

    Jones, Amy V.; Campbell, Peter J.; Beer, Philip A.; Schnittger, Susanne; Vannucchi, Alessandro M.; Zoi, Katerina; Percy, Melanie J.; McMullin, Mary Frances; Scott, Linda M.; Tapper, William; Silver, Richard T.; Oscier, David; Harrison, Claire N.; Grallert, Harald; Kisialiou, Aliaksei; Strike, Paul; Chase, Andrew J.; Green, Anthony R.

    2010-01-01

    The 46/1 JAK2 haplotype predisposes to V617F-positive myeloproliferative neoplasms, but the underlying mechanism is obscure. We analyzed essential thrombocythemia patients entered into the PT-1 studies and, as expected, found that 46/1 was overrepresented in V617F-positive cases (n = 404) versus controls (n = 1492, P = 3.9 × 10−11). The 46/1 haplotype was also overrepresented in cases without V617F (n = 347, P = .009), with an excess seen for both MPL exon 10 mutated and V617F, MPL exon 10 nonmutated cases. Analysis of further MPL-positive, V617F-negative cases confirmed an excess of 46/1 (n = 176, P = .002), but no association between MPL mutations and MPL haplotype was seen. An excess of 46/1 was also seen in JAK2 exon 12 mutated cases (n = 69, P = .002), and these mutations preferentially arose on the 46/1 chromosome (P = .029). No association between 46/1 and clinical or laboratory features was seen in the PT-1 cohort either with or without V617F. The excess of 46/1 in JAK2 exon 12 cases is compatible with both the “hypermutability” and “fertile ground” hypotheses, but the excess in MPL-mutated cases argues against the former. No difference in sequence, splicing, or expression of JAK2 was found on 46/1 compared with other haplotypes, suggesting that any functional difference of JAK2 on 46/1, if it exists, must be relatively subtle. PMID:20304805

  15. JAK2 mutations and clinical practice in myeloproliferative neoplasms.

    PubMed

    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.

  16. Mutational subtypes of JAK2 and CALR correlate with different clinical features in Japanese patients with myeloproliferative neoplasms.

    PubMed

    Misawa, Kyohei; Yasuda, Hajime; Araki, Marito; Ochiai, Tomonori; Morishita, Soji; Shirane, Shuichi; Edahiro, Yoko; Gotoh, Akihiko; Ohsaka, Akimichi; Komatsu, Norio

    2018-06-01

    The majority of patients with Philadelphia chromosome-negative myeloproliferative neoplasms (MPNs) harbor JAK2, CALR, or MPL mutations. We compared clinical manifestations of different subtypes of JAK2 and CALR mutations in Japanese patients with MPNs. Within our cohort, we diagnosed 166 patients as polycythemia vera (PV), 212 patients as essential thrombocythemia (ET), 23 patients as pre-primary myelofibrosis (PMF), 65 patients as overt PMF, and 27 patients as secondary myelofibrosis following the 2016 WHO criteria. Compared to patients with JAK2V617F-mutated PV, JAK2 exon 12-mutated PV patients were younger, showed lower white blood cell (WBC) counts, lower platelet counts, higher red blood cell counts, and higher frequency of thrombotic events. Compared to JAK2-mutated ET patients, CALR-mutated ET patients were younger, showed lower WBC counts, lower hemoglobin levels, higher platelet counts, and fewer thrombotic events. CALR type 1-like mutation was the dominant subtype in CALR-mutated overt PMF patients. Compared with JAK2V617F-mutated ET patients, JAK2V617F-mutated pre-PMF patients showed higher LDH levels, lower hemoglobin levels, higher JAK2V617F allele burden, and higher frequency of splenomegaly. In conclusion, Japanese patients with MPNs grouped by different mutation subtypes exhibit characteristics similar to those of their Western counterparts. In addition, ET and pre-PMF patients show different characteristics, even when restricted to JAK2V617F-mutated patients.

  17. The Stilbenoid Tyrosine Kinase Inhibitor, G6, Suppresses Jak2-V617F-mediated Human Pathological Cell Growth in Vitro and in Vivo*

    PubMed Central

    Kirabo, Annet; Embury, Jennifer; Kiss, Róbert; Polgár, Tímea; Gali, Meghanath; Majumder, Anurima; Bisht, Kirpal S.; Cogle, Christopher R.; Keserű, György M.; Sayeski, Peter P.

    2011-01-01

    Using structure-based virtual screening, we previously identified a novel stilbenoid inhibitor of Jak2 tyrosine kinase named G6. Here, we hypothesized that G6 suppresses Jak2-V617F-mediated human pathological cell growth in vitro and in vivo. We found that G6 inhibited proliferation of the Jak2-V617F expressing human erythroleukemia (HEL) cell line by promoting marked cell cycle arrest and inducing apoptosis. The G6-dependent increase in apoptosis levels was concomitant with increased caspase 3/7 activity and cleavage of PARP. G6 also selectively inhibited phosphorylation of STAT5, a downstream signaling target of Jak2. Using a mouse model of Jak2-V617F-mediated hyperplasia, we found that G6 significantly decreased the percentage of blast cells in the peripheral blood, reduced splenomegaly, and corrected a pathologically low myeloid to erythroid ratio in the bone marrow by eliminating HEL cell engraftment in this tissue. In addition, drug efficacy correlated with the presence of G6 in the plasma, marrow, and spleen. Collectively, these data demonstrate that the stilbenoid compound, G6, suppresses Jak2-V617F-mediated aberrant cell growth. As such, G6 may be a potential therapeutic lead candidate against Jak2-mediated, human disease. PMID:21127060

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

    PubMed Central

    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

    Background The detection of molecular and cytogenetic alterations is important for the diagnosis, prognosis and classification of myeloproliferative neoplasms. Objectives 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 or primary

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

    PubMed

    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

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

    PubMed

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

    PubMed

    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.

  2. Physiological Jak2V617F expression causes a lethal myeloproliferative neoplasm with differential effects on hematopoietic stem and progenitor cells.

    PubMed

    Mullally, Ann; Lane, Steven W; Ball, Brian; Megerdichian, Christine; Okabe, Rachel; Al-Shahrour, Fatima; Paktinat, Mahnaz; Haydu, J Erika; Housman, Elizabeth; Lord, Allegra M; Wernig, Gerlinde; Kharas, Michael G; Mercher, Thomas; Kutok, Jeffery L; Gilliland, D Gary; Ebert, Benjamin L

    2010-06-15

    We report a Jak2V617F knockin mouse myeloproliferative neoplasm (MPN) model resembling human polycythemia vera (PV). The MPN is serially transplantable and we demonstrate that the hematopoietic stem cell (HSC) compartment has the unique capacity for disease initiation but does not have a significant selective competitive advantage over wild-type HSCs. In contrast, myeloid progenitor populations are expanded and skewed toward the erythroid lineage, but cannot transplant the disease. Treatment with a JAK2 kinase inhibitor ameliorated the MPN phenotype, but did not eliminate the disease-initiating population. These findings provide insights into the consequences of JAK2 activation on HSC differentiation and function and have the potential to inform therapeutic approaches to JAK2V617F-positive MPN. Copyright 2010 Elsevier Inc. All rights reserved.

  3. Germline and somatic JAK2 mutations and susceptibility to chronic myeloproliferative neoplasms

    PubMed Central

    2009-01-01

    Myeloproliferative neoplasms (MPNs) are a group of closely related stem-cell-derived clonal proliferative diseases. Most cases are sporadic but first-degree relatives of MPN patients have a five- to seven-fold increased risk for developing an MPN. The tumors of most patients carry a mutation in the Janus kinase 2 gene (JAK2V617F). Recently, three groups have described a strong association of JAK2 germline polymorphisms with MPN in patients positive for JAK2V617F. The somatic mutation occurs primarily on one particular germline JAK2 haplotype, which may account for as much as 50% of the risk to first-degree relatives. This finding provides new directions for unraveling the pathogenesis of MPN. PMID:19490586

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

    PubMed

    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.

  5. JAK and MPL mutations in myeloid malignancies.

    PubMed

    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.

  6. Sequential treatment of CD34+ cells from patients with primary myelofibrosis with chromatin-modifying agents eliminate JAK2V617F-positive NOD/SCID marrow repopulating cells

    PubMed Central

    Wang, Xiaoli; Zhang, Wei; Tripodi, Joseph; Lu, Min; Xu, Mingjiang; Najfeld, Vesna; Li, Yan

    2010-01-01

    Because primary myelofibrosis (PMF) originates at the level of the pluripotent hematopoietic stem cell (HSC), we examined the effects of various therapeutic agents on the in vitro and in vivo behavior of PMF CD34+ cells. Treatment of PMF CD34+ cells with chromatin-modifying agents (CMAs) but not hydroxyurea, Janus kinase 2 (JAK2) inhibitors, or low doses of interferon-α led to the generation of greater numbers of CD34+ chemokine (C-X-C motif) receptor (CXCR)4+ cells, which were capable of migrating in response to chemokine (C-X-C motif) ligand (CXCL)12 and resulted in a reduction in the proportion of hematopoietic progenitor cells (HPCs) that were JAK2V617F+. Furthermore, sequential treatment of PMF CD34+ cells but not normal CD34+ cells with decitabine (5-aza-2′-deoxycytidine [5azaD]), followed by suberoylanilide hydroxamic acid (SAHA; 5azaD/SAHA), or trichostatin A (5azaD/TSA) resulted in a higher degree of apoptosis. Two to 6 months after the transplantation of CMAs treated JAK2V617F+ PMF CD34+ cells into nonobese diabetic/severe combined immunodeficient (SCID)/IL-2Rγnull mice, the percentage of JAK2V617F/JAK2total in human CD45+ marrow cells was dramatically reduced. These findings suggest that both PMF HPCs, short-term and long-term SCID repopulating cells (SRCs), are JAK2V617F+ and that JAK2V617F+ HPCs and SRCs can be eliminated by sequential treatment with CMAs. Sequential treatment with CMAs, therefore, represents a possible effective means of treating PMF at the level of the malignant SRC. PMID:20858855

  7. Essential role for Stat5a/b in myeloproliferative neoplasms induced by BCR-ABL1 and JAK2V617F in mice

    PubMed Central

    Walz, Christoph; Ahmed, Wesam; Lazarides, Katherine; Betancur, Monica; Patel, Nihal; Hennighausen, Lothar; Zaleskas, Virginia M.

    2012-01-01

    STAT5 proteins are constitutively activated in malignant cells from many patients with leukemia, including the myeloproliferative neoplasms (MPNs) chronic myeloid leukemia (CML) and polycythemia vera (PV), but whether STAT5 is essential for the pathogenesis of these diseases is not known. In the present study, we used mice with a conditional null mutation in the Stat5a/b gene locus to determine the requirement for STAT5 in MPNs induced by BCR-ABL1 and JAK2V617F in retroviral transplantation models of CML and PV. Loss of one Stat5a/b allele resulted in a decrease in BCR-ABL1–induced CML-like MPN and the appearance of B-cell acute lymphoblastic leukemia, whereas complete deletion of Stat5a/b prevented the development of leukemia in primary recipients. However, BCR-ABL1 was expressed and active in Stat5-null leukemic stem cells, and Stat5 deletion did not prevent progression to lymphoid blast crisis or abolish established B-cell acute lymphoblastic leukemia. JAK2V617F failed to induce polycythemia in recipients after deletion of Stat5a/b, although the loss of STAT5 did not prevent the development of myelofibrosis. These results demonstrate that STAT5a/b is essential for the induction of CML-like leukemia by BCR-ABL1 and of polycythemia by JAK2V617F, and validate STAT5a/b and the genes they regulate as targets for therapy in these MPNs. PMID:22234689

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

    PubMed

    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.

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

    PubMed Central

    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

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

    PubMed

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

    PubMed Central

    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.

    2014-01-01

    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. PMID:24986690

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

    PubMed

    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 <0.001) , but not for patients with CALR[57 (17-89) y] or MPL mutation[59 (22-71) y] ( P >0.05) . Patients with JAK2V617F had higher white blood cell count and hemoglobin level ( P <0.05) when compared with patients with CALR mutation or without mutations, or only significantly higher white blood cell count when compared with patients with 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 <0.001]. ③Karyotype analysis

  13. JAK2 Exon 14 Deletion in Patients with Chronic Myeloproliferative Neoplasms

    PubMed Central

    Ma, Wanlong; Kantarjian, Hagop; Zhang, Xi; Wang, Xiuqiang; Zhang, Zhong; Yeh, Chen-Hsiung; O'Brien, Susan; Giles, Francis; Bruey, Jean Marie; Albitar, Maher

    2010-01-01

    Background The JAK2 V617F mutation in exon 14 is the most common mutation in chronic myeloproliferative neoplasms (MPNs); deletion of the entire exon 14 is rarely detected. In our previous study of >10,000 samples from patients with suspected MPNs tested for JAK2 mutations by reverse transcription-PCR (RT-PCR) with direct sequencing, complete deletion of exon 14 (Δexon14) constituted <1% of JAK2 mutations. This appears to be an alternative splicing mutation, not detectable with DNA-based testing. Methodology/Principal Findings We investigated the possibility that MPN patients may express the JAK2 Δexon14 at low levels (<15% of total transcript) not routinely detectable by RT-PCR with direct sequencing. Using a sensitive RT-PCR–based fluorescent fragment analysis method to quantify JAK2 Δexon14 mRNA expression relative to wild-type, we tested 61 patients with confirmed MPNs, 183 with suspected MPNs (93 V617F-positive, 90 V617F-negative), and 46 healthy control subjects. The Δexon14 variant was detected in 9 of the 61 (15%) confirmed MPN patients, accounting for 3.96% to 33.85% (mean  = 12.04%) of total JAK2 transcript. This variant was also detected in 51 of the 183 patients with suspected MPNs (27%), including 20 of the 93 (22%) with V617F (mean [range] expression  = 5.41% [2.13%–26.22%]) and 31 of the 90 (34%) without V617F (mean [range] expression  = 3.88% [2.08%–12.22%]). Immunoprecipitation studies demonstrated that patients expressing Δexon14 mRNA expressed a corresponding truncated JAK2 protein. The Δexon14 variant was not detected in the 46 control subjects. Conclusions/Significance These data suggest that expression of the JAK2 Δexon14 splice variant, leading to a truncated JAK2 protein, is common in patients with MPNs. This alternatively spliced transcript appears to be more frequent in MPN patients without V617F mutation, in whom it might contribute to leukemogenesis. This mutation is missed if DNA rather than RNA is used for

  14. 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.

    PubMed

    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.

  15. Aberrant let7a/HMGA2 signaling activity with unique clinical phenotype in JAK2-mutated myeloproliferative neoplasms

    PubMed Central

    Chen, Chih-Cheng; You, Jie-Yu; Lung, Jrhau; Huang, Cih-En; Chen, Yi-Yang; Leu, Yu-Wei; Ho, Hsing-Ying; Li, Chian-Pei; Lu, Chang-Hsien; Lee, Kuan-Der; Hsu, Chia-Chen; Gau, Jyh-Pyng

    2017-01-01

    High mobility group AT-hook 2 (HMGA2) is an architectural transcription factor that is negatively regulated by let-7 microRNA through binding to it’s 3′-untranslated region. Transgenic mice expressing Hmga2 with a truncation of its 3′-untranslated region has been shown to exhibit a myeloproliferative phenotype. To decipher the let-7-HMGA2 axis in myeloproliferative neoplasms, we employed an in vitro model supplemented with clinical correlation. Ba/F3 cells with inducible JAK2V617F expression (Ton.JAK2.V617F cells) showed upregulation of HMGA2 with concurrent let-7a repression. Ton.JAK2.V617F cells treated with a let-7a inhibitor exhibited further escalation of Hmga2 expression, while a let-7a mimic diminished the Hmga2 transcript level. Hmga2 overexpression conferred JAK2-mutated cells with a survival advantage through inhibited apoptosis. A pan-JAK inhibitor, INC424, increased the expression of let-7a, downregulated the level of Hmga2, and led to increased apoptosis in Ton.JAK2.V617F cells in a dose-dependent manner. In samples from 151 patients with myeloproliferative neoplasms, there was a modest inverse correlation between the expression levels of let-7a and HMGA2. Overexpression of HMGA2 was detected in 29 (19.2%) of the cases, and it was more commonly seen in patients with essential thrombocythemia than in those with polycythemia vera (26.9% vs. 12.7%, P=0.044). Patients with upregulated HMGA2 showed an increased propensity for developing major thrombotic events, and they were more likely to harbor one of the 3 driver myeloproliferative neoplasm mutations in JAK2, MPL and CALR. Our findings suggest that, in a subset of myeloproliferative neoplasm patients, the let-7-HMGA2 axis plays a prominent role in the pathogenesis of the disease that leads to unique clinical phenotypes. PMID:28057739

  16. 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.

    PubMed

    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.

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

    PubMed

    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?

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

    PubMed

    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.

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

    PubMed

    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.

  20. Jak2 FERM Domain Interaction with the Erythropoietin Receptor Regulates Jak2 Kinase Activity▿

    PubMed Central

    Funakoshi-Tago, Megumi; Pelletier, Stéphane; Moritake, Hiroshi; Parganas, Evan; Ihle, James N.

    2008-01-01

    Janus kinases are essential for signal transduction by a variety of cytokine receptors and when inappropriately activated can cause hematopoietic disorders and oncogenesis. Consequently, it can be predicted that the interaction of the kinases with receptors and the events required for activation are highly controlled. In a screen to identify phosphorylation events regulating Jak2 activity in EpoR signaling, we identified a mutant (Jak2-Y613E) which has the property of being constitutively activated, as well as an inactivating mutation (Y766E). Although no evidence was obtained to indicate that either site is phosphorylated in signaling, the consequences of the Y613E mutation are similar to those observed with recently described activating mutations in Jak2 (Jak2-V617F and Jak2-L611S). However, unlike the V617F or L611S mutant, the Y613E mutant requires the presence of the receptor but not Epo stimulation for activation and downstream signaling. The properties of the Jak2-Y613E mutant suggest that under normal conditions, Jak2 that is not associated with a receptor is locked into an inactive state and receptor binding through the FERM domain relieves steric constraints, allowing the potential to be activated with receptor engagement. PMID:18160720

  1. Differential effects of hydroxyurea and INC424 on mutant allele burden and myeloproliferative phenotype in a JAK2-V617F polycythemia vera mouse model.

    PubMed

    Kubovcakova, Lucia; Lundberg, Pontus; Grisouard, Jean; Hao-Shen, Hui; Romanet, Vincent; Andraos, Rita; Murakami, Masato; Dirnhofer, Stephan; Wagner, Kay-Uwe; Radimerski, Thomas; Skoda, Radek C

    2013-02-14

    To establish a preclinical animal model for testing drugs with potential effects on myeloproliferative neoplasms (MPNs), we first performed a detailed phenotypic characterization of Cre-inducible transgenic JAK2-V617F mice. Deleting the conditional mouse Jak2-knockout alleles increased erythropoiesis and accentuated the polycythemia vera phenotype, but did not alter platelet or granulocyte levels. In a transplantation assay, JAK2-V617F(+) BM cells had an advantage over wild-type competitor cells. Using this competitive repopulation assay, we compared the effects of INC424 (ruxolitinib), a dual Jak1/Jak2 inhibitor, and hydroxyurea (HU). HU led to weight loss, but did not reduce spleen weight. The hematologic parameters were lowered and a slight decrease of the mutant allele burden was noted. INC424 had little effect on body weight, but strongly decreased spleen size and rapidly normalized RBC and neutrophil parameters. No significant decrease in the mutant allele burden was observed. INC424 reduced the phospho-Stat5 levels, whereas HU strongly increased phospho-Stat5, most likely because of the elevated erythropoietin levels in response to the HU-induced anemia. This compensatory increase in JAK/STAT signaling may counteract the beneficial effects of cytoreduction at higher doses of HU and represents an adverse effect that should be avoided.

  2. 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.

    PubMed

    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.

  3. JAK2 V617F positive essential thrombocythemia developing in a patient with CD5⁻ chronic lymphocytic leukemia.

    PubMed

    Wei, Ju; Wang, Chun; Qin, You-Wen; Zhu, Jun; Gao, Yang-Rong; Cai, Qi; Yan, Shi-Ke

    2012-06-01

    Coexistence of chronic lymphocytic leukemia (CLL) and essential thrombocythemia (ET) in a patient is extremely rare, with only 10 cases reported thus far in literature. This paper describes a 94-year-old male having atypical B-CLL with CD5⁻ (CD5⁻) phenotype and ET. In this patient, we performed interphase fluorescence in situ hybridization (FISH) analysis which revealed 13q14.3 deletion in 31% of B-lymphocyte nuclei and RB1 deletion in 27% of B-lymphocyte nuclei, but not in neutrophils and T-lymphocytes. Furthermore, we identified JAK2 V617F mutation in the peripheral blood nucleated cells and neutrophils, but not in the B- and T-lymphocyte populations. Therefore, it was concluded that the occurrence of CD5− B-CLL and ET in this patient was pathogenically independent.

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

    PubMed

    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.

  5. SOCS3 tyrosine phosphorylation as a potential bio-marker for myeloproliferative neoplasms associated with mutant JAK2 kinases

    PubMed Central

    Elliott, Joanne; Suessmuth, Yvonne; Scott, Linda M.; Nahlik, Krystyna; McMullin, Mary Frances; Constantinescu, Stefan N.; Green, Anthony R.; Johnston, James A.

    2009-01-01

    JAK2 V617F, identified in the majority of patients with myeloproliferative neoplasms, tyrosine phosphorylates SOCS3 and escapes its inhibition. Here, we demonstrate that the JAK2 exon 12 mutants described in a subset of V617F-negative MPN cases, also stabilize tyrosine phosphorylated SOCS3. SOCS3 tyrosine phosphorylation was also observed in peripheral blood mononuclear cells and granulocytes isolated from patients with JAK2 H538QK539L or JAK2 F537-K539delinsL mutations. JAK kinase inhibitors, which effectively inhibited the proliferation of cells expressing V617F or K539L, also caused a dose-dependent reduction in both mutant JAK2 and SOCS3 tyrosine phosphorylation. We propose, therefore, that SOCS3 tyrosine phosphorylation may be a novel bio-marker of myeloproliferative neoplasms resulting from a JAK2 mutation and a potential reporter of effective JAK2 inhibitor therapy currently in clinical development. PMID:19229050

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

    PubMed Central

    2012-01-01

    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 significantly to the

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

    PubMed

    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.

  8. JAK2 haplotype is a major risk factor for the development of myeloproliferative neoplasms

    PubMed Central

    Jones, Amy V; Chase, Andrew; Silver, Richard T; Oscier, David; Zoi, Katerina; Wang, Y Lynn; Cario, Holger; Pahl, Heike L; Collins, Andrew; Reiter, Andreas; Grand, Francis; Cross, Nicholas C P

    2014-01-01

    Chronic myeloproliferative neoplasms (MPNs) are a group of related conditions characterized by the overproduction of cells from one or more myeloid lineages. More than 95% of cases of polycythemia vera, and roughly half of essential thrombocythemia and primary myelofibrosis acquire a unique somatic 1849G>T JAK2 mutation (encoding V617F) that is believed to be a critical driver of excess proliferation1–4. We report here that JAK2V617F-associated disease is strongly associated with a specific constitutional JAK2 haplotype, designated 46/1, in all three disease entities compared to healthy controls (polycythemia vera, n = 192, P = 2.9 × 10−16; essential thrombocythemia, n = 78, P = 8.2 × 10−9 and myelofibrosis, n = 41, P = 8.0 × 10−5). Furthermore, JAK2V617F specifically arises on the 46/1 allele in most cases. The 46/1 JAK2 haplotype thus predisposes to the development of JAK2V617F-associated MPNs (OR = 3.7; 95% CI = 3.1–4.3) and provides a model whereby a constitutional genetic factor is associated with an increased risk of acquiring a specific somatic mutation. PMID:19287382

  9. Preclinical characterization of the selective JAK1/2 inhibitor INCB018424: therapeutic implications for the treatment of myeloproliferative neoplasms

    PubMed Central

    Quintás-Cardama, Alfonso; Vaddi, Kris; Liu, Phillip; Manshouri, Taghi; Li, Jun; Scherle, Peggy A.; Caulder, Eian; Wen, Xiaoming; Li, Yanlong; Waeltz, Paul; Rupar, Mark; Burn, Timothy; Lo, Yvonne; Kelley, Jennifer; Covington, Maryanne; Shepard, Stacey; Rodgers, James D.; Haley, Patrick; Kantarjian, Hagop

    2010-01-01

    Constitutive JAK2 activation in hematopoietic cells by the JAK2V617F mutation recapitulates myeloproliferative neoplasm (MPN) phenotypes in mice, establishing JAK2 inhibition as a potential therapeutic strategy. Although most polycythemia vera patients carry the JAK2V617F mutation, half of those with essential thrombocythemia or primary myelofibrosis do not, suggesting alternative mechanisms for constitutive JAK-STAT signaling in MPNs. Most patients with primary myelofibrosis have elevated levels of JAK-dependent proinflammatory cytokines (eg, interleukin-6) consistent with our observation of JAK1 hyperactivation. Accordingly, we evaluated the effectiveness of selective JAK1/2 inhibition in experimental models relevant to MPNs and report on the effects of INCB018424, the first potent, selective, oral JAK1/JAK2 inhibitor to enter the clinic. INCB018424 inhibited interleukin-6 signaling (50% inhibitory concentration [IC50] = 281nM), and proliferation of JAK2V617F+ Ba/F3 cells (IC50 = 127nM). In primary cultures, INCB018424 preferentially suppressed erythroid progenitor colony formation from JAK2V617F+ polycythemia vera patients (IC50 = 67nM) versus healthy donors (IC50 > 400nM). In a mouse model of JAK2V617F+ MPN, oral INCB018424 markedly reduced splenomegaly and circulating levels of inflammatory cytokines, and preferentially eliminated neoplastic cells, resulting in significantly prolonged survival without myelosuppressive or immunosuppressive effects. Preliminary clinical results support these preclinical data and establish INCB018424 as a promising oral agent for the treatment of MPNs. PMID:20130243

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

    PubMed Central

    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

    2016-01-01

    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. PMID:26423830

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

    PubMed

    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.

  12. The mutation profile of JAK2 and CALR in Chinese Han patients with Philadelphia chromosome-negative myeloproliferative neoplasms

    PubMed Central

    2014-01-01

    Mutations in JAK2, MPL and CALR are highly relevant to the Philadelphia chromosome (Ph)-negative myeloproliferative neoplasms (MPNs). We performed high resolution melting analysis and Sanger sequencing together with T-A cloning to elucidate the unique mutation profile of these genes, in Chinese patients with MPNs. Peripheral blood DNA samples were obtained from 80 patients with polycythemia vera (PV), 80 patients with essential thrombocytosis (ET) and 50 patients with primary myelofibrosis (PMF). Ten PV patients were identified with diverse JAK2 exon 12 mutations. Five novel JAK2 Exon 12 mutation patterns (M532V/E543G, N533D, M535I/H538Y/K549I, E543G and D544N) were described. JAK2 V617F was detected in 140 samples (66 PV, 45 ET and 29 PMF). JAK2 Exon 12 mutations were prevalent (13%) and variable in the Chinese patients. Compared with PV patients with JAK2 V617F mutations, PV patients with JAK2 exon 12 mutations had an earlier median onset of disease (P = 0.0013). MPL W515L/K mutations were discerned in 4 ET and 3 PMF patients. Two kinds of CALR mutation, c. 1179_1230del and c. 1234_1235insTTGTC were detected in 20 ET and 16 PMF patients. A novel CALR mutation pattern (c. 1173_1223del/c. 1179_1230del) was identified in 2 PMF samples. In addition, 17 scattered point mutations in CALR c.1153 to c.1255 were also detected in 13 cases with CALR frame-shifting variations and 2 cases without CALR frame-shifting variations. Female patients showed a predisposition to CALR mutations (P = 0.0035). Chinese Ph-negative MPN patients have a unique mutation landscape in the common molecular markers of MPN diagnosis. Validation of the molecular diagnostic pipeline should be emphasized since there is a considerable ethnical diversity in the molecular profiles of Ph-negative MPNs. PMID:25023898

  13. Co-targeting the PI3K/mTOR and JAK2 signalling pathways produces synergistic activity against myeloproliferative neoplasms

    PubMed Central

    Bartalucci, Niccolò; Tozzi, Lorenzo; Bogani, Costanza; Martinelli, Serena; Rotunno, Giada; Villeval, Jean-Luc; Vannucchi, Alessandro M

    2013-01-01

    Aberrant JAK2 signalling plays a central role in myeloproliferative neoplasms (MPN). JAK2 inhibitors have proven to be clinically efficacious, however, they are not mutation-specific and competent enough to suppress neoplastic clonal haematopoiesis. We hypothesized that, by simultaneously targeting multiple activated signalling pathways, MPN could be more effectively treated. To this end we investigated the efficacy of BEZ235, a dual PI3K/mTOR inhibitor, alone and in combination with the JAK1/JAK2 inhibitor ruxolitinib, in different preclinical models of MPN. Single-agent BEZ235 inhibited the proliferation and induced cell cycle arrest and apoptosis of mouse and human JAK2V617F mutated cell lines at concentrations significantly lower than those required to inhibit the wild-type counterpart, and preferentially prevented colony formation from JAK2V617F knock-in mice and patients' progenitor cells compared with normal ones. Co-treatment of BEZ235 and ruxolitinib produced significant synergism in all these in-vitro models. Co-treatment was also more effective than single drugs in reducing the extent of disease and prolonging survival of immunodeficient mice injected with JAK2V617F-mutated Ba/F3-EPOR cells and in reducing spleen size, decreasing reticulocyte count and improving spleen histopathology in conditional JAK2V617F knock-in mice. In conclusion, combined inhibition of PI3K/mTOR and JAK2 signalling may represent a novel therapeutic strategy in MPN. PMID:24237791

  14. Structure-Function Correlation of G6, a Novel Small Molecule Inhibitor of Jak2

    PubMed Central

    Majumder, Anurima; Govindasamy, Lakshmanan; Magis, Andrew; Kiss, Róbert; Polgár, Tímea; Baskin, Rebekah; Allan, Robert W.; Agbandje-McKenna, Mavis; Reuther, Gary W.; Keserű, György M.; Bisht, Kirpal S.; Sayeski, Peter P.

    2010-01-01

    Somatic mutations in the Jak2 protein, such as V617F, cause aberrant Jak/STAT signaling and can lead to the development of myeloproliferative neoplasms. This discovery has led to the search for small molecule inhibitors that target Jak2. Using structure-based virtual screening, our group recently identified a novel small molecule inhibitor of Jak2 named G6. Here, we identified a structure-function correlation of this compound. Specifically, five derivative compounds of G6 having structural similarity to the original lead compound were obtained and analyzed for their ability to (i) inhibit Jak2-V617F-mediated cell growth, (ii) inhibit the levels of phospho-Jak2, phospho-STAT3, and phospho-STAT5; (iii) induce apoptosis in human erythroleukemia cells; and (iv) suppress pathologic cell growth of Jak2-V617F-expressing human bone marrow cells ex vivo. Additionally, we computationally examined the interactions of these compounds with the ATP-binding pocket of the Jak2 kinase domain. We found that the stilbenoid core-containing derivatives of G6 significantly inhibited Jak2-V617F-mediated cell proliferation in a time- and dose-dependent manner. They also inhibited phosphorylation of Jak2, STAT3, and STAT5 proteins within cells, resulting in higher levels of apoptosis via the intrinsic apoptotic pathway. Finally, the stilbenoid derivatives inhibited the pathologic growth of Jak2-V617F-expressing human bone marrow cells ex vivo. Collectively, our data demonstrate that G6 has a stilbenoid core that is indispensable for maintaining its Jak2 inhibitory potential. PMID:20667821

  15. Genetic variation at MECOM, TERT, JAK2 and HBS1L-MYB predisposes to myeloproliferative neoplasms

    PubMed Central

    Tapper, William; Jones, Amy V.; Kralovics, Robert; Harutyunyan, Ashot S.; Zoi, Katerina; Leung, William; Godfrey, Anna L.; Guglielmelli, Paola; Callaway, Alison; Ward, Daniel; Aranaz, Paula; White, Helen E.; Waghorn, Katherine; Lin, Feng; Chase, Andrew; Joanna Baxter, E.; Maclean, Cathy; Nangalia, Jyoti; Chen, Edwin; Evans, Paul; Short, Michael; Jack, Andrew; Wallis, Louise; Oscier, David; Duncombe, Andrew S.; Schuh, Anna; Mead, Adam J.; Griffiths, Michael; Ewing, Joanne; Gale, Rosemary E.; Schnittger, Susanne; Haferlach, Torsten; Stegelmann, Frank; Döhner, Konstanze; Grallert, Harald; Strauch, Konstantin; Tanaka, Toshiko; Bandinelli, Stefania; Giannopoulos, Andreas; Pieri, Lisa; Mannarelli, Carmela; Gisslinger, Heinz; Barosi, Giovanni; Cazzola, Mario; Reiter, Andreas; Harrison, Claire; Campbell, Peter; Green, Anthony R.; Vannucchi, Alessandro; Cross, Nicholas C.P.

    2015-01-01

    Clonal proliferation in myeloproliferative neoplasms (MPN) is driven by somatic mutations in JAK2, CALR or MPL, but the contribution of inherited factors is poorly characterized. Using a three-stage genome-wide association study of 3,437 MPN cases and 10,083 controls, we identify two SNPs with genome-wide significance in JAK2V617F-negative MPN: rs12339666 (JAK2; meta-analysis P=1.27 × 10−10) and rs2201862 (MECOM; meta-analysis P=1.96 × 10−9). Two additional SNPs, rs2736100 (TERT) and rs9376092 (HBS1L/MYB), achieve genome-wide significance when including JAK2V617F-positive cases. rs9376092 has a stronger effect in JAK2V617F-negative cases with CALR and/or MPL mutations (Breslow–Day P=4.5 × 10−7), whereas in JAK2V617F-positive cases rs9376092 associates with essential thrombocythemia (ET) rather than polycythemia vera (allelic χ2 P=7.3 × 10−7). Reduced MYB expression, previously linked to development of an ET-like disease in model systems, associates with rs9376092 in normal myeloid cells. These findings demonstrate that multiple germline variants predispose to MPN and link constitutional differences in MYB expression to disease phenotype. PMID:25849990

  16. Results of a phase 2 study of pacritinib (SB1518), a JAK2/JAK2(V617F) inhibitor, in patients with myelofibrosis

    PubMed Central

    Seymour, John F.; Roberts, Andrew W.; Wadleigh, Martha; To, L. Bik; Scherber, Robyn; Turba, Elyce; Dorr, Andrew; Zhu, Joy; Wang, Lixia; Granston, Tanya; Campbell, Mary S.; Mesa, Ruben A.

    2015-01-01

    Pacritinib (SB1518) is a Janus kinase 2 (JAK2), JAK2(V617F), and Fms-like tyrosine kinase 3 inhibitor that does not inhibit JAK1. It demonstrated a favorable safety profile with promising efficacy in phase 1 studies in patients with primary and secondary myelofibrosis (MF). This multicenter phase 2 study further characterized the safety and efficacy of pacritinib in the treatment of patients with MF. Eligible patients had clinical splenomegaly poorly controlled with standard therapies or were newly diagnosed with intermediate- or high-risk Lille score. Patients with any degree of cytopenia were eligible. Thirty-five patients were enrolled. At entry, 40% had hemoglobin <10 g/dL and 43% had platelets <100 000× 109/L. Up to week 24, 8 of 26 evaluable patients (31%) achieved a ≥35% decrease in spleen volume determined by magnetic resonance imaging and 14 of 33 (42%) attained a ≥50% reduction in spleen size by physical examination. Median MF symptom improvement was ≥50% for all symptoms except fatigue. Grade 1 or 2 diarrhea (69%) and nausea (49%) were the most common treatment-emergent adverse events. The study drug was discontinued in 9 patients (26%) due to adverse events (4 severe). Pacritinib is an active agent in patients with MF, offering a potential treatment option for patients with preexisting anemia and thrombocytopenia. This trial was registered at www.clinicaltrials.gov as #NCT00745550. PMID:25762180

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

    PubMed

    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 <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.

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

    PubMed

    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

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

    PubMed Central

    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 (IC50) 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; IC50=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. PMID:22829185

  20. Molecular drug targets in myeloproliferative neoplasms: mutant ABL1, JAK2, MPL, KIT, PDGFRA, PDGFRB and FGFR1

    PubMed Central

    Tefferi, Ayalew

    2009-01-01

    Abstract Therapeutically validated oncoproteins in myeloproliferative neoplasms (MPN) include BCR-ABL1 and rearranged PDGFR proteins. The latter are products of intra- (e.g. FIP1L1-PDGFRA) or inter-chromosomal (e.g.ETV6-PDGFRB) gene fusions. BCR-ABL1 is associated with chronic myelogenous leukaemia (CML) and mutant PDGFR with an MPN phenotype characterized by eosinophilia and in addition, in case of FIP1L1-PDGFRA, bone marrow mastocytosis. These genotype-phenotype associations have been effectively exploited in the development of highly accurate diagnostic assays and molecular targeted therapy. It is hoped that the same will happen in other MPN with specific genetic alterations: polycythemia vera (JAK2V617F and other JAK2 mutations), essential thrombocythemia (JAK2V617F and MPL515 mutations), primary myelofibrosis (JAK2V617F and MPL515 mutations), systemic mastocytosis (KITD816V and other KIT mutations) and stem cell leukaemia/lymphoma (ZNF198-FGFR1 and other FGFR1 fusion genes). The current review discusses the above-listed mutant molecules in the context of their value as drug targets. PMID:19175693

  1. Stimulation of the amino acid transporter SLC6A19 by JAK2

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Bhavsar, Shefalee K.; Hosseinzadeh, Zohreh; Merches, Katja

    Highlights: Black-Right-Pointing-Pointer The amino acid transporter SLC6A19 is upregulated by Janus kinase-2 JAK2. Black-Right-Pointing-Pointer The {sup V617F}JAK2 mutant, causing myeloproliferative disease, is more effective. Black-Right-Pointing-Pointer JAK2 inhibitor AG490 reverses stimulation of SLC6A19 by {sup V617F}JAK2. Black-Right-Pointing-Pointer JAK2 enhances SLC6A19 protein insertion into the cell membrane. Black-Right-Pointing-Pointer SLC6A19 may contribute to amino acid uptake into {sup V617F}JAK2 expressing tumor cells. -- Abstract: JAK2 (Janus kinase-2) is expressed in a wide variety of cells including tumor cells and contributes to the proliferation and survival of those cells. The gain of function mutation {sup V617F}JAK2 mutant is found in the majority of myeloproliferativemore » diseases. Cell proliferation depends on the availability of amino acids. Concentrative cellular amino acid uptake is in part accomplished by Na{sup +} coupled amino acid transport through SLC6A19 (B(0)AT). The present study thus explored whether JAK2 activates SLC6A19. To this end, SLC6A19 was expressed in Xenopus oocytes with or without wild type JAK2, {sup V617F}JAK2 or inactive {sup K882E}JAK2 and electrogenic amino acid transport determined by dual electrode voltage clamp. In SLC6A19-expressing oocytes but not in oocytes injected with water or JAK2 alone, the addition of leucine (2 mM) to the bath generated a current (I{sub le}), which was significantly increased following coexpression of JAK2 or {sup V617F}JAK2, but not by coexpression of {sup K882E}JAK2. Coexpression of JAK2 enhanced the maximal transport rate without significantly modifying the affinity of the carrier. Exposure of the oocytes to the JAK2 inhibitor AG490 (40 {mu}M) resulted in a gradual decline of I{sub le}. According to chemiluminescence JAK2 enhanced the carrier protein abundance in the cell membrane. The decline of I{sub le} following inhibition of carrier insertion by brefeldin A (5 {mu}M) was

  2. A novel splicing site IRP1 somatic mutation in a patient with pheochromocytoma and JAK2V617F positive polycythemia vera: a case report.

    PubMed

    Pang, Ying; Gupta, Garima; Yang, Chunzhang; Wang, Herui; Huynh, Thanh-Truc; Abdullaev, Ziedulla; Pack, Svetlana D; Percy, Melanie J; Lappin, Terence R J; Zhuang, Zhengping; Pacak, Karel

    2018-03-13

    The role of the hypoxia signaling pathway in the pathogenesis of pheochromocytoma/paraganglioma (PPGL)-polycythemia syndrome has been elucidated. Novel somatic mutations in hypoxia-inducible factor type 2A (HIF2A) and germline mutations in prolyl hydroxylase type 1 and type 2 (PHD1 and PHD2) have been identified to cause upregulation of the hypoxia signaling pathway and its target genes including erythropoietin (EPO) and its receptor (EPOR). However, in a minority of patients presenting with this syndrome, the genetics and molecular pathogenesis remain unexplained. The aim of the present study was to uncover novel genetic causes of PPGL-polycythemia syndrome. A female presented with a history of JAK2 V617F positive PV, diagnosed in 2007, and right adrenal pheochromocytoma diagnosed and resected in 2011. Her polycythemia symptoms and hematocrit levels continued to worsen from 2007 to 2011, with an increased frequency of phlebotomies. Postoperatively, until early 2013, her hematocrit levels remained normalized. Following this, the hematocrit levels ranged between 46.4 and 48.9% [35-45%]. Tumor tissue from the patient was further tested for mutations in genes related to upregulation of the hypoxia signaling pathway including iron regulatory protein 1 (IRP1), which is a known regulator of HIF-2α mRNA translation. Functional studies were performed to investigate the consequences of these mutations, especially their effect on the HIF signaling pathway and EPO. Indel mutations (c.267-1_267delGGinsTA) were discovered at the exon 3 splicing site of IRP1. Minigene construct and splicing site analysis showed that the mutation led to a new splicing site and a frameshift mutation of IRP1, which caused a truncated protein. Fluorescence in situ hybridization analysis demonstrated heterozygous IRP1 deletions in tumor cells. Immunohistochemistry results confirmed the truncated IRP1 and overexpressed HIF-2α, EPO and EPOR in tumor cells. This is the first report which provides

  3. High Resolution Melting Analysis for JAK2 Exon 14 and Exon 12 Mutations

    PubMed Central

    Rapado, Inmaculada; Grande, Silvia; Albizua, Enriqueta; Ayala, Rosa; Hernández, José-Angel; Gallardo, Miguel; Gilsanz, Florinda; Martinez-Lopez, Joaquin

    2009-01-01

    JAK2 mutations are important criteria for the diagnosis of Philadelphia chromosome-negative myeloproliferative neoplasms. We aimed to assess JAK2 exon 14 and exon 12 mutations by high-resolution melting (HRM) analysis, which allows variation screening. The exon 14 analysis included 163 patients with polycythemia vera, secondary erythrocytoses, essential thrombocythemia, or secondary thrombocytoses, and 126 healthy subjects. The study of exon 12 included 40 JAK2 V617F-negative patients (nine of which had polycythemia vera, and 31 with splanchnic vein thrombosis) and 30 healthy subjects. HRM analyses of JAK2 exons 14 and 12 gave analytical sensitivities near 1% and both intra- and interday coefficients of variation of less than 1%. For HRM analysis of JAK2 exon 14 in polycythemia vera and essential thrombocythemia, clinical sensitivities were 93.5% and 67.9%, clinical specificities were 98.8% and 97.0%, positive predictive values were 93.5% and 79.2%, and negative predictive values were 98.8% and 94.6, respectively. Correlations were observed between the results from HRM and three commonly used analytical methods. The JAK2 exon 12 HRM results agreed completely with those from sequencing analysis, and the three mutations in exon 12 were detected by both methods. Hence, HRM analysis of exons 14 and 12 in JAK2 shows better diagnostic values than three other routinely used methods against which it was compared. In addition, HRM analysis has the advantage of detecting unknown mutations. PMID:19225136

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

    PubMed

    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.

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

    PubMed

    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.

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

    PubMed Central

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

    2015-01-01

    Background 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. Material and Methods 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. Results 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. Conclusions 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. PMID:25914801

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

    PubMed

    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.

  8. [Clinical Analysis of Driver Mutations in Patients with Ph Negative Myeloproliferative Neoplasms].

    PubMed

    He, Zhi-Peng; Tian, Hui-Yun; Tan, Ming; Wu, Yong

    2018-06-01

    To explore the relationship between driver mutations and clinical characteristics in patients with Philadelphia chromosome (Ph) negative myeloproliferative neoplasms (MPN), so as to provide evidence for diagno-sis and treatment of the disease. The clinical data of 410 patients with classic Ph negative MPN including 150 cases of polycythemia vera (PV), 188 cases of essential thrombocythemia (ET) and 72 cases of primary myelofibrosis (PMF) from January 2013 to December 2016 in Fujian Medical University Union Hospital were retrospectively analyzed. The PCR or DNA sequencing were used for JAK2 V617F, JAK2 exon12, CALR and MPL W515L/K mutation analyses, and follow-up information on patients was updated by direct phone call or follow-up in outpatient. Among the 410 patients with Ph negative MPN, 136 (33.2%) cases were asymptomatic at diagnosis. 389 cases were sequenced and JAK2 V617F was detected in 87.1% (122/140) of PV, 64.1% (118/184) of ET, 64.6% (42/65) of PMF; JAK2 exon 12 mutation in 1 case of PV; MPL W515L/K mutation in 1 case of ET and PMF, respectively; CALR mutation in 18(9.8%) cases of ET and 5 (7.7%) cases of PMF. JAK2 V617F mutated PV patients ocourred in older age: the white blood cell count, platelet count and incidence of splenomegaly were higher than JAK2-negative PV cases(P<0.05). Compared with JAK2 V617F mutated ET patients, CALR mutated ET cases displayed younger age, lower leukocyte count, higher platelet count and lower incidence of thrombosis; JAK2-negative ET cases had younger age, lower leukocyte count, lower hemoglobin level, higher platelet count and lower incidence of thrombosis(P<0.05). The incidence of splenomegaly in JAK2 V617F or CALR mutated PMF patients was both higher than that in JAK2-negative PMF cases, but the incidence of leukemia transformation in JAK2-negative PMF patients was higher than that in JAK2 V617F mutated cases (P<0.05). The types of driver mutations are closely related with the clinical features and prognosis in Ph

  9. Prospect of JAK2 inhibitor therapy in myeloproliferative neoplasms

    PubMed Central

    Atallah, Ehab; Verstovsek, Srdan

    2016-01-01

    The discovery of the Janus kinase (JAK)2 V617F mutation in patients with myeloproliferative neoplasms was a major milestone in understanding the biology of those disorders. Several groups simultaneously reported on the high incidence of this mutation in patients with myeloproliferative neoplasms: almost all patients with polycythemia vera harbor the mutation and about 50% of patients with essential thrombocythemia and primary myelofibrosis have the mutation, making the development of JAK2 tyrosine kinase inhibitors an attractive therapeutic goal. In addition, inhibition of JAK2 kinase may have a therapeutic role in other hematologic malignancies, such as chronic myeloid leukemia or lymphoma. A number of molecules that inhibit JAK2 kinase have been described in the literature, and several are being evaluated in a clinical setting. Here, we summarize current clinical experience with JAK2 inhibitors. PMID:19445582

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

    PubMed

    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.

  11. Antagonistic activities of the immunomodulator and PP2A-activating drug FTY720 (Fingolimod, Gilenya) in Jak2-driven hematologic malignancies

    PubMed Central

    Oaks, Joshua J.; Santhanam, Ramasamy; Walker, Christopher J.; Roof, Steve; Harb, Jason G.; Ferenchak, Greg; Eisfeld, Ann-Kathrin; Van Brocklyn, James R.; Briesewitz, Roger; Saddoughi, Sahar A.; Nagata, Kyosuke; Bittman, Robert; Caligiuri, Michael A.; Abdel-Wahab, Omar; Levine, Ross; Arlinghaus, Ralph B.; Quintas-Cardama, Alfonso; Goldman, John M.; Apperley, Jane; Reid, Alistair; Milojkovic, Dragana; Ziolo, Mark T.; Marcucci, Guido; Ogretmen, Besim; Neviani, Paolo

    2013-01-01

    FTY720 (Fingolimod, Gilenya) is a sphingosine analog used as an immunosuppressant in multiple sclerosis patients. FTY720 is also a potent protein phosphatase 2A (PP2A)–activating drug (PAD). PP2A is a tumor suppressor found inactivated in different types of cancer. We show here that PP2A is inactive in polycythemia vera (PV) and other myeloproliferative neoplasms characterized by the expression of the transforming Jak2V617F oncogene. PP2A inactivation occurs in a Jak2V617F dose/kinase-dependent manner through the PI-3Kγ-PKC–induced phosphorylation of the PP2A inhibitor SET. Genetic or PAD-mediated PP2A reactivation induces Jak2V617F inactivation/downregulation and impairs clonogenic potential of Jak2V617F cell lines and PV but not normal CD34+ progenitors. Likewise, FTY720 decreases leukemic allelic burden, reduces splenomegaly, and significantly increases survival of Jak2V617F leukemic mice without adverse effects. Mechanistically, we show that in Jak2V617F cells, FTY720 antileukemic activity requires neither FTY720 phosphorylation (FTY720-P) nor SET dimerization or ceramide induction but depends on interaction with SET K209. Moreover, we show that Jak2V617F also utilizes an alternative sphingosine kinase-1–mediated pathway to inhibit PP2A and that FTY720-P, acting as a sphingosine-1-phosphate-receptor-1 agonist, elicits signals leading to the Jak2-PI-3Kγ-PKC-SET–mediated PP2A inhibition. Thus, PADs (eg, FTY720) represent suitable therapeutic alternatives for Jak2V617F MPNs. PMID:23926298

  12. Effect of Mutation Order on Myeloproliferative Neoplasms

    PubMed Central

    Nangalia, Jyoti; Silber, Yvonne; Wedge, David C.; Grinfeld, Jacob; Baxter, E. Joanna; Massie, Charles E.; Papaemmanuil, Elli; Menon, Suraj; Godfrey, Anna L.; Dimitropoulou, Danai; Guglielmelli, Paola; Bellosillo, Beatriz; Besses, Carles; Döhner, Konstanze; Harrison, Claire N.; Vassiliou, George S.; Vannucchi, Alessandro; Campbell, Peter J.; Green, Anthony R.

    2015-01-01

    BACKGROUND Cancers result from the accumulation of somatic mutations, and their properties are thought to reflect the sum of these mutations. However, little is known about the effect of the order in which mutations are acquired. METHODS We determined mutation order in patients with myeloproliferative neoplasms by genotyping hematopoietic colonies or by means of next-generation sequencing. Stem cells and progenitor cells were isolated to study the effect of mutation order on mature and immature hematopoietic cells. RESULTS The age at which a patient presented with a myeloproliferative neoplasm, acquisition of JAK2 V617F homozygosity, and the balance of immature progenitors were all influenced by mutation order. As compared with patients in whom the TET2 mutation was acquired first (hereafter referred to as “TET2-first patients”), patients in whom the Janus kinase 2 (JAK2) mutation was acquired first (“JAK2-first patients”) had a greater likelihood of presenting with polycythemia vera than with essential thrombocythemia, an increased risk of thrombosis, and an increased sensitivity of JAK2-mutant progenitors to ruxolitinib in vitro. Mutation order influenced the proliferative response to JAK2 V617F and the capacity of double-mutant hematopoietic cells and progenitor cells to generate colony-forming cells. Moreover, the hematopoietic stem-and-progenitor-cell compartment was dominated by TET2 single-mutant cells in TET2-first patients but by JAK2–TET2 double-mutant cells in JAK2-first patients. Prior mutation of TET2 altered the transcriptional consequences of JAK2 V617F in a cell-intrinsic manner and prevented JAK2 V617F from up-regulating genes associated with proliferation. CONCLUSIONS The order in which JAK2 and TET2 mutations were acquired influenced clinical features, the response to targeted therapy, the biology of stem and progenitor cells, and clonal evolution in patients with myeloproliferative neoplasms. (Funded by Leukemia and Lymphoma Research

  13. Mechanisms of mutations in myeloproliferative neoplasms.

    PubMed

    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.

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

    PubMed

    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.

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

    PubMed

    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.

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

    PubMed Central

    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.

    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 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. PMID:20154217

  17. Novel mutations in the inhibitory adaptor protein LNK drive JAK-STAT signaling in patients with myeloproliferative neoplasms

    PubMed Central

    Oh, Stephen T.; Simonds, Erin F.; Jones, Carol; Hale, Matthew B.; Goltsev, Yury; Gibbs, Kenneth D.; Merker, Jason D.; Zehnder, James L.; Nolan, Garry P.

    2010-01-01

    Dysregulated Janus kinase–signal transducer and activator of transcription (JAK-STAT) signaling due to activation of tyrosine kinases is a common feature of myeloid malignancies. Here we report the first human disease-related mutations in the adaptor protein LNK, a negative regulator of JAK-STAT signaling, in 2 patients with JAK2 V617F–negative myeloproliferative neoplasms (MPNs). One patient exhibited a 5 base-pair deletion and missense mutation leading to a premature stop codon and loss of the pleckstrin homology (PH) and Src homology 2 (SH2) domains. A second patient had a missense mutation (E208Q) in the PH domain. BaF3-MPL cells transduced with these LNK mutants displayed augmented and sustained thrombopoietin-dependent growth and signaling. Primary samples from MPN patients bearing LNK mutations exhibited aberrant JAK-STAT activation, and cytokine-responsive CD34+ early progenitors were abnormally abundant in both patients. These findings indicate that JAK-STAT activation due to loss of LNK negative feedback regulation is a novel mechanism of MPN pathogenesis. PMID:20404132

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

    PubMed

    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.

  19. CYT387, a novel JAK2 inhibitor, induces hematologic responses and normalizes inflammatory cytokines in murine myeloproliferative neoplasms

    PubMed Central

    Tyner, Jeffrey W.; Bumm, Thomas G.; Deininger, Jutta; Wood, Lisa; Aichberger, Karl J.; Loriaux, Marc M.; Druker, Brian J.; Burns, Christopher J.; Fantino, Emmanuelle

    2010-01-01

    Activating alleles of Janus kinase 2 (JAK2) such as JAK2V617F are central to the pathogenesis of myeloproliferative neoplasms (MPN), suggesting that small molecule inhibitors targeting JAK2 may be therapeutically useful. We have identified an aminopyrimidine derivative (CYT387), which inhibits JAK1, JAK2, and tyrosine kinase 2 (TYK2) at low nanomolar concentrations, with few additional targets. Between 0.5 and 1.5μM CYT387 caused growth suppression and apoptosis in JAK2-dependent hematopoietic cell lines, while nonhematopoietic cell lines were unaffected. In a murine MPN model, CYT387 normalized white cell counts, hematocrit, spleen size, and restored physiologic levels of inflammatory cytokines. Despite the hematologic responses and reduction of the JAK2V617F allele burden, JAK2V617F cells persisted and MPN recurred upon cessation of treatment, suggesting that JAK2 inhibitors may be unable to eliminate JAK2V617F cells, consistent with preliminary results from clinical trials of JAK2 inhibitors in myelofibrosis. While the clinical benefit of JAK2 inhibitors may be substantial, not the least due to reduction of inflammatory cytokines and symptomatic improvement, our data add to increasing evidence that kinase inhibitor monotherapy of malignant disease is not curative, suggesting a need for drug combinations to optimally target the malignant cells. PMID:20385788

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

    PubMed

    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.

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

    PubMed

    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.

  2. The oral HDAC inhibitor pracinostat (SB939) is efficacious and synergistic with the JAK2 inhibitor pacritinib (SB1518) in preclinical models of AML

    PubMed Central

    Novotny-Diermayr, V; Hart, S; Goh, K C; Cheong, A; Ong, L-C; Hentze, H; Pasha, M K; Jayaraman, R; Ethirajulu, K; Wood, J M

    2012-01-01

    Acute myeloid leukemia (AML) is currently treated with aggressive chemotherapy that is not well tolerated in many elderly patients, hence the unmet medical need for effective therapies with less toxicity and better tolerability. Inhibitors of FMS-like tyrosine kinase 3 (FLT3), JAK2 and histone deacetylase inhibitors (HDACi) have been tested in clinical studies, but showed only moderate single-agent activity. High efficacy of the HDACi pracinostat treating AML and synergy with the JAK2/FLT3 inhibitor pacritinib is demonstrated. Both compounds inhibit JAK-signal transducer and activator of transcription (STAT) signaling in AML cells with JAK2V617F mutations, but also diminish FLT3 signaling, particularly in FLT3-ITD (internal tandem duplication) cell lines. In vitro, this combination led to decreased cell proliferation and increased apoptosis. The synergy translated in vivo in two different AML models, the SET-2 megakaryoblastic AML mouse model carrying a JAK2V617F mutation, and the MOLM-13 model of FLT3-ITD-driven AML. Pracinostat and pacritinib in combination showed synergy on tumor growth, reduction of metastases and synergistically decreased JAK2 or FLT signaling, depending on the cellular context. In addition, several plasma cytokines/growth factors/chemokines triggered by the tumor growth were normalized, providing a rationale for combination therapy with an HDACi and a JAK2/FLT3 inhibitor for the treatment of AML patients, particularly those with FLT3 or JAK2 mutations. PMID:22829971

  3. Molecular analyses of 15,542 patients with suspected BCR-ABL1-negative myeloproliferative disorders allow to develop a stepwise diagnostic workflow

    PubMed Central

    Schnittger, Susanne; Bacher, Ulrike; Eder, Christiane; Dicker, Frank; Alpermann, Tamara; Grossmann, Vera; Kohlmann, Alexander; Kern, Wolfgang; Haferlach, Claudia; Haferlach, Torsten

    2012-01-01

    We investigated 15,542 patients with suspected BCR-ABL1- negative myeloproliferative or myelodysplastic/myeloproliferative neoplasm (including 359 chronic myelomonocytic leukemia) by a molecular marker set. JAK2V617F was detected in the suspected categories as follows: polycythemia vera 88.3%, primary myelofibrosis 53.8%, essential thrombocythemia 50.2%, and not further classifiable myeloproliferative neoplasms 38.0%. JAK2 exon 12 mutations were detected in 40.0% JAK2V617F-negative suspected polycythemia vera, MPLW515 mutations in 13.2%JAK2V617F-negative primary myelofibrosis and 7.1% JAK2V617F-negative essential thrombocythemia. TET2 mutations were distributed across all entities but were most frequent in suspected chronic myelomonocytic leukemia (77.8%). CBL mutations were identified in suspected chronic myelomonocytic leukemia (13.9%), primary myelofibrosis (8.0%), and not further classifiable myeloproliferative neoplasm (7.0%). This leads to a stepwise workflow for suspected myeloproliferative neoplasms starting with JAK2V617F and investigating JAK2V617F-negative patients for JAK2 exon 12 or MPL mutations, respectively. In cases in which a myeloproliferative neoplasm cannot be established, analysis for TET2, CBL and EZH2 mutations may be indicated. PMID:22511494

  4. MPLW515L Is a Novel Somatic Activating Mutation in Myelofibrosis with Myeloid Metaplasia

    PubMed Central

    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

    2006-01-01

    Background 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). Methods and Findings 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 × 10 12/L), marked splenomegaly due to extramedullary hematopoiesis, and increased reticulin fibrosis. Conclusions 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

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

    PubMed

    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

  6. An accurate, simple prognostic model consisting of age, JAK2, CALR, and MPL mutation status for patients with primary myelofibrosis.

    PubMed

    Rozovski, Uri; Verstovsek, Srdan; Manshouri, Taghi; Dembitz, Vilma; Bozinovic, Ksenija; Newberry, Kate; Zhang, Ying; Bove, Joseph E; Pierce, Sherry; Kantarjian, Hagop; Estrov, Zeev

    2017-01-01

    In most patients with primary myelofibrosis, one of three mutually exclusive somatic mutations is detected. In approximately 60% of patients, the Janus kinase 2 gene is mutated, in 20%, the calreticulin gene is mutated, and in 5%, the myeloproliferative leukemia virus gene is mutated. Although patients with mutated calreticulin or myeloproliferative leukemia genes have a favorable outcome, and those with none of these mutations have an unfavorable outcome, prognostication based on mutation status is challenging due to the heterogeneous survival of patients with mutated Janus kinase 2. To develop a prognostic model based on mutation status, we screened primary myelofibrosis patients seen at the MD Anderson Cancer Center, Houston, USA, between 2000 and 2013 for the presence of Janus kinase 2, calreticulin, and myeloproliferative leukemia mutations. Of 344 primary myelofibrosis patients, Janus kinase 2 V617F was detected in 226 (66%), calreticulin mutation in 43 (12%), and myeloproliferative leukemia mutation in 16 (5%); 59 patients (17%) were triple-negatives. A 50% cut-off dichotomized Janus kinase 2-mutated patients into those with high Janus kinase 2 V617F allele burden and favorable survival and those with low Janus kinase 2 V617F allele burden and unfavorable survival. Patients with a favorable mutation status (high Janus kinase 2 V617F allele burden/myeloproliferative leukemia/calreticulin mutation) and aged 65 years or under had a median survival of 126 months. Patients with one risk factor (low Janus kinase 2 V617F allele burden/triple-negative or age >65 years) had an intermediate survival duration, and patients aged over 65 years with an adverse mutation status (low Janus kinase 2 V617F allele burden or triple-negative) had a median survival of only 35 months. Our simple and easily applied age- and mutation status-based scoring system accurately predicted the survival of patients with primary myelofibrosis. Copyright© Ferrata Storti Foundation.

  7. JAK inhibitors for the treatment of myeloproliferative neoplasms and other disorders

    PubMed Central

    Vainchenker, William; Leroy, Emilie; Gilles, Laure; Marty, Caroline; Plo, Isabelle; Constantinescu, Stefan N.

    2018-01-01

    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 molecule. In

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

    PubMed

    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.

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

    PubMed

    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

  10. MECOM, HBS1L-MYB, THRB-RARB, JAK2, and TERT polymorphisms defining the genetic predisposition to myeloproliferative neoplasms: A study on 939 patients.

    PubMed

    Trifa, Adrian P; Bănescu, Claudia; Bojan, Anca S; Voina, Cristian M; Popa, Ștefana; Vișan, Simona; Ciubean, Alina D; Tripon, Florin; Dima, Delia; Popov, Viola M; Vesa, Ștefan C; Andreescu, Mihaela; Török-Vistai, Tünde; Mihăilă, Romeo G; Berbec, Nicoleta; Macarie, Ioan; Coliţă, Andrei; Iordache, Maria; Cătană, Alina C; Farcaș, Marius F; Tomuleasa, Ciprian; Vasile, Kinga; Truică, Cristina; Todincă, Adriana; Pop-Muntean, Lavinia; Manolache, Raluca; Bumbea, Horia; Vlădăreanu, Ana-Maria; Gaman, Mihaela; Ciufu, Cristina M; Popp, Radu A

    2018-01-01

    Polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF) are classical myeloproliferative neoplasms (MPN), characterized by specific somatic mutations in JAK2, CALR or MPL genes. JAK2 46/1 and TERT rs2736100 polymorphisms are known to significantly predispose to MPN. This study aimed to establish the additional contribution of the recently described MECOM rs2201862, HBS1L-MYB rs9376092 and THRB-RARB rs4858647 polymorphisms to the occurrence of MPN. These three polymorphisms, along with JAK2 46/1 and TERT rs2736100 were genotyped in 939 MPN patients (454 with ET, 337 with PV and 148 with PMF) and 483 controls. MECOM rs2201862 associated significantly with each MPN entity, except for ET, and with all major molecular sub-types, especially those CALR-mutated (OR = 1.4; 95% CI = 1.1-1.8; P-value = .005). HBS1L-MYB rs9376092 associated only with JAK2 V617F-mutated ET (OR = 1.4; 95% CI = 1.1-1.7; P-value = .003). THRB-RARB rs4858647 had a weak association with PMF only (OR = 1.5; 95% CI = 1-2.1; P-value = .04). Surprisingly, JAK2 46/1 haplotype was associated significantly not only with JAK2 V617F-mutated MPN, but also with CALR-mutated MPN (OR = 1.4; 95% CI = 1.1-1.8; P-value = .01). TERT rs2736100 was associated equally strong with all MPN, regardless of phenotype or molecular sub-type. In conclusion, JAK2 46/1, TERT rs2736100 and MECOM rs2201862 are the chief predisposing polymorphisms to MPN. © 2017 Wiley Periodicals, Inc.

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

    PubMed

    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.

  12. Contribution of JAK2 mutations to T-cell lymphoblastic lymphoma development.

    PubMed

    Roncero, A M; López-Nieva, P; Cobos-Fernández, M A; Villa-Morales, M; González-Sánchez, L; López-Lorenzo, J L; Llamas, P; Ayuso, C; Rodríguez-Pinilla, S M; Arriba, M C; Piris, M A; Fernández-Navarro, P; Fernández, A F; Fraga, M F; Santos, J; Fernández-Piqueras, J

    2016-01-01

    The JAK-STAT pathway has a substantial role in lymphoid precursor cell proliferation, survival and differentiation. Nonetheless, the contribution of JAK2 to T-cell lymphoblastic lymphoma (T-LBL) development remains poorly understood. We have identified one activating TEL-JAK2 translocation and four missense mutations accumulated in 2 out of 16 T-LBL samples. Two of them are novel JAK2 mutations and the other two are reported for the first time in T-LBL. Notably, R683G and I682T might have arisen owing to RNA editing. Mutated samples showed different mutated transcripts suggesting sub-clonal heterogeneity. Functional approaches revealed that two JAK2 mutations (H574R and R683G) constitutively activate JAK-STAT signaling in γ2A cells and can drive the proliferation of BaF3-EpoR cytokine-dependent cell line. In addition, aberrant hypermethylation of SOCS3 might contribute to enhance the activation of JAK-STAT signaling. Of utmost interest is that primary T-LBL samples harboring JAK2 mutations exhibited increased expression of LMO2, suggesting a mechanistic link between JAK2 mutations and the expression of LMO2, which was confirmed for the four missense mutations in transfected γ2A cells. We therefore propose that active JAK2 contribute to T-LBL development by two different mechanisms, and that the use of pan-JAK inhibitors in combination with epigenetic drugs should be considered in future treatments.

  13. Contribution of JAK2 mutations to T-cell lymphoblastic lymphoma development

    PubMed Central

    Roncero, A M; López-Nieva, P; Cobos-Fernández, M A; Villa-Morales, M; González-Sánchez, L; López-Lorenzo, J L; Llamas, P; Ayuso, C; Rodríguez-Pinilla, S M; Arriba, M C; Piris, M A; Fernández-Navarro, P; Fernández, A F; Fraga, M F; Santos, J; Fernández-Piqueras, J

    2016-01-01

    The JAK-STAT pathway has a substantial role in lymphoid precursor cell proliferation, survival and differentiation. Nonetheless, the contribution of JAK2 to T-cell lymphoblastic lymphoma (T-LBL) development remains poorly understood. We have identified one activating TEL-JAK2 translocation and four missense mutations accumulated in 2 out of 16 T-LBL samples. Two of them are novel JAK2 mutations and the other two are reported for the first time in T-LBL. Notably, R683G and I682T might have arisen owing to RNA editing. Mutated samples showed different mutated transcripts suggesting sub-clonal heterogeneity. Functional approaches revealed that two JAK2 mutations (H574R and R683G) constitutively activate JAK-STAT signaling in γ2A cells and can drive the proliferation of BaF3-EpoR cytokine-dependent cell line. In addition, aberrant hypermethylation of SOCS3 might contribute to enhance the activation of JAK-STAT signaling. Of utmost interest is that primary T-LBL samples harboring JAK2 mutations exhibited increased expression of LMO2, suggesting a mechanistic link between JAK2 mutations and the expression of LMO2, which was confirmed for the four missense mutations in transfected γ2A cells. We therefore propose that active JAK2 contribute to T-LBL development by two different mechanisms, and that the use of pan-JAK inhibitors in combination with epigenetic drugs should be considered in future treatments. PMID:26216197

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

    PubMed

    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.

  15. Impact of genotype on leukaemic transformation in polycythaemia vera and essential thrombocythaemia.

    PubMed

    Alvarez-Larrán, Alberto; Senín, Alicia; Fernández-Rodríguez, Concepción; Pereira, Arturo; Arellano-Rodrigo, Eduardo; Gómez, Montse; Ferrer-Marin, Francisca; Martínez-López, Joaquín; Camacho, Laura; Colomer, Dolors; Angona, Anna; Navarro, Blanca; Cervantes, Francisco; Besses, Carlos; Bellosillo, Beatriz; Hernández-Boluda, Juan Carlos

    2017-09-01

    The influence of driver mutations on leukaemic transformation was analysed in 1747 patients with polycythaemia vera or essential thrombocythaemia. With a median follow-up of 7·2 years, 349 patients died and 62 progressed to acute leukaemia or myelodysplastic syndrome. Taking death as a competing risk, CALR genotype was associated with a lower risk of transformation [subdistribution hazard ratio (SHR): 0·13, 95% confidence interval (CI): 0·2-0·9, P = 0·039], whereas JAK2 V617F showed borderline significance for higher risk (SHR: 2·05, 95% CI: 0·9-4·6, P = 0·09). Myelofibrotic transformation increased leukaemic risk, except in CALR-mutated patients. Next generation sequencing of 51 genes at the time of transformation showed additional mutations (median number: 3; range: 1-5) in 25 out of 29 (86%) assessable cases. Mutations (median: 1; range: 1-3) were detected in 67% of paired samples from the chronic phase. Leukaemia appeared in a JAK2 V617F negative clone in 17 (58%) cases, eleven of them being previously JAK2 V617F-positive. JAK2 V617F-mutated leukaemia was significantly associated with complex karyotype and acquisition of TP53 mutations, whereas EZH2 and RUNX1 mutations were more frequent in JAK2 V617F-negative leukaemia. Survival was longer in JAK2 V617F-unmutated leukaemia (343 days vs. 95 days, P = 0·003). In conclusion, CALR genotype is associated with a lower risk of leukaemic transformation. Leukaemia arising in a JAK2 V617F-negative clone is TP53 independent and shows better survival. © 2017 John Wiley & Sons Ltd.

  16. PO-19 - Platelet (PLT) adhesion under flow condition in essential thrombocythemia (ET) and polycythemia vera (PV) is variably influenced according to patient mutational status.

    PubMed

    Vignoli, A; Tessarolo, S; Marchetti, M; Gamba, S; Piras, F; Finazzi, G; van der Meijden, P E J; Swieringa, F; Ten Cate, H; Heemskerk, J W M; Rambaldi, A; Falanga, A

    2016-04-01

    The myeloproliferative neoplasms ET and PV are characterized by a high incidence of both arterial and venous thrombosis, and/or microcirculatory disturbances. Three somatic mutations, i.e. JAK2-V617F, Calreticulin (CalR) and MPL, commonly found in these diseases, correlate with different thrombotic risk levels. To analyze the influence of JAK2-V617F, CalR and MPL mutations on PLT adhesion, evaluated by a dynamic method under flow conditions in a group of patients with ET and PV. 86 patients, i.e. 51 ET (19 M/32 F; age range 32-86 years) and 35PV (22 M/13 F; 41-83 yrs.), and 24 healthy controls (13 M/11 F; 28-61 yrs.) were enrolled upon informed consent. For the adhesion assay, peripheral venous whole blood was perfused over collagen for 4' at a 1,000 s-1 shear rate. PLTs were then stained with an anti-P-selectin-FITC antibody to evaluate PLT activation, and annexin V-AlexaFluor647 to detect procoagulant phosphatidylserine expression. Then, images of adherent PLTs in random fields were taken using phase contrast and fluorescence imaging by EVOS® fluorescence microscope. Results are mean±SEM of the % area covered by PLTs, or as the % of adherent PLTs positive for P-selectin or phosphatidylserine. Main hematological parameters and mutational status were recorded. PLT adhesion was significantly (p<0.01) greater in ET (44.6±1.6%) and PV patients (49.0±1.9%) compared to controls (37.9±1.7%). In ET, PLT adhesion was highest in JAK2-V617F mutation carriers (n=23), followed by CalR-positive (n=16) and triple negative subjects (n=9), and lowest in the MPL-positive patients (n=3). In PV, no difference in PLT adhesion was observed between JAK2-V617F heterozygous and homozygous subjects. P-selectin expression by adherent PLTs was not statistically different between patients and controls. Differently, phosphatidylserine expression on adherent PLTs was significantly reduced (p<0.01) in both ET and PV compared to healthy subjects. In ET patients, a significant (p<0

  17. A risk of essential thrombocythemia in carriers of constitutional CHEK2 gene mutations.

    PubMed

    Janiszewska, Hanna; Bak, Aneta; Pilarska, Maria; Heise, Marta; Junkiert-Czarnecka, Anna; Kuliszkiewicz-Janus, Małgorzata; Całbecka, Małgorzata; Jaźwiec, Bozena; Wołowiec, Dariusz; Kuliczkowski, Kazimierz; Haus, Olga

    2012-03-01

    Germline mutations of the CHEK2 gene have been reported in some myeloid and lymphoid malignancies, but their impact on development of essential thrombocythemia has not been studied. In 16 out of 106 (15.1%) consecutive patients, newly diagnosed with essential thrombocythemia, we found one of four analyzed CHEK2 mutations: I157T, 1100delC, IVS2+1G>A or del5395. They were associated with the increased risk of disease (OR=3.8; P=0.002). The median age at ET diagnosis among CHEK2+/JAK2V617F+ patients was seven years lower than that among CHEK2-/JAK2V617F+ (52 vs. 59 years; P=0.04), whereas there was no difference in the medians of hematologic parameters between these groups. The results obtained suggest that CHEK2 mutations could potentially contribute to the susceptibility to essential thrombocythemia. The germline inactivation of CHEK2, as it seems, has no direct impact on the development of disease, but it could cause disruption of cell cycle checkpoints and initiate or support the cancerogenic process of essential thrombocythemia at a younger age.

  18. A risk of essential thrombocythemia in carriers of constitutional CHEK2 gene mutations

    PubMed Central

    Janiszewska, Hanna; Bąk, Aneta; Pilarska, Maria; Heise, Marta; Junkiert-Czarnecka, Anna; Kuliszkiewicz-Janus, Małgorzata; Całbecka, Małgorzata; JaŸwiec, Bożena; Wołowiec, Dariusz; Kuliczkowski, Kazimierz; Haus, Olga

    2012-01-01

    Germline mutations of the CHEK2 gene have been reported in some myeloid and lymphoid malignancies, but their impact on development of essential thrombocythemia has not been studied. In 16 out of 106 (15.1%) consecutive patients, newly diagnosed with essential thrombocythemia, we found one of four analyzed CHEK2 mutations: I157T, 1100delC, IVS2+1G>A or del5395. They were associated with the increased risk of disease (OR=3.8; P=0.002). The median age at ET diagnosis among CHEK2+/JAK2V617F+ patients was seven years lower than that among CHEK2−/JAK2V617F+ (52 vs. 59 years; P=0.04), whereas there was no difference in the medians of hematologic parameters between these groups. The results obtained suggest that CHEK2 mutations could potentially contribute to the susceptibility to essential thrombocythemia. The germline inactivation of CHEK2, as it seems, has no direct impact on the development of disease, but it could cause disruption of cell cycle checkpoints and initiate or support the cancerogenic process of essential thrombocythemia at a younger age. PMID:22058216

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

    PubMed

    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.

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

    PubMed

    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.

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

    PubMed

    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.

  2. Targeting glutamine metabolism in myeloproliferative neoplasms

    PubMed Central

    Zhan, Huichun; Ciano, Kristen; Dong, Katherine; Zucker, Stanley

    2016-01-01

    JAK2V617F mutation can be detected in the majority of myeloproliferative neoplasm (MPN) patients. The JAK2 inhibitor Ruxolitinib is the first FDA-approved treatment for MPNs. However, its use is limited by various dose related toxicities. Here, we studied the metabolic state and glutamine metabolism of BaF3-hEPOR-JAK2V617F and BaF3-hEPOR-JAK2WT cells. We found that the JAK2V617F-mutant cells were associated with increased oxygen consumption rate and extracellular acidification rate than the JAK2WT cells and there was an increased glutamine metabolism in JAK2V617F-mutant cells compared to wild-type cells. Glutaminase (GLS), the key enzyme in gluta-mine metabolism, was upregulated in the JAK2V617F-mutant BaF3 cells compared to the JAK2WT BaF3 cells. In MPN patient peripheral blood CD34+ cells, GLS expression was increased in JAK2V617F-mutant progenitor cells compared to JAK2 wild-type progenitor cells from the same patients and GLS levels were increased at the time of disease progression compared to at earlier time points. Moreover, GLS inhibitor increased the growth inhibitory effect of Ruxolitinib in both JAK2V617F-mutant cell lines and peripheral blood CD34+ cells from MPN patients. Therefore, GLS inhibitor should be further explored to enhance the therapeutic effectiveness of JAK2 inhibitor and allow the administration of lower doses of the drug to avoid its toxicity. PMID:26227854

  3. The Small Molecule Inhibitor G6 Significantly Reduces Bone Marrow Fibrosis and the Mutant Burden in a Mouse Model of Jak2-Mediated Myelofibrosis

    PubMed Central

    Kirabo, Annet; Park, Sung O.; Wamsley, Heather L.; Gali, Meghanath; Baskin, Rebekah; Reinhard, Mary K.; Zhao, Zhizhuang J.; Bisht, Kirpal S.; Keserű, György M.; Cogle, Christopher R.; Sayeski, Peter P.

    2013-01-01

    Philadelphia chromosome–negative myeloproliferative neoplasms, including polycythemia vera, essential thrombocytosis, and myelofibrosis, are disorders characterized by abnormal hematopoiesis. Among these myeloproliferative neoplasms, myelofibrosis has the most unfavorable prognosis. Furthermore, currently available therapies for myelofibrosis have little to no efficacy in the bone marrow and hence, are palliative. We recently developed a Janus kinase 2 (Jak2) small molecule inhibitor called G6 and found that it exhibits marked efficacy in a xenograft model of Jak2-V617F–mediated hyperplasia and a transgenic mouse model of Jak2-V617F–mediated polycythemia vera/essential thrombocytosis. However, its efficacy in Jak2-mediated myelofibrosis has not previously been examined. Here, we hypothesized that G6 would be efficacious in Jak2-V617F–mediated myelofibrosis. To test this, mice expressing the human Jak2-V617F cDNA under the control of the vav promoter were administered G6 or vehicle control solution, and efficacy was determined by measuring parameters within the peripheral blood, liver, spleen, and bone marrow. We found that G6 significantly reduced extramedullary hematopoiesis in the liver and splenomegaly. In the bone marrow, G6 significantly reduced pathogenic Jak/STAT signaling by 53%, megakaryocytic hyperplasia by 70%, and the Jak2 mutant burden by 68%. Furthermore, G6 significantly improved the myeloid to erythroid ratio and significantly reversed the myelofibrosis. Collectively, these results indicate that G6 is efficacious in Jak2-V617F–mediated myelofibrosis, and given its bone marrow efficacy, it may alter the natural history of this disease. PMID:22796437

  4. Simultaneous screening for JAK2 and calreticulin gene mutations in myeloproliferative neoplasms with high resolution melting.

    PubMed

    Matsumoto, Nariyoshi; Mori, Sayaka; Hasegawa, Hiroo; Sasaki, Daisuke; Mori, Hayato; Tsuruda, Kazuto; Imanishi, Daisuke; Imaizumi, Yoshitaka; Hata, Tomoko; Kaku, Norihito; Kosai, Kousuke; Uno, Naoki; Miyazaki, Yasushi; Yanagihara, Katsunori

    2016-11-01

    Recently, novel calreticulin (CALR) mutations were discovered in Janus kinase 2 (JAK2) non-mutated myelofibrosis (PMF) and essential thrombocythemia (ET) cases, with a frequency of 60-80%. We examined clinical correlations and CALR mutation frequency in our myeloproliferative neoplasms (MPN) cases, and introduce an effective test method for use in clinical practice. We examined 177 samples previously investigated for the JAK2 mutation for differential diagnosis of MPN. JAK2 and CALR mutations were analyzed using melting curve analysis and microchip electrophoresis, respectively. Next, we constructed a test for simultaneous screening of the JAK2 and CALR mutations utilizing high resolution melting (HRM). Among 99 MPN cases, 60 possessed the JAK2 mutation alone. Of the 39 MPN cases without the JAK2 mutation, 14 were positive for the CALR mutation, all of which were ET. Using our novel screening test for the JAK2 and CALR mutations by HRM, the concordance rate of conventional analysis with HRM was 96% for the JAK2 mutation and 95% for the CALR mutation. Our novel simultaneous screening test for the JAK2 and CALR gene mutations with HRM is useful for diagnosis of MPN. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  5. Germline variations at JAK2, TERT, HBS1L-MYB and MECOM and the risk of myeloproliferative neoplasms in Taiwanese population

    PubMed Central

    Chiang, Yi-Hao; Chang, Yu-Cheng; Lin, Huan-Chau; Huang, Ling; Cheng, Chun-Chia; Wang, Wei-Ting; Cheng, Hung-I; Su, Nai-Wen; Chen, Caleb Gon-Shen; Lin, Johnson; Chang, Yi-Fang; Chang, Ming-Chih; Hsieh, Ruey-Kuen; Chou, Wen-Chien; Lim, Ken-Hong; Kuo, Yuan-Yeh

    2017-01-01

    Germline variations at JAK2, TERT, HBS1L-MYB and MECOM have been found to associate with myeloproliferative neoplasms (MPNs) in European populations. Whether these germline variations are associated with MPNs in Taiwanese population is obscure. Here we aimed to evaluate the association of five germline variations (JAK2 46/1 haplotype tagged by rs12343867, JAK2 intron 8 rs12339666, TERT rs2736100, HBS1L-MYB rs9376092 and MECOM rs2201862) and the risk of MPNs in Taiwanese population. A total of 178 MPN patients (109 essential thrombocythemia, 54 polycythemia vera and 15 primary myelofibrosis) were enrolled into this study. The information of 17033 control subjects was obtained from Taiwan Biobank database. The JAK2 46/1 haplotype, JAK2 rs12339666 and TERT rs2736100 were significantly associated with Taiwanese MPNs (P = 3.6×10-19, 1.9×10-19 and 3.1×10-6, respectively), and JAK2V617F-positive MPNs (n=121) (P = 5.6×10-21, 4.4×10-21 and 8.6×10-7, respectively). In JAK2V617F-negative cases (n=55), only the JAK2 46/1 haplotype and JAK2 rs12339666 remained statistically significant (P= 0.009 and 0.007, respectively). When stratified by disease subtypes, the JAK2 46/1 haplotype and JAK2 rs12339666 were significantly associated with all three MPN subtypes, but TERT rs2736100 was only associated with essential thrombocythemia and polycythemia vera. We did not find any association of these five SNPs with CALR mutations in our cohort. Furthermore, the risk alleles of MECOM rs2201862 and HBS1L-MYB rs9376092 were demonstrated to be negatively associated with the risk of developing polycythemia vera. In conclusion, germline variations at JAK2 (both the 46/1 haplotype and rs12339666) and TERT rs2736100 were associated with MPNs in Taiwanese population. PMID:29100304

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

    PubMed Central

    Anelli, Luisa; Zagaria, Antonella; Specchia, Giorgina

    2018-01-01

    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. PMID:29641446

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

    PubMed

    Anelli, Luisa; Zagaria, Antonella; Specchia, Giorgina; Albano, Francesco

    2018-04-11

    The germline JAK2 haplotype known as "GGCC or 46/1 haplotype" (haplotype GGCC_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 haplotype GGCC_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 haplotype GGCC_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 haplotype GGCC_46/1 and blood cell count, survival, or disease progression.

  8. 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.

    PubMed

    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.

  9. Erythrocytes from patients with myeloproliferative neoplasms and splanchnic venous thrombosis show greater expression of Lu/BCAM.

    PubMed

    Novitzky-Basso, I; Spring, F; Anstee, D; Tripathi, D; Chen, F

    2018-05-13

    Lutheran/BCAM protein (Lu) on the surface of erythrocytes is key for their adhesion to the endothelium, and erythrocytes from individuals with JAK2V617F-mutated myeloproliferative neoplasms (MPN) have increased endothelial adhesion. Splanchnic vein thrombosis (SVT) is a devastating thrombotic complication of MPN, and frequently, the only diagnostic feature is the JAK2V617F mutation. We sought to examine whether erythrocytes from patients with JAK2V617F mutated SVT (MPN-SVT) exhibited increased Lu expression, thereby supporting a mechanistic contribution to the development of thrombosis. We report the validation of a novel flow cytometry assay for Lu expression on erythrocytes. We examined the expression of Lu on erythrocytes from a cohort of MPN patients with and without SVT, and healthy controls. Samples were obtained from 20 normal individuals, 22 with MPN (both JAK2V617F-mutated and wild-type) and 8 with JAK2V617F-mutated MPN-SVT. Lu expression by erythrocytes from patients with MPN and MPN-SVT is significantly increased compared to erythrocytes from healthy individuals (P < .05), but there was no significant difference between patients with MPN-SVT and MPN. Patients with MPN have increased expression of the red cell Lu/BCAM adhesion molecule. Further work is required to determine the role of the increased Lu/BCAM adhesion to the endothelium in the development of thrombosis in MPN of all genotypes. © 2018 John Wiley & Sons Ltd.

  10. 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

    PubMed Central

    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

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

    PubMed

    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.

  12. Janus kinase 2 inhibitors in myeloproliferative disorders.

    PubMed

    Lucia, Eugenio; Recchia, Anna Grazia; Gentile, Massimo; Bossio, Sabrina; Vigna, Ernesto; Mazzone, Carla; Madeo, Antonio; Morabito, Lucio; Gigliotti, Vincenzo; De Stefano, Laura; Caruso, Nadia; Servillo, Pasquale; Franzese, Stefania; Bisconte, Maria Grazia; Gentile, Carlo; Morabito, Fortunato

    2011-01-01

    JAK2 is an obligatory kinase for the proliferation and differentiation of erythroid cells and megakaryocytes thus representing a relevant therapeutic target for agents that specifically inhibit its activity particularly in myeloproliferative disorders (MPD) harboring JAK2(V617F) mutations. We discuss the physiopathology of the JAK2 signaling pathway and review clinical trials of JAK2 inhibitors for the treatment of MPD using papers and meeting abstracts published up to September 2010. This review helps in understanding the potential role of JAK2 inhibitors in MPD clinical trials and provides a comprehensive review regarding their efficacy and safety in these disorders. JAK2 inhibitors may prove to be useful only for suppressing disease manifestations. However, unlike drugs such as IFN which are capable of eliminating the malignant clone, JAK2 inhibitors are unable to eradicate the disease. In fact, results to date indicate that although these inhibitors reduce splenomegaly and alleviate constitutional symptoms irrespective of JAK2 mutational status, most have only a modest impact on the JAK2(V617F) allele burden. Considering the relevant risk of serious complications in patients undergoing splenectomy, these drugs could find a suitable indication in patients with myelofibrosis awaiting bone marrow transplantation.

  13. Stem and Progenitor Cell Subsets Are Affected by JAK2 Signaling and Can Be Monitored by Flow Cytometry

    PubMed Central

    Iida, Ryuji; Welner, Robert S.; Zhao, Wanke; Alberola-lla, José; Medina, Kay L.; Zhao, Zhizhuang Joe; Kincade, Paul W.

    2014-01-01

    Although extremely rare, hematopoietic stem cells (HSCs) are divisible into subsets that differ with respect to differentiation potential and cell surface marker expression. For example, we recently found that CD86− CD150+ CD48− HSCs have limited potential for lymphocyte production. This could be an important new tool for studying hematological abnormalities. Here, we analyzed HSC subsets with a series of stem cell markers in JAK2V617F transgenic (Tg) mice, where the mutation is sufficient to cause myeloproliferative neoplasia with lymphocyte deficiency. Total numbers of HSC were elevated 3 to 20 fold in bone marrow of JAK2V617F mice. Careful analysis suggested the accumulation involved multiple HSC subsets, but particularly those characterized as CD150HI CD86− CD18L°CD41+ and excluding Hoechst dye. Real-Time PCR analysis of their HSC revealed that the erythropoiesis associated gene transcripts Gata1, Klf1 and Epor were particularly high. Flow cytometry analyses based on two differentiation schemes for multipotent progenitors (MPP) also suggested alteration by JAK2 signals. The low CD86 on HSC and multipotent progenitors paralleled the large reductions we found in lymphoid progenitors, but the few that were produced functioned normally when sorted and placed in culture. Either of two HSC subsets conferred disease when transplanted. Thus, flow cytometry can be used to observe the influence of abnormal JAK2 signaling on stem and progenitor subsets. Markers that similarly distinguish categories of human HSCs might be very valuable for monitoring such conditions. They could also serve as indicators of HSC fitness and suitability for transplantation. PMID:24699465

  14. Different expression patterns of LGALS1 and LGALS3 in polycythemia vera, essential thrombocythemia and primary myelofibrosis.

    PubMed

    Moura, L G; Tognon, R; Nunes, N S; Rodrigues, L Cataldi; Ferreira, A F; Kashima, S; Covas, D T; Santana, M; Souto, E X; Perobelli, L; Simões, B P; Dias-Baruffi, M; Castro, F A

    2016-10-01

    Despite all the knowledge, the cellular and molecular mechanisms involved in myeloproliferative neoplasm (MPN) pathophysiology remain unclear. Authors have shown galectin-1 (Gal-1) and 3 playing roles in tumour angiogenesis and fibrosis, which were correlated with poor prognosis in patients with MPN. In the present study LGALS1 and LGALS3 were differently expressed between polycythemia vera, essential thrombocythemia (ET) and primary myelofibrosis (PMF) diseases. Increased LGALS3 expression was associated with a negative JAK2 V617F status mutation in leucocytes from PMF but not in patients with ET without this mutation. However, a positive Janus kinase 2 (JAK2) V617F cell line established from patients with ET (SET-2 cells) when treated with JAK inhibitor presented high levels of LGALS3. Additionally, high LGALS1 expression was found in CD34(+) cells but not in leucocytes from patients with PMF, in absence of JAK2 V617F mutation, and also in SET-2 cells treated with JAK inhibitor. Thus, our findings indicate that differential expression of LGALS1 and/or LGALS3 in patients with MPN is linked with JAK2 V617F status mutation in these diseases and state of cell differentiation. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

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

    PubMed

    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.

  16. Single Nucleotide Polymorphism (SNP)-Based Loss of Heterozygosity (LOH) Testing by Real Time PCR in Patients Suspect of Myeloproliferative Disease

    PubMed Central

    Huijsmans, Cornelis J. J.; Poodt, Jeroen; Damen, Jan; van der Linden, Johannes C.; Savelkoul, Paul H. M.; Pruijt, Johannes F. M.; Hilbink, Mirrian; Hermans, Mirjam H. A.

    2012-01-01

    During tumor development, loss of heterozygosity (LOH) often occurs. When LOH is preceded by an oncogene activating mutation, the mutant allele may be further potentiated if the wild-type allele is lost or inactivated. In myeloproliferative neoplasms (MPN) somatic acquisition of JAK2V617F may be followed by LOH resulting in loss of the wild type allele. The occurrence of LOH in MPN and other proliferative diseases may lead to a further potentiating the mutant allele and thereby increasing morbidity. A real time PCR based SNP profiling assay was developed and validated for LOH detection of the JAK2 region (JAK2LOH). Blood of a cohort of 12 JAK2V617F-positive patients (n = 6 25–50% and n = 6>50% JAK2V617F) and a cohort of 81 patients suspected of MPN was stored with EDTA and subsequently used for validation. To generate germ-line profiles, non-neoplastic formalin-fixed paraffin-embedded tissue from each patient was analyzed. Results of the SNP assay were compared to those of an established Short Tandem Repeat (STR) assay. Both assays revealed JAK2LOH in 1/6 patients with 25–50% JAK2V617F. In patients with >50% JAK2V617F, JAK2LOH was detected in 6/6 by the SNP assay and 5/6 patients by the STR assay. Of the 81 patients suspected of MPN, 18 patients carried JAK2V617F. Both the SNP and STR assay demonstrated the occurrence of JAK2LOH in 5 of them. In the 63 JAK2V617F-negative patients, no JAK2LOH was observed by SNP and STR analyses. The presented SNP assay reliably detects JAK2LOH and is a fast and easy to perform alternative for STR analyses. We therefore anticipate the SNP approach as a proof of principle for the development of LOH SNP-assays for other clinically relevant LOH loci. PMID:22768290

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

    PubMed

    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.

  18. Splanchnic Vein Thrombosis in the Myeloproliferative Neoplasms.

    PubMed

    Akpan, Imo J; Stein, Brady Lee

    2018-06-01

    To review the epidemiology, diagnostic challenges, pathogenesis, and treatment strategies for patients with myeloproliferative neoplasm-associated splanchnic vein thrombosis. The epidemiology of myeloproliferative neoplasm-associated splanchnic vein thrombosis (MPN-SVT) has been well characterized. While typical MPN-associated thrombosis affects older patients and involves the arterial circulation, MPN-SVT mostly impacts younger women. An association with JAK2 V617F is well-known; recent studies have demonstrated only a weak association with CALR mutations. JAK inhibition may represent a novel treatment strategy, complementing anticoagulation, and management of portal hypertension. While the epidemiology has been well characterized, more work is needed to identify novel contributors to disease pathogenesis, beyond the JAK2 V617F mutation itself, and endothelial compromise. Testing for MPN mutations in the setting of non-cirrhotic SVT is commonplace; JAK2 V617F is the most likely to be identified. Testing for CALR or MPL mutations requires clinical judgement, though not unreasonable. The mainstay of therapy is indefinite anticoagulation; the role of direct oral anticoagulants is unclear. JAK inhibition may play a role in addressing associated splenomegaly and portal hypertension.

  19. Risk factors for vascular complications and treatment patterns at diagnosis of 2389 PV and ET patients: Real-world data from the Swedish MPN Registry.

    PubMed

    Abdulkarim, Khadija; Samuelsson, Jan; Johansson, Peter; Andréasson, Björn

    2017-06-01

    The study mainly aimed at investigating possible correlations between peripheral blood counts, erythropoietin (EPO), JAK2 V617F mutation, and vascular complications prior to diagnosis of a population-based cohort of newly diagnosed patients with myeloproliferative neoplasms (MPN). The study comprises 1105 patients with polycythemia vera (PV) and 1284 patients with essential thrombocythemia (ET) registered in the Swedish MPN Registry. Vascular complications, prior to diagnosis, were registered in 37% of PV patients. In multivariate analysis, low hemoglobin was the only significant risk factor (P=.0120). Among ET patients, 35% had encountered a vascular complication. Risk factors for thromboembolic complications in ET were identified as age>65 years, white cell count>12×10 9 /L, and the presence of JAK2 V617F mutation (P=.0004, P=.0038, and P=.0016, respectively). A JAK2 V617F mutation was present in 71% of ET patients with vascular complications, compared to 60% in patients without. A majority of complications were thromboembolic, in both PV and ET. We conclude that vascular complications among newly diagnosed patients had affected more than one-third of our study population. Risk factors for vascular complications prior to diagnosis were lower hemoglobin in PV, and the presence of JAK2 V617F mutation, higher age, and leukocytosis in ET. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Somatic CALR Mutations in Myeloproliferative Neoplasms with Nonmutated JAK2

    PubMed Central

    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.; Van Loo, P.; 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.P.; Harrison, C.N.; Cross, N.C.P.; Ron, D.; Vannucchi, A.M.; Papaemmanuil, E.; Campbell, P.J.; Green, A.R.

    2014-01-01

    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 of samples obtained from 151 patients with myeloproliferative neoplasms. The mutation status of the gene encoding calreticulin (CALR) was assessed in an additional 1345 hematologic cancers, 1517 other cancers, and 550 controls. We established phylogenetic trees using hematopoietic colonies. We assessed calreticulin subcellular localization using immunofluorescence and flow cytometry. RESULTS Exome sequencing identified 1498 mutations in 151 patients, with medians of 6.5, 6.5, and 13.0 mutations per patient in samples of polycythemia vera, essential thrombocythemia, and myelofibrosis, respectively. Somatic CALR mutations were found in 70 to 84% of samples of myeloproliferative neoplasms with nonmutated JAK2, in 8% of myelodysplasia samples, in occasional samples of other myeloid cancers, and in none of the other cancers. A total of 148 CALR mutations were identified with 19 distinct variants. Mutations were located in exon 9 and generated a +1 base-pair frameshift, which would result in a mutant protein with a novel C-terminal. Mutant calreticulin was observed in the endoplasmic reticulum without increased cell-surface or Golgi accumulation. Patients with myeloproliferative neoplasms carrying CALR mutations presented with higher platelet counts and lower hemoglobin levels than patients with mutated JAK2. Mutation of CALR was detected in hematopoietic stem and progenitor cells. Clonal analyses showed CALR mutations in the earliest phylogenetic node, a finding consistent with its role as an initiating mutation in some patients. CONCLUSIONS Somatic mutations in the endoplasmic reticulum chaperone CALR were found in a majority of patients with myeloproliferative neoplasms with

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

    PubMed

    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 (P<0.01). In the Florence only cohort, the presence of mutant MPL was associated with older age (P<0.01) and constitutional symptoms (P=0.04) and JAK2V617F with higher hemoglobin (P<0.01) and leukocyte (P=0.03) count; neither patient cohort showed significant associations with platelet count, hemoglobin <10 g/dl, abnormal/unfavorable karyotype, spleen size or prognostic score distribution. To date, 240 deaths and 79 leukemic transformations have been documented among all 603 study patients. Multivariable analysis disclosed no significant difference in overall or leukemia-free survival between the three molecular subgroups. We conclude that the presence of mutant MPL has narrow and inconsistent phenotypic effect in PMF and does not influence overall or leukemia-free survival.

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

    PubMed Central

    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

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

    PubMed

    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.

  4. Coexistence of JAK2 and CALR mutations and their clinical implications in patients with essential thrombocythemia.

    PubMed

    Kang, Min-Gu; Choi, Hyun-Woo; Lee, Jun Hyung; Choi, Yong Jun; Choi, Hyun-Jung; Shin, Jong-Hee; Suh, Soon-Pal; Szardenings, Michael; Kim, Hye-Ran; Shin, Myung-Geun

    2016-08-30

    Janus kinase 2 (JAK2) and calreticulin (CALR) constitute the two most frequent mutations in essential thrombocythemia (ET), and both are reported to be mutually exclusive. Hence, we examined a cohort of 123 myeloproliferative neoplasm (MPN) patients without BCR-ABL1 rearrangement and additional ET patients (n=96) for coexistence of JAK2 and CALR mutations. The frequency of CALR mutations was 20.3% in 123 MPN patients; 31.1% in ET (n=74), 25% in primary myelofibrosis (n=4) and 2.2% in polycythemia vera (n=45). JAK2 and CALR mutations coexisted in 7 (4.2%) of 167 ET patients. Clinical characteristics, progression-free survival (PFS), and elapsed time to achieve partial remission across 4 groups (JAK2+/CALR+, JAK2+/CALR-, JAK2-/CALR+, JAK2-/CALR-) were reviewed. The JAK2+/CALR- group had higher leukocyte counts and hemoglobin levels and more frequent thrombotic events than JAK2-/CALR- group. JAK2 mutations have a greater effect on the disease phenotype and the clinical features of MPN patients rather than do CALR mutation. JAK2+ groups showed a tendency of poor PFS than JAK2- groups regardless of CALR mutation. CALR+ was a predictor of late response to the treatment. Our study also showed that thrombosis was more frequent in ET patients with type 2 CALR mutations than in those with type 1 CALR mutations.

  5. Aggressive B-cell lymphomas in patients with myelofibrosis receiving JAK1/2 inhibitor therapy.

    PubMed

    Porpaczy, Edit; Tripolt, Sabrina; Hoelbl-Kovacic, Andrea; Gisslinger, Bettina; Bago-Horvath, Zsuzsanna; Casanova-Hevia, Emilio; Clappier, Emmanuelle; Decker, Thomas; Fajmann, Sabine; Fux, Daniela A; Greiner, Georg; Gueltekin, Sinan; Heller, Gerwin; Herkner, Harald; Hoermann, Gregor; Kiladjian, Jean-Jacques; Kolbe, Thomas; Kornauth, Christoph; Krauth, Maria-Theresa; Kralovics, Robert; Muellauer, Leonhard; Mueller, Mathias; Prchal-Murphy, Michaela; Putz, Eva Maria; Raffoux, Emmanuel; Schiefer, Ana-Iris; Schmetterer, Klaus; Schneckenleithner, Christine; Simonitsch-Klupp, Ingrid; Skrabs, Cathrin; Sperr, Wolfgang R; Staber, Philipp Bernhard; Strobl, Birgit; Valent, Peter; Jaeger, Ulrich; Gisslinger, Heinz; Sexl, Veronika

    2018-06-14

    Inhibition of Janus-kinase 1/2 (JAK1/2) is a mainstay to treat myeloproliferative neoplasms (MPN). Sporadic observations reported the co-incidence of B-cell non-Hodgkin lymphomas during treatment of MPN with JAK1/2 inhibitors. We assessed 626 MPN patients including 69 with myelofibrosis receiving JAK1/2 inhibitors for lymphoma development. B-cell lymphomas evolved in 4/69 patients (5.8%) upon JAK1/2 inhibition compared to 2/557 (0.36%) with conventional treatment (16-fold increased risk). A similar 15-fold increase was observed in an independent cohort of 929 MPN patients. Considering primary myelofibrosis only (N=216), 3 lymphomas were observed in 31 inhibitor-treated patients (9.7%) versus 1/185 controls (0.54%). Lymphomas were of aggressive B-cell type, extra-nodal or leukemic with high MYC expression in the absence of JAK2 V617F or other MPN-associated mutations. Median time from initiation of inhibitor therapy to lymphoma diagnosis was 25 months. Clonal immunoglobulin gene rearrangements were already detected in the bone marrow during myelofibrosis in 16.3% of patients. Lymphomas occurring during JAK1/2 inhibitor treatment were preceded by a pre-existing B-cell clone in all 3 patients tested. Sequencing verified clonal identity in 2 patients. The effects of JAK1/2 inhibition were mirrored in Stat1 -/- mice: 16/24 mice developed a spontaneous myeloid hyperplasia with the concomitant presence of aberrant B-cells. Transplantations of bone marrow from diseased mice unmasked the outgrowth of a malignant B-cell clone evolving into aggressive B-cell leukemia-lymphoma. We conclude that JAK/STAT1 pathway inhibition in myelofibrosis is associated with an elevated frequency of aggressive B-cell lymphomas. Detection of a pre-existing B-cell clone may identify individuals at risk. Copyright © 2018 American Society of Hematology.

  6. Use of CBL exon 8 and 9 mutations in diagnosis of myeloproliferative neoplasms and myelodysplastic/myeloproliferative disorders: an analysis of 636 cases

    PubMed Central

    Schnittger, Susanne; Bacher, Ulrike; Alpermann, Tamara; Reiter, Andreas; Ulke, Madlen; Dicker, Frank; Eder, Christiane; Kohlmann, Alexander; Grossmann, Vera; Kowarsch, Andreas; Kern, Wolfgang; Haferlach, Claudia; Haferlach, Torsten

    2012-01-01

    We analyzed 636 patients with diverse myeloproliferative neoplasms or myelodysplastic/myeloproliferative neoplasms for mutations of the Casitas B-cell lymphoma gene (CBLmut) in exons 8 and 9 and performed correlations to other genetic alterations. CBLmut were detected in 63 of 636 (9.9%) of these selected patients. CBLmut were more frequent in myelodysplastic/myeloproliferative neoplasms than myeloproliferative neoplasms (51 of 328, 15.5% vs. 12 of 291, 4.1%; P<0.001). Frequency was 48 of 278 (17.3%) in chronic myelomonocytic leukemia and 3 of 33 (9.1%) in unclassifiable myelodysplastic/myeloproliferative neoplasms. CBLmut was not detected in polycythemia vera, primary myelofibrosis, essential thrombocythemia, or refractory anemia with ring sideroblasts and marked thrombocytosis. CBLmut were underrepresented in JAK2V617F mutated as compared to JAK2V617wt cases (P<0.001), and mutually exclusive of JAK2exon12mut and MPLW515mut. CBLmut were associated with monosomy 7 (P=0.008) and TET2mut (P=0.003). In chronic myelomonocytic leukemia, CBLmut had no significant impact on survival outcomes. Therefore, CBLmut are frequent in chronic myelomonocytic leukemia, absent in classical myeloproliferative neoplasms, and are only exceptionally found in coincidence with JAK-STAT pathway activating mutations. PMID:22733026

  7. Mutant calreticulin-expressing cells induce monocyte hyperreactivity through a paracrine mechanism

    PubMed Central

    Garbati, Michael R.; Welgan, Catherine A.; Landefeld, Sally H.; Newell, Laura F.; Agarwal, Anupriya; Dunlap, Jennifer B.; Chourasia, Tapan K.; Lee, Hyunjung; Elferich, Johannes; Traer, Elie; Rattray, Rogan; Cascio, Michael J.; Press, Richard D.; Bagby, Grover C.; Tyner, Jeffrey W.; Druker, Brian J.; Dao, Kim-Hien T.

    2016-01-01

    Mutations in the calreticulin gene (CALR) were recently identified in approximately 70–80% of patients with JAK2-V617F-negative essential thrombocytosis and primary myelofibrosis. All frameshift mutations generate a recurring novel C-terminus. Here we provide evidence that mutant calreticulin does not accumulate efficiently in cells and is abnormally enriched in the nucleus and extracellular space compared to wildtype calreticulin. The main determinant of these findings is the loss of the calcium-binding and KDEL domains. Expression of type I mutant CALR in Ba/F3 cells confers minimal IL-3-independent growth. Interestingly, expression of type I and type II mutant CALR in a non-hematopoietic cell line does not directly activate JAK/STAT signaling compared to JAK2-V617F expression. These results led us to investigate paracrine mechanisms of JAK/STAT activation. Here we show that conditioned media from cells expressing type I mutant CALR exaggerate cytokine production from normal monocytes with or without treatment with a toll-like receptor agonist. These effects are not dependent on the novel C-terminus. These studies offer novel insights into the mechanism of JAK/STAT activation in patients with JAK2-V617F-negative essential thrombocytosis and primary myelofibrosis. PMID:26573090

  8. Evaluation of the association between the JAK2 46/1 haplotype and chronic myeloproliferative neoplasms in a Brazilian population

    PubMed Central

    Silva, Sarah Pagliarini- e-; Santos, Bruna Cunha; de Figueiredo Pereira, Elizangela Mendes; Ferreira, Mari Ellen; Baraldi, Elaine Cristina; Sell, Ana Maria; Visentainer, Jeane Eliete Laguila

    2013-01-01

    OBJECTIVE: The JAK2 46/1 haplotype has recently been described as a major contributing factor to the development of myeloproliferative neoplasm, whether positive or negative for the JAK2 V617F mutation. The G allele, identified by a single-nucleotide polymorphism known as JAK2 rs10974944, is part of the JAK2 46/1 haplotype. The aim of this study was to verify the association between the presence of the G allele and the development of BCR-ABL-negative chronic myeloproliferative neoplasms in our population. METHODS: Blood and oral mucosa swab samples were obtained from 56 patients of two local Brazilian hospitals who had previously been diagnosed with BCR-ABL-negative chronic myeloproliferative neoplasms. Blood samples from 90 local blood donors were used as controls. The presence of the G allele was assessed using a PCR-RFLP assay after extracting DNA from the samples. RESULTS: The presence of the G allele was strongly associated with the presence of BCR-ABL-negative chronic myeloproliferative neoplasms (p = 0.0001; OR = 2.674; 95% CI = 1.630−4.385) in the studied population. CONCLUSION: In agreement with previous reports, the JAK2 46/1 haplotype, represented in this study by the presence of the G allele, is an important predisposing factor in the oncogenetic development of these neoplasms in our population. PMID:23420150

  9. Comprehensive review of JAK inhibitors in myeloproliferative neoplasms

    PubMed Central

    Sonbol, Mohamad Bassam; Firwana, Belal; Zarzour, Ahmad; Morad, Mohammad; Rana, Vishal

    2013-01-01

    Myeloproliferative neoplasms (MPNs) are clonal hematopoietic stem-cell disorders, characterized phenotypically by the abnormal accumulation of mature-appearing myeloid cells. Polycythemia vera, essential thrombocythemia, primary myelofibrosis (also known as ‘BCR-ABL1-negative’ MPNs), and chronic myeloid leukemia (CML) are the primary types of MPNs. After the discovery of the BCR-ABL1 fusion protein in CML, several oncogenic tyrosine kinases have been identified in ‘BCR-ABL1-negative’ MPNs, most importantly, JAK2V617F mutation. The similarity in the clinical characteristics of the BCR-ABL1-negative MPN patients along with the prevalence of the Janus kinase mutation in this patient population provided a strong rationale for the development of a new class of pharmacologic inhibitors that target this pathway. The first of its class, ruxolitinib, has now been approved by the food and drug administration (FDA) for the management of patients with intermediate- to high-risk myelofibrosis. Ruxolitinib provides significant and sustained improvements in spleen related and constitutional symptoms secondary to the disease. Although noncurative, ruxolitinib represents a milestone in the treatment of myelofibrosis patients. Other types of JAK2 inhibitors are being tested in various clinical trials at this point and may provide better efficacy data and safety profile than its predecessor. In this article, we comprehensively reviewed and summarized the available preclinical and clinical trials pertaining to JAK inhibitors. PMID:23610611

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

    PubMed

    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.

  11. Myeloproliferative neoplasms: Current molecular biology and genetics.

    PubMed

    Saeidi, Kolsoum

    2016-02-01

    Myeloproliferative neoplasms (MPNs) are clonal disorders characterized by increased production of mature blood cells. Philadelphia chromosome-negative MPNs (Ph-MPNs) consist of polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF). A number of stem cell derived mutations have been identified in the past 10 years. These findings showed that JAK2V617F, as a diagnostic marker involving JAK2 exon 14 with a high frequency, is the best molecular characterization of Ph-MPNs. Somatic mutations in an endoplasmic reticulum chaperone, named calreticulin (CALR), is the second most common mutation in patients with ET and PMF after JAK2 V617F mutation. Discovery of CALR mutations led to the increased molecular diagnostic of ET and PMF up to 90%. It has been shown that JAK2V617F is not the unique event in disease pathogenesis. Some other genes' location such as TET oncogene family member 2 (TET2), additional sex combs-like 1 (ASXL1), casitas B-lineage lymphoma proto-oncogene (CBL), isocitrate dehydrogenase 1/2 (IDH1/IDH2), IKAROS family zinc finger 1 (IKZF1), DNA methyltransferase 3A (DNMT3A), suppressor of cytokine signaling (SOCS), enhancer of zeste homolog 2 (EZH2), tumor protein p53 (TP53), runt-related transcription factor 1 (RUNX1) and high mobility group AT-hook 2 (HMGA2) have also identified to be involved in MPNs phenotypes. Here, current molecular biology and genetic mechanisms involved in MNPs with a focus on the aforementioned factors is presented. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  12. A Genetic Screen Reveals an Unexpected Role for Yorkie Signaling in JAK/STAT-Dependent Hematopoietic Malignancies in Drosophila melanogaster

    PubMed Central

    Anderson, Abigail M.; Bailetti, Alessandro A.; Rodkin, Elizabeth; De, Atish; Bach, Erika A.

    2017-01-01

    A gain-of-function mutation in the tyrosine kinase JAK2 (JAK2V617F) causes human myeloproliferative neoplasms (MPNs). These patients present with high numbers of myeloid lineage cells and have numerous complications. Since current MPN therapies are not curative, there is a need to find new regulators and targets of Janus kinase/Signal transducer and activator of transcription (JAK/STAT) signaling that may represent additional clinical interventions . Drosophila melanogaster offers a low complexity model to study MPNs as JAK/STAT signaling is simplified with only one JAK [Hopscotch (Hop)] and one STAT (Stat92E). hopTumorous-lethal (Tum-l) is a gain-of-function mutation that causes dramatic expansion of myeloid cells, which then form lethal melanotic tumors. Through an F1 deficiency (Df) screen, we identified 11 suppressors and 35 enhancers of melanotic tumors in hopTum-l animals. Dfs that uncover the Hippo (Hpo) pathway genes expanded (ex) and warts (wts) strongly enhanced the hopTum-l tumor burden, as did mutations in ex, wts, and other Hpo pathway genes. Target genes of the Hpo pathway effector Yorkie (Yki) were significantly upregulated in hopTum-l blood cells, indicating that Yki signaling was increased. Ectopic hematopoietic activation of Yki in otherwise wild-type animals increased hemocyte proliferation but did not induce melanotic tumors. However, hematopoietic depletion of Yki significantly reduced the hopTum-l tumor burden, demonstrating that Yki is required for melanotic tumors in this background. These results support a model in which elevated Yki signaling increases the number of hemocytes, which become melanotic tumors as a result of elevated JAK/STAT signaling. PMID:28620086

  13. Janus kinase (JAK) inhibitors in the treatment of inflammatory and neoplastic diseases.

    PubMed

    Roskoski, Robert

    2016-09-01

    The Janus kinase (JAK) family of non-receptor protein-tyrosine kinases consists of JAK1, JAK2, JAK3, and TYK2 (tyrosine kinase-2). Each of these proteins contains a JAK homology pseudokinase (JH2) domain that regulates the adjacent protein kinase domain (JH1). JAK1/2 and TYK2 are ubiquitously expressed whereas JAK3 is found predominantly in hematopoietic cells. The Janus kinase family is regulated by numerous cytokines including interleukins, interferons, and hormones such as erythropoietin, thrombopoietin, and growth hormone. Ligand binding to cytokine and hormone receptors leads to the activation of associated Janus kinases, which then mediate the phosphorylation of the receptors. The SH2 domain of STATs (signal transducers and activators of transcription) binds to the receptor phosphotyrosines thereby promoting STAT phosphorylation by the Janus kinases and consequent activation. STAT dimers are translocated to the nucleus where they participate in the regulation of the expression of thousands of proteins. JAK-STAT dysregulation results in autoimmune disorders such as rheumatoid arthritis, ulcerative colitis, and Crohn disease. JAK-STAT dysregulation also plays a role in the pathogenesis of myelofibrosis, polycythemia vera, and other myeloproliferative illnesses. An activating JAK2 V617F mutation occurs in 95% of people with polycythemia vera and in a lower percentage of people with other neoplasms. JAK1/3 signaling participates in the pathogenesis of inflammatory afflictions while JAK1/2 signaling participates in the development of several malignancies including leukemias and lymphomas as well as myeloproliferative neoplasms. Tofacitinib is a pan-JAK inhibitor that is approved by the FDA for the treatment of rheumatoid arthritis and ruxolitinib is a JAK1/2 inhibitor that is approved for the treatment of polycythemia vera and myelofibrosis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. 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.

    PubMed

    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.

  15. Multifaceted Intervention by the Hsp90 Inhibitor Ganetespib (STA-9090) in Cancer Cells with Activated JAK/STAT Signaling

    PubMed Central

    Proia, David A.; Foley, Kevin P.; Korbut, Tim; Sang, Jim; Smith, Don; Bates, Richard C.; Liu, Yuan; Rosenberg, Alex F.; Zhou, Dan; Koya, Keizo; Barsoum, James; Blackman, Ronald K.

    2011-01-01

    There is accumulating evidence that dysregulated JAK signaling occurs in a wide variety of cancer types. In particular, mutations in JAK2 can result in the constitutive activation of STAT transcription factors and lead to oncogenic growth. JAK kinases are established Hsp90 client proteins and here we show that the novel small molecule Hsp90 inhibitor ganetespib (formerly STA-9090) exhibits potent in vitro and in vivo activity in a range of solid and hematological tumor cells that are dependent on JAK2 activity for growth and survival. Of note, ganetespib treatment results in sustained depletion of JAK2, including the constitutively active JAK2V617F mutant, with subsequent loss of STAT activity and reduced STAT-target gene expression. In contrast, treatment with the pan-JAK inhibitor P6 results in only transient effects on these processes. Further differentiating these modes of intervention, RNA and protein expression studies show that ganetespib additionally modulates cell cycle regulatory proteins, while P6 does not. The concomitant impact of ganetespib on both cell growth and cell division signaling translates to potent antitumor efficacy in mouse models of xenografts and disseminated JAK/STAT-driven leukemia. Overall, our findings support Hsp90 inhibition as a novel therapeutic approach for combating diseases dependent on JAK/STAT signaling, with the multimodal action of ganetespib demonstrating advantages over JAK-specific inhibitors. PMID:21533169

  16. CBL, CBLB, TET2, ASXL1, and IDH1/2 mutations and additional chromosomal aberrations constitute molecular events in chronic myelogenous leukemia

    PubMed Central

    Makishima, Hideki; Jankowska, Anna M.; McDevitt, Michael A.; O'Keefe, Christine; Dujardin, Simon; Cazzolli, Heather; Przychodzen, Bartlomiej; Prince, Courtney; Nicoll, John; Siddaiah, Harish; Shaik, Mohammed; Szpurka, Hadrian; Hsi, Eric; Advani, Anjali; Paquette, Ronald

    2011-01-01

    Progression of chronic myelogenous leukemia (CML) to accelerated (AP) and blast phase (BP) is because of secondary molecular events, as well as additional cytogenetic abnormalities. On the basis of the detection of JAK2, CBL, CBLB, TET2, ASXL1, and IDH1/2 mutations in myelodysplastic/myeloproliferative neoplasms, we hypothesized that they may also contribute to progression in CML. We screened these genes for mutations in 54 cases with CML (14 with chronic phase, 14 with AP, 20 with myeloid, and 6 with nonmyeloid BP). We identified 1 CBLB and 2 TET2 mutations in AP, and 1 CBL, 1 CBLB, 4 TET2, 2 ASXL1, and 2 IDH family mutations in myeloid BP. However, none of these mutations were found in chronic phase. No cases with JAK2V617F mutations were found. In 2 cases, TET2 mutations were found concomitant with CBLB mutations. By single nucleotide polymorphism arrays, uniparental disomy on chromosome 5q, 8q, 11p, and 17p was found in AP and BP but not involving 4q24 (TET2) or 11q23 (CBL). Microdeletions on chromosomes 17q11.2 and 21q22.12 involved tumor associated genes NF1 and RUNX1, respectively. Our results indicate that CBL family, TET2, ASXL1, and IDH family mutations and additional cryptic karyotypic abnormalities can occur in advanced phase CML. PMID:21346257

  17. LNK mutations and myeloproliferative disorders.

    PubMed

    McMullin, Mary Frances; Cario, Holger

    2016-02-01

    The lymphocyte adaptor protein (LNK) is one of a family of adaptor proteins involved cell signaling and control of B cell populations. It has a critical role in regulation of signaling in hematopoiesis. Lnk negatively regulates cytokine initiated cell signaling and it functions as a negative regulator of the mutant protein in myeloproliferative neoplasms JAK2V617F. A number of mutations in LNK have been described in a variety of myeloproliferative neoplasms some of which have been demonstrated to cause increased cellular proliferation. The majority of mutations occur in exon 2. In a small number of cases idiopathic erythrocytosis with subnormal erythropoietin levels LNK mutations have been found which may account for the clinical phenotype. Thus investigation for LNK mutations should be considered in the investigation of idiopathic erythrocytosis and perhaps other myeloproliferative neoplasms. © 2015 Wiley Periodicals, Inc.

  18. Identification of Tyrosine 972 as a Novel Site of Jak2 Tyrosine Kinase Phosphorylation and its Role in Jak2 Activation

    PubMed Central

    McDoom, Issam; Ma, Xianyue; Kirabo, Annet; Lee, Kuang-Yung; Ostrov, David A.; Sayeski, Peter P.

    2013-01-01

    Jak2 is a 130 kDa tyrosine kinase that is important in a number of cellular signaling pathways. Its function is intrinsically regulated by the phosphorylation of a handful of its 49 tyrosines. Here, we report that tyrosine 972 (Y972) is a novel site of Jak2 phosphorylation, and hence auto-regulation. Specifically, we found that Y972 is phosphorylated and confirmed that this residue resides on the surface of the protein. Using expression plasmids that expressed either wild type Jak2 or a full length Jak2 cDNA containing a single Y972F substitution mutation, we investigated the consequences of losing Y972 phosphorylation on Jak2 function. We determined that the loss of Y972 phosphorylation significantly reduced both Jak2 total tyrosine phosphorylation and phosphorylation of Y1007/Y1008. Additionally, Y972 phosphorylation was shown to be important for maximal kinase function. Interestingly, in response to classical cytokine activation, the Jak2-Y972F mutant exhibited a moderately impaired level of activation when compared to wild type protein. However, when Jak2 was activated via a GPCR ligand, the ability of the Y972F mutant to activate was completely lost, therefore suggesting a differential role of Y972 in Jak2 activation. Finally, we found that phosphorylation of Y972 enhances Jak2 kinase function via a mechanism that appears to stabilize the active conformation of the protein. Collectively, our results suggest that Y972 is a novel site of Jak2 phosphorylation and plays an important differential role in ligand-dependent Jak2 activation via a mechanism that involves stabilization of the Jak2 active conformation. PMID:18636744

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

    PubMed

    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.

  20. Methotrexate Is a JAK/STAT Pathway Inhibitor

    PubMed Central

    Thomas, Sally; Fisher, Katherine H.; Snowden, John A.; Danson, Sarah J.; Brown, Stephen; Zeidler, Martin P.

    2015-01-01

    Background The JAK/STAT pathway transduces signals from multiple cytokines and controls haematopoiesis, immunity and inflammation. In addition, pathological activation is seen in multiple malignancies including the myeloproliferative neoplasms (MPNs). Given this, drug development efforts have targeted the pathway with JAK inhibitors such as ruxolitinib. Although effective, high costs and side effects have limited its adoption. Thus, a need for effective low cost treatments remains. Methods & Findings We used the low-complexity Drosophila melanogaster pathway to screen for small molecules that modulate JAK/STAT signalling. This screen identified methotrexate and the closely related aminopterin as potent suppressors of STAT activation. We show that methotrexate suppresses human JAK/STAT signalling without affecting other phosphorylation-dependent pathways. Furthermore, methotrexate significantly reduces STAT5 phosphorylation in cells expressing JAK2 V617F, a mutation associated with most human MPNs. Methotrexate acts independently of dihydrofolate reductase (DHFR) and is comparable to the JAK1/2 inhibitor ruxolitinib. However, cells treated with methotrexate still retain their ability to respond to physiological levels of the ligand erythropoietin. Conclusions Aminopterin and methotrexate represent the first chemotherapy agents developed and act as competitive inhibitors of DHFR. Methotrexate is also widely used at low doses to treat inflammatory and immune-mediated conditions including rheumatoid arthritis. In this low-dose regime, folate supplements are given to mitigate side effects by bypassing the biochemical requirement for DHFR. Although independent of DHFR, the mechanism-of-action underlying the low-dose effects of methotrexate is unknown. Given that multiple pro-inflammatory cytokines signal through the pathway, we suggest that suppression of the JAK/STAT pathway is likely to be the principal anti-inflammatory and immunosuppressive mechanism-of-action of low

  1. Novel compounds TAD-1822-7-F2 and F5 inhibited HeLa cells growth through the JAK/Stat signaling pathway.

    PubMed

    Yang, Tianfeng; Shi, Xianpeng; Kang, Yuan; Zhu, Man; Fan, Mengying; Zhang, Dongdong; Zhang, Yanmin

    2018-07-01

    Cervical carcinoma remains the second most common malignancy with a high mortality rate among women worldwide. TAD-1822-7-F2 (F2) and TAD-1822-7-F5 (F5) are novel compounds synthesized on the chemical structure of taspine derivatives, and show an effective suppression for HeLa cells. Our study aims to confirm the potential targets of F2 and F5, and investigate the underlying mechanism of the inhibitory effect on HeLa cells. In this study, Real Time Cell Analysis and crystal violet staining assay were conducted to investigate the effect of F2 and F5 on HeLa cells proliferation. And the analytical methods of surface plasmon resonance and quartz crystal microbalance were established and employed to study the interaction between F2 and F5 and potential target protein JAK2, suggesting that both compounds have strong interaction with the JAK2 protein. Western blot analysis, immunofluorescence staining study and PCR was conducted to investigate the molecules of JAK/Stat signaling pathway. Interestingly, F2 and F5 showed diverse regulation for signaling molecules because of their different chemical structure. F2 increased the expression of JAK2 and downregulated the level of P-JAK1 and P-JAK2, and decreased P-Stat3 (Ser727). While F5 could increase the expression of JAK2 and naturally decrease the phosphorylation of JAK1 and Tyk2, and decreased the expression of P-Stat6. Moreover, F2 and F5 showed the same downregulation on the P-Stat3 (Tyr705). Therefore, F2 and F5 could target the JAK2 protein and prevent the phosphorylation of JAKs to suppress the phosphorylation of the downstream effector Stats, which suggested that F2 and F5 have great potential to be the inhibitors of the JAK/Stat signaling pathway. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  2. A novel somatic JAK2 kinase-domain mutation in pediatric acute lymphoblastic leukemia with rapid on-treatment development of LOH.

    PubMed

    Sadras, Teresa; Heatley, Susan L; Kok, Chung H; McClure, Barbara J; Yeung, David; Hughes, Timothy P; Sutton, Rosemary; Ziegler, David S; White, Deborah L

    2017-10-01

    We report a novel somatic mutation in the kinase domain of JAK2 (R938Q) in a high-risk pediatric case of B-cell acute lymphoblastic leukemia (ALL). The patient developed on-therapy relapse at 12 months, and interestingly, the JAK2 locus acquired loss of heterozygosity during treatment resulting in 100% mutation load. Furthermore, we show that primary ALL mononuclear cells harboring the JAK2 R938Q mutation display reduced sensitivity to the JAK1/2 ATP-competitive inhibitor ruxolitinib in vitro, compared to ALL cells that carry a more common JAK2 pseudokinase domain mutation. Our findings are in line with previous reports that demonstrate that mutations within the kinase domain of JAK2 are associated with resistance to type I JAK inhibitors. Importantly, given the recent inclusion of ruxolitinib in trial protocols for children with JAK pathway alterations, we predict that inter-patient genetic variability may result in suboptimal responses to JAK inhibitor therapy in a subset of cases. The need for alternate targeted and/or combination therapies for patients who display inherent or developed resistance to JAK inhibitor therapy will be warranted, and we propose that kinase-mutants less sensitive to type I JAK inhibitors may present a currently unexplored platform for investigation of improved therapies. Copyright © 2017. Published by Elsevier Inc.

  3. Clonal heterogeneity as a driver of disease variability in the evolution of myeloproliferative neoplasms.

    PubMed

    Prick, Janine; de Haan, Gerald; Green, Anthony R; Kent, David G

    2014-10-01

    Myeloproliferative neoplasms (MPNs) are clonal hematological diseases in which cells of the myelo-erythroid lineage are overproduced and patients are predisposed to leukemic transformation. Hematopoietic stem cells are the suspected disease-initiating cells, and these cells must acquire a clonal advantage relative to nonmutant hematopoietic stem cells to perpetuate disease. In 2005, several groups identified a single gain-of-function point mutation in JAK2 that associated with the majority of MPNs, and subsequent studies have led to a comprehensive understanding of the mutational landscape in MPNs. However, confusion still exists as to how a single genetic aberration can be associated with multiple distinct disease entities. Many explanations have been proposed, including JAK2V617F homozygosity, individual patient heterogeneity, and the differential regulation of downstream JAK2 signaling pathways. Several groups have made knock-in mouse models expressing JAK2V617F and have observed divergent phenotypes, each recapitulating some aspects of disease. Intriguingly, most of these models do not observe a strong hematopoietic stem cell self-renewal advantage compared with wild-type littermate controls, raising the question of how a clonal advantage is established in patients with MPNs. This review summarizes the current molecular understanding of MPNs and the diversity of disease phenotypes and proposes that the increased proliferation induced by JAK2V617F applies a selection pressure on the mutant clone that results in highly diverse clonal evolution in individuals. Copyright © 2014 ISEH - International Society for Experimental Hematology. Published by Elsevier Inc. All rights reserved.

  4. ASXL1/EZH2 mutations promote clonal expansion of neoplastic HSC and impair erythropoiesis in PMF.

    PubMed

    Triviai, Ioanna; Zeschke, Silke; Rentel, Jan; Spanakis, Marios; Scherer, Theo; Gabdoulline, Razif; Panagiota, Victoria; Thol, Felicitas; Heuser, Michael; Stocking, Carol; Kröger, Nicolaus

    2018-06-15

    Primary myelofibrosis (PMF) is a hematopoietic stem cell (HSC) disease, characterized by aberrant differentiation of all myeloid lineages and profound disruption of the bone marrow niche. PMF samples carry several mutations, but their cell origin and hierarchy in regulating the different waves of clonal and aberrant myeloproliferation from the prime HSC compartment is poorly understood. Genotyping of >2000 colonies from CD133+HSC and progenitors from PMF patients confirmed the complex genetic heterogeneity within the neoplastic population. Notably, mutations in chromatin regulators ASXL1 and/or EZH2 were identified as the first genetic lesions, preceding both JAK2-V617F and CALR mutations, and are thus drivers of clonal myelopoiesis in a PMF subset. HSC from PMF patients with double ASXL1/EZH2 mutations exhibited significantly higher engraftment in immunodeficient mice than those from patients without histone modifier mutations. EZH2 mutations correlate with aberrant erythropoiesis in PMF patients, exemplified by impaired maturation and cell cycle arrest of erythroid progenitors. These data underscore the importance of post-transcriptional modifiers of histones in neoplastic stem cells, whose clonal growth sustains aberrant myelopoiesis and expansion of pre-leukemic clones in PMF.

  5. Increased neutrophil extracellular trap formation promotes thrombosis in myeloproliferative neoplasms.

    PubMed

    Wolach, Ofir; Sellar, Rob S; Martinod, Kimberly; Cherpokova, Deya; McConkey, Marie; Chappell, Ryan J; Silver, Alexander J; Adams, Dylan; Castellano, Cecilia A; Schneider, Rebekka K; Padera, Robert F; DeAngelo, Daniel J; Wadleigh, Martha; Steensma, David P; Galinsky, Ilene; Stone, Richard M; Genovese, Giulio; McCarroll, Steven A; Iliadou, Bozenna; Hultman, Christina; Neuberg, Donna; Mullally, Ann; Wagner, Denisa D; Ebert, Benjamin L

    2018-04-11

    Thrombosis is a major cause of morbidity and mortality in Philadelphia chromosome-negative myeloproliferative neoplasms (MPNs), clonal disorders of hematopoiesis characterized by activated Janus kinase (JAK)-signal transducer and activator of transcription (STAT) signaling. Neutrophil extracellular trap (NET) formation, a component of innate immunity, has been linked to thrombosis. We demonstrate that neutrophils from patients with MPNs are primed for NET formation, an effect blunted by pharmacological inhibition of JAK signaling. Mice with conditional knock-in of Jak2 V617F , the most common molecular driver of MPN, have an increased propensity for NET formation and thrombosis. Inhibition of JAK-STAT signaling with the clinically available JAK2 inhibitor ruxolitinib abrogated NET formation and reduced thrombosis in a deep vein stenosis murine model. We further show that expression of PAD4, a protein required for NET formation, is increased in JAK2 V617F -expressing neutrophils and that PAD4 is required for Jak2 V617F -driven NET formation and thrombosis in vivo. Finally, in a population study of more than 10,000 individuals without a known myeloid disorder, JAK2 V617F -positive clonal hematopoiesis was associated with an increased incidence of thrombosis. In aggregate, our results link JAK2 V617F expression to NET formation and thrombosis and suggest that JAK2 inhibition may reduce thrombosis in MPNs through cell-intrinsic effects on neutrophil function. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  6. Mutant JAK3 phosphoproteomic profiling predicts synergism between JAK3 inhibitors and MEK/BCL2 inhibitors for the treatment of T-cell acute lymphoblastic leukemia

    PubMed Central

    Degryse, S; de Bock, C E; Demeyer, S; Govaerts, I; Bornschein, S; Verbeke, D; Jacobs, K; Binos, S; Skerrett-Byrne, D A; Murray, H C; Verrills, N M; Van Vlierberghe, P; Cools, J; Dun, M D

    2018-01-01

    Mutations in the interleukin-7 receptor (IL7R) or the Janus kinase 3 (JAK3) kinase occur frequently in T-cell acute lymphoblastic leukemia (T-ALL) and both are able to drive cellular transformation and the development of T-ALL in mouse models. However, the signal transduction pathways downstream of JAK3 mutations remain poorly characterized. Here we describe the phosphoproteome downstream of the JAK3(L857Q)/(M511I) activating mutations in transformed Ba/F3 lymphocyte cells. Signaling pathways regulated by JAK3 mutants were assessed following acute inhibition of JAK1/JAK3 using the JAK kinase inhibitors ruxolitinib or tofacitinib. Comprehensive network interrogation using the phosphoproteomic signatures identified significant changes in pathways regulating cell cycle, translation initiation, mitogen-activated protein kinase and phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)/AKT signaling, RNA metabolism, as well as epigenetic and apoptotic processes. Key regulatory proteins within pathways that showed altered phosphorylation following JAK inhibition were targeted using selumetinib and trametinib (MEK), buparlisib (PI3K) and ABT-199 (BCL2), and found to be synergistic in combination with JAK kinase inhibitors in primary T-ALL samples harboring JAK3 mutations. These data provide the first detailed molecular characterization of the downstream signaling pathways regulated by JAK3 mutations and provide further understanding into the oncogenic processes regulated by constitutive kinase activation aiding in the development of improved combinatorial treatment regimens. PMID:28852199

  7. Molecular insights into regulation of JAK2 in myeloproliferative neoplasms

    PubMed Central

    Hubbard, Stevan R.

    2015-01-01

    The critical role of Janus kinase-2 (JAK2) in regulation of myelopoiesis was established 2 decades ago, but identification of mutations in the pseudokinase domain of JAK2 in myeloproliferative neoplasms (MPNs) and in other hematologic malignancies highlighted the role of JAK2 in human disease. These findings have revolutionized the diagnostics of MPNs and led to development of novel JAK2 therapeutics. However, the molecular mechanisms by which mutations in the pseudokinase domain lead to hyperactivation of JAK2 and clinical disease have been unclear. Here, we describe recent advances in the molecular characterization of the JAK2 pseudokinase domain and how pathogenic mutations lead to constitutive activation of JAK2. PMID:25824690

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

    PubMed Central

    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

  9. The role of JAK2 abnormalities in hematologic neoplasms

    PubMed Central

    Alabdulaali, Mohammed K.

    2009-01-01

    In 2005, an activating mutation in the Janus kinase 2 (JAK2) was identified in a significant proportion of patients with myeloproliferative neoplasms, mainly polycythemia vera, essential thrombocythemia and primary myelofibrosis. Many types of mutations in the JAK-STAT pathway have been identified, the majority are related to JAK2. Currently JAK2 mutations are important in the area of diagnosis of myeloid neoplasms, but its role beyond the confirmation of clonality is growing and widening our knowledge about these disorders. In addition to that, clinical trials to target JAK2-STAT pathway will widen our knowledge and hopefully will offer more therapeutic options. In this review, we will discuss the role of JAK2 abnormalities in the pathogenesis, diagnosis, classification, severity and management of hematologic neoplasms.

  10. Clinical and molecular characterisation of a prospectively collected cohort of children and adolescents with polycythemia vera.

    PubMed

    Cario, Holger; Schwarz, Klaus; Herter, Jan M; Komrska, Vladimir; McMullin, Mary F; Minkov, Milen; Niemeyer, Charlotte; Pospisilova, Dagmar; Reinhard, Harald; Debatin, Klaus-Michael; Pahl, Heike L

    2008-08-01

    The clinical, haematological, molecular and treatment data of eight paediatric patients with polycythemia vera (PV) were collected prospectively. One patient developed PV after treatment for large-cell anaplastic lymphoma. Budd-Chiari syndrome was diagnosed in two patients, necessitating orthotopic liver transplantation in one and transjugular portosystemic shunting in the other. The remaining patients presented with non-specific symptoms. Endogenous erythroid colonies were detected in all cases examined. The JAK2(V617F) mutation was found in six patients; two patients displayed JAK2 exon 12 mutations, including one novel mutation (JAK2(H538-K539delinsI)). CD177 (PRV-1) mRNA expression was increased in three of five patients tested.

  11. Clinical and molecular characterisation of a prospectively collected cohort of children and adolescents with polycythemia vera

    PubMed Central

    Cario, Holger; Schwarz, Klaus; Herter, Jan M.; Komrska, Vladimir; McMullin, Mary F.; Minkov, Milen; Niemeyer, Charlotte; Pospisilova, Dagmar; Reinhard, Harald; Debatin, Klaus-Michael; Pahl, Heike L.

    2014-01-01

    Summary The clinical, haematological, molecular and treatment data of eight paediatric patients with polycythemia vera (PV) were collected prospectively. One patient developed PV after treatment for large-cell anaplastic lymphoma. Budd-Chiari syndrome was diagnosed in two patients, necessitating orthotopic liver transplantation in one and transjugular portosystemic shunting in the other. The remaining patients presented with non-specific symptoms. Endogenous erythroid colonies were detected in all cases examined. The JAK2V617F mutation was found in six patients; two patients displayed JAK2 exon 12 mutations, including one novel mutation (JAK2H538-K539delinsI). CD177 (PRV-1) mRNA expression was increased in three of five patients tested. PMID:18557746

  12. How I treat polycythemia vera.

    PubMed

    Passamonti, Francesco

    2012-07-12

    Polycythemia vera (PV) is a clonal disorder characterized by unwarranted production of red blood cells. In the majority of cases, PV is driven by oncogenic mutations that constitutively activate the JAK-STAT signal transduction pathway, such as JAK2 V617F, or exon 12 mutations or LNK mutations. Diagnosis of PV is based on the WHO criteria. Diagnosis of post-PV myelofibrosis is established according to the International Working Group for Myeloproliferative Neoplasms Research and Treatment criteria. Different clinical presentations of PV are discussed. Prognostication of PV is tailored to the most frequent complication during follow-up, namely, thrombosis. Age older than 60 years and prior history of thrombosis are the 2 main risk factors for disease stratification. Correlations are emerging between leukocytosis, JAK2(V617F) mutation, BM fibrosis, and different outcomes of PV, which need to be confirmed in prospective studies. In my practice, hydroxyurea is still the "gold standard" when cytoreduction is needed, even though pegylated IFN-alfa-2a and ruxolitinib might be useful in particular settings. Results of phase 1 or 2 studies concerning these latter agents should however be confirmed by the ongoing randomized phase 3 clinical trials. In this paper, I discuss the main problems encountered in daily clinical practice with PV patients regarding diagnosis, prognostication, and therapy.

  13. AKT is a therapeutic target in myeloproliferative neoplasms

    PubMed Central

    Khan, Irum; Huang, Zan; Wen, Qiang; Stankiewicz, Monika J.; Gilles, Laure; Goldenson, Benjamin; Schultz, Rachael; Diebold, Lauren; Gurbuxani, Sandeep; Finke, Christy M.; Lasho, Terra L.; Koppikar, Priya; Pardanani, Animesh; Stein, Brady; Altman, Jessica K.; Levine, Ross L.; Tefferi, Ayalew; Crispino, John D.

    2014-01-01

    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 (PMF) 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. PMID:23748344

  14. AKT is a therapeutic target in myeloproliferative neoplasms.

    PubMed

    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.

  15. Identification of a novel functional JAK1 S646P mutation in acute lymphoblastic leukemia

    PubMed Central

    Hu, Liangding; Ning, Hongmei; Jiang, Min; Wang, Danhong; Liu, Tingting; Zhang, Bin; Chen, Hu

    2017-01-01

    The survival rate of childhood acute lymphoblastic leukemia (ALL) is approaching 90%, while the prognosis of adults remains poor due to the limited therapeutic approaches. In order to identify new targets for ALL, we performed whole-exome sequencing on four adults with B-ALL and discovered a somatic JAK1 S646P mutation. Sanger sequencing of JAK1 was conducted on 53 ALL patients, and two cases exhibited A639G and P960S mutations separately. Functional studies demonstrated that only JAK1 S646P mutation could activate multiple signaling pathways, drive cytokine-independent cell growth, and promote proliferation of malignant cells in nude mice. Moreover, a high sensitivity to the JAK1/2 inhibitor ruxolitinib was observed in S646P mutant model. Exploration in a total of 209 ALL cases showed that JAK1 mutations occur at a frequency of 10.5% in T-ALL (2/19) and 1.6% in B-ALL (3/190). Collectively, our results suggested that JAK1 S646P is an activating mutation in vitro and in vivo. JAK-STAT pathway might represent a promising therapeutic target for ALL. PMID:28410228

  16. Identification of a novel functional JAK1 S646P mutation in acute lymphoblastic leukemia.

    PubMed

    Li, Qian; Li, Botao; Hu, Liangding; Ning, Hongmei; Jiang, Min; Wang, Danhong; Liu, Tingting; Zhang, Bin; Chen, Hu

    2017-05-23

    The survival rate of childhood acute lymphoblastic leukemia (ALL) is approaching 90%, while the prognosis of adults remains poor due to the limited therapeutic approaches. In order to identify new targets for ALL, we performed whole-exome sequencing on four adults with B-ALL and discovered a somatic JAK1 S646P mutation. Sanger sequencing of JAK1 was conducted on 53 ALL patients, and two cases exhibited A639G and P960S mutations separately. Functional studies demonstrated that only JAK1 S646P mutation could activate multiple signaling pathways, drive cytokine-independent cell growth, and promote proliferation of malignant cells in nude mice. Moreover, a high sensitivity to the JAK1/2 inhibitor ruxolitinib was observed in S646P mutant model. Exploration in a total of 209 ALL cases showed that JAK1 mutations occur at a frequency of 10.5% in T-ALL (2/19) and 1.6% in B-ALL (3/190). Collectively, our results suggested that JAK1 S646P is an activating mutation in vitro and in vivo. JAK-STAT pathway might represent a promising therapeutic target for ALL.

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

    PubMed

    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.

  18. Novel mutations and their functional and clinical relevance in myeloproliferative neoplasms: JAK2, MPL, TET2, ASXL1, CBL, IDH and IKZF1

    PubMed Central

    Tefferi, A

    2010-01-01

    Myeloproliferative neoplasms (MPNs) originate from genetically transformed hematopoietic stem cells that retain the capacity for multilineage differentiation and effective myelopoiesis. Beginning in early 2005, a number of novel mutations involving Janus kinase 2 (JAK2), Myeloproliferative Leukemia Virus (MPL), TET oncogene family member 2 (TET2), Additional Sex Combs-Like 1 (ASXL1), Casitas B-lineage lymphoma proto-oncogene (CBL), Isocitrate dehydrogenase (IDH) and IKAROS family zinc finger 1 (IKZF1) have been described in BCR-ABL1-negative MPNs. However, none of these mutations were MPN specific, displayed mutual exclusivity or could be traced back to a common ancestral clone. JAK2 and MPL mutations appear to exert a phenotype-modifying effect and are distinctly associated with polycythemia vera, essential thrombocythemia and primary myelofibrosis; the corresponding mutational frequencies are ∼99, 55 and 65% for JAK2 and 0, 3 and 10% for MPL mutations. The incidence of TET2, ASXL1, CBL, IDH or IKZF1 mutations in these disorders ranges from 0 to 17% these latter mutations are more common in chronic (TET2, ASXL1, CBL) or juvenile (CBL) myelomonocytic leukemias, mastocytosis (TET2), myelodysplastic syndromes (TET2, ASXL1) and secondary acute myeloid leukemia, including blast-phase MPN (IDH, ASXL1, IKZF1). The functional consequences of MPN-associated mutations include unregulated JAK-STAT (Janus kinase/signal transducer and activator of transcription) signaling, epigenetic modulation of transcription and abnormal accumulation of oncoproteins. However, it is not clear as to whether and how these abnormalities contribute to disease initiation, clonal evolution or blastic transformation. PMID:20428194

  19. HDAC8 overexpression in mesenchymal stromal cells from JAK2+ myeloproliferative neoplasms: a new therapeutic target?

    PubMed Central

    Ramos, Teresa L.; Sánchez-Abarca, Luis Ignacio; Redondo, Alba; Hernández-Hernández, Ángel; Almeida, Antonio M.; Puig, Noemí; Rodríguez, Concepción; Ortega, Rebeca; Preciado, Silvia; Rico, Ana; Muntión, Sandra; González Porras, José Ramón; Cañizo, Consuelo Del; Sánchez-Guijo, Fermín

    2017-01-01

    Histone deacetylases (HDACs) are involved in epigenetic modulation and their aberrant expression has been demonstrated in myeloproliferative neoplasms (MPN). HDAC8 inhibition has been shown to inhibit JAK2/STAT5 signaling in hematopoietic cells from MPN. Nevertheless, the role of HDAC8 expression in bone marrow-mesenchymal stromal cells (BM-MSC) has not been assessed. In the current work we describe that HDAC8 is significantly over-expressed in MSC from in JAK-2 positive MPN compared to those from healthy-donors (HD-MSC). Using a selective HDAC8 inhibitor (PCI34051), we verified that the subsequent decrease in the protein and mRNA expression of HDAC8 is linked with an increased apoptosis of malignant MSC whereas it has no effects on normal MSC. In addition, HDAC8 inhibition in MPN-MSC also decreased their capacity to maintain neoplastic hematopoiesis, by increasing the apoptosis, cell-cycle arrest and colony formation of JAK2+-hematopoietic cells. Mechanistic studies using different MPN cell lines revealed that PCI34051 induced their apoptosis, which is enhanced when were co-cultured with JAK2V617F-MSC, decreased their colony formation and the phosphorylation of STAT3 and STAT5. In summary, we show for the first time that the inhibition of HDAC8 in MSC from JAK2+ MPN patients selectively decreases their hematopoietic-supporting ability, suggesting that HDAC8 may be a potential therapeutic target in this setting by acting not only on hematopoietic cells but also on the malignant microenvironment. PMID:28390197

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

    PubMed

    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. Heterodimeric JAK-STAT Activation as a Mechanism of Persistence to JAK2 Inhibitor Therapy

    PubMed Central

    Koppikar, Priya; Bhagwat, Neha; Kilpivaara, Outi; Manshouri, Taghi; Adli, Mazhar; Hricik, Todd; Liu, Fan; Saunders, Lindsay M.; Mullally, Ann; Abdel-Wahab, Omar; Leung, Laura; Weinstein, Abby; Marubayashi, Sachie; Goel, Aviva; Gönen, Mithat; Estrov, Zeev; Ebert, Benjamin L.; Chiosis, Gabriela; Nimer, Stephen D.; Bernstein, Bradley E.; Verstovsek, Srdan; Levine, Ross L.

    2012-01-01

    The identification of somatic activating mutations in JAK21–4 and in the thrombopoietin receptor (MPL)5 in the majority of myeloproliferative neoplasm (MPN) patients led to the clinical development of JAK2 kinase inhibitors6,7. JAK2 inhibitor therapy improves MPN-associated splenomegaly and systemic symptoms, but does not significantly reduce or eliminate the MPN clone in most MPN patients. We therefore sought to characterize mechanisms by which MPN cells persist despite chronic JAK2 inhibition. Here we show that JAK2 inhibitor persistence is associated with reactivation of JAK-STAT signaling and with heterodimerization between activated JAK2 and JAK1/TYK2, consistent with activation of JAK2 in trans by other JAK kinases. Further, this phenomenon is reversible, such that JAK2 inhibitor withdrawal is associated with resensitization to JAK2 kinase inhibitors and with reversible changes in JAK2 expression. We saw increased JAK2 heterodimerization and sustained JAK2 activation in cell lines, murine models, and patients treated with JAK2 inhibitors. RNA interference and pharmacologic studies demonstrate that JAK2 inhibitor persistent cells remain dependent on JAK2 protein expression. Consequently, therapies that result in JAK2 degradation retain efficacy in persistent cells and may provide additional benefit to patients with JAK2-dependent malignancies treated with JAK2 inhibitors. PMID:22820254

  2. Two Clinical Phenotypes in Polycythemia Vera

    PubMed Central

    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

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

    PubMed

    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.

  4. Mutations in TP53 and JAK2 are independent prognostic biomarkers in B-cell precursor acute lymphoblastic leukaemia.

    PubMed

    Forero-Castro, Maribel; Robledo, Cristina; Benito, Rocío; Bodega-Mayor, Irene; Rapado, Inmaculada; Hernández-Sánchez, María; Abáigar, María; Maria Hernández-Sánchez, Jesús; Quijada-Álamo, Miguel; María Sánchez-Pina, José; Sala-Valdés, Mónica; Araujo-Silva, Fernanda; Kohlmann, Alexander; Luis Fuster, José; Arefi, Maryam; de Las Heras, Natalia; Riesco, Susana; Rodríguez, Juan N; Hermosín, Lourdes; Ribera, Jordi; Camos Guijosa, Mireia; Ramírez, Manuel; de Heredia Rubio, Cristina Díaz; Barragán, Eva; Martínez, Joaquín; Ribera, José M; Fernández-Ruiz, Elena; Hernández-Rivas, Jesús-María

    2017-07-11

    In B-cell precursor acute lymphoblastic leukaemia (B-ALL), the identification of additional genetic alterations associated with poor prognosis is still of importance. We determined the frequency and prognostic impact of somatic mutations in children and adult cases with B-ALL treated with Spanish PETHEMA and SEHOP protocols. Mutational status of hotspot regions of TP53, JAK2, PAX5, LEF1, CRLF2 and IL7R genes was determined by next-generation deep sequencing in 340 B-ALL patients (211 children and 129 adults). The associations between mutation status and clinicopathological features at the time of diagnosis, treatment outcome and survival were assessed. Univariate and multivariate survival analyses were performed to identify independent prognostic factors associated with overall survival (OS), event-free survival (EFS) and relapse rate (RR). A mutation rate of 12.4% was identified. The frequency of adult mutations was higher (20.2% vs 7.6%, P=0.001). TP53 was the most frequently mutated gene (4.1%), followed by JAK2 (3.8%), CRLF2 (2.9%), PAX5 (2.4%), LEF1 (0.6%) and IL7R (0.3%). All mutations were observed in B-ALL without ETV6-RUNX1 (P=0.047) or BCR-ABL1 fusions (P<0.0001). In children, TP53mut was associated with lower OS (5-year OS: 50% vs 86%, P=0.002) and EFS rates (5-year EFS: 50% vs 78.3%, P=0.009) and higher RR (5-year RR: 33.3% vs 18.6% P=0.037), and was independently associated with higher RR (hazard ratio (HR)=4.5; P=0.04). In adults, TP53mut was associated with a lower OS (5-year OS: 0% vs 43.3%, P=0.019) and a higher RR (5-year RR: 100% vs 61.4%, P=0.029), whereas JAK2mut was associated with a lower EFS (5-year EFS: 0% vs 30.6%, P=0.035) and a higher RR (5-year RR: 100% vs 60.4%, P=0.002). TP53mut was an independent risk factor for shorter OS (HR=2.3; P=0.035) and, together with JAK2mut, also were independent markers of poor prognosis for RR (TP53mut: HR=5.9; P=0.027 and JAK2mut: HR=5.6; P=0.036). TP53mut and JAK2mut are potential biomarkers associated

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

    PubMed

    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.

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

    PubMed

    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.

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

    PubMed Central

    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 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. PMID:15143187

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

    PubMed Central

    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. PMID:22829077

  9. TLR4 and RAGE conversely mediate pro-inflammatory S100A8/9-mediated inhibition of proliferation-linked signaling in myeloproliferative neoplasms.

    PubMed

    Kovačić, Marijana; Mitrović-Ajtić, Olivera; Beleslin-Čokić, Bojana; Djikić, Dragoslava; Subotički, Tijana; Diklić, Miloš; Leković, Danijela; Gotić, Mirjana; Mossuz, Pascal; Čokić, Vladan P

    2018-06-26

    Previously, the family of S100A proteins has been found to be associated with inflammation and myelopoiesis and to be able to induce or support myeloproliferation during chronic inflammation. Here, we studied the inflammatory myeloid-related proteins S100A4, S100A8, S100A9 and S100A12 in myeloproliferative neoplasms (MPNs) in order to assess the involvement of chronic inflammation in the pathogenesis of MPN. We analyzed the S100A4, S100A8, S100A9 and S100A12 mRNA and protein levels in the bone marrow and circulation of 140 patients with MPN and 15 healthy controls using Western blotting, microarray-based mRNA expression profiling and ELISA assays, respectively. In addition we performed functional studies on the proliferation-related AKT and ERK1/2 signaling pathways in MPN-derived granulocytes using Western blotting and proteomic analyses. We found that the S100A mRNA levels were increased in MPN patient-derived circulatory CD34 + cells, and that their protein expression levels were also augmented in their granulocytes and bone marrow stroma cells, depending on the JAK2V617F mutation allele burden. We also found that calreticulin (CALR) mutations were related to reduced S100A8 plasma levels in primary myelofibrosis (PMF). The S100A8 plasma levels were found to be increased in MPN, the S100A9 plasma levels in PMF and essential thrombocythemia (ET), and the S100A12 plasma levels in polycythemia vera (PV). These S100A plasma levels showed a positive correlation with the systemic inflammation marker IL-8, as well as with the numbers of leukocytes and thrombocytes, depending on the JAK2V617F mutation status. Additionally, we found that heterodimeric S100A8/9 can inhibit the AKT pathway in MPN-derived granulocytes mediated by the Toll-like receptor 4 (TLR4), depending on the CALR mutation status. Conversely, we found that blocking of the receptor for advanced glycation end products (RAGE) increased the S100A8/9-mediated inhibition of AKT signaling in the MPN

  10. Thrombocytosis and thrombosis.

    PubMed

    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.

  11. Cytokine receptor signaling is required for the survival of ALK− anaplastic large cell lymphoma, even in the presence of JAK1/STAT3 mutations

    PubMed Central

    Chen, Jing; Zhang, Yong; Petrus, Michael N.; Xiao, Wenming; Nicolae, Alina; Raffeld, Mark; Pittaluga, Stefania; Bamford, Richard N.; Nakagawa, Masao; Ouyang, Sunny Tianyi; Epstein, Alan L.; Kadin, Marshall E.; Del Mistro, Annarose; Woessner, Richard; Jaffe, Elaine S.; Waldmann, Thomas A.

    2017-01-01

    Activating Janus kinase (JAK) and signal transducer and activator of transcription (STAT) mutations have been discovered in many T-cell malignancies, including anaplastic lymphoma kinase (ALK)− anaplastic large cell lymphomas (ALCLs). However, such mutations occur in a minority of patients. To investigate the clinical application of targeting JAK for ALK− ALCL, we treated ALK− cell lines of various histological origins with JAK inhibitors. Interestingly, most exogenous cytokine-independent cell lines responded to JAK inhibition regardless of JAK mutation status. JAK inhibitor sensitivity correlated with the STAT3 phosphorylation status of tumor cells. Using retroviral shRNA knockdown, we have demonstrated that these JAK inhibitor-sensitive cells are dependent on both JAK1 and STAT3 for survival. JAK1 and STAT3 gain-of-function mutations were found in some, but not all, JAK inhibitor-sensitive cells. Moreover, the mutations alone cannot explain the JAK1/STAT3 dependency, given that wild-type JAK1 or STAT3 was sufficient to promote cell survival in the cells that had either JAK1or STAT3 mutations. To investigate whether other mechanisms were involved, we knocked down upstream receptors GP130 or IL-2Rγ. Knockdown of GP130 or IL-2Rγ induced cell death in selected JAK inhibitor-sensitive cells. High expression levels of cytokines, including IL-6, were demonstrated in cell lines as well as in primary ALK− ALCL tumors. Finally, ruxolitinib, a JAK1/2 inhibitor, was effective in vivo in a xenograft ALK− ALCL model. Our data suggest that cytokine receptor signaling is required for tumor cell survival in diverse forms of ALK− ALCL, even in the presence of JAK1/STAT3 mutations. Therefore, JAK inhibitor therapy might benefit patients with ALK− ALCL who are phosphorylated STAT3+. PMID:28356514

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

    PubMed Central

    Boissinot, Marjorie; Vilaine, Mathias; Hermouet, Sylvie

    2014-01-01

    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). PMID:25119536

  13. Pathogenesis of Myeloproliferative Neoplasms: Role and Mechanisms of Chronic Inflammation.

    PubMed

    Hermouet, Sylvie; Bigot-Corbel, Edith; Gardie, Betty

    2015-01-01

    Myeloproliferative neoplasms (MPNs) are a heterogeneous group of clonal diseases characterized by the excessive and chronic production of mature cells from one or several of the myeloid lineages. Recent advances in the biology of MPNs have greatly facilitated their molecular diagnosis since most patients present with mutation(s) in the JAK2, MPL, or CALR genes. Yet the roles played by these mutations in the pathogenesis and main complications of the different subtypes of MPNs are not fully elucidated. Importantly, chronic inflammation has long been associated with MPN disease and some of the symptoms and complications can be linked to inflammation. Moreover, the JAK inhibitor clinical trials showed that the reduction of symptoms linked to inflammation was beneficial to patients even in the absence of significant decrease in the JAK2-V617F mutant load. These observations suggested that part of the inflammation observed in patients with JAK2-mutated MPNs may not be the consequence of JAK2 mutation. The aim of this paper is to review the different aspects of inflammation in MPNs, the molecular mechanisms involved, the role of specific genetic defects, and the evidence that increased production of certain cytokines depends or not on MPN-associated mutations, and to discuss possible nongenetic causes of inflammation.

  14. Pathogenesis of Myeloproliferative Neoplasms: Role and Mechanisms of Chronic Inflammation

    PubMed Central

    Bigot-Corbel, Edith; Gardie, Betty

    2015-01-01

    Myeloproliferative neoplasms (MPNs) are a heterogeneous group of clonal diseases characterized by the excessive and chronic production of mature cells from one or several of the myeloid lineages. Recent advances in the biology of MPNs have greatly facilitated their molecular diagnosis since most patients present with mutation(s) in the JAK2, MPL, or CALR genes. Yet the roles played by these mutations in the pathogenesis and main complications of the different subtypes of MPNs are not fully elucidated. Importantly, chronic inflammation has long been associated with MPN disease and some of the symptoms and complications can be linked to inflammation. Moreover, the JAK inhibitor clinical trials showed that the reduction of symptoms linked to inflammation was beneficial to patients even in the absence of significant decrease in the JAK2-V617F mutant load. These observations suggested that part of the inflammation observed in patients with JAK2-mutated MPNs may not be the consequence of JAK2 mutation. The aim of this paper is to review the different aspects of inflammation in MPNs, the molecular mechanisms involved, the role of specific genetic defects, and the evidence that increased production of certain cytokines depends or not on MPN-associated mutations, and to discuss possible nongenetic causes of inflammation. PMID:26538820

  15. Targeted sequencing identifies associations between IL7R-JAK mutations and epigenetic modulators in T-cell acute lymphoblastic leukemia

    PubMed Central

    Vicente, Carmen; Schwab, Claire; Broux, Michaël; Geerdens, Ellen; Degryse, Sandrine; Demeyer, Sofie; Lahortiga, Idoya; Elliott, Alannah; Chilton, Lucy; La Starza, Roberta; Mecucci, Cristina; Vandenberghe, Peter; Goulden, Nicholas; Vora, Ajay; Moorman, Anthony V.; Soulier, Jean; Harrison, Christine J.; Clappier, Emmanuelle; Cools, Jan

    2015-01-01

    T-cell acute lymphoblastic leukemia is caused by the accumulation of multiple oncogenic lesions, including chromosomal rearrangements and mutations. To determine the frequency and co-occurrence of mutations in T-cell acute lymphoblastic leukemia, we performed targeted re-sequencing of 115 genes across 155 diagnostic samples (44 adult and 111 childhood cases). NOTCH1 and CDKN2A/B were mutated/deleted in more than half of the cases, while an additional 37 genes were mutated/deleted in 4% to 20% of cases. We found that IL7R-JAK pathway genes were mutated in 27.7% of cases, with JAK3 mutations being the most frequent event in this group. Copy number variations were also detected, including deletions of CREBBP or CTCF and duplication of MYB. FLT3 mutations were rare, but a novel extracellular mutation in FLT3 was detected and confirmed to be transforming. Furthermore, we identified complex patterns of pairwise associations, including a significant association between mutations in IL7R-JAK genes and epigenetic regulators (WT1, PRC2, PHF6). Our analyses showed that IL7R-JAK genetic lesions did not confer adverse prognosis in T-cell acute lymphoblastic leukemia cases enrolled in the UK ALL2003 trial. Overall, these results identify interconnections between the T-cell acute lymphoblastic leukemia genome and disease biology, and suggest a potential clinical application for JAK inhibitors in a significant proportion of patients with T-cell acute lymphoblastic leukemia. PMID:26206799

  16. Loss of function JAK1 mutations occur at high frequency in cancers with microsatellite instability and are suggestive of immune evasion.

    PubMed

    Albacker, Lee A; Wu, Jeremy; Smith, Peter; Warmuth, Markus; Stephens, Philip J; Zhu, Ping; Yu, Lihua; Chmielecki, Juliann

    2017-01-01

    Immune evasion is a well-recognized hallmark of cancer and recent studies with immunotherapy agents have suggested that tumors with increased numbers of neoantigens elicit greater immune responses. We hypothesized that the immune system presents a common selective pressure on high mutation burden tumors and therefore immune evasion mutations would be enriched in high mutation burden tumors. The JAK family of kinases is required for the signaling of a host of immune modulators in tumor, stromal, and immune cells. Therefore, we analyzed alterations in this family for the hypothesized signature of an immune evasion mutation. Here, we searched a database of 61,704 unique solid tumors for alterations in the JAK family kinases (JAK1/2/3, TYK2). We used The Cancer Genome Atlas and Cancer Cell Line Encyclopedia data to confirm and extend our findings by analyzing gene expression patterns. Recurrent frameshift mutations in JAK1 were associated with high mutation burden and microsatellite instability. These mutations occurred in multiple tumor types including endometrial, colorectal, stomach, and prostate carcinomas. Analyzing gene expression signatures in endometrial and stomach adenocarcinomas revealed that tumors with a JAK1 frameshift exhibited reduced expression of interferon response signatures and multiple anti-tumor immune signatures. Importantly, endometrial cancer cell lines exhibited similar gene expression changes that were expected to be tumor cell intrinsic (e.g. interferon response) but not those expected to be tumor cell extrinsic (e.g. NK cells). From these data, we derive two primary conclusions: 1) JAK1 frameshifts are loss of function alterations that represent a potential pan-cancer adaptation to immune responses against tumors with microsatellite instability; 2) The mechanism by which JAK1 loss of function contributes to tumor immune evasion is likely associated with loss of the JAK1-mediated interferon response.

  17. A rapid, highly accurate method for quantifying CALR mutant allele burden in persons with myeloproliferative neoplasms.

    PubMed

    Yao, Qiu-Mei; Zhou, Jiao; Gale, Robert Peter; Li, Jin-Lan; Li, Ling-Di; Li, Ning; Chen, Shan-Shan; Ruan, Guo-Rui

    2015-10-01

    Calreticulin (CALR) mutations were recently identified in a substantial proportion of persons with essential thrombocythemia (ET) and with primary myelofibrosis (PMF) without JAK2(V617F). Consequently rapid, sensitive, and specific methods to detect and quantify these mutations are needed. We studied samples from 1088 persons with myeloproliferative neoplasms (MPNs) including 421 JAK2(V617F) negative subjects with ET, PMF, polycythemia vera (PV), chronic myeloid leukemia (CML) and hyper-eosinophilic syndrome (HES). Detection of CALR exon 9 mutations was done by PCR amplification followed by fragment length analysis and direct sequencing. Dilution assays were used to determine CALR mutant allele burden. We detected CALR mutations in blood and bone marrow samples from 152 subjects with ET and with PMF but not in samples from normal or persons with PV, CML, or HES. CALR mutant peaks were distinct from wild-type peaks and dilution experiments indicated a sensitivity level of 0.5-5% for a CALR mutant allele in a wild-type background. Diverse types of mutations were detected including deletions, insertions, and complex indels. All mutations were confirmed by direct sequencing. We also used dilution experiments to quantify mutant allele burden. We were able to reproducibly detect mutant allele levels as low 5% (0.5-5%) in a wild-type background. PCR amplification followed by fragment length analysis is a rapid, sensitive, and specific method for screening persons with MPNs for CALR mutations, especially those with ET and PMF and for estimating mutant allele burden.

  18. Use of molecular testing to identify a cluster of patients with polycythemia vera in eastern Pennsylvania.

    PubMed

    Seaman, Vincent; Jumaan, Aisha; Yanni, Emad; Lewis, Brian; Neyer, Jonathan; Roda, Paul; Xu, Mingjiang; Hoffman, Ronald

    2009-02-01

    The role of the environment in the origin of polycythemia vera has not been well documented. Recently, molecular diagnostic tools have been developed to facilitate the diagnosis of polycythemia vera. A cluster of patients with polycythemia vera was suspected in three countries in eastern Pennsylvania where there have long been a concern about environment hazards. Rigorous clinical criteria and JAK2 617V>F testing were used to confirm the diagnosis of polycythemia vera in patients in this area. Participants included cases of polycythemia vera from the 2001 to 2005 state cancer registry as well as self- and physician-referred cases. A diagnosis of polycythemia vera was confirmed in 53% of 62 participants using WHO criteria, which includes JAK2 617V>F testing. A statistically significant cluster of cases (P < 0.001) was identified where the incidence of polycythemia vera was 4.3 times that of the rest of the study area. The area of the cluster contained numerous sources of hazardous material including waste-coal power plants and U.S. Environmental Protection Agency Superfund sites. The diagnosis of polycythemia vera based solely on clinical criteria is frequently erroneous, suggesting that our prior knowledge of the epidemiology of this disease might be inaccurate. The JAK2 617V>F mutational analysis provides diagnostic clarity and permitted the confirmation of a cluster of polycythemia vera cases not identified by traditional clinical and pathologic diagnostic criteria. The close proximity of this cluster to known areas of hazardous material exposure raises concern that such environmental factors might play a role in the origin of polycythemia vera.

  19. Genetic studies reveal an unexpected negative regulatory role for Jak2 in thrombopoiesis

    PubMed Central

    Meyer, Sara C.; Keller, Matthew D.; Woods, Brittany A.; LaFave, Lindsay M.; Bastian, Lennart; Kleppe, Maria; Bhagwat, Neha; Marubayashi, Sachie

    2014-01-01

    JAK inhibitor treatment is limited by the variable development of anemia and thrombocytopenia thought to be due to on-target JAK2 inhibition. We evaluated the impact of Jak2 deletion in platelets (PLTs) and megakaryocytes (MKs) on blood counts, stem/progenitor cells, and Jak-Stat signaling. Pf4-Cre–mediated Jak2 deletion in PLTs and MKs did not compromise PLT formation but caused thrombocytosis, and resulted in expansion of MK progenitors and Lin−Sca1+Kit+ cells. Serum thrombopoietin (TPO) was maintained at normal levels in Pf4-Cre–positive Jak2f/f mice, consistent with reduced internalization/turnover by Jak2-deficient PLTs. These data demonstrate that Jak2 in terminal megakaryopoiesis is not required for PLT production, and that Jak2 loss in PLTs and MKs results in non-autonomous expansion of stem/progenitors and of MKs and PLTs via dysregulated TPO turnover. This suggests that the thrombocytopenia frequently seen with JAK inhibitor treatment is not due to JAK2 inhibition in PLTs and MKs, but rather due to JAK2 inhibition in stem/progenitor cells. PMID:25115888

  20. Historical views, conventional approaches, and evolving management strategies for myeloproliferative neoplasms.

    PubMed

    Stein, Brady L; Gotlib, Jason; Arcasoy, Murat; Nguyen, Marie Huong; Shah, Neil; Moliterno, Alison; Jamieson, Catriona; Pollyea, Daniel A; Scott, Bart; Wadleigh, Martha; Levine, Ross; Komrokji, Rami; Klisovic, Rebecca; Gundabolu, Krishna; Kropf, Patricia; Wetzler, Meir; Oh, Stephen T; Ribeiro, Raul; Paschal, Rita; Mohan, Sanjay; Podoltsev, Nikolai; Prchal, Josef; Talpaz, Moshe; Snyder, David; Verstovsek, Srdan; Mesa, Ruben A

    2015-04-01

    The classical Philadelphia chromosome-negative myeloproliferative neoplasms (MPN), which include essential thrombocythemia, polycythemia vera, and myelofibrosis (MF), are in a new era of molecular diagnosis, ushered in by the identification of the JAK2(V617F) and cMPL mutations in 2005 and 2006, respectively, and the CALR mutations in 2013. Coupled with increased knowledge of disease pathogenesis and refined diagnostic criteria and prognostic scoring systems, a more nuanced appreciation has emerged of the burden of MPN in the United States, including the prevalence, symptom burden, and impact on quality of life. Biological advances in MPN have translated into the rapid development of novel therapeutics, culminating in the approval of the first treatment for MF, the JAK1/JAK2 inhibitor ruxolitinib. However, certain practical aspects of care, such as those regarding diagnosis, prevention of vascular events, choice of cytoreductive agent, and planning for therapies, present challenges for hematologists/oncologists, and are discussed in this article. Copyright © 2015 by the National Comprehensive Cancer Network.

  1. Evaluation of Inflammation Parameters in Philadelphia Negative Chronic Myeloproliferative Neoplasia Patients.

    PubMed

    Hacibekiroglu, Tuba; Akinci, Sema; Basturk, Abdulkadir; inal, Besime; Guney, Tekin; Bakanay, Sule Mine; Dilek, Imdat

    2015-01-01

    Chronic myeloproliferative diseases are clonal stem cell diseases which occur as a result of uncontrollable growth and reproduction of hematopoietic stem cells, which are the myeloid series source in bone marrow. Recent studies have suggested that chronic inflammation can be a triggering factor in the clonal change in chronic myeloproliferative neoplasia (CMPN). In our study, we evaluated the existence of a chronic inflammation process in our Philadelphia negative (Ph-)CMPN patients using inflammation parameters in combination with demographic, laboratory and clinical characteristics of the patients. Demographic characteristics, clinical and laboratorial data, and thrombosis histories of 99 Ph-CMPN patients, who were diagnosed at our outpatient clinic of hematology in accordance with WHO 2008 criteria, were analyzed retrospectively,with 80 healthy individuals of matching gender and age included as controls. Complete blood counts, sedimentation, C reactive protein (CRP), JAK V617F gene mutations, abdomen ultrasound images and previous thrombosis histories of these patients were retrospectively analyzed. Ph-CMPN and healthy control groups included 99 and 80 cases, respectively. PV, ET and MF diagnoses of patients were 43 (%43.4), 44 (44.4%) and 12 (12.1%), respectively. JAK V617F gene mutation was found to be positive in 64 (71.1%) of all cases and in 27(65.8%), 32 (82%), 5 (50%) of the cases in PV, ET and PMF groups, respectively. Thrombosis was determined as 12 (12%) in the entire group, 12.5% in the JAK V617F negative and 15.3% in the positive patients, with no statistical significance (p=0.758). No significant difference was observed between patients with and without previous thrombosis history in respect to hemogram parameters, sedimentation and CRP (p>0.05), neutrophil to lymphocyte ratio (NLR), erythrocyte distribution width (RDW), mean platelet volume (MPV) and sedimentation levels of the patient.

  2. The role of the JAK2 GGCC haplotype and the TET2 gene in familial myeloproliferative neoplasms

    PubMed Central

    Olcaydu, Damla; Rumi, Elisa; Harutyunyan, Ashot; Passamonti, Francesco; Pietra, Daniela; Pascutto, Cristiana; Berg, Tiina; Jäger, Roland; Hammond, Emma; Cazzola, Mario; Kralovics, Robert

    2011-01-01

    Background Myeloproliferative neoplasms constitute a group of diverse chronic myeloid malignancies that share pathogenic features such as acquired mutations in the JAK2, TET2, CBL and MPL genes. There are recent reports that a JAK2 gene haplotype (GGCC or 46/1) confers susceptibility to JAK2 mutation-positive myeloproliferative neoplasms. The aim of this study was to examine the role of the JAK2 GGCC haplotype and germline mutations of TET2, CBL and MPL in familial myeloproliferative neoplasms. Design and Methods We investigated patients with familial (n=88) or sporadic (n=684) myeloproliferative neoplasms, and a control population (n=203) from the same demographic area in Italy. Association analysis was performed using tagged single nucleotide polymorphisms (rs10974944 and rs12343867) of the JAK2 haplotype. Sequence analysis of TET2, CBL and MPL was conducted in the 88 patients with familial myeloproliferative neoplasms. Results Association analysis revealed no difference in haplotype frequency between familial and sporadic cases of myeloproliferative neoplasms (P=0.6529). No germline mutations in TET2, CBL or MPL that segregate with the disease phenotype were identified. As we observed variability in somatic mutations in the affected members of a pedigree with myeloproliferative neoplasms, we postulated that somatic mutagenesis is increased in familial myeloproliferative neoplasms. Accordingly, we compared the incidence of malignant disorders between sporadic and familial patients. Although the overall incidence of malignant disorders did not differ significantly between cases of familial and sporadic myeloproliferative neoplasms, malignancies were more frequent in patients with familial disease aged between 50 to 70 years (P=0.0198) than in patients in the same age range with sporadic myeloproliferative neoplasms. Conclusions We conclude that the JAK2 GGCC haplotype and germline mutations of TET2, CBL or MPL do not explain familial clustering of

  3. A novel mutation in the JH4 domain of JAK3 causing severe combined immunodeficiency complicated by vertebral osteomyelitis.

    PubMed

    Qamar, Farah; Junejo, Samina; Qureshi, Sonia; Seleman, Michael; Bainter, Wayne; Massaad, Michel; Chou, Janet; Geha, Raif S

    2017-10-01

    JAK3 is a tyrosine kinase essential for signaling downstream of the common gamma chain subunit shared by multiple cytokine receptors. JAK3 deficiency results in T - B + NK - severe combined immune deficiency (SCID). We report a patient with SCID due to a novel mutation in the JAK3 JH4 domain. The function of the JH4 domain remains unknown. This is the first report of a missense mutation in the JAK3 JH4 domain, thereby demonstrating the importance of the JH4 domain of JAK3 in host immunity. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Direct Interaction of Jak1 and v-Abl Is Required for v-Abl-Induced Activation of STATs and Proliferation

    PubMed Central

    Danial, Nika N.; Losman, Julie A.; Lu, Tianhong; Yip, Natalie; Krishnan, Kartik; Krolewski, John; Goff, Stephen P.; Wang, Jean Y. J.; Rothman, Paul B.

    1998-01-01

    In Abelson murine leukemia virus (A-MuLV)-transformed cells, members of the Janus kinase (Jak) family of non-receptor tyrosine kinases and the signal transducers and activators of transcription (STAT) family of signaling proteins are constitutively activated. In these cells, the v-Abl oncoprotein and the Jak proteins physically associate. To define the molecular mechanism of constitutive Jak-STAT signaling in these cells, the functional significance of the v-Abl–Jak association was examined. Mapping the Jak1 interaction domain in v-Abl demonstrates that amino acids 858 to 1080 within the carboxyl-terminal region of v-Abl bind Jak1 through a direct interaction. A mutant of v-Abl lacking this region exhibits a significant defect in Jak1 binding in vivo, fails to activate Jak1 and STAT proteins, and does not support either the proliferation or the survival of BAF/3 cells in the absence of cytokine. Cells expressing this v-Abl mutant show extended latency and decreased frequency in generating tumors in nude mice. In addition, inducible expression of a kinase-inactive mutant of Jak1 protein inhibits the ability of v-Abl to activate STATs and to induce cytokine-independent proliferation, indicating that an active Jak1 is required for these v-Abl-induced signaling pathways in vivo. We propose that Jak1 is a mediator of v-Abl-induced STAT activation and v-Abl induced proliferation in BAF/3 cells, and may be important for efficient transformation of immature B cells by the v-abl oncogene. PMID:9774693

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

    PubMed Central

    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

    2014-01-01

    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. PMID:25143485

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

    PubMed

    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.

  7. Improved targeting of JAK2 leads to increased therapeutic efficacy in myeloproliferative neoplasms

    PubMed Central

    Bhagwat, Neha; Koppikar, Priya; Keller, Matthew; Marubayashi, Sachie; Shank, Kaitlyn; Rampal, Raajit; Qi, Jun; Kleppe, Maria; Patel, Hardik J.; Shah, Smit K.; Taldone, Tony; Bradner, James E.; Chiosis, Gabriela

    2014-01-01

    The discovery of JAK2/MPL mutations in patients with myeloproliferative neoplasms (MPN) led to clinical development of Janus kinase (JAK) inhibitors for treatment of MPN. These inhibitors improve constitutional symptoms and splenomegaly but do not significantly reduce mutant allele burden in patients. We recently showed that chronic exposure to JAK inhibitors results in inhibitor persistence via JAK2 transactivation and persistent JAK–signal transducer and activator of transcription signaling. We performed genetic and pharmacologic studies to determine whether improved JAK2 inhibition would show increased efficacy in MPN models and primary samples. Jak2 deletion in vivo led to profound reduction in disease burden not seen with JAK inhibitors, and deletion of Jak2 following chronic ruxolitinib therapy markedly reduced mutant allele burden. This demonstrates that JAK2 remains an essential target in MPN cells that survive in the setting of chronic JAK inhibition. Combination therapy with the heat shock protein 90 (HSP90) inhibitor PU-H71 and ruxolitinib reduced total and phospho-JAK2 and achieved more potent inhibition of downstream signaling than ruxolitinib monotherapy. Combination treatment improved blood counts, spleen weights, and reduced bone marrow fibrosis compared with ruxolitinib alone. These data suggest alternate approaches that increase JAK2 targeting, including combination JAK/HSP90 inhibitor therapy, are warranted in the clinical setting. PMID:24470592

  8. Mesenchymal stromal cells (MSC) from JAK2+ myeloproliferative neoplasms differ from normal MSC and contribute to the maintenance of neoplastic hematopoiesis

    PubMed Central

    Sánchez-Abarca, Luis Ignacio; Rosón-Burgo, Beatriz; Redondo, Alba; Rico, Ana; Preciado, Silvia; Ortega, Rebeca; Rodríguez, Concepción; Muntión, Sandra; Hernández-Hernández, Ángel; De Las Rivas, Javier; González, Marcos; González Porras, José Ramón; del Cañizo, Consuelo; Sánchez-Guijo, Fermín

    2017-01-01

    There is evidence of continuous bidirectional cross-talk between malignant cells and bone marrow-derived mesenchymal stromal cells (BM-MSC), which favors the emergence and progression of myeloproliferative neoplastic (MPN) diseases. In the current work we have compared the function and gene expression profile of BM-MSC from healthy donors (HD-MSC) and patients with MPN (JAK2V617F), showing no differences in the morphology, proliferation and differentiation capacity between both groups. However, BM-MSC from MPN expressed higher mean fluorescence intensity (MIF) of CD73, CD44 and CD90, whereas CD105 was lower when compared to controls. Gene expression profile of BM-MSC showed a total of 169 genes that were differentially expressed in BM-MSC from MPN patients compared to HD-MSC. In addition, we studied the ability of BM-MSC to support the growth and survival of hematopoietic stem/progenitor cells (HSPC), showing a significant increase in the number of CFU-GM colonies when MPN-HSPC were co-cultured with MPN-MSC. Furthermore, MPN-MSC showed alteration in the expression of genes associated to the maintenance of hematopoiesis, with an overexpression of SPP1 and NF-kB, and a downregulation of ANGPT1 and THPO. Our results suggest that BM-MSC from JAK2+ patients differ from their normal counterparts and favor the maintenance of malignant clonal hematopoietic cells. PMID:28796790

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

    PubMed

    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.

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

    PubMed

    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.

  11. F1174V mutation alters the ALK active conformation in response to Crizotinib in NSCLC: Insight from molecular simulations.

    PubMed

    Dehghanian, Fariba; Kay, Maryam; Vallian, Sadeq

    2017-08-01

    Crizotinib is an efficient antineoplastic drug for treatment of non-small cell lung carcinoma (NSCLC), which is identified as an anaplastic lymphoma kinase (ALK) inhibitor. F1174V is a recently identified acquired point mutation relating to the Crizotinib resistance in NSCLC patients. The mechanism of Crizotinib resistance relating to F1174V mutation as a non-active site mutation remains unclear. In this study, the molecular dynamic simulation was used to investigate the possible mechanisms by which F1174V mutation may affect the structure and activity of ALK kinase domain. The results suggested that F1174V mutation could cause two important secondary structure alterations, which led to the local conformational change in ALK kinase domain. This causes more positive free energy in the mutant complex in comparison with the wild-type one. In addition, our structural analyses illustrated that F1174V mutation could result in some important interactions, which represent the key characteristics of the ALK active conformation. This study provided a molecular mechanism for ALK Crizotinib resistance caused by F1174V mutation,which could facilitate designing more efficient drugs. Copyright © 2017 Elsevier Inc. All rights reserved.

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

    PubMed

    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.

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

    PubMed

    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.

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

    PubMed Central

    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

    2013-01-01

    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. PMID:23575445

  15. Activation of JAK3, but not JAK1, is critical to interleukin-4 (IL4) stimulated proliferation and requires a membrane-proximal region of IL4 receptor alpha.

    PubMed

    Malabarba, M G; Kirken, R A; Rui, H; Koettnitz, K; Kawamura, M; O'Shea, J J; Kalthoff, F S; Farrar, W L

    1995-04-21

    The tyrosine kinases JAK1 and JAK3 have been shown to undergo tyrosine phosphorylation in response to interleukin-2 (IL), IL4, IL7, and IL9, cytokines which share the common IL2 receptor gamma-chain (IL2R gamma), and evidence has been found for a preferential coupling of JAK3 to IL2R gamma and JAK1 to IL2R beta. Here we show, using human premyeloid TF-1 cells, that IL4 stimulates JAK3 to a larger extent than JAK1, based upon three different evaluation criteria. These include a more vigorous tyrosine phosphorylation of JAK3 as measured by anti-phosphotyrosine immunoblotting, a more marked activation of JAK3 as determined by in vitro tyrosine kinase assays and a more manifest presence of JAK3 in activated IL4-receptor complexes. These observations suggest that IL4 receptor signal transduction does not depend on equimolar heterodimerization of JAK1 and JAK3 following IL4-induced heterodimerization of IL4R alpha and IL2R gamma. Indeed, when human IL4R alpha was stably expressed in mouse BA/F3 cells, robust IL4-induced proliferation and JAK3 activation occurred without detectable involvement of JAK1, JAK2, or TYK2. The present study suggests that JAK1 plays a subordinate role in IL4 receptor signaling, and that in certain cells exclusive JAK3 activation may mediate IL4-induced cell growth. Moreover, mutational analysis of human IL4R alpha showed that a membrane-proximal cytoplasmic region was critical for JAK3 activation, while the I4R motif was not, which is compatible with a role of JAK3 upstream of the recruitment of the insulin receptor substrate-1/4PS signaling proteins by IL4 receptors.

  16. Recent advances in diagnosis and treatment of chronic myeloproliferative neoplasms

    PubMed Central

    Guglielmelli, Paola

    2010-01-01

    The Philadelphia chromosome-negative chronic myeloproliferative neoplasms (MPNs) have recently been the focus of tremendous advances in basic knowledge of disease pathophysiology following the recognition of mutations in JAK2 and MPL. These discoveries also led to refinement of the criteria employed for diagnosis. The prognostic roles of the JAK2 V617F mutation and of leukocytosis as independent risk factors for thrombosis, which represents the leading cause of death in patients with polycythemia vera and essential thrombocythemia, are supported by retrospective studies. A new risk stratification approach to the patient with primary myelofibrosis allows clinicians to distinguish categories of patients with significantly different expected survival. Finally, new drugs are currently being tested for MPNs, and molecular discoveries could ultimately lead to the development of a specific targeted therapy. Overall, significant advances in diagnosis, prognostication, and treatment have taken place in the last couple of years in the field of MPNs. PMID:20948870

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

    PubMed

    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.

  18. CBL family E3 ubiquitin ligases control JAK2 ubiquitination and stability in hematopoietic stem cells and myeloid malignancies

    PubMed Central

    Lv, Kaosheng; Jiang, Jing; Donaghy, Ryan; Riling, Christopher R.; Cheng, Ying; Chandra, Vemika; Rozenova, Krasimira; An, Wei; Mohapatra, Bhopal C.; Goetz, Benjamin T.; Pillai, Vinodh; Han, Xu; Todd, Emily A.; Jeschke, Grace R.; Langdon, Wallace Y.; Kumar, Suresh; Hexner, Elizabeth O.

    2017-01-01

    Janus kinase 2 (JAK2) is a central kinase in hematopoietic stem/progenitor cells (HSPCs), and its uncontrolled activation is a prominent oncogenic driver of hematopoietic neoplasms. However, molecular mechanisms underlying the regulation of JAK2 have remained elusive. Here we report that the Casitas B-cell lymphoma (CBL) family E3 ubiquitin ligases down-regulate JAK2 stability and signaling via the adaptor protein LNK/SH2B3. We demonstrated that depletion of CBL/CBL-B or LNK abrogated JAK2 ubiquitination, extended JAK2 half-life, and enhanced JAK2 signaling and cell growth in human cell lines as well as primary murine HSPCs. Built on these findings, we showed that JAK inhibitor (JAKi) significantly reduced aberrant HSPCs and mitigated leukemia development in a mouse model of aggressive myeloid leukemia driven by loss of Cbl and Cbl-b. Importantly, primary human CBL mutated (CBLmut) leukemias exhibited increased JAK2 protein levels and signaling and were hypersensitive to JAKi. Loss-of-function mutations in CBL E3 ubiquitin ligases are found in a wide range of myeloid malignancies, which are diseases without effective treatment options. Hence, our studies reveal a novel signaling axis that regulates JAK2 in normal and malignant HSPCs and suggest new therapeutic strategies for treating CBLmut myeloid malignancies. PMID:28611190

  19. Aggressive natural killer-cell leukemia mutational landscape and drug profiling highlight JAK-STAT signaling as therapeutic target.

    PubMed

    Dufva, Olli; Kankainen, Matti; Kelkka, Tiina; Sekiguchi, Nodoka; Awad, Shady Adnan; Eldfors, Samuli; Yadav, Bhagwan; Kuusanmäki, Heikki; Malani, Disha; Andersson, Emma I; Pietarinen, Paavo; Saikko, Leena; Kovanen, Panu E; Ojala, Teija; Lee, Dean A; Loughran, Thomas P; Nakazawa, Hideyuki; Suzumiya, Junji; Suzuki, Ritsuro; Ko, Young Hyeh; Kim, Won Seog; Chuang, Shih-Sung; Aittokallio, Tero; Chan, Wing C; Ohshima, Koichi; Ishida, Fumihiro; Mustjoki, Satu

    2018-04-19

    Aggressive natural killer-cell (NK-cell) leukemia (ANKL) is an extremely aggressive malignancy with dismal prognosis and lack of targeted therapies. Here, we elucidate the molecular pathogenesis of ANKL using a combination of genomic and drug sensitivity profiling. We study 14 ANKL patients using whole-exome sequencing (WES) and identify mutations in STAT3 (21%) and RAS-MAPK pathway genes (21%) as well as in DDX3X (29%) and epigenetic modifiers (50%). Additional alterations include JAK-STAT copy gains and tyrosine phosphatase mutations, which we show recurrent also in extranodal NK/T-cell lymphoma, nasal type (NKTCL) through integration of public genomic data. Drug sensitivity profiling further demonstrates the role of the JAK-STAT pathway in the pathogenesis of NK-cell malignancies, identifying NK cells to be highly sensitive to JAK and BCL2 inhibition compared to other hematopoietic cell lineages. Our results provide insight into ANKL genetics and a framework for application of targeted therapies in NK-cell malignancies.

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

    PubMed

    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.

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

    PubMed

    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. Measles virus V protein blocks Jak1-mediated phosphorylation of STAT1 to escape IFN-{alpha}/{beta} signaling

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Caignard, Gregory; Guerbois, Mathilde; Labernardiere, Jean-Louis

    2007-11-25

    Viruses have evolved various strategies to escape the antiviral activity of type I interferons (IFN-{alpha}/{beta}). For measles virus, this function is carried by the polycistronic gene P that encodes, by an unusual editing strategy, for the phosphoprotein P and the virulence factor V (MV-V). MV-V prevents STAT1 nuclear translocation by either sequestration or phosphorylation inhibition, thereby blocking IFN-{alpha}/{beta} pathway. We show that both the N- and C-terminal domains of MV-V (PNT and VCT) contribute to the inhibition of IFN-{alpha}/{beta} signaling. Using the two-hybrid system and co-affinity purification experiments, we identified STAT1 and Jak1 as interactors of MV-V and demonstrate thatmore » MV-V can block the direct phosphorylation of STAT1 by Jak1. A deleterious mutation within the PNT domain of MV-V (Y110H) impaired its ability to interact and block STAT1 phosphorylation. Thus, MV-V interacts with at least two components of IFN-{alpha}/{beta} receptor complex to block downstream signaling.« less

  3. Assisted stellar suicide in V617 Sagittarii

    NASA Astrophysics Data System (ADS)

    Steiner, J. E.; Oliveira, A. S.; Cieslinski, D.; Ricci, T. V.

    2006-02-01

    Context: .V617 Sgr is a V Sagittae star - a group of binaries thought to be the galactic counterparts of the Compact Binary Supersoft X-ray Sources - CBSS. Aims: .To check this hypothesis, we measured the time derivative of its orbital period. Methods: .Observed timings of eclipse minima spanning over 30 000 orbital cycles are presented. Results: .We found that the orbital period evolves quite rapidly: P/dot{P} = 1.1×106 years. This is consistent with the idea that V617 Sgr is a wind driven accretion supersoft source. As the binary system evolves with a time-scale of about one million years, which is extremely short for a low mass evolved binary, it is likely that the system will soon end either by having its secondary completely evaporated or by the primary exploding as a supernova of type Ia. Conclusions: .

  4. Molecular diagnostics of myeloproliferative neoplasms.

    PubMed

    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.

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

    PubMed Central

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

    2014-01-01

    Myeloproliferative neoplasms (MPNs) are often characterized by JAK2 or calreticulin 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 ER. Even in Jak2 sufficient cells, Mpl accumulates in punctate structures that partially co-localize 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. PMID:24931576

  6. Management of polycythaemia vera: a critical review of current data.

    PubMed

    McMullin, Mary F; Wilkins, Bridget S; Harrison, Claire N

    2016-02-01

    Polycythaemia vera (PV) is a chronic blood cancer; its clinical features are dominated by myeloproliferation (erythrocytosis, often leucocytosis and/or thrombocytosis) and a tendency for thrombosis and transformation to myelofibrosis or acute myeloid leukaemia. In the past 10 years the pathophysiology of this condition has been defined as JAK/STAT pathway activation, almost always due to mutations in JAK2 exons 12 or 14 (JAK2 V617F). In the same time period our understanding of the optimal management of PV has expanded, most recently culminating in the approval of JAK inhibitors for the treatment of PV patients who are resistant or intolerant to therapy with hydroxycarbamide. It has also been demonstrated that life expectancy for many patients with PV is not normal, nor is their quality of life. We critically explore these findings and discuss their impact. In addition, we highlight persisting gaps in our current management strategy; for example, what is the optimal first line cytoreductive therapy and, indeed, which patients need cytoreductive drugs. © 2015 John Wiley & Sons Ltd.

  7. Identification of JAK2 as a Mediator of FIP1L1-PDGFRA-Induced Eosinophil Growth and Function in CEL

    PubMed Central

    Li, Bin; Zhang, Guangsen; Li, Cui; He, Dan; Li, Xinying; Zhang, Chunfang; Tang, Faqing; Deng, Xiyun; Lu, Jingchen; Tang, Youhong; Li, Ruijuan; Chen, Zhuchu; Duan, Chaojun

    2012-01-01

    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 induction

  8. Recombinant interferon-α in myelofibrosis reduces bone marrow fibrosis, improves its morphology and is associated with clinical response.

    PubMed

    Pizzi, Marco; Silver, Richard T; Barel, Ariella; Orazi, Attilio

    2015-10-01

    Recombinant interferon-α represents a well-established therapeutic option for the treatment of polycythemia vera and essential thrombocythemia. Recent studies also suggest a role for recombinant interferon-α in the treatment of 'early stage' primary myelofibrosis, but few studies have reported the bone marrow changes after clinically successful interferon therapy. The aim of the present study is to detail the histological responses to recombinant interferon-α in primary myelofibrosis and post-polycythemia vera/post-essential thrombocythemia myelofibrosis and to correlate these with clinical findings. We retrospectively studied 12 patients with primary myelofibrosis or post-polycythemia vera/post-essential thrombocythemia myelofibrosis, who had been treated with recombinant interferon-α. Six patients had received other prior cytoreductive therapies. Bone marrow biopsy was assessed for the following histological parameters: (i) cellularity; (ii) myeloid-to-erythroid ratio; (iii) megakaryocyte tight clusters; (iv) megakaryocyte and naked nuclei density; (v) megakaryocytic atypia; (vi) fibrosis; and (vii) the percentage of blasts. Clinical and laboratory data were included: (i) constitutional symptoms; (ii) splenomegaly, if present; and (iii) complete cell blood count. The clinical response to therapy was evaluated using the International Working Group for Myelofibrosis Research and Treatment/European LeukemiaNet response criteria. The Dynamic International Prognostic Scoring System (DIPSS) score was calculated before and after recombinant interferon-α administration. Successful interferon therapy for myelofibrosis was associated with a significant reduction of marrow fibrosis, cellularity, megakaryocyte density and naked nuclei density. The presence of JAK2(V617F) mutation correlated with improved DIPSS score. JAK2(V617F)-negative cases showed worsening of such score or evolution to acute myeloid leukemia. Cytogenetic analysis documented a normal karyotype in all

  9. HSP90 is a therapeutic target in JAK2-dependent myeloproliferative neoplasms in mice and humans

    PubMed Central

    Marubayashi, Sachie; Koppikar, Priya; Taldone, Tony; Abdel-Wahab, Omar; West, Nathan; Bhagwat, Neha; Caldas-Lopes, Eloisi; Ross, Kenneth N.; Gönen, Mithat; Gozman, Alex; Ahn, James H.; Rodina, Anna; Ouerfelli, Ouathek; Yang, Guangbin; Hedvat, Cyrus; Bradner, James E.; Chiosis, Gabriela; Levine, Ross L.

    2010-01-01

    JAK2 kinase inhibitors were developed for the treatment of myeloproliferative neoplasms (MPNs), following the discovery of activating JAK2 mutations in the majority of patients with MPN. However, to date JAK2 inhibitor treatment has shown limited efficacy and apparent toxicities in clinical trials. We report here that an HSP90 inhibitor, PU-H71, demonstrated efficacy in cell line and mouse models of the MPN polycythemia vera (PV) and essential thrombocytosis (ET) by disrupting JAK2 protein stability. JAK2 physically associated with both HSP90 and PU-H71 and was degraded by PU-H71 treatment in vitro and in vivo, demonstrating that JAK2 is an HSP90 chaperone client. PU-H71 treatment caused potent, dose-dependent inhibition of cell growth and signaling in JAK2 mutant cell lines and in primary MPN patient samples. PU-H71 treatment of mice resulted in JAK2 degradation, inhibition of JAK-STAT signaling, normalization of peripheral blood counts, and improved survival in MPN models at doses that did not degrade JAK2 in normal tissues or cause substantial toxicity. Importantly, PU-H71 treatment also reduced the mutant allele burden in mice. These data establish what we believe to be a novel therapeutic rationale for HSP90 inhibition in the treatment of JAK2-dependent MPN. PMID:20852385

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

    PubMed Central

    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. PMID:28955303

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

    PubMed

    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. Refractory Anemia with Ring Sideroblasts (RARS) and RARS with Thrombocytosis (RARS-T) – “2017 Update on Diagnosis, Risk-stratification, and Management”

    PubMed Central

    Patnaik, Mrinal M.; Tefferi, Ayalew

    2017-01-01

    Disease Overview Ring sideroblasts (RS) are erythroid precursors with abnormal perinuclear mitochondrial iron accumulation. Two myeloid neoplasms defined by the presence of RS, include refractory anemia with ring sideroblasts (RARS), now classified under myelodysplastic syndromes with RS (MDS-RS) and RARS with thrombocytosis (RARS-T); now called myelodysplastic/myeloproliferative neoplasm with RS and thrombocytosis (MDS/MPN-RS-T). Diagnosis MDS-RS is a lower risk MDS, with single or multilineage dysplasia (SLD/MLD), <5% bone marrow (BM) blasts and ≥15% BM RS (≥5% in the presence of SF3B1 mutations). MDS/MPN-RS-T, now a formal entity in the MDS/MPN overlap syndromes, has diagnostic features of MDS-RS-SLD, along with a platelet count ≥ 450 × 10(9)/L and large atypical megakaryocytes (similar to BCR-ABL1 negative MPN). Mutations and Karyotype Mutations in SF3B1 are seen in ≥80% of patients with MDS-RS-SLD and MDS/MPN-RS-T, and strongly correlate with the presence of BM RS; MDS/MPN-RS-T patients also demonstrate JAK2V617F, ASXL1, DNMT3A, SETBP1, and TET2 mutations; with ASXL1/SETBP1 mutations adversely impacting survival. Cytogenetic abnormalities are uncommon in both diseases. Risk stratification Most patients with MDS-RS-SLD are stratified into lower risk groups by the revised-International Prognostic Scoring System (R-IPSS). Disease outcome in MDS/MPN-RS-T is better than that of MDS-RS-SLD, but worse than that of essential thrombocythemia. Both diseases have a low risk of leukemic transformation. Treatment Anemia and iron overload are complications seen in both and are managed similar to lower risk MDS and MPN. Aspirin therapy is reasonable in MDS/MPN-RS-T, especially in the presence of JAK2V617F, but the value of platelet-lowering drugs is uncertain. PMID:28188970

  13. An ENU mutagenesis-derived mouse model with a dominant Jak1 mutation resembling phenotypes of systemic autoimmune disease.

    PubMed

    Sabrautzki, Sibylle; Janas, Eva; Lorenz-Depiereux, Bettina; Calzada-Wack, Julia; Aguilar-Pimentel, Juan A; Rathkolb, Birgit; Adler, Thure; Cohrs, Christian; Hans, Wolfgang; Diener, Susanne; Fuchs, Helmut; Gailus-Durner, Valerie; Busch, Dirk H; Höfler, Heinz; Ollert, Markus; Strom, Tim M; Wolf, Eckhard; Neff, Frauke; Hrabě de Angelis, Martin

    2013-08-01

    Within the Munich, Germany, N-ethyl-N-nitrosourea mouse mutagenesis program, we isolated a dominant Jak1 mouse model resembling phenotypic characteristics related to autoimmune disease. Chromosomal sequencing revealed a new Jak1 (p.Ser645Pro) point mutation at the conserved serine of the pseudokinase domain, corresponding to a somatic human mutation (p.Ser646Phe) inducing a constitutive activation of the Janus kinase (JAK)/STAT pathway. Morphologically, all Jak1(S645P+/-) mice showed a progressive structural deterioration of ears starting at the age of 4 months, with mononuclear cell infiltration into the dermis. Female mutant mice, in particular, developed severe skin lesions in the neck from 7 months of age. The IHC analysis of these lesions showed an activation of Stat3 downstream to Jak1(S645P) and elevated tissue levels of IL-6. Histopathological analysis of liver revealed a nodular regenerative hyperplasia. In the spleen, the number of Russell bodies was doubled, correlating with significant increased levels of all immunoglobulin isotypes and anti-DNA antibodies in serum. Older mutant mice developed thrombocytopenia and altered microcytic red blood cell counts. Jak1(S645P+/-) mice showed phenotypes related to impaired bone metabolism as increased carboxy-terminal collagen cross-link-1 levels and alkaline phosphatase activities in plasma, hypophosphatemia, and strongly decreased bone morphometric values. Taken together, Jak1(S645P+/-) mice showed an increased activation of the IL-6-JAK-STAT pathway leading to a systemic lupus erythematosus-like phenotype and offering a new valuable tool to study the role of the JAK/STAT pathway in disease development. Copyright © 2013 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  14. Repurposed JAK1/JAK2 Inhibitor Reverses Established Autoimmune Insulitis in NOD Mice.

    PubMed

    Trivedi, Prerak M; Graham, Kate L; Scott, Nicholas A; Jenkins, Misty R; Majaw, Suktilang; Sutherland, Robyn M; Fynch, Stacey; Lew, Andrew M; Burns, Christopher J; Krishnamurthy, Balasubramanian; Brodnicki, Thomas C; Mannering, Stuart I; Kay, Thomas W; Thomas, Helen E

    2017-06-01

    Recent advances in immunotherapeutics have not yet changed the routine management of autoimmune type 1 diabetes. There is an opportunity to repurpose therapeutics used to treat other diseases to treat type 1 diabetes, especially when there is evidence for overlapping mechanisms. Janus kinase (JAK) 1/JAK2 inhibitors are in development or clinical use for indications including rheumatoid arthritis. There is good evidence for activation of the JAK1/JAK2 and signal transducer and activator of transcription (STAT) 1 pathway in human type 1 diabetes and in mouse models, especially in β-cells. We tested the hypothesis that using these drugs to block the JAK-STAT pathway would prevent autoimmune diabetes. The JAK1/JAK2 inhibitor AZD1480 blocked the effect of cytokines on mouse and human β-cells by inhibiting MHC class I upregulation. This prevented the direct interaction between CD8 + T cells and β-cells, and reduced immune cell infiltration into islets. NOD mice treated with AZD1480 were protected from autoimmune diabetes, and diabetes was reversed in newly diagnosed NOD mice. This provides mechanistic groundwork for repurposing clinically approved JAK1/JAK2 inhibitors for type 1 diabetes. © 2017 by the American Diabetes Association.

  15. Oncogenes in myeloproliferative disorders.

    PubMed

    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.

  16. 45 CFR 617.2 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Definitions. 617.2 Section 617.2 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION NONDISCRIMINATION ON THE BASIS OF AGE IN PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE FROM NSF § 617.2 Definitions...

  17. Integrated genomic sequencing reveals mutational landscape of T-cell prolymphocytic leukemia

    PubMed Central

    Kiel, Mark J.; Velusamy, Thirunavukkarasu; Rolland, Delphine; Sahasrabuddhe, Anagh A.; Chung, Fuzon; Bailey, Nathanael G.; Schrader, Alexandra; Li, Bo; Li, Jun Z.; Ozel, Ayse B.; Betz, Bryan L.; Miranda, Roberto N.; Medeiros, L. Jeffrey; Zhao, Lili; Herling, Marco

    2014-01-01

    The comprehensive genetic alterations underlying the pathogenesis of T-cell prolymphocytic leukemia (T-PLL) are unknown. To address this, we performed whole-genome sequencing (WGS), whole-exome sequencing (WES), high-resolution copy-number analysis, and Sanger resequencing of a large cohort of T-PLL. WGS and WES identified novel mutations in recurrently altered genes not previously implicated in T-PLL including EZH2, FBXW10, and CHEK2. Strikingly, WGS and/or WES showed largely mutually exclusive mutations affecting IL2RG, JAK1, JAK3, or STAT5B in 38 of 50 T-PLL genomes (76.0%). Notably, gain-of-function IL2RG mutations are novel and have not been reported in any form of cancer. Further, high-frequency mutations in STAT5B have not been previously reported in T-PLL. Functionally, IL2RG-JAK1-JAK3-STAT5B mutations led to signal transducer and activator of transcription 5 (STAT5) hyperactivation, transformed Ba/F3 cells resulting in cytokine-independent growth, and/or enhanced colony formation in Jurkat T cells. Importantly, primary T-PLL cells exhibited constitutive activation of STAT5, and targeted pharmacologic inhibition of STAT5 with pimozide induced apoptosis in primary T-PLL cells. These results for the first time provide a portrait of the mutational landscape of T-PLL and implicate deregulation of DNA repair and epigenetic modulators as well as high-frequency mutational activation of the IL2RG-JAK1-JAK3-STAT5B axis in the pathogenesis of T-PLL. These findings offer opportunities for novel targeted therapies in this aggressive leukemia. PMID:24825865

  18. Integrated genomic sequencing reveals mutational landscape of T-cell prolymphocytic leukemia.

    PubMed

    Kiel, Mark J; Velusamy, Thirunavukkarasu; Rolland, Delphine; Sahasrabuddhe, Anagh A; Chung, Fuzon; Bailey, Nathanael G; Schrader, Alexandra; Li, Bo; Li, Jun Z; Ozel, Ayse B; Betz, Bryan L; Miranda, Roberto N; Medeiros, L Jeffrey; Zhao, Lili; Herling, Marco; Lim, Megan S; Elenitoba-Johnson, Kojo S J

    2014-08-28

    The comprehensive genetic alterations underlying the pathogenesis of T-cell prolymphocytic leukemia (T-PLL) are unknown. To address this, we performed whole-genome sequencing (WGS), whole-exome sequencing (WES), high-resolution copy-number analysis, and Sanger resequencing of a large cohort of T-PLL. WGS and WES identified novel mutations in recurrently altered genes not previously implicated in T-PLL including EZH2, FBXW10, and CHEK2. Strikingly, WGS and/or WES showed largely mutually exclusive mutations affecting IL2RG, JAK1, JAK3, or STAT5B in 38 of 50 T-PLL genomes (76.0%). Notably, gain-of-function IL2RG mutations are novel and have not been reported in any form of cancer. Further, high-frequency mutations in STAT5B have not been previously reported in T-PLL. Functionally, IL2RG-JAK1-JAK3-STAT5B mutations led to signal transducer and activator of transcription 5 (STAT5) hyperactivation, transformed Ba/F3 cells resulting in cytokine-independent growth, and/or enhanced colony formation in Jurkat T cells. Importantly, primary T-PLL cells exhibited constitutive activation of STAT5, and targeted pharmacologic inhibition of STAT5 with pimozide induced apoptosis in primary T-PLL cells. These results for the first time provide a portrait of the mutational landscape of T-PLL and implicate deregulation of DNA repair and epigenetic modulators as well as high-frequency mutational activation of the IL2RG-JAK1-JAK3-STAT5B axis in the pathogenesis of T-PLL. These findings offer opportunities for novel targeted therapies in this aggressive leukemia. © 2014 by The American Society of Hematology.

  19. 20 CFR 617.2 - Purpose.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Purpose. 617.2 Section 617.2 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR TRADE ADJUSTMENT ASSISTANCE FOR WORKERS UNDER THE TRADE ACT OF 1974 General § 617.2 Purpose. The Act created a program of trade adjustment...

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

    PubMed

    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.

  1. Inborn errors of human JAKs and STATs.

    PubMed

    Casanova, Jean-Laurent; Holland, Steven M; Notarangelo, Luigi D

    2012-04-20

    Inborn errors of the genes encoding two of the four human JAKs (JAK3 and TYK2) and three of the six human STATs (STAT1, STAT3, and STAT5B) have been described. We review the disorders arising from mutations in these five genes, highlighting the way in which the molecular and cellular pathogenesis of these conditions has been clarified by the discovery of inborn errors of cytokines, hormones, and their receptors, including those interacting with JAKs and STATs. The phenotypic similarities between mice and humans lacking individual JAK-STAT components suggest that the functions of JAKs and STATs are largely conserved in mammals. However, a wide array of phenotypic differences has emerged between mice and humans carrying biallelic null alleles of JAK3, TYK2, STAT1, or STAT5B. Moreover, the high degree of allelic heterogeneity at the human JAK3, TYK2, STAT1, and STAT3 loci has revealed highly diverse immunological and clinical phenotypes, which had not been anticipated. Copyright © 2012 Elsevier Inc. All rights reserved.

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

    PubMed Central

    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

  3. Inborn Errors of Human JAKs and STATs

    PubMed Central

    Casanova, Jean-Laurent; Holland, Steven M.; Notarangelo, Luigi D.

    2012-01-01

    Inborn errors of the genes encoding two of the four human JAKs (JAK3 and TYK2) and three of the six human STATs (STAT1, STAT3, and STAT5B) have been described. We review the disorders arising from mutations in these five genes, highlighting the way in which the molecular and cellular pathogenesis of these conditions has been clarified by the discovery of inborn errors of cytokines, hormones, and their receptors, including those interacting with JAKs and STATs. The phenotypic similarities between mice and humans lacking individual JAK-STAT components suggest that the functions of JAKs and STATs are largely conserved in mammals. However, a wide array of phenotypic differences has emerged between mice and humans carrying bi-allelic null alleles of JAK3, TYK2, STAT1, or STAT5B. Moreover, the high level of allelic heterogeneity at the human JAK3, STAT1, and STAT3 loci has revealed highly diverse immunological and clinical phenotypes, which had not been anticipated. PMID:22520845

  4. Comparison Between 64Cu-PSMA-617 PET/CT and 18F-Choline PET/CT Imaging in Early Diagnosis of Prostate Cancer Biochemical Recurrence.

    PubMed

    Cantiello, Francesco; Crocerossa, Fabio; Russo, Giorgio Ivan; Gangemi, Vincenzo; Ferro, Matteo; Vartolomei, Mihai Dorin; Lucarelli, Giuseppe; Mirabelli, Maria; Scafuro, Chiara; Ucciero, Giuseppe; De Cobelli, Ottavio; Morgia, Giuseppe; Damiano, Rocco; Cascini, Giuseppe Lucio

    2018-06-04

    To evaluate the diagnostic performance of 64 Cu-PSMA-617 positron emission tomography (PET) with computed tomography (CT) for restaging prostate cancer after biochemical recurrence (BCR) and to compare it with 18 F-choline PET/CT in a per-patient analysis. An observational study was performed of 43 patients with BCR after laparoscopic radical prostatectomy who underwent 64 Cu-PSMA-617 PET/CT and subsequently 18 F-choline PET/CT for restaging. The detection rates (DR) of 64 Cu-PSMA-617 PET/CT and of 18 F-choline PET/CT were calculated by standardized maximum uptake value (SUV max ) at 4 hours and SUV max at 1 hour as reference, respectively. Furthermore, univariate logistic regression analysis was carried out to identify independent predictive factors of positivity with 64 Cu-PSMA-617 PET/CT. An overall positivity with 64 Cu-PSMA-617 PET/CT was found in 32 patients (74.4%) versus 19 (44.2%) with 18 F-choline PET/CT. Specifically, after stratifying for prostate-specific antigen (PSA) values, we found a good performance of 64 Cu-PSMA-617 PET/CT at low PSA levels compared to 18 F-choline PET/CT, with a DR of 57.1% versus 14.3% for PSA 0.2-0.5 ng/mL (P = .031), and of 60% versus 30% with PSA 0.5-1 ng/mL. At univariate binary logistic regression analysis, PSA level was the only independent predictor of 64 Cu-PSMA-617 PET/CT positivity. No significant difference in terms of DR for both 64 Cu-PSMA-617 PET/CT and 18 F-choline PET/CT was found according to different Gleason score subgroups. In our study cohort, a better performance was observed for 64 Cu-PSMA-617 PET/CT compared to 18 F-choline PET/CT in restaging after BCR, especially in patients with low PSA values. Copyright © 2018 Elsevier Inc. All rights reserved.

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

    PubMed

    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.

  6. Splanchnic vein thrombosis in myeloproliferative neoplasms: pathophysiology and molecular mechanisms of disease

    PubMed Central

    How, Joan; Zhou, Amy; Oh, Stephen T.

    2016-01-01

    Myeloproliferative neoplasms (MPNs) are the most common underlying prothrombotic disorder found in patients with splanchnic vein thrombosis (SVT). Clinical risk factors for MPN-associated SVTs include younger age, female sex, concomitant hypercoagulable disorders, and the JAK2 V617F mutation. These risk factors are distinct from those associated with arterial or deep venous thrombosis (DVT) in MPN patients, suggesting disparate disease mechanisms. The pathophysiology of SVT is thought to derive from local interactions between activated blood cells and the unique splanchnic endothelial environment. Other mutations commonly found in MPNs, including CALR and MPL, are rare in MPN-associated SVT. The purpose of this article is to review the clinical and molecular risk factors for MPN-associated SVT, with particular focus on the possible mechanisms of SVT formation in MPN patients. PMID:28246554

  7. Confirmation and revision on the orbital period change of the possible type Ia supernova progenitor V617 Sagittarii

    NASA Astrophysics Data System (ADS)

    Shi, Guang; Qian, Sheng-Bang; Fernández Lajús, Eduardo

    2014-02-01

    This work reports new photometric results of eclipsing cataclysmic variable V617 Sagittarii (V617 Sgr). We analyzed the orbital period change of V617 Sgr by employing three new (since 2010) CCD eclipse timings along with all the available data from the literature. It was found that the orbital period of V617 Sgr undergoes an obvious long-term increase, which confirms the result revealed by Steiner et al. (2006). The rate of orbital period increase was calculated to be {dot{P}} = +2.14(0.05) × 10-7 d yr-1. This suggests the lifetime of the secondary star will end in a timescale of 0.97 × 106 yr faster than that predicted previously. In particular, a cyclic variation with a period of 4.5 yr and an amplitude of 2.3 min may appear in the O - C diagram. Dominated by the wind-accretion mechanism, high mass transfer from the low mass secondary to the white dwarf is expected to continue in the V Sge-type star V617 Sgr during its long-term evolution. The mass transfer rate |skew4dot{M}_{ tr}| was estimated to be in the range of about 2.2 × 10-7 to 5.2 × 10-7 M⊙ yr-1. Accordingly, the already massive (≥ 1.2 M⊙) white dwarf primary will process stable nuclear burning, accrete a fraction of the mass from its companion to reach the standard Chandrasekhar mass limit (≃ 1.38 M⊙), and ultimately produce a type Ia supernova (SN Ia) within about 4-8 × 105 yr or earlier.

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

    PubMed Central

    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

  9. HBV core promoter mutations promote cellular proliferation through E2F1-mediated upregulation of S-phase kinase-associated protein 2 transcription.

    PubMed

    Huang, Yuehua; Tai, Andrew W; Tong, Shuping; Lok, Anna S F

    2013-06-01

    Hepatitis B virus (HBV) core promoter (CP) mutations have been associated with an increased risk of hepatocellular carcinoma (HCC) in clinical studies. We previously reported that a combination of CP mutations seen in HCC patients, expressed in HBx gene, increased SKP2 (S-phase kinase-associated protein 2) expression, thereby promoting cellular proliferation. Here, we investigate the possible mechanisms by which CP mutations upregulate SKP2. We used immunoblotting and ATPlite assay to validate the effect of CP mutations in full-length HBV genome on cell cycle regulator levels and cell proliferation. Activation of SKP2 mRNA was assessed by quantitative real-time PCR in primary human hepatocytes (PHH) and HCC cell lines. Effect of CP mutations on SKP2 promoter activity was determined by luciferase assay. Target regulation of E2F1 on SKP2 was analyzed by siRNAs. CP mutations in full-length HBV genome upregulated SKP2 expression, thereby downregulating cell cycle inhibitors and accelerating cellular proliferation. CP mutations enhanced SKP2 promoter activity but had no effect on SKP2 protein stability. Mapping of the SKP2 promoter identified a region necessary for activation by CP mutations that contains an E2F1 response element. Knocking down E2F1 reduced the effects of CP mutations on SKP2 and cellular proliferation. The effect of CP mutations on E2F1 might be mediated through hyperphosphorylation of RB. HBV CP mutations enhance SKP2 transcription by activating the E2F1 transcription factor and in turn downregulate cell cycle inhibitors, thus providing a potential mechanism for an association between CP mutations and HCC. Copyright © 2013 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

  10. The Janus Kinase (JAK) FERM and SH2 Domains: Bringing Specificity to JAK-Receptor Interactions.

    PubMed

    Ferrao, Ryan; Lupardus, Patrick J

    2017-01-01

    The Janus kinases (JAKs) are non-receptor tyrosine kinases essential for signaling in response to cytokines and interferons and thereby control many essential functions in growth, development, and immune regulation. JAKs are unique among tyrosine kinases for their constitutive yet non-covalent association with class I and II cytokine receptors, which upon cytokine binding bring together two JAKs to create an active signaling complex. JAK association with cytokine receptors is facilitated by N-terminal FERM and SH2 domains, both of which are classical mediators of peptide interactions. Together, the JAK FERM and SH2 domains mediate a bipartite interaction with two distinct receptor peptide motifs, the proline-rich "Box1" and hydrophobic "Box2," which are present in the intracellular domain of cytokine receptors. While the general sidechain chemistry of Box1 and Box2 peptides is conserved between receptors, they share very weak primary sequence homology, making it impossible to posit why certain JAKs preferentially interact with and signal through specific subsets of cytokine receptors. Here, we review the structure and function of the JAK FERM and SH2 domains in light of several recent studies that reveal their atomic structure and elucidate interaction mechanisms with both the Box1 and Box2 receptor motifs. These crystal structures demonstrate how evolution has repurposed the JAK FERM and SH2 domains into a receptor-binding module that facilitates interactions with multiple receptors possessing diverse primary sequences.

  11. Oncogenic activation of JAK3-STAT signaling confers clinical sensitivity to PRN371, a novel selective and potent JAK3 inhibitor, in natural killer/T-cell lymphoma.

    PubMed

    Nairismägi, M -L; Gerritsen, M E; Li, Z M; Wijaya, G C; Chia, B K H; Laurensia, Y; Lim, J Q; Yeoh, K W; Yao, X S; Pang, W L; Bisconte, A; Hill, R J; Bradshaw, J M; Huang, D; Song, T L L; Ng, C C Y; Rajasegaran, V; Tang, T; Tang, Q Q; Xia, X J; Kang, T B; Teh, B T; Lim, S T; Ong, C K; Tan, J

    2018-05-01

    Aberrant activation of the JAK3-STAT signaling pathway is a characteristic feature of many hematological malignancies. In particular, hyperactivity of this cascade has been observed in natural killer/T-cell lymphoma (NKTL) cases. Although the first-in-class JAK3 inhibitor tofacitinib blocks JAK3 activity in NKTL both in vitro and in vivo, its clinical utilization in cancer therapy has been limited by the pan-JAK inhibition activity. To improve the therapeutic efficacy of JAK3 inhibition in NKTL, we have developed a highly selective and durable JAK3 inhibitor PRN371 that potently inhibits JAK3 activity over the other JAK family members JAK1, JAK2, and TYK2. PRN371 effectively suppresses NKTL cell proliferation and induces apoptosis through abrogation of the JAK3-STAT signaling. Moreover, the activity of PRN371 has a more durable inhibition on JAK3 compared to tofacitinib in vitro, leading to significant tumor growth inhibition in a NKTL xenograft model harboring JAK3 activating mutation. These findings provide a novel therapeutic approach for the treatment of NKTL.

  12. Association of a genetic marker at the bovine Janus kinase 2 locus (JAK2/RsaI) with milk production traits of four cattle breeds.

    PubMed

    Szewczuk, Małgorzata

    2015-08-01

    In addition to the main components of the somatotrophic axis (GH/GHR/IGF-I/IGF-IR), great importance in the control of growth and development is also attached to the Janus kinase 2 (JAK2) pathway. Induced by the GH/GHR complex, JAK2 activates signal transducer and activator of transcription 5 (STAT5), and in consequence, may be involved in the regulation of expression of insulin-like growth factor I (IGF-I) in the mammary gland. Silent mutation (rs110298451) has been identified within exon 20 using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). A total of 904 individuals of four dairy or dual-purpose breeds (Polish Holstein-Friesian, Montbeliarde, Simmental and Jersey) were genotyped. A genotypic imbalance in the populations was observed. In the case of dual-purpose breeds (Montbeliarde and Simmental), the frequencies of both alleles were almost equal. In contrary, the JAK2G allele was predominant in the Polish Holstein-Friesian breed while JAK2A allele in Jersey. A pronounced relationship between JAK2/RsaI polymorphism and milk production traits was found where, irrespective of breed and lactation order, the GG genotype was significantly associated with higher milk, protein and fat yields, as compared to the AA genotype. Heterozygous individuals were generally characterised by intermediate values of the analysed milk traits. It can be argued that the JAK2 gene polymorphism is a potential marker for milk production traits. However, due to the fact that rs110298451 SNP does not directly affect amino acid sequence, other association studies involving missense mutation should also be performed.

  13. Association of Oesophageal Varices and Splanchnic Vein Thromboses in Patients with JAK2-Positive Myeloproliferative Neoplasms: Presentation of Two Cases and Data from a Retrospective Analysis

    PubMed Central

    Link, Cornelia S.; Platzbecker, Uwe; Kroschinsky, Frank; Pannach, Sven; Thiede, Christian; Platzek, Ivan; Ehninger, Gerhard; Schuler, Markus K.

    2013-01-01

    Background Oesophageal varices and gastrointestinal bleeding are common complications of liver cirrhosis. More rarely, oesophageal varices occur in patients with non-cirrhotic portal hypertension that results from thromboses of portal or splanchnic veins. Case Report We describe 2 young men who initially presented with varices as a result of portal vein thromboses. In the clinical follow-up, both were tested positive for a JAK2 mutation and consequently diagnosed with myeloproliferative neoplasms (MPNs). In an attempt to characterise the frequency of gastrointestinal complications in patients with JAK2-positive MPNs, we retrospectively analysed all known affected patients from our clinic for the diagnosis of portal vein thromboses and oesophageal varices. Strikingly, 48% of those who had received an oesophagogastroduodenoscopy had detectable oesophageal or gastric varices, and 82% of those suffered from portal or splanchnic vein thromboses. Conclusion While the association between JAK2, myeloproliferative disease and thrombotic events is well established, patients with idiopathic oesophageal varices are not regularly tested for JAK2 mutations. However, the occurrence of oesophageal varices may be the first presenting symptom of a MPN with a JAK2 mutation, and affected patients may profit from a close haematological monitoring to assure the early detection of developing MPN. PMID:23898274

  14. Estrogen signaling selectively induces apoptosis of hematopoietic progenitors and myeloid neoplasms without harming steady-state hematopoiesis.

    PubMed

    Sánchez-Aguilera, Abel; Arranz, Lorena; Martín-Pérez, Daniel; García-García, Andrés; Stavropoulou, Vaia; Kubovcakova, Lucia; Isern, Joan; Martín-Salamanca, Sandra; Langa, Xavier; Skoda, Radek C; Schwaller, Jürg; Méndez-Ferrer, Simón

    2014-12-04

    Estrogens are potent regulators of mature hematopoietic cells; however, their effects on primitive and malignant hematopoietic cells remain unclear. Using genetic and pharmacological approaches, we observed differential expression and function of estrogen receptors (ERs) in hematopoietic stem cell (HSC) and progenitor subsets. ERα activation with the selective ER modulator (SERM) tamoxifen induced apoptosis in short-term HSCs and multipotent progenitors. In contrast, tamoxifen induced proliferation of quiescent long-term HSCs, altered the expression of self-renewal genes, and compromised hematopoietic reconstitution after myelotoxic stress, which was reversible. In mice, tamoxifen treatment blocked development of JAK2(V617F)-induced myeloproliferative neoplasm in vivo, induced apoptosis of human JAK2(V617F+) HSPCs in a xenograft model, and sensitized MLL-AF9(+) leukemias to chemotherapy. Apoptosis was selectively observed in mutant cells, and tamoxifen treatment only had a minor impact on steady-state hematopoiesis in disease-free animals. Together, these results uncover specific regulation of hematopoietic progenitors by estrogens and potential antileukemic properties of SERMs. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Production and crystallization of recombinant JAK proteins.

    PubMed

    Lucet, Isabelle S; Bamert, Rebecca

    2013-01-01

    JAK kinases are critical mediators in development, differentiation, and homeostasis and accordingly, have become well-validated targets for drug discovery efforts. In recent years, the integration of X-ray crystallography in kinase-focused drug discovery programs has provided a powerful rationale for chemical modification by allowing a unique glimpse of a bound inhibitor to its target. Such structural information has not only led to an improved understanding of the key drivers of potency and specificity of several JAK-specific compounds but has greatly facilitated and accelerated the design of compounds with improved pharmacokinetic properties.JAK kinases are traditionally difficult candidates to express in significant quantities, generally requiring eukaryotic expression systems, protein engineering, mutations to yield soluble, homogeneous samples suitable for crystallization studies. Here we review the key methods utilized to express, purify, and crystallize the JAK kinases and provide a detail description of the methods that we have developed to express, purify, and crystallize recombinant JAK1 and JAK2 proteins in the presence of small molecule inhibitors.

  16. [Diagnostic algorithm in chronic myeloproliferative diseases (CMPD)].

    PubMed

    Haferlach, Torsten; Bacher, Ulrike; Kern, Wolfgang; Schnittger, Susanne; Haferlach, Claudia

    2007-09-15

    The Philadelphia-negative chronic myeloproliferative diseases (CMPD) are very complex and heterogeneous disorders. They are represented by polycythemia vera (PV), chronic idiopathic myelofibrosis (CIMF), essential thrombocythemia (ET), CMPD/unclassifiable (CMPD-U), chronic neutrophilic leukemia (CNL), and chronic eosinophilic leukemia/hypereosinophilic syndrome (CEL/HES) according to the WHO classification. Before, diagnostics were mainly focused on clinical and morphological aspects, but in recent years cytogenetics and fluorescence in situ hybridization (FISH) found entrance in routine schedules as chromosomal abnormalities are relevant for prognosis and classification. Recently, there is rapid progress in the field of molecular characterization: the JAK2V617F mutation which shows a high incidence in PV, CIMF, and ET already plays a central role and will probably soon be included in follow-up procedures. Due to the detection of mutations in exon 12 of the JAK2 gene or mutations in the MPL gene the variety of activating mutations in the CMPD is still increasing. In CEL/HES the detection of the FIP1L1-PDGFRA fusion gene and overexpression of PDGFRA and PDGFRB led to targeted therapy with tyrosine kinase inhibitors. Thus, diagnostics in the CMPD transform toward a multimodal diagnostic concept based on a combination of methods - cyto-/histomorphology, cytogenetics, and individual molecular methods which can be included in a diagnostic algorithm.

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

    PubMed

    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 <100  nM. In vivo, topical application of INCB018424 resulted in suppression of STAT3 phosphorylation, edema, lymphocyte infiltration, and 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.

  18. ALK F1174V mutation confers sensitivity while ALK I1171 mutation confers resistance to alectinib. The importance of serial biopsy post progression.

    PubMed

    Ou, Sai-Hong; Milliken, Jeffrey C; Azada, Michele C; Miller, Vincent A; Ali, Siraj M; Klempner, Samuel J

    2016-01-01

    Many acquired resistant mutations to the anaplastic lymphoma kinase (ALK) gene have been identified during treatment of ALK-rearranged non-small cell lung cancer (NSCLC) patients with crizotinib, ceritinib, and alectinib. These various acquired resistant ALK mutations confer differential sensitivities to various ALK inhibitors and may provide guidance on how to sequence the use of many of the second generation ALK inhibitors. We described a patient who developed an acquired ALK F1174V resistant mutation on progression from crizotinib that responded to alectinib for 18 months but then developed an acquired ALK I1171S mutation to alectinib. Both tumor samples had essentially the same genomic profile by comprehensive genomic profiling otherwise. This is the first patient report that demonstrates ALK F1174V mutation is sensitive to alectinib and further confirms missense acquired ALK I1171 mutation is resistant to alectinib. Sequential tumor re-biopsy for comprehensive genomic profiling (CGP) is important to appreciate the selective pressure during treatment with various ALK inhibitors underpinning the evolution of the disease course of ALK+NSCLC patients while on treatment with the various ALK inhibitors. This approach will likely help inform the optimal sequencing strategy as more ALK inhibitors become available. This case report also validates the importance of developing structurally distinct ALK inhibitors for clinical use to overcome non-cross resistant ALK mutations. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  19. CHZ868, a Type II JAK2 Inhibitor, Reverses Type I JAK Inhibitor Persistence and Demonstrates Efficacy in Myeloproliferative Neoplasms

    PubMed Central

    Meyer, Sara C.; Keller, Matthew D.; Chiu, Sophia; Koppikar, Priya; Guryanova, Olga A.; Rapaport, Franck; Xu, Ke; Manova, Katia; Pankov, Dmitry; O’Reilly, Richard J.; Kleppe, Maria; McKenney, Anna Sophia; Shih, Alan H.; Shank, Kaitlyn; Ahn, Jihae; Papalexi, Eftymia; Spitzer, Barbara; Socci, Nick; Viale, Agnes; Mandon, Emeline; Ebel, Nicolas; Andraos, Rita; Rubert, Joëlle; Dammassa, Ernesta; Romanet, Vincent; Dölemeyer, Arno; Zender, Michael; Heinlein, Melanie; Rampal, Rajit; Weinberg, Rona Singer; Hoffman, Ron; Sellers, William R.; Hofmann, Francesco; Murakami, Masato; Baffert, Fabienne; Gaul, Christoph; Radimerski, Thomas; Levine, Ross L.

    2015-01-01

    Summary Although clinically tested JAK inhibitors reduce splenomegaly and systemic symptoms, molecular responses are not observed in most myeloproliferative neoplasms (MPN) patients. We previously demonstrated that MPN cells become persistent to type I JAK inhibitors that bind the active conformation of JAK2. We investigated if CHZ868, a type II JAK inhibitor, would demonstrate activity in JAK inhibitor persistent cells, murine MPN models, and MPN patient samples. JAK2- and MPL-mutant cell lines were sensitive to CHZ868, including type I JAK inhibitor persistent cells. CHZ868 showed significant activity in murine MPN models and induced reductions in mutant allele burden not observed with type I JAK inhibitors. These data demonstrate that type II JAK inhibition is a viable therapeutic approach for MPN patients. PMID:26175413

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

    PubMed

    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; P<0.0001) compared with PA from control subjects (n=10). PA remodelling was evaluated in human pulmonary 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.

  1. The JAK2 pathway is activated in idiopathic pulmonary fibrosis.

    PubMed

    Milara, Javier; Hernandez, Gracia; Ballester, Beatriz; Morell, Anselm; Roger, Inés; Montero, P; Escrivá, Juan; Lloris, José M; Molina-Molina, Maria; Morcillo, Esteban; Cortijo, Julio

    2018-02-06

    Idiopathic pulmonary fibrosis (IPF) is the most rapidly progressive and fatal fibrotic disorder, with no curative therapies. The signal transducer and activator of transcription 3 (STAT3) protein is activated in lung fibroblasts and alveolar type II cells (ATII), thereby contributing to lung fibrosis in IPF. Although activation of Janus kinase 2 (JAK2) has been implicated in proliferative disorders, its role in IPF is unknown. The aim of this study was to analyze JAK2 activation in IPF, and to determine whether JAK2/STAT3 inhibition is a potential therapeutic strategy for this disease. JAK2/p-JAK2 and STAT3/pSTAT3 expression was evaluated using quantitative real time-PCR, western blotting, and immunohistochemistry. Compared to human healthy lung tissue (n = 10) both proteins were upregulated in the lung tissue of IPF patients (n = 12). Stimulating primary ATII and lung fibroblasts with transforming growth factor beta 1 or interleukin (IL)-6/IL-13 activated JAK2 and STAT3, inducing epithelial to mesenchymal and fibroblast to myofibroblast transitions. Dual p-JAK2/p-STAT3 inhibition with JSI-124 or silencing of JAK2 and STAT3 genes suppressed ATII and the fibroblast to myofibroblast transition, with greater effects than the sum of those obtained using JAK2 or STAT3 inhibitors individually. Dual rather than single inhibition was also more effective for inhibiting fibroblast migration, preventing increases in fibroblast senescence and Bcl-2 expression, and ameliorating impaired autophagy. In rats administered JSI-124, a dual inhibitor of p-JAK2/p-STAT3, at a dose of 1 mg/kg/day, bleomycin-induced lung fibrosis was reduced and collagen deposition in the lung was inhibited, as were JAK2 and STAT3 activation and several markers of fibrosis, autophagy, senescence, and anti-apoptosis. JAK2 and STAT3 are activated in IPF, and their dual inhibition may be an attractive strategy for treating this disease.

  2. Thrombosis in Philadelphia negative classical myeloproliferative neoplasms: a narrative review on epidemiology, risk assessment, and pathophysiologic mechanisms.

    PubMed

    Ball, Somedeb; Thein, Kyaw Zin; Maiti, Abhishek; Nugent, Kenneth

    2018-05-01

    Thrombosis is common in cancer patients and is associated with increased morbidity and mortality. Myeloproliferative neoplasms (MPN) are common malignancies in elderly individuals and are known for a high incidence of thrombotic complications. Different risk factors have been identified in studies, and risk models have been developed to identify patients with MPN at higher risk for thrombosis. Several pathophysiological mechanisms help explain the increased likelihood of thrombosis in these patients. Factors, such as leukocyte and platelet activation leading to the formation of leukocyte-platelet aggregates, activation of the coagulation cascade by microparticles, high levels of inflammatory cytokines, and endothelial dysfunction have a crucial role in thrombosis in MPN patients. Recent studies have demonstrated a significant association between the allele burden of specific genetic mutations (mainly JAK2V617F) associated with MPN and the incidence of thrombotic events, thus suggesting a possible role for these mutations in thrombogenesis.

  3. JAK signaling globally counteracts heterochromatic gene silencing.

    PubMed

    Shi, Song; Calhoun, Healani C; Xia, Fan; Li, Jinghong; Le, Long; Li, Willis X

    2006-09-01

    The JAK/STAT pathway has pleiotropic roles in animal development, and its aberrant activation is implicated in multiple human cancers. JAK/STAT signaling effects have been attributed largely to direct transcriptional regulation by STAT of specific target genes that promote tumor cell proliferation or survival. We show here in a Drosophila melanogaster hematopoietic tumor model, however, that JAK overactivation globally disrupts heterochromatic gene silencing, an epigenetic tumor suppressive mechanism. This disruption allows derepression of genes that are not direct targets of STAT, as evidenced by suppression of heterochromatin-mediated position effect variegation. Moreover, mutations in the genes encoding heterochromatin components heterochromatin protein 1 (HP1) and Su(var)3-9 enhance tumorigenesis induced by an oncogenic JAK kinase without affecting JAK/STAT signaling. Consistently, JAK loss of function enhances heterochromatic gene silencing, whereas overexpressing HP1 suppresses oncogenic JAK-induced tumors. These results demonstrate that the JAK/STAT pathway regulates cellular epigenetic status and that globally disrupting heterochromatin-mediated tumor suppression is essential for tumorigenesis induced by JAK overactivation.

  4. JAK signaling globally counteracts heterochromatic gene silencing

    PubMed Central

    Shi, Song; Calhoun, Healani C; Xia, Fan; Li, Jinghong; Le, Long; Li, Willis X

    2011-01-01

    The JAK/STAT pathway has pleiotropic roles in animal development, and its aberrant activation is implicated in multiple human cancers1–3. JAK/STAT signaling effects have been attributed largely to direct transcriptional regulation by STAT of specific target genes that promote tumor cell proliferation or survival. We show here in a Drosophila melanogaster hematopoietic tumor model, however, that JAK overactivation globally disrupts heterochromatic gene silencing, an epigenetic tumor suppressive mechanism4. This disruption allows derepression of genes that are not direct targets of STAT, as evidenced by suppression of heterochromatin-mediated position effect variegation. Moreover, mutations in the genes encoding heterochromatin components heterochromatin protein 1 (HP1) and Su(var)3-9 enhance tumorigenesis induced by an oncogenic JAK kinase without affecting JAK/STAT signaling. Consistently, JAK loss of function enhances heterochromatic gene silencing, whereas overexpressing HP1 suppresses oncogenic JAK-induced tumors. These results demonstrate that the JAK/STAT pathway regulates cellular epigenetic status and that globally disrupting heterochromatin-mediated tumor suppression is essential for tumorigenesis induced by JAK overactivation. PMID:16892059

  5. Mutated and Bacteriophage T4 Nanoparticle Arrayed F1-V Immunogens from Yersinia pestis as Next Generation Plague Vaccines

    PubMed Central

    Tao, Pan; Mahalingam, Marthandan; Kirtley, Michelle L.; van Lier, Christina J.; Sha, Jian; Yeager, Linsey A.; Chopra, Ashok K.; Rao, Venigalla B.

    2013-01-01

    Pneumonic plague is a highly virulent infectious disease with 100% mortality rate, and its causative organism Yersinia pestis poses a serious threat for deliberate use as a bioterror agent. Currently, there is no FDA approved vaccine against plague. The polymeric bacterial capsular protein F1, a key component of the currently tested bivalent subunit vaccine consisting, in addition, of low calcium response V antigen, has high propensity to aggregate, thus affecting its purification and vaccine efficacy. We used two basic approaches, structure-based immunogen design and phage T4 nanoparticle delivery, to construct new plague vaccines that provided complete protection against pneumonic plague. The NH2-terminal β-strand of F1 was transplanted to the COOH-terminus and the sequence flanking the β-strand was duplicated to eliminate polymerization but to retain the T cell epitopes. The mutated F1 was fused to the V antigen, a key virulence factor that forms the tip of the type three secretion system (T3SS). The F1mut-V protein showed a dramatic switch in solubility, producing a completely soluble monomer. The F1mut-V was then arrayed on phage T4 nanoparticle via the small outer capsid protein, Soc. The F1mut-V monomer was robustly immunogenic and the T4-decorated F1mut-V without any adjuvant induced balanced TH1 and TH2 responses in mice. Inclusion of an oligomerization-deficient YscF, another component of the T3SS, showed a slight enhancement in the potency of F1-V vaccine, while deletion of the putative immunomodulatory sequence of the V antigen did not improve the vaccine efficacy. Both the soluble (purified F1mut-V mixed with alhydrogel) and T4 decorated F1mut-V (no adjuvant) provided 100% protection to mice and rats against pneumonic plague evoked by high doses of Y. pestis CO92. These novel platforms might lead to efficacious and easily manufacturable next generation plague vaccines. PMID:23853602

  6. Efficacy of ALK5 inhibition in myelofibrosis

    PubMed Central

    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

  7. Tensile properties of haynes alloy 230 and inconel 617 after long exposures to LiF-22CaF2 and vacuum at 1093 K

    NASA Astrophysics Data System (ADS)

    Whittenberger, J. D.

    1994-12-01

    As a part of a study of a space-based thermal energy storage system utilizing the latent heat of fusion of the eutectic salt LiF-20CaF2 (mole%), the two wrought Ni-base superalloys Haynes alloy 230 and Inconel 617 were subjected to molten salt, its vapor, and vacuum for periods as long as 10,000 h at 1093 K. Following exposure, the microstructures were characterized, and samples from each superalloy were tensile tested between 77 and 1200 K. Neither the structure nor mechanical properties revealed evidence for additional degradation due to exposures to the salt. Although some loss in tensile properties was noted, particularly at 77 K, this reduction could be ascribed to the influence of simple aging at 1093 K.

  8. Drug-resistant molecular mechanism of CRF01_AE HIV-1 protease due to V82F mutation

    NASA Astrophysics Data System (ADS)

    Liu, Xiaoqing; Xiu, Zhilong; Hao, Ce

    2009-05-01

    Human immunodeficiency virus type 1 protease (HIV-1 PR) is one of the major targets of anti-AIDS drug discovery. The circulating recombinant form 01 A/E (CRF01_AE, abbreviated AE) subtype is one of the most common HIV-1 subtypes, which is infecting more humans and is expanding rapidly throughout the world. It is, therefore, necessary to develop inhibitors against subtype AE HIV-1 PR. In this work, we have performed computer simulation of subtype AE HIV-1 PR with the drugs lopinavir (LPV) and nelfinavir (NFV), and examined the mechanism of resistance of the V82F mutation of this protease against LPV both structurally and energetically. The V82F mutation at the active site results in a conformational change of 79's loop region and displacement of LPV from its proper binding site, and these changes lead to rotation of the side-chains of residues D25 and I50'. Consequently, the conformation of the binding cavity is deformed asymmetrically and some interactions between PR and LPV are destroyed. Additionally, by comparing the interactive mechanisms of LPV and NFV with HIV-1 PR we discovered that the presence of a dodecahydroisoquinoline ring at the P1' subsite, a [2-(2,6-dimethylphenoxy)acetyl]amino group at the P2' subsite, and an N2 atom at the P2 subsite could improve the binding affinity of the drug with AE HIV-1 PR. These findings are helpful for promising drug design.

  9. INTERFERON α ACTIVATES NF-κ B IN JAK1-DEFICIENT CELLS THROUGH A TYK2-DEPENDENT PATHWAY

    PubMed Central

    Yang, Chuan He; Murti, Aruna; Valentine, William J.; Du, Ziyun; Pfeffer, Lawrence M.

    2005-01-01

    In addition to activating members of the STAT transcription factor family, IFN α/β activates the NF-κ B transcription factor. To determine the role of the JAK-STAT pathway in NF-κ B activation by IFN, we examined NF-κ B activation in JAK1-deficient mutant human fibrosarcoma cells. In wild-type fibrosarcoma cells (2fTGH) IFN activates STAT1, STAT2 and STAT3, as well as NF-κB complexes comprised of p50 and p65. In contrast, in JAK1-deficient cells IFN induces NF-κB activation and NF-κB dependent gene transcription, but does not activate these STAT proteins and has no effect on STAT-dependent gene transcription. Expression of a catalytically-inactive TYK2 tyrosine kinase in JAK1-deficient cells, as well as in the highly IFN-sensitive Daudi lymphoblastoid cell line, abrogates NF-κB activation by IFN. Moreover, IFN does not promote NF-κB activation in TYK2-deficient mutant fibrosarcoma cells. Our results demonstrate a dichotomy between the classical JAK-STAT pathway and the NF-κB signaling pathway. In the IFN signaling pathway leading to STAT activation both JAK1 and TYK2 are essential, while NF-κB activation requires only TYK2. PMID:15883164

  10. JAK2 and genomic instability in the myeloproliferative neoplasms: a case of the chicken or the egg?

    PubMed Central

    Scott, Linda M.; Rebel, Vivienne I.

    2012-01-01

    The myeloproliferative neoplasms (MPNs) are a particularly useful model for studying mutation accumulation in neoplastic and the mechanisms of the molecular cells, understanding underlying defects our current This review summarizes acquisition. present their in patients with an MPN, and the effects of mutations targeting Janus kinase 2 (JAK2)-mediated intracellular signaling on DNA damage, and on the elimination of mutation-bearing cells by programmed cell death. Moreover, we discuss findings that suggest that the acquisition of disease-initiating mutations in hematopoietic stem cells of some MPN patients may be the consequence of an inherent genomic instability that was not previously appreciated. PMID:22641564

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

    PubMed

    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.

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

    PubMed

    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.

  13. Characterization of an apparently synonymous F5 mutation causing aberrant splicing and factor V deficiency.

    PubMed

    Nuzzo, F; Bulato, C; Nielsen, B I; Lee, K; Wielders, S J; Simioni, P; Key, N S; Castoldi, E

    2015-03-01

    Coagulation factor V (FV) deficiency is a rare autosomal recessive bleeding disorder. We investigated a patient with severe FV deficiency (FV:C < 3%) and moderate bleeding symptoms. Thrombin generation experiments showed residual FV expression in the patient's plasma, which was quantified as 0.7 ± 0.3% by a sensitive prothrombinase-based assay. F5 gene sequencing identified a novel missense mutation in exon 4 (c.578G>C, p.Cys193Ser), predicting the abolition of a conserved disulphide bridge, and an apparently synonymous variant in exon 8 (c.1281C>G). The observation that half of the patient's F5 mRNA lacked the last 18 nucleotides of exon 8 prompted us to re-evaluate the c.1281C>G variant for its possible effects on splicing. Bioinformatics sequence analysis predicted that this transversion would activate a cryptic donor splice site and abolish an exonic splicing enhancer. Characterization in a F5 minigene model confirmed that the c.1281C>G variant was responsible for the patient's splicing defect, which could be partially corrected by a mutation-specific morpholino antisense oligonucleotide. The aberrantly spliced F5 mRNA, whose stability was similar to that of the normal mRNA, encoded a putative FV mutant lacking amino acids 427-432. Expression in COS-1 cells indicated that the mutant protein is poorly secreted and not functional. In conclusion, the c.1281C>G mutation, which was predicted to be translationally silent and hence neutral, causes FV deficiency by impairing pre-mRNA splicing. This finding underscores the importance of cDNA analysis for the correct assessment of exonic mutations. © 2014 John Wiley & Sons Ltd.

  14. The synthetic α-bromo-2',3,4,4'-tetramethoxychalcone (α-Br-TMC) inhibits the JAK/STAT signaling pathway.

    PubMed

    Pinz, Sophia; Unser, Samy; Brueggemann, Susanne; Besl, Elisabeth; Al-Rifai, Nafisah; Petkes, Hermina; Amslinger, Sabine; Rascle, Anne

    2014-01-01

    Signal transducer and activator of transcription STAT5 and its upstream activating kinase JAK2 are essential mediators of cytokine signaling. Their activity is normally tightly regulated and transient. However, constitutive activation of STAT5 is found in numerous cancers and a driving force for malignant transformation. We describe here the identification of the synthetic chalcone α-Br-2',3,4,4'-tetramethoxychalcone (α-Br-TMC) as a novel JAK/STAT inhibitor. Using the non-transformed IL-3-dependent B cell line Ba/F3 and its oncogenic derivative Ba/F3-1*6 expressing constitutively activated STAT5, we show that α-Br-TMC targets the JAK/STAT pathway at multiple levels, inhibiting both JAK2 and STAT5 phosphorylation. Moreover, α-Br-TMC alters the mobility of STAT5A/B proteins in SDS-PAGE, indicating a change in their post-translational modification state. These alterations correlate with a decreased association of STAT5 and RNA polymerase II with STAT5 target genes in chromatin immunoprecipitation assays. Interestingly, expression of STAT5 target genes such as Cis and c-Myc was differentially regulated by α-Br-TMC in normal and cancer cells. While both genes were inhibited in IL-3-stimulated Ba/F3 cells, expression of the oncogene c-Myc was down-regulated and that of the tumor suppressor gene Cis was up-regulated in transformed Ba/F3-1*6 cells. The synthetic chalcone α-Br-TMC might therefore represent a promising novel anticancer agent for therapeutic intervention in STAT5-associated malignancies.

  15. Polycythemia is associated with bone loss and reduced osteoblast activity in mice.

    PubMed

    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 < 0.01) suggesting a more severe bone phenotype than JAK2(V617F). Decreased osteoblast numbers and bone formation along with normal osteoclast numbers and activity were found in both mice. This study indicates that PV is associated with low bone mass and decreased osteoblast activity in mice. Our results support future studies of osteoporosis in affected humans. Polycythemia caused by chronically elevated circulating EPO also results in bone loss, and implications on patients treated with rEPO should be evaluated.

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

    PubMed Central

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

    2017-01-01

    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. PMID:28724798

  17. Essential thrombocythemia in young individuals: frequency and risk factors for vascular events and evolution to myelofibrosis in 126 patients.

    PubMed

    Alvarez-Larrán, A; Cervantes, F; Bellosillo, B; Giralt, M; Juliá, A; Hernández-Boluda, J C; Bosch, A; Hernández-Nieto, L; Clapés, V; Burgaleta, C; Salvador, C; Arellano-Rodrigo, E; Colomer, D; Besses, C

    2007-06-01

    The frequency of vascular events and evolution to myelofibrosis (MF) in young individuals with essential thrombocythemia (ET) is not well known. The incidence and predisposing factors to such complications was studied in 126 subjects diagnosed with ET at a median age of 31 years (range: 5-40). Overall survival and probability of survival free of thrombosis, bleeding and MF were analyzed by the Kaplan-Meier method and the presence of the Janus Kinase 2 (JAK2) V617F mutation correlated with the appearance of such complications. The JAK2 mutation (present in 43% of patients) was associated with higher hemoglobin (Hb) (P<0.001) and lower platelets at diagnosis. With a median follow-up of 10 years (range: 4-25), 31 thrombotic events were registered (incidence rate: 2.2 thromboses/100 patients/year). When compared with the general population, young ET patients showed a significant increase in stroke (odds ratio 50, 95% CI: 21.5-115) and venous thromboses (odds ratio 5.3, 95% CI: 3.9-10.6). Thrombosis-free survival was 84% at 10 years, with tobacco use being associated with higher risk of thrombosis. Actuarial freedom from evolution to MF was 97% at 10 years. In conclusion, young ET patients have thrombotic events, especially stroke and venous thrombosis, more frequently than generally considered, whereas they rarely transform to MF.

  18. JAK inhibitors suppress t(8;21) fusion protein-induced leukemia

    PubMed Central

    Lo, Miao-Chia; Peterson, Luke F.; Yan, Ming; Cong, Xiuli; Hickman, Justin H.; DeKelver, Russel C.; Niewerth, Denise; Zhang, Dong-Er

    2014-01-01

    Oncogenic mutations in components of the JAK/STAT pathway, including those in cytokine receptors and JAKs, lead to increased activity of downstream signaling and are frequently found in leukemia and other hematological disorders. Thus, small-molecule inhibitors of this pathway have been the focus of targeted therapy in these hematological diseases. We previously showed that t(8;21) fusion protein AML1-ETO and its alternatively spliced variant AML1-ETO9a (AE9a) enhance the JAK/STAT pathway via down-regulation of CD45, a negative regulator of this pathway. To investigate the therapeutic potential of targeting JAK/STAT in t(8;21) leukemia, we examined the effects of a JAK2-selective inhibitor TG101209 and a JAK1/2-selective inhibitor INCB18424 on t(8;21) leukemia cells. TG101209 and INCB18424 inhibited proliferation and promoted apoptosis of these cells. Furthermore, TG101209 treatment in AE9a leukemia mice reduced tumor burden and significantly prolonged survival. TG101209 also significantly impaired the leukemia-initiating potential of AE9a leukemia cells in secondary recipient mice. These results demonstrate the potential therapeutic efficacy of JAK inhibitors in treating t(8;21) AML. PMID:23812420

  19. V2 Vasopressin Receptor (V2R) Mutations in Partial Nephrogenic Diabetes Insipidus Highlight Protean Agonism of V2R Antagonists*

    PubMed Central

    Takahashi, Kazuhiro; Makita, Noriko; Manaka, Katsunori; Hisano, Masataka; Akioka, Yuko; Miura, Kenichiro; Takubo, Noriyuki; Iida, Atsuko; Ueda, Norishi; Hashimoto, Makiko; Fujita, Toshiro; Igarashi, Takashi; Sekine, Takashi; Iiri, Taroh

    2012-01-01

    Inactivating mutations of the V2 vasopressin receptor (V2R) cause cross-linked congenital nephrogenic diabetes insipidus (NDI), resulting in renal resistance to the antidiuretic hormone AVP. In two families showing partial NDI, characterized by an apparently normal response to diagnostic tests and an increase in the basal ADH levels suggesting AVP resistance, we have identified two V2R mutations, Ser-333del and Y128S. Both mutant V2Rs, when expressed in COS-7 cells, show partial defects in vasopressin-stimulated cAMP accumulation and intracellular localization. The inhibition of internalization does not rescue their localization. In contrast, the non-peptide V2R antagonists OPC41061 and OPC31260 partially rescue the membrane localization and basal function of these V2R mutants, whereas they inhibit the basal activity of the wild-type V2R. These results indicate that a partial loss of function of Ser-333del and Y128S mutant V2Rs results from defective membrane trafficking. These findings further indicate that V2R antagonists can act as protean agonists, serving as pharmacological chaperones for inactivating V2R mutants and also as inverse agonists of wild-type receptors. We speculate that this protean agonism could underlie the possible dual beneficial effects of the V2R antagonist: improvement of hyponatremia with heart failure or polycystic kidney disease and potential rescue of NDI. PMID:22144672

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

    PubMed

    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. Copyright© Ferrata Storti Foundation.

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

    PubMed Central

    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

  2. Suppressors and activators of JAK-STAT signaling at diagnosis and relapse of acute lymphoblastic leukemia in Down syndrome

    PubMed Central

    Schwartzman, Omer; Savino, Angela Maria; Gombert, Michael; Palmi, Chiara; Cario, Gunnar; Schrappe, Martin; Eckert, Cornelia; von Stackelberg, Arend; Huang, Jin-Yan; Hameiri-Grossman, Michal; Avigad, Smadar; te Kronnie, Geertruy; Geron, Ifat; Birger, Yehudit; Rein, Avigail; Zarfati, Giulia; Fischer, Ute; Mukamel, Zohar; Stanulla, Martin; Biondi, Andrea; Cazzaniga, Giovanni; Vetere, Amedeo; Wagner, Bridget K.; Chen, Zhu; Chen, Sai-Juan; Tanay, Amos; Borkhardt, Arndt; Izraeli, Shai

    2017-01-01

    Children with Down syndrome (DS) are prone to development of high-risk B-cell precursor ALL (DS-ALL), which differs genetically from most sporadic pediatric ALLs. Increased expression of cytokine receptor-like factor 2 (CRLF2), the receptor to thymic stromal lymphopoietin (TSLP), characterizes about half of DS-ALLs and also a subgroup of sporadic “Philadelphia-like” ALLs. To understand the pathogenesis of relapsed DS-ALL, we performed integrative genomic analysis of 25 matched diagnosis-remission and -relapse DS-ALLs. We found that the CRLF2 rearrangements are early events during DS-ALL evolution and generally stable between diagnoses and relapse. Secondary activating signaling events in the JAK-STAT/RAS pathway were ubiquitous but highly redundant between diagnosis and relapse, suggesting that signaling is essential but that no specific mutations are “relapse driving.” We further found that activated JAK2 may be naturally suppressed in 25% of CRLF2pos DS-ALLs by loss-of-function aberrations in USP9X, a deubiquitinase previously shown to stabilize the activated phosphorylated JAK2. Interrogation of large ALL genomic databases extended our findings up to 25% of CRLF2pos, Philadelphia-like ALLs. Pharmacological or genetic inhibition of USP9X, as well as treatment with low-dose ruxolitinib, enhanced the survival of pre-B ALL cells overexpressing mutated JAK2. Thus, somehow counterintuitive, we found that suppression of JAK-STAT “hypersignaling” may be beneficial to leukemic B-cell precursors. This finding and the reduction of JAK mutated clones at relapse suggest that the therapeutic effect of JAK specific inhibitors may be limited. Rather, combined signaling inhibitors or direct targeting of the TSLP receptor may be a useful therapeutic strategy for DS-ALL. PMID:28461505

  3. Suppressors and activators of JAK-STAT signaling at diagnosis and relapse of acute lymphoblastic leukemia in Down syndrome.

    PubMed

    Schwartzman, Omer; Savino, Angela Maria; Gombert, Michael; Palmi, Chiara; Cario, Gunnar; Schrappe, Martin; Eckert, Cornelia; von Stackelberg, Arend; Huang, Jin-Yan; Hameiri-Grossman, Michal; Avigad, Smadar; Te Kronnie, Geertruy; Geron, Ifat; Birger, Yehudit; Rein, Avigail; Zarfati, Giulia; Fischer, Ute; Mukamel, Zohar; Stanulla, Martin; Biondi, Andrea; Cazzaniga, Giovanni; Vetere, Amedeo; Wagner, Bridget K; Chen, Zhu; Chen, Sai-Juan; Tanay, Amos; Borkhardt, Arndt; Izraeli, Shai

    2017-05-16

    Children with Down syndrome (DS) are prone to development of high-risk B-cell precursor ALL (DS-ALL), which differs genetically from most sporadic pediatric ALLs. Increased expression of cytokine receptor-like factor 2 (CRLF2), the receptor to thymic stromal lymphopoietin (TSLP), characterizes about half of DS-ALLs and also a subgroup of sporadic "Philadelphia-like" ALLs. To understand the pathogenesis of relapsed DS-ALL, we performed integrative genomic analysis of 25 matched diagnosis-remission and -relapse DS-ALLs. We found that the CRLF2 rearrangements are early events during DS-ALL evolution and generally stable between diagnoses and relapse. Secondary activating signaling events in the JAK-STAT/RAS pathway were ubiquitous but highly redundant between diagnosis and relapse, suggesting that signaling is essential but that no specific mutations are "relapse driving." We further found that activated JAK2 may be naturally suppressed in 25% of CRLF2 pos DS-ALLs by loss-of-function aberrations in USP9X, a deubiquitinase previously shown to stabilize the activated phosphorylated JAK2. Interrogation of large ALL genomic databases extended our findings up to 25% of CRLF2 pos , Philadelphia-like ALLs. Pharmacological or genetic inhibition of USP9X, as well as treatment with low-dose ruxolitinib, enhanced the survival of pre-B ALL cells overexpressing mutated JAK2. Thus, somehow counterintuitive, we found that suppression of JAK-STAT "hypersignaling" may be beneficial to leukemic B-cell precursors. This finding and the reduction of JAK mutated clones at relapse suggest that the therapeutic effect of JAK specific inhibitors may be limited. Rather, combined signaling inhibitors or direct targeting of the TSLP receptor may be a useful therapeutic strategy for DS-ALL.

  4. Jak2 is Necessary for Neuroendocrine Control of Female Reproduction

    PubMed Central

    Wu, Sheng; Divall, Sara; Hoffman, Gloria E.; Le, Wei Wei; Wagner, Kay-Uwe; Wolfe, Andrew

    2011-01-01

    GnRH neurons represent the final common output of signals from the brain that regulates reproductive function. A wide range of environmental factors impact GnRH neuron activity including disease, stress, nutrition, and seasonal cues, as well as gonadal steroid hormones. The CNS response is thought to be mediated, at least in part, through intermediate signaling molecules that affect GnRH neuronal activity. In vitro, GnRH neuronal cell lines respond to a variety of ligands which activate the Jak/STAT intracellular signaling pathway. In order to determine its biological function in reproduction, we used Cre/LoxP technology to generate GnRH neuron specific Jak2 conditional knockout (Jak2 G−/−) mice. GnRH mRNA levels were reduced in Jak2 G−/− mice when compared to controls, while the number of GnRH neurons was equivalent, indicating a reduction in GnRH gene expression. Secretion of GnRH is also reduced as basal serum LH levels were significantly lower in female Jak2 G−/− mice while the pituitary responded normally to exogenous GnRH. Preovulatory LH surge levels were blunted in Jak2 G−/− mice, which was correlated with reduced GnRH neuronal activation as assessed by c-Fos. However the activation of GnRH neurons following release from estrogen negative feedback is retained. Female Jak2 G−/− mice exhibited significantly delayed puberty and first estrus, abnormal estrous cyclicity and impaired fertility. These results demonstrate an essential role for Jak2 signaling in GnRH neurons for normal reproductive development and fertility in female mice. PMID:21209203

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

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kim, Hyunho; Department of Medicine, University of Maryland, Baltimore, MD; Kang, Ah-Young

    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. Overexpressionmore » 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.« less

  6. TC-PTP and PTP1B: Regulating JAK-STAT signaling, controlling lymphoid malignancies.

    PubMed

    Pike, Kelly A; Tremblay, Michel L

    2016-06-01

    Lymphoid malignancies are characterized by an accumulation of genetic lesions that act co-operatively to perturb signaling pathways and alter gene expression programs. The Janus kinases (JAK)-signal transducers and activators of transcription (STATs) pathway is one such pathway that is frequently mutated in leukemia and lymphoma. In response to cytokines and growth factors, a cascade of reversible tyrosine phosphorylation events propagates the JAK-STAT pathway from the cell surface to the nucleus. Activated STAT family members then play a fundamental role in establishing the transcriptional landscape of the cell. In leukemia and lymphoma, somatic mutations have been identified in JAK and STAT family members, as well as, negative regulators of the pathway. Most recently, inactivating mutations in the protein tyrosine phosphatase (PTP) genes PTPN1 (PTP1B) and PTPN2 (TC-PTP) were sequenced in B cell lymphoma and T cell acute lymphoblastic leukemia (T-ALL) respectively. The loss of PTP1B and TC-PTP phosphatase activity is associated with an increase in cytokine sensitivity, elevated JAK-STAT signaling, and changes in gene expression. As inactivation mutations in PTPN1 and PTPN2 are restricted to distinct subsets of leukemia and lymphoma, a future challenge will be to identify in which cellular contexts do they contributing to the initiation or maintenance of leukemogenesis or lymphomagenesis. As well, the molecular mechanisms by which PTP1B and TC-PTP loss co-operates with other genetic aberrations will need to be elucidated to design more effective therapeutic strategies. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Inhibition on JAK-STAT3 Signaling Transduction Cascade Is Taken by Bioactive Peptide Alpha-S2 Casein Protein from Goat Ethawah Breed Milk

    PubMed Central

    Rohmah, Rista Nikmatu; Hardiyanti, Ferlany; Fatchiyah, Fatchiyah

    2015-01-01

    Background: RA is a systemic inflammatory disease that causes developing comorbidity conditions. This condition can cause by overproduction of pro-inflammatory cytokine. In a previous study, we have found bioactive peptide CSN1S2 from Ethawah goat milk for anti-inflammatory for repair the ileum destruction. However, the signaling transduction cascade of bioactive peptides inhibits inflammation still not clear yet. Therefore, we analyzed the signaling transduction cascade via JAK-STAT3 pathway by in vivo and in silico. Methods: The ileum was isolated DNA and amplification with specific primer. The sequence was analyzed using the Sanger sequencing method. Modeling 3D-structure was predicted by SWISS-MODEL and virtual interaction was analyzed by docking system using Pymol and Discovery Studio 4.0 software. Results: This study showed that STAT3 has target gene 480bp. The normal group and normal treating- CSN1S2 of goat milk have similarity from gene bank. Whereas, RA group had transversion mutation that the purine change into pyrimidine even cause frameshift mutation. Interestingly, after treating with the CSN1S2 protein of goat milk shows reverse to the normal acid sequence group. Based on in silico study, from eight peptides, only three peptides of CSN1S2 protein, which carried by PePT1 to enter the small intestine. The fragments are PepT1-41-NMAIHPR-47; PepT1-182-KISQYYQK-189 and PepT1-214-TNAIPYVR-221. We have found just one bioactive peptide of f182-KISQYYQK-189 is able bind to STAT3. The energy binding of f182-KISQYYQK-189 and RA-STAT3 amino acid, it was Σ = -402.43 kJ/mol and the energy binding of f182-KISQYYQK-189 and RAS-STAT3 amino acid is decreasing into Σ = -407.09 kJ/mol. Conclusion: This study suggested that the fragment 182-KISQYYQK-189 peptides from Ethawah goat milk may act as an anti-inflammatory agent via JAK-STAT3 signal transduction cascade at the cellular level. PMID:26483598

  8. DNA Methylation as an Epigenetic Factor in the Development and Progression of Polycythemia Vera

    DTIC Science & Technology

    2009-06-01

    Table 2). ID Diagnosis at analysis Original Dx Transformation JAK2 V617F MPD01 PV PV 41% MPD02 PV PV 48% MPD03 PV PV 86% MPD04 MF PV 47...Pathol Biol ( Paris ). 2001;49:164-166. 2. Spivak JL. Diagnosis of the myeloproliferative disorders: resolving phenotypic mimicry. Semin Hematol...Less than 10% of a single isolated BFU-E colony, originating from a single progenitor, is sufficient for determination of allele frequency. The

  9. CMML AND aCML: NOVEL PATHOGENETIC LESIONS

    PubMed Central

    Muramatsu, Hideki; Makishima, Hideki; Maciejewski, Jaroslaw P.

    2012-01-01

    Summary Chronic myelomonocytic leukemia (CMML) and atypical chronic myeloid leukemia (aCML) are distinct, yet related, entities of myelodysplastic/myeloproliferative neoplasms (MDS/MPN) characterized by morphologic dysplasia with accumulation of monocytes or neutrophils, respectively. Our understanding of the molecular pathogenesis of CMML and aCML has advanced, mainly due to the application of novel technologies such as array-based karyotyping or next generation sequencing. In addition to previously known recurrent aberrations, somatic uniparental disomy affecting chromosomes 3, 4, 7, and 11 frequently occurs in CMML. Novel somatic mutations of genes, including those associated with proliferation signaling (CBL, RAS, RUNX1, JAK2 (V617F)) and with modification of epigenetic status (TET2, ASXL1, UTX, EZH2) have been found. Various combinations of mutations suggest a multistep pathogenesis and may account for clinical heterogeneity. The prognostic and diagnostic significance of these molecular lesions, in particular their value as biomarkers of response or resistance to specific therapies, while uncertain now is likely to be clarified as large systematic studies come to completion. PMID:22289493

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

    PubMed

    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.

  11. The Synthetic α-Bromo-2′,3,4,4′-Tetramethoxychalcone (α-Br-TMC) Inhibits the JAK/STAT Signaling Pathway

    PubMed Central

    Brueggemann, Susanne; Besl, Elisabeth; Al-Rifai, Nafisah; Petkes, Hermina; Amslinger, Sabine; Rascle, Anne

    2014-01-01

    Signal transducer and activator of transcription STAT5 and its upstream activating kinase JAK2 are essential mediators of cytokine signaling. Their activity is normally tightly regulated and transient. However, constitutive activation of STAT5 is found in numerous cancers and a driving force for malignant transformation. We describe here the identification of the synthetic chalcone α-Br-2′,3,4,4′-tetramethoxychalcone (α-Br-TMC) as a novel JAK/STAT inhibitor. Using the non-transformed IL-3-dependent B cell line Ba/F3 and its oncogenic derivative Ba/F3-1*6 expressing constitutively activated STAT5, we show that α-Br-TMC targets the JAK/STAT pathway at multiple levels, inhibiting both JAK2 and STAT5 phosphorylation. Moreover, α-Br-TMC alters the mobility of STAT5A/B proteins in SDS-PAGE, indicating a change in their post-translational modification state. These alterations correlate with a decreased association of STAT5 and RNA polymerase II with STAT5 target genes in chromatin immunoprecipitation assays. Interestingly, expression of STAT5 target genes such as Cis and c-Myc was differentially regulated by α-Br-TMC in normal and cancer cells. While both genes were inhibited in IL-3-stimulated Ba/F3 cells, expression of the oncogene c-Myc was down-regulated and that of the tumor suppressor gene Cis was up-regulated in transformed Ba/F3-1*6 cells. The synthetic chalcone α-Br-TMC might therefore represent a promising novel anticancer agent for therapeutic intervention in STAT5-associated malignancies. PMID:24595334

  12. The natural history and treatment outcome of blast phase BCR-ABL− myeloproliferative neoplasms

    PubMed Central

    Tam, Constantine S.; Nussenzveig, Roberto M.; Popat, Uday; Bueso-Ramos, Carlos E.; Thomas, Deborah A.; Cortes, Jorge A.; Champlin, Richard E.; Ciurea, Stefan E.; Manshouri, Taghi; Pierce, Sherry M.; Kantarjian, Hagop M.

    2008-01-01

    We analyzed the outcomes of 74 patients diagnosed with BCR-ABL− myeloproliferative neoplasms in blast phase receiving induction chemotherapy (55%), low-intensity therapy (16%), stem cell transplantation (SCT; 3%), or supportive care (26%). Median survival from the date of blastic transformation was 5 months. Patients receiving supportive therapy had a median survival of 6 weeks. Complete remission with or without blood recovery was achieved in 46% of patients receiving induction chemotherapy, but remissions were not durable with a median progression-free survival of only 5 months. Eight patients received SCT either as first therapy or after responding to antileukemia therapy. These patients had a markedly superior survival, with 73% alive at a median follow-up of 31 months. JAK2V617F kinetics were assessed in 16 patients: 0 of 4 negative patients became positive at transformation, and among 12 positive patients, 1 had an increase in JAK2V617F% at transformation, 7 had a substantial decrease, and 4 had stable levels. Myeloproliferative neoplasm blast phase is associated with a dismal prognosis. Responses to chemotherapy can be achieved but are not durable. Long-term survivors had all received SCT either as first therapy or in first remission. PMID:18566326

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

    PubMed

    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.

  14. JAK2 inhibitor TG101348 overcomes erlotinib-resistance in non-small cell lung carcinoma cells with mutated EGF receptor

    PubMed Central

    Duan, Shan-zhou; Xia, Ying-chen; Zhu, Rong-ying; Chen, Yong-bing

    2015-01-01

    Non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutations are responsive to EGFR-tyrosine kinase inhibitor (EGFR-TKI). However, NSCLC patients with secondary somatic EGFR mutations are resistant to EGFR-TKI treatment. In this study, we investigated the effect of TG101348 (a JAK2 inhibitor) on the tumor growth of erlotinib-resistant NSCLC cells. Cell proliferation, apoptosis, gene expression and tumor growth were evaluated by diphenyltetrazolium bromide (MTT) assay, flow cytometry, terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL) staining, Western Blot and a xenograft mouse model, respectively. Results showed that erlotinib had a stronger impact on the induction of apoptosis in erlotinib-sensitive PC-9 cells but had a weaker effect on erlotinib-resistant H1975 and H1650 cells than TG101348. TG101348 significantly enhanced the cytotoxicity of erlotinib to erlotinib-resistant NSCLC cells, stimulated erlotinib-induced apoptosis and downregulated the expressions of EGFR, p-EGFR, p-STAT3, Bcl-xL and survivin in erlotinib-resistant NSCLC cells. Moreover, the combined treatment of TG101348 and erlotinib induced apoptosis, inhibited the activation of p-EGFR and p-STAT3, and inhibited tumor growth of erlotinib-resistant NSCLC cells in vivo. Our results indicate that TG101348 is a potential adjuvant for NSCLC patients during erlotinib treatment. PMID:25869210

  15. JAK/Stat signaling regulates heart precursor diversification in Drosophila

    PubMed Central

    Johnson, Aaron N.; Mokalled, Mayssa H.; Haden, Tom N.; Olson, Eric N.

    2011-01-01

    Intercellular signal transduction pathways regulate the NK-2 family of transcription factors in a conserved gene regulatory network that directs cardiogenesis in both flies and mammals. The Drosophila NK-2 protein Tinman (Tin) was recently shown to regulate Stat92E, the Janus kinase (JAK) and Signal transducer and activator of transcription (Stat) pathway effector, in the developing mesoderm. To understand whether the JAK/Stat pathway also regulates cardiogenesis, we performed a systematic characterization of JAK/Stat signaling during mesoderm development. Drosophila embryos with mutations in the JAK/Stat ligand upd or in Stat92E have non-functional hearts with luminal defects and inappropriate cell aggregations. Using strong Stat92E loss-of-function alleles, we show that the JAK/Stat pathway regulates tin expression prior to heart precursor cell diversification. tin expression can be subdivided into four phases and, in Stat92E mutant embryos, the broad phase 2 expression pattern in the dorsal mesoderm does not restrict to the constrained phase 3 pattern. These embryos also have an expanded pericardial cell domain. We show the E(spl)-C gene HLHm5 is expressed in a pattern complementary to tin during phase 3 and that this expression is JAK/Stat dependent. In addition, E(spl)-C mutant embryos phenocopy the cardiac defects of Stat92E embryos. Mechanistically, JAK/Stat signals activate E(spl)-C genes to restrict Tin expression and the subsequent expression of the T-box transcription factor H15 to direct heart precursor diversification. This study is the first to characterize a role for the JAK/Stat pathway during cardiogenesis and identifies an autoregulatory circuit in which tin limits its own expression domain. PMID:21965617

  16. Cell type-specific roles of Jak3 in IL-2-induced proliferative signal transduction

    PubMed Central

    Fujii, Hodaka

    2007-01-01

    Binding of IL-2 to its specific receptor induces activation of two members of Jak family protein tyrosine kinases, Jak1 and Jak3. An IL-2R-reconstituted NIH 3T3 fibroblast cell line proliferates in response to IL-2 only when hematopoietic lineage-specific Jak3 is ectopically expressed. However, the mechanism of Jak3-dependent proliferation in the fibroblast cell line is not known. Here, I showed that Jak3 expression is dispensable for IL-2-induced activation of Jak1 and Stat proteins and expression of nuclear proto-oncogenes in the IL-2R-reconstituted fibroblast cell line. However, Jak3 expression markedly enhanced these IL-2-induced signaling events. In contrast, Jak3 expression was essential for induction of cyclin genes involved in the G1-S transition. These data suggest a critical role of Jak3 in IL-2 signaling in the fibroblast cell line and may provide further insight into the cell type-specific mechanism of cytokine signaling. PMID:17266928

  17. Frequent POLE1 p.S297F mutation in Chinese patients with ovarian endometrioid carcinoma.

    PubMed

    Zou, Yang; Liu, Fa-Ying; Liu, Huai; Wang, Feng; Li, Wei; Huang, Mei-Zhen; Huang, Yan; Yuan, Xiao-Qun; Xu, Xiao-Yun; Huang, Ou-Ping; He, Ming

    2014-03-01

    The catalytic subunit of DNA polymerase epsilon (POLE1) functions primarily in nuclear DNA replication and repair. Recently, POLE1 mutations were detected frequently in colorectal and endometrial carcinomas while with lower frequency in several other types of cancer, and the p.P286R and p.V411L mutations were the potential mutation hotspots in human cancers. Nevertheless, the mutation frequency of POLE1 in ovarian cancer still remains largely unknown. Here, we screened a total of 251 Chinese samples with distinct subtypes of ovarian carcinoma for the presence of POLE1 hotspot mutations by direct sequencing. A heterozygous somatic POLE1 mutation, p.S297F (c.890C>T), but not p.P286R and p.V411L hotspot mutations observed in other cancer types, was identified in 3 out of 37 (8.1%) patients with ovarian endometrioid carcinoma; this mutation was evolutionarily highly conserved from Homo sapiens to Schizosaccharomyces. Of note, the POLE1 mutation coexisted with mutation in the ovarian cancer-associated PPP2R1A (protein phosphatase 2, regulatory subunit A, α) gene in a 46-year-old patient, who was also diagnosed with ectopic endometriosis in the benign ovary. In addition, a 45-year-old POLE1-mutated ovarian endometrioid carcinoma patient was also diagnosed with uterine leiomyoma while the remaining 52-year-old POLE1-mutated patient showed no additional distinctive clinical manifestation. In contrast to high frequency of POLE1 mutations in ovarian endometrioid carcinoma, no POLE1 mutations were identified in patients with other subtypes of ovarian carcinoma. Our results showed for the first time that the POLE1 p.S297F mutation, but not p.P286R and p.V411L hotspot mutations observed in other cancer types, was frequent in Chinese ovarian endometrioid carcinoma, but absent in other subtypes of ovarian carcinoma. These results implicated that POLE1 p.S297F mutation might be actively involved in the pathogenesis of ovarian endometrioid carcinoma, but might not be actively

  18. Jahn-Teller effect on the [TiF 4F 4F int] 6-(C 4v) and [NiF 4F 4F int] 7-(C 4v) clusters embedded into SrF 2 crystals

    NASA Astrophysics Data System (ADS)

    Ulanov, V. A.; Zhiteitcev, E. R.; Varlamov, A. G.

    2007-07-01

    By means of EPR method the associative [TiF 4F 4F int] 6-(C 4v) and [NiF 4F 4F int] 7-(C 4v) centers were revealed in the fluorite type SrF 2:Ti and SrF 2:Ni crystals grown by Bridgman method in helium atmosphere containing some amount of a fluorine gas. It was found that at low temperatures the local structures of these associative centers were exposed to a static rhombic distortion. The reasons of such distortions were accounted for by the assumption that the E ⊗ ( b1 + b2) vibronic interaction became effective due to that the ground orbital states of the [TiF 4F 4F int] 6-(C 4v) and [NiF 4F 4F int] 7-(C 4v) centers occurred to be doubly degenerated.

  19. E2F1 somatic mutation within miRNA target site impairs gene regulation in colorectal cancer.

    PubMed

    Lopes-Ramos, Camila M; Barros, Bruna P; Koyama, Fernanda C; Carpinetti, Paola A; Pezuk, Julia; Doimo, Nayara T S; Habr-Gama, Angelita; Perez, Rodrigo O; Parmigiani, Raphael B

    2017-01-01

    Genetic studies have largely concentrated on the impact of somatic mutations found in coding regions, and have neglected mutations outside of these. However, 3' untranslated regions (3' UTR) mutations can also disrupt or create miRNA target sites, and trigger oncogene activation or tumor suppressor inactivation. We used next-generation sequencing to widely screen for genetic alterations within predicted miRNA target sites of oncogenes associated with colorectal cancer, and evaluated the functional impact of a new somatic mutation. Target sequencing of 47 genes was performed for 29 primary colorectal tumor samples. For 71 independent samples, Sanger methodology was used to screen for E2F1 mutations in miRNA predicted target sites, and the functional impact of these mutations was evaluated by luciferase reporter assays. We identified germline and somatic alterations in E2F1. Of the 100 samples evaluated, 3 had germline alterations at the MIR205-5p target site, while one had a somatic mutation at MIR136-5p target site. E2F1 gene expression was similar between normal and tumor tissues bearing the germline alteration; however, expression was increased 4-fold in tumor tissue that harbored a somatic mutation compared to that in normal tissue. Luciferase reporter assays revealed both germline and somatic alterations increased E2F1 activity relative to wild-type E2F1. We demonstrated that somatic mutation within E2F1:MIR136-5p target site impairs miRNA-mediated regulation and leads to increased gene activity. We conclude that somatic mutations that disrupt miRNA target sites have the potential to impact gene regulation, highlighting an important mechanism of oncogene activation.

  20. 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.

    PubMed

    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 <45% without phlebotomy, resolution of palpable splenomegaly, normalization of white blood 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 <45% without phlebotomy was achieved in 97% of patients by week 24.Only 1 patient required a phlebotomy after week 4. Among patients with palpable splenomegaly at baseline, 44% and 63%, respectively, achieved nonpalpable spleen measurements at weeks 24 and 144. Clinically meaningful improvements in pruritus, 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.

  1. Quantification of the Mutant CALR Allelic Burden by Digital PCR: Application to Minimal Residual Disease Evaluation after Bone Marrow Transplantation.

    PubMed

    Mansier, Olivier; Migeon, Marina; Saint-Lézer, Arnaud; James, Chloé; Verger, Emmanuelle; Robin, Marie; Socié, Gérard; Bidet, Audrey; Mahon, François-Xavier; Cassinat, Bruno; Lippert, Eric

    2016-01-01

    With the recent discovery of CALR mutations, >80% of patients with myeloproliferative neoplasms carry a phenotype-driving mutation. For JAK2 V617F, the most frequent mutation in myeloproliferative neoplasms, accurate determination of mutational loads is of interest at diagnosis, for phenotypic and prognostic purposes, and during follow-up for minimal residual disease assessment. We developed a digital PCR technique that allowed the accurate determination of CALR allelic burdens for the main mutations (types 1 and 2). Compared with the commonly used fluorescent PCR product analysis, digital PCR is more precise, reproducible, and accurate. Furthermore, this method reached a very high sensitivity. We detected at least 0.025% CALR mutants. It can thus be used for patient characterization at diagnosis and for minimal residual disease monitoring. When applied to patients with primary myelofibrosis who underwent hematopoietic stem cell transplant, the digital PCR detected low levels of minimal residual disease. After negativation of the mutational load in all patients, the disease reappeared at a low level in one patient, preceding hematologic relapse. In conclusion, digital PCR adapted to type 1 and 2 CALR mutations is an inexpensive, highly precise, and sensitive technique suitable for evaluation of myeloproliferative neoplasm patients during follow-up. Copyright © 2016 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

  2. The Colony-Stimulating Factor 3 Receptor T640N Mutation Is Oncogenic, Sensitive to JAK Inhibition, and Mimics T618I.

    PubMed

    Maxson, Julia E; Luty, Samuel B; MacManiman, Jason D; Paik, Jason C; Gotlib, Jason; Greenberg, Peter; Bahamadi, Swaleh; Savage, Samantha L; Abel, Melissa L; Eide, Christopher A; Loriaux, Marc M; Stevens, Emily A; Tyner, Jeffrey W

    2016-02-01

    Colony-stimulating factor 3 receptor (CSF3R) mutations have been identified in the majority of chronic neutrophilic leukemia (CNL) and a smaller percentage of atypical chronic myeloid leukemia (aCML) cases. Although CSF3R point mutations (e.g., T618I) are emerging as key players in CNL/aCML, the significance of rarer CSF3R mutations is unknown. In this study, we assess the importance of the CSF3R T640N mutation as a marker of CNL/aCML and potential therapeutic target. Sanger sequencing of leukemia samples was performed to identify CSF3R mutations in CNL and aCML. The oncogenicity of the CSF3R T640N mutation relative to the T618I mutation was assessed by cytokine independent growth assays and by mouse bone marrow transplant. Receptor dimerization and O-glycosylation of the mutants was assessed by Western blot, and JAK inhibitor sensitivity was assessed by colony assay. Here, we identify a CSF3R T640N mutation in two patients with CNL/aCML, one of whom was originally diagnosed with MDS and acquired the T640N mutation upon evolution of disease to aCML. The T640N mutation is oncogenic in cellular transformation assays and an in vivo mouse bone marrow transplantation model. It exhibits many similar phenotypic features to T618I, including ligand independence and altered patterns of O-glycosylation--despite the transmembrane location of T640 preventing access by GalNAc transferase enzymes. Cells transformed by the T640N mutation are sensitive to JAK kinase inhibition to a similar degree as cells transformed by CSF3R T618I. Because of its similarities to CSF3R T618I, the T640N mutation likely has diagnostic and therapeutic relevance in CNL/aCML. ©2015 American Association for Cancer Research.

  3. Constacyclic codes over the ring F_q+v{F}_q+v2F_q and their applications of constructing new non-binary quantum codes

    NASA Astrophysics Data System (ADS)

    Ma, Fanghui; Gao, Jian; Fu, Fang-Wei

    2018-06-01

    Let R={F}_q+v{F}_q+v2{F}_q be a finite non-chain ring, where q is an odd prime power and v^3=v. In this paper, we propose two methods of constructing quantum codes from (α +β vv2)-constacyclic codes over R. The first one is obtained via the Gray map and the Calderbank-Shor-Steane construction from Euclidean dual-containing (α +β vv2)-constacyclic codes over R. The second one is obtained via the Gray map and the Hermitian construction from Hermitian dual-containing (α +β vv2)-constacyclic codes over R. As an application, some new non-binary quantum codes are obtained.

  4. A case of pediatric B-Lymphoblastic leukemia presenting with a t(9;12)(p24;q11.2) involving JAK2 and concomitant MLL rearrangement with apparent insertion at 6q27

    PubMed Central

    2013-01-01

    Background B-cell acute lymphoblastic leukemia (B-ALL) is the most common malignancy in pediatric patients and the leading cause of cancer-related death in children and young adults. Translocations of 9p24 involving JAK2 (9p24) and gain-of-function mutations of JAK2 with subsequent activation of the JAK2 kinase have been described in several hematological malignancies including B-ALL. However, rearrangements involving JAK2 are rare in B-ALL as only few cases have been described in the literature. Findings Herein, we present a case of pediatric B-ALL whose conventional cytogenetics revealed an abnormal karyotype with a reciprocal translocation involving 9p24 (JAK2) and 12p11.2. Fluorescence in situ hybridization (FISH) studies using the RP11-927H16 Spectrum Green JAK2 probe on previously G-banded metaphases confirmed the involvement of JAK2 in this rearrangement. Further FISH studies on the same previously G-banded metaphases using the LSI MLL probe helped to characterize an insertion of MLL into 6q27 as an additional abnormality in this karyotype. FISH studies performed on interphase nuclei also revealed an abnormal clone with MLL rearrangements in 23.6% of the nuclei examined as well as an abnormal clonal population with a deletion of the 5'IGH@ region in 88.3% of the nuclei examined. Conclusions Rearrangements of 9p24 can result in constitutive activation of JAK2, and have been observed in B-ALL. Rearrangements of the MLL gene have also been described extensively in B-ALL. However, rearrangements of MLL with a partner at 6q27 and in conjunction with a translocation involving JAK2 have not been previously described. This case pinpoints the importance of FISH and conventional cytogenetics to characterize complex rearrangements in which JAK2 and MLL are involved. The therapeutic targeting of JAK2 and MLL in cases like this may be prognostically beneficial. PMID:24274401

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

    PubMed

    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.

  6. Novel C617Y mutation in the 7th transmembrane segment of luteinizing hormone/choriogonadotropin receptor in a Japanese boy with peripheral precocious puberty.

    PubMed

    Nagasaki, Keisuke; Katsumata, Noriyuki; Ogawa, Yohei; Kikuchi, Toru; Uchiyama, Makoto

    2010-01-01

    Testotoxicosis, also known as familial male-limited precocious puberty, is an autosomal dominant form of gonadotropin-independent precocious puberty caused by heterozygous constitutively activating mutations of the LHCGR gene encoding the luteinizing hormone/choriogonadotropin receptor (LH/CGR). The patient is an 8-year-old boy who started to develop pubic hair and penile enlargement at 6 years of age. The patient had elevated serum testosterone levels, but initially exhibited a prepubertal response of gonadotropins to GnRH, which was followed by central activation of the hypothalamo-pituitary-gonadal axis. The father reported having experienced precocious puberty, and is 158 cm tall. There is no history of short stature and precocious puberty in the family except for the father. The LHCGR gene was analyzed by direct DNA sequencing of amplified PCR products from the patient and his parents. The wild-type and mutant LH/CGRs were transiently expressed in COS-1 cells and cAMP levels in the cells were determined with or without hCG stimulation. Genetic analysis revealed a novel C617Y mutation of the LHCGR gene in the patient and his mother, while his father had no mutations. Functional expression study demonstrated around 15% increase in the basal intracellular cAMP level in cells expressing the mutant LH/CGR compared with that in cells expressing the wild-type receptor. We have reported the first missense C617Y mutation located in the 7th transmembrane segment of LH/CGR causing testotoxicosis. The modest phenotype of our patient may be explained, at least in part, by the modest increase in the intracellular cAMP level caused by the C617Y mutation.

  7. Multifunctional imaging signature for V-KI-RAS2 Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations in colorectal cancer.

    PubMed

    Miles, Kenneth A; Ganeshan, Balaji; Rodriguez-Justo, Manuel; Goh, Vicky J; Ziauddin, Zia; Engledow, Alec; Meagher, Marie; Endozo, Raymondo; Taylor, Stuart A; Halligan, Stephen; Ell, Peter J; Groves, Ashley M

    2014-03-01

    This study explores the potential for multifunctional imaging to provide a signature for V-KI-RAS2 Kirsten rat sarcoma viral oncogene homolog (KRAS) gene mutations in colorectal cancer. This prospective study approved by the institutional review board comprised 33 patients undergoing PET/CT before surgery for proven primary colorectal cancer. Tumor tissue was examined histologically for presence of the KRAS mutations and for expression of hypoxia-inducible factor-1 (HIF-1) and minichromosome maintenance protein 2 (mcm2). The following imaging parameters were derived for each tumor: (18)F-FDG uptake ((18)F-FDG maximum standardized uptake value [SUVmax]), CT texture (expressed as mean of positive pixels [MPP]), and blood flow measured by dynamic contrast-enhanced CT. A recursive decision tree was developed in which the imaging investigations were applied sequentially to identify tumors with KRAS mutations. Monte Carlo analysis provided mean values and 95% confidence intervals for sensitivity, specificity, and accuracy. The final decision tree comprised 4 decision nodes and 5 terminal nodes, 2 of which identified KRAS mutants. The true-positive rate, false-positive rate, and accuracy (95% confidence intervals) of the decision tree were 82.4% (63.9%-93.9%), 0% (0%-10.4%), and 90.1% (79.2%-96.0%), respectively. KRAS mutants with high (18)F-FDG SUVmax and low MPP showed greater frequency of HIF-1 expression (P = 0.032). KRAS mutants with low (18)F-FDG SUV(max), high MPP, and high blood flow expressed mcm2 (P = 0.036). Multifunctional imaging with PET/CT and recursive decision-tree analysis to combine measurements of tumor (18)F-FDG uptake, CT texture, and perfusion has the potential to identify imaging signatures for colorectal cancers with KRAS mutations exhibiting hypoxic or proliferative phenotypes.

  8. Correction of the Abnormal Trafficking of Primary Myelofibrosis CD34+ Cells by Treatment with Chromatin Modifying Agents

    PubMed Central

    Wang, Xiaoli; Zhang, Wei; Ishii, Takefumi; Sozer, Selcuk; Wang, Jiapeng; Xu, Mingjiang; Hoffman, Ronald

    2011-01-01

    The abnormal trafficking of CD34+ cells is a unique characteristic of primary myelofibrosis (PMF). We have further studied the behavior of PMF CD34+ cells by examining their homing to the marrow and the spleens of NOD/SCID mice. Following the infusion of PMF and normal G-CSF mobilized peripheral blood (mPB) CD34+ cells into NOD/SCID mice, reduced numbers of PMF CD34+ cells and CFU-GM as compared to mPB were detected in the marrow of these mice while similar numbers of PMF and mPB CD34+ cells and CFU-GM homed to their spleens. The abnormal homing of PMF CD34+ cells was associated with reduced expression of CXCR4, but was not related to the presence of JAK2V617F. The sequential treatment of PMF CD34+ cell with the chromatin modifying agents, 5-aza-2'-deoxycytidine (5azaD) and trichostatin A (TSA) but not treatment with small molecule inhibitors of JAK2 resulted in the generation of increased numbers of CD34+CXCR4+ cells which was accompanied by enhanced homing of PMF CD34+ cells to the marrow but not the spleens of NOD/SCID mice. Following 5azaD/TSA treatment JAK2V617F negative PMF hematopoietic progenitor cells preferentially homed to the marrow but not the spleens of recipient mice. Our data suggest that PMF CD34+ cells are characterized by a reduced ability to home to the marrow but not the spleens of NOD/SCID mice and that this homing defect can be corrected by sequential treatment with chromatin modifying agents. PMID:19752087

  9. Antisense-based RNA therapy of factor V deficiency: in vitro and ex vivo rescue of a F5 deep-intronic splicing mutation.

    PubMed

    Nuzzo, Francesca; Radu, Claudia; Baralle, Marco; Spiezia, Luca; Hackeng, Tilman M; Simioni, Paolo; Castoldi, Elisabetta

    2013-11-28

    Antisense molecules are emerging as a powerful tool to correct splicing defects. Recently, we identified a homozygous deep-intronic mutation (F5 c.1296+268A>G) activating a cryptic donor splice site in a patient with severe coagulation factor V (FV) deficiency and life-threatening bleeding episodes. Here, we assessed the ability of 2 mutation-specific antisense molecules (a morpholino oligonucleotide [MO] and an engineered U7 small nuclear RNA [snRNA]) to correct this splicing defect. COS-1 and HepG2 cells transfected with a F5 minigene construct containing the patient's mutation expressed aberrant messenger RNA (mRNA) in excess of normal mRNA. Treatment with mutation-specific antisense MO (1-5 µM) or a construct expressing antisense U7snRNA (0.25-2 µg) dose-dependently increased the relative amount of correctly spliced mRNA by 1 to 2 orders of magnitude, whereas control MO and U7snRNA were ineffective. Patient-derived megakaryocytes obtained by differentiation of circulating progenitor cells did not express FV, but became positive for FV at immunofluorescence staining after administration of antisense MO or U7snRNA. However, treatment adversely affected cell viability, mainly because of the transfection reagents used to deliver the antisense molecules. Our data provide in vitro and ex vivo proof of principle for the efficacy of RNA therapy in severe FV deficiency, but additional cytotoxicity studies are warranted.

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

    PubMed

    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.

  11. JAK2 inhibition sensitizes resistant EGFR-mutant lung adenocarcinoma to tyrosine kinase inhibitors

    PubMed Central

    Gao, Sizhi P.; Chang, Qing; Mao, Ninghui; Daly, Laura A.; Vogel, Robert; Chan, Tyler; Liu, Shu Hui; Bournazou, Eirini; Schori, Erez; Zhang, Haiying; Brewer, Monica Red; Pao, William; Morris, Luc; Ladanyi, Marc; Arcila, Maria; Manova-Todorova, Katia; de Stanchina, Elisa; Norton, Larry; Levine, Ross L.; Altan-Bonnet, Gregoire; Solit, David; Zinda, Michael; Huszar, Dennis; Lyden, David; Bromberg, Jacqueline F.

    2016-01-01

    Lung adenocarcinomas with mutant epidermal growth factor receptor (EGFR) respond to EGFR-targeted tyrosine kinase inhibitors (TKIs), but resistance invariably occurs. We found that the Janus kinase (JAK)/signal transduction and activator of transcription 3 (STAT3) signaling pathway was aberrantly increased in TKI-resistant EGFR-mutant non–small cell lung cancer (NSCLC) cells. JAK2 inhibition restored sensitivity to the EGFR inhibitor erlotinib in TKI-resistant cell lines and xenograft models of EGFR-mutant TKI-resistant lung cancer. JAK2 inhibition uncoupled EGFR from its negative regulator, suppressor of cytokine signaling 5 (SOCS5), consequently increasing EGFR abundance and restoring the tumor cells’ dependence on EGFR signaling. Furthermore, JAK2 inhibition led to heterodimerization of mutant and wild-type EGFR subunits, the activity of which was then blocked by TKIs. Our results reveal a mechanism whereby JAK2 inhibition overcomes acquired resistance to EGFR inhibitors and support the use of combination therapy with JAK and EGFR inhibitors for the treatment of EGFR-dependent NSCLC. PMID:27025877

  12. Highly preferential association of NonF508del CF mutations with the M470 allele.

    PubMed

    Ciminelli, B M; Bonizzato, A; Bombieri, C; Pompei, F; Gabaldo, M; Ciccacci, C; Begnini, A; Holubova, A; Zorzi, P; Piskackova, T; Macek, M; Castellani, C; Modiano, G; Pignatti, P F

    2007-01-01

    On the basis of previous findings on random individuals, we hypothesized a preferential association of CF causing mutations with the M allele of the M470V polymorphic site of the CFTR gene. We have determined the M/V-CF mutation haplotype in a series of 201 North East Italian and 73 Czech CF patients who were not F508del homozygotes, as F508del was already known to be fully associated with the M allele. Out of 358 not F508del CF genes, 84 carried the V allele and 274 the less common M allele. In the N-E Italian population, MM subjects have a risk of carrying a CF causing mutation 6.9x greater than VV subjects when F508del is excluded and 15.4x when F508del is included. In the Czech population a similar, although less pronounced, association is observed. Besides the possible biological significance of this association, the possibility of exploiting it for a pilot screening program has been explored in a local North East Italian population for which CF patients were characterized for their CF mutation. General M470V genotyping followed by common CF mutation screening limited to couples in which each partner carries at least one M allele would need testing only 39% of the couples, which contribute 89% of the total risk, with a cost benefit.

  13. Detached-Eddy Simulation Based on the V2-F Model

    NASA Technical Reports Server (NTRS)

    Jee, Sol Keun; Shariff, Karim R.

    2012-01-01

    Detached-eddy simulation (DES) based on the v(sup 2)-f Reynolds-averaged Navier-Stokes (RANS) model is developed and tested. The v(sup 2)-f model incorporates the anisotropy of near-wall turbulence which is absent in other RANS models commonly used in the DES community. The v(sup 2)-f RANS model is modified in order the proposed v(sup 2)-f-based DES formulation reduces to a transport equation for the subgrid-scale kinetic energy isotropic turbulence. First, three coefficients in the elliptic relaxation equation are modified, which is tested in channel flows with friction Reynolds number up to 2000. Then, the proposed v(sup 2)-f DES model formulation is derived. The constant, C(sub DES), required in the DES formulation was calibrated by simulating both decaying and statistically-steady isotropic turbulence. After C(sub DES) was calibrated, the v(sub 2)-f DES formulation is tested for flow around a circular cylinder at a Reynolds number of 3900, in which case turbulence develops after separation. Simulations indicate that this model represents the turbulent wake nearly as accurately as the dynamic Smagorinsky model. Spalart-Allmaras-based DES is also included in the cylinder flow simulation for comparison.

  14. Severe Early-Onset Combined Immunodeficiency due to Heterozygous Gain-of-Function Mutations in STAT1.

    PubMed

    Baris, Safa; Alroqi, Fayhan; Kiykim, Ayca; Karakoc-Aydiner, Elif; Ogulur, Ismail; Ozen, Ahmet; Charbonnier, Louis-Marie; Bakır, Mustafa; Boztug, Kaan; Chatila, Talal A; Barlan, Isil B

    2016-10-01

    Loss and gain-of-function (GOF) mutations in human signal transducer and activator of transcription 1 (STAT1) lead to distinct phenotypes. Although recurrent infections are common to both types of STAT1 mutations, GOF mutations are distinguished by chronic mucocutaneous candidiasis and autoimmunity. However, the clinical spectra of STAT1 GOF mutations continue to expand. We here describe two patients with STAT1 GOF mutations presenting early in life with combined immunodeficiency (CID). Clinical data and laboratory findings including immunophenotyping, level of interferon (IFN)-γ/IL-17(+) T cells, interferon-induced STAT1 phosphorylation, and JAK inhibitor assays were evaluated. Sequencing of STAT1 gene was performed by Sanger sequencer. Patient 1 (P1) had persistent oral candidiasis and cytomegalovirus (CMV) infection since 2 months of age and later developed cavitary lung lesions due to Mycobacterium tuberculosis. Patient 2 (P2) presented with oral candidiasis and recurrent pneumonia at 4 months of age and subsequently developed CMV pneumonitis. Both patients suffered heterozygous missense mutations in STAT1, leading to deleterious amino acid substitutions in the DNA binding domain (P1: c.1154C > T; p.T385M; P2. c.971G > T; p.C324F). Circulating CD4(+) T cells of both patients exhibited increased interferon-γ and decreased IL-17 expression as compared to controls. They also exhibited increased IFN-β and -γ-induced STAT1 phosphorylation that was reversed upon treatment with the JAK kinase inhibitor ruxolitinib. STAT1 GOF mutations may present early in life with CID, consistent with the clinical heterogeneity of the disease. JAK kinase inhibitors may potentially be useful in some patients as adjunct therapy pending definitive treatment with bone marrow transplantation.

  15. Krüppel-like factor 1 mutations and expression of hemoglobins F and A2 in homozygous hemoglobin E syndrome.

    PubMed

    Tepakhan, Wanicha; Yamsri, Supawadee; Fucharoen, Goonnapa; Sanchaisuriya, Kanokwan; Fucharoen, Supan

    2015-07-01

    The basis for variability of hemoglobin (Hb) F in homozygous Hb E disease is not well understood. We have examined multiple mutations of the Krüppel-like factor 1 (KLF1) gene; an erythroid specific transcription factor and determined their associations with Hbs F and A2 expression in homozygous Hb E. Four KLF1 mutations including G176AfsX179, T334R, R238H, and -154 (C-T) were screened using specific PCR assays on 461 subjects with homozygous Hb E and 100 normal controls. None of these four mutations were observed in 100 normal controls. Among 461 subjects with homozygous Hb E, 306 had high (≥5 %) and 155 had low (<5 %) Hb F. DNA analysis identified the KLF1 mutations in 35 cases of the former group with high Hb F, including the G176AfsX179 mutation (17/306 = 5.6 %), T334R mutation (9/306 = 2.9 %), -154 (C-T) mutation (7/306 = 2.3 %), and R328H mutation (2/306 = 0.7 %). Only two subjects in the latter group with low Hb F carried the G176AfsX179 and -154 (C-T) mutations. Significant higher Hb A2 level was observed in those of homozygous Hb E with the G176AfsX179 mutation as compared to those without KLF1 mutations. These results indicate that KLF1 is among the genetic factors associated with increased Hbs F and A2, and in combination with other factors could explain the variabilities of these Hb expression in Hb E syndrome.

  16. Succinyl-CoA:3-ketoacid CoA transferase (SCOT) deficiency: two pathogenic mutations, V133E and C456F, in Japanese siblings.

    PubMed

    Song, X Q; Fukao, T; Watanabe, H; Shintaku, H; Hirayama, K; Kassovska-Bratinova, S; Kondo, N; Mitchell, G A

    1998-01-01

    Succinyl-CoA:3-ketoacid CoA transferase (SCOT; EC 2.8.3.5; locus symbol OXCT) is the key enzyme of ketone body utilization. Hereditary SCOT deficiency (MIM 245050) causes episodes of severe ketoacidosis. We developed a transient expression system for mutant SCOT cDNAs, using immortalized SCOT-deficient fibroblasts. This paper describes and characterizes three missense mutations in two SCOT-deficient siblings from Japan. They are genetic compounds who inherited the mutation C456F (c1367 G-->T) from their mother. Their paternal allele contains two mutations in cis, T58M (c173 C-->T) and V133E (c398T-->A). Expression of SCOT cDNAs containing either V133E or C456F produces no detectable SCOT activity, whereas T58M is functionally neutral. T58M is a rare sequence variant not detected in 100 control Japanese alleles. In fibroblasts from the proband (GS02), in whom immunoblot demonstrated no detectable SCOT peptide, we measured an apparent residual SCOT activity of 20-35%. We hypothesize that the high residual SCOT activity in homogenates may be an artifact caused by use of the substrate, acetoacetyl-CoA by other enzymes. Expression of mutant SCOT cDNAs more accurately reflects the residual activity of SCOT than do currently available assays in cell or tissue homogenates.

  17. Drug sensitivity profiling identifies potential therapies for lymphoproliferative disorders with overactive JAK/STAT3 signaling

    PubMed Central

    Kuusanmäki, Heikki; Dufva, Olli; Parri, Elina; van Adrichem, Arjan J.; Rajala, Hanna; Majumder, Muntasir M.; Yadav, Bhagwan; Parsons, Alun; Chan, Wing C.; Wennerberg, Krister; Mustjoki, Satu; Heckman, Caroline A.

    2017-01-01

    Constitutive JAK/STAT3 signaling contributes to disease progression in many lymphoproliferative disorders. Recent genetic analyses have revealed gain-of-function STAT3 mutations in lymphoid cancers leading to hyperactivation of STAT3, which may represent a potential therapeutic target. Using a functional reporter assay, we screened 306 compounds with selective activity against various target molecules to identify drugs capable of inhibiting the cellular activity of STAT3. Top hits were further validated with additional models including STAT3-mutated natural killer (NK)-cell leukemia/lymphoma cell lines and primary large granular lymphocytic (LGL) leukemia cells to assess their ability to inhibit STAT3 phosphorylation and STAT3 dependent cell viability. We identified JAK, mTOR, Hsp90 and CDK inhibitors as potent inhibitors of both WT and mutant STAT3 activity. The Hsp90 inhibitor luminespib was highly effective at reducing the viability of mutant STAT3 NK cell lines and LGL leukemia patient samples. Luminespib decreased the phosphorylation of mutant STAT3 at Y705, whereas JAK1/JAK2 inhibitor ruxolitinib had reduced efficacy on mutant STAT3 phosphorylation. Additionally, combinations involving Hsp90, JAK and mTOR inhibitors were more effective at reducing cell viability than single agents. Our findings show alternative approaches to inhibit STAT3 activity and suggest Hsp90 as a therapeutic target in lymphoproliferative disorders with constitutively active STAT3. PMID:29228628

  18. TET2 Mutations Are Associated with Specific 5-Methylcytosine and 5-Hydroxymethylcytosine Profiles in Patients with Chronic Myelomonocytic Leukemia

    PubMed Central

    Pérez, Cristina; Martínez-Calle, Nicolas; Martín-Subero, José Ignacio; Segura, Victor; Delabesse, Eric; Fernandez-Mercado, Marta; Garate, Leire; Alvarez, Sara; Rifon, José; Varea, Sara; Boultwood, Jacqueline; Wainscoat, James S.; Cigudosa, Juan Cruz; Calasanz, María José; Cross, Nicholas C. P.

    2012-01-01

    Chronic myelomonocytic leukemia (CMML) has recently been associated with a high incidence of diverse mutations in genes such as TET2 or EZH2 that are implicated in epigenetic mechanisms. We have performed genome-wide DNA methylation arrays and mutational analysis of TET2, IDH1, IDH2, EZH2 and JAK2 in a group of 24 patients with CMML. 249 genes were differentially methylated between CMML patients and controls. Using Ingenuity pathway analysis, we identified enrichment in a gene network centered around PLC, JNK and ERK suggesting that these pathways, whose deregulation has beenrecently described in CMML, are affected by epigenetic mechanisms. Mutations of TET2, JAK2 and EZH2 were found in 15 patients (65%), 4 patients (17%) and 1 patient (4%) respectively while no mutations in the IDH1 and IDH2 genes were identified. Interestingly, patients with wild type TET2 clustered separately from patients with TET2 mutations, showed a higher degree of hypermethylation and were associated with higher risk karyotypes. Our results demonstrate the presence of aberrant DNA methylation in CMML and identifies TET2 mutant CMML as a biologically distinct disease subtype with a different epigenetic profile. PMID:22328940

  19. Suppressor of Cytokine Signaling 2 Negatively Regulates NK Cell Differentiation by Inhibiting JAK2 Activity

    PubMed Central

    Kim, Won Sam; Kim, Mi Jeong; Kim, Dong Oh; Byun, Jae-Eun; Huy, Hangsak; Song, Hae Young; Park, Young-Jun; Kim, Tae-Don; Yoon, Suk Ran; Choi, Eun-Ji; Jung, Haiyoung; Choi, Inpyo

    2017-01-01

    Suppressor of cytokine signaling (SOCS) proteins are negative regulators of cytokine responses. Although recent reports have shown regulatory roles for SOCS proteins in innate and adaptive immunity, their roles in natural killer (NK) cell development are largely unknown. Here, we show that SOCS2 is involved in NK cell development. SOCS2−/− mice showed a high frequency of NK cells in the bone marrow and spleen. Knockdown of SOCS2 was associated with enhanced differentiation of NK cells in vitro, and the transplantation of hematopoietic stem cells (HSCs) into congenic mice resulted in enhanced differentiation in SOCS2−/− HSCs. We found that SOCS2 could inhibit Janus kinase 2 (JAK2) activity and JAK2-STAT5 signaling pathways via direct interaction with JAK2. Furthermore, SOCS2−/− mice showed a reduction in lung metastases and an increase in survival following melanoma challenge. Overall, our findings suggest that SOCS2 negatively regulates the development of NK cells by inhibiting JAK2 activity via direct interaction. PMID:28383049

  20. HER2 activating mutations are targets for colorectal cancer treatment

    PubMed Central

    Kavuri, Shyam M.; Jain, Naveen; Galimi, Francesco; Cottino, Francesca; Leto, Simonetta M.; Migliardi, Giorgia; Searleman, Adam C.; Shen, Wei; Monsey, John; Trusolino, Livio; Jacobs, Samuel A.; Bertotti, Andrea; Bose, Ron

    2015-01-01

    The Cancer Genome Atlas project identified HER2 somatic mutations and gene amplification in 7% of colorectal cancer patients. Introduction of the HER2 mutations, S310F, L755S, V777L, V842I, and L866M, into colon epithelial cells increased signaling pathways and anchorage-independent cell growth, indicating that they are activating mutations. Introduction of these HER2 activating mutations into colorectal cancer cell lines produced resistance to cetuximab and panitumumab by sustaining MAPK phosphorylation. HER2 mutations are potently inhibited by low nanomolar doses of the irreversible tyrosine kinase inhibitors, neratinib and afatinib. HER2 gene sequencing of 48 cetuximab resistant, quadruple (KRAS, NRAS, BRAF, and PIK3CA) WT colorectal cancer patient-derived xenografts (PDX’s) identified 4 PDX’s with HER2 mutations. HER2 targeted therapies were tested on two PDX’s. Treatment with a single HER2 targeted drug (trastuzumab, neratinib, or lapatinib) delayed tumor growth, but dual HER2 targeted therapy with trastuzumab plus tyrosine kinase inhibitors produced regression of these HER2 mutated PDX’s. PMID:26243863

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

    PubMed

    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.

  2. Single molecule molecular inversion probes for targeted, high-accuracy detection of low-frequency variation.

    PubMed

    Hiatt, Joseph B; Pritchard, Colin C; Salipante, Stephen J; O'Roak, Brian J; Shendure, Jay

    2013-05-01

    The detection and quantification of genetic heterogeneity in populations of cells is fundamentally important to diverse fields, ranging from microbial evolution to human cancer genetics. However, despite the cost and throughput advances associated with massively parallel sequencing, it remains challenging to reliably detect mutations that are present at a low relative abundance in a given DNA sample. Here we describe smMIP, an assay that combines single molecule tagging with multiplex targeted capture to enable practical and highly sensitive detection of low-frequency or subclonal variation. To demonstrate the potential of the method, we simultaneously resequenced 33 clinically informative cancer genes in eight cell line and 45 clinical cancer samples. Single molecule tagging facilitated extremely accurate consensus calling, with an estimated per-base error rate of 8.4 × 10(-6) in cell lines and 2.6 × 10(-5) in clinical specimens. False-positive mutations in the single molecule consensus base-calls exhibited patterns predominantly consistent with DNA damage, including 8-oxo-guanine and spontaneous deamination of cytosine. Based on mixing experiments with cell line samples, sensitivity for mutations above 1% frequency was 83% with no false positives. At clinically informative sites, we identified seven low-frequency point mutations (0.2%-4.7%), including BRAF p.V600E (melanoma, 0.2% alternate allele frequency), KRAS p.G12V (lung, 0.6%), JAK2 p.V617F (melanoma, colon, two lung, 0.3%-1.4%), and NRAS p.Q61R (colon, 4.7%). We anticipate that smMIP will be broadly adoptable as a practical and effective method for accurately detecting low-frequency mutations in both research and clinical settings.

  3. Molecular profiling of appendiceal epithelial tumors using massively parallel sequencing to identify somatic mutations.

    PubMed

    Liu, Xiaoying; Mody, Kabir; de Abreu, Francine B; Pipas, J Marc; Peterson, Jason D; Gallagher, Torrey L; Suriawinata, Arief A; Ripple, Gregory H; Hourdequin, Kathryn C; Smith, Kerrington D; Barth, Richard J; Colacchio, Thomas A; Tsapakos, Michael J; Zaki, Bassem I; Gardner, Timothy B; Gordon, Stuart R; Amos, Christopher I; Wells, Wendy A; Tsongalis, Gregory J

    2014-07-01

    Some epithelial neoplasms of the appendix, including low-grade appendiceal mucinous neoplasm and adenocarcinoma, can result in pseudomyxoma peritonei (PMP). Little is known about the mutational spectra of these tumor types and whether mutations may be of clinical significance with respect to therapeutic selection. In this study, we identified somatic mutations using the Ion Torrent AmpliSeq Cancer Hotspot Panel v2. Specimens consisted of 3 nonneoplastic retention cysts/mucocele, 15 low-grade mucinous neoplasms (LAMNs), 8 low-grade/well-differentiated mucinous adenocarcinomas with pseudomyxoma peritonei, and 12 adenocarcinomas with/without goblet cell/signet ring cell features. Barcoded libraries were prepared from up to 10 ng of extracted DNA and multiplexed on single 318 chips for sequencing. Data analysis was performed using Golden Helix SVS. Variants that remained after the analysis pipeline were individually interrogated using the Integrative Genomics Viewer. A single Janus kinase 3 (JAK3) mutation was detected in the mucocele group. Eight mutations were identified in the V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) and GNAS complex locus (GNAS) genes among LAMN samples. Additional gene mutations were identified in the AKT1 (v-akt murine thymoma viral oncogene homolog 1), APC (adenomatous polyposis coli), JAK3, MET (met proto-oncogene), phosphatidylinositol-4,5-bisphosphate 3-kinase (PIK3CA), RB1 (retinoblastoma 1), STK11 (serine/threonine kinase 11), and tumor protein p53 (TP53) genes. Among the PMPs, 6 mutations were detected in the KRAS gene and also in the GNAS, TP53, and RB1 genes. Appendiceal cancers showed mutations in the APC, ATM (ataxia telangiectasia mutated), KRAS, IDH1 [isocitrate dehydrogenase 1 (NADP+)], NRAS [neuroblastoma RAS viral (v-ras) oncogene homolog], PIK3CA, SMAD4 (SMAD family member 4), and TP53 genes. Our results suggest molecular heterogeneity among epithelial tumors of the appendix. Next generation sequencing efforts

  4. JAK-STAT Pathway Activation in Malignant and Non-Malignant Cells Contributes to MPN Pathogenesis and Therapeutic Response

    PubMed Central

    Kleppe, Maria; Kwak, Minsuk; Koppikar, Priya; Riester, Markus; Keller, Matthew; Bastian, Lennart; Hricik, Todd; Bhagwat, Neha; McKenney, Anna Sophia; Papalexi, Efthymia; Abdel-Wahab, Omar; Rampal, Raajit; Marubayashi, Sachie; Chen, Jonathan J.; Romanet, Vincent; Fridman, Jordan S.; Bromberg, Jacqueline; Teruya-Feldstein, Julie; Murakami, Masato; Radimerski, Thomas; Michor, Franziska; Fan, Rong; Levine, Ross L.

    2015-01-01

    The identification of JAK2/MPL mutations in patients with myeloproliferative neoplasms (MPN) led to the clinical development of JAK kinase inhibitors, including ruxolitinib. Ruxolitinib reduces splenomegaly and systemic symptoms in myelofibrosis (MF) and improves overall survival; however the mechanism by which JAK inhibitors achieve efficacy has not been delineated. MPN patients present with increased levels of circulating pro-inflammatory cytokines, which are mitigated by JAK inhibitor therapy. We sought to elucidate mechanisms by which JAK inhibitors attenuate cytokine-mediated pathophysiology. Single cell profiling demonstrated that hematopoietic cells from MF models and patient samples aberrantly secrete inflammatory cytokines. Pan-hematopoietic Stat3 deletion reduced disease severity and attenuated cytokine secretion, with similar efficacy as observed with ruxolitinib therapy. By contrast, Stat3 deletion restricted to MPN cells did not reduce disease severity or cytokine production. Consistent with these observations, we found that malignant and non-malignant cells aberrantly secrete cytokines and JAK inhibition reduces cytokine production from both populations. PMID:25572172

  5. Extramedullary haematopoiesis presenting with cardiac tamponade in a patient with polycythaemia vera.

    PubMed

    Haroun, Faysal; Elkis, Viktoria; Chen, Anne; Lee, Elsie

    2017-08-10

    A 71-year-old man with a history of polycythaemia vera, diagnosed 4 years ago, presented to the emergency room with shortness of breath. A bedside echocardiogram revealed a large pericardial effusion with features concerning for pericardial tamponade. A left anterior thoracotomy and a pericardial window were emergently performed in the operating room and relieved the patient's symptoms. Histology evaluation of the pericardial fragments and pericardial fluid revealed the presence of trilineage haematopoietic elements without any increase in the blasts. A bone marrow core biopsy revealed an increase in reticulin fibre and increase in the number of blasts of 5%-10%, whereas peripheral blood testing was positive for JAK2 V617F mutation. This case report reviews the literature for cases of extramedullary haematopoiesis associated with myeloproliferative neoplasms. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  6. How We Identify and Manage Patients with Inadequately Controlled Polycythemia Vera.

    PubMed

    Reiter, Andreas; Harrison, Claire

    2016-10-01

    Polycythemia vera (PV) is a chronic myeloproliferative neoplasm (MPN) characterized by an overactive Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway through mutations in JAK2 exons 12 or 14 (JAK2 V617F). The dominant clinical characteristics include erythrocytosis (with or without leukocytosis/thrombocytosis), thrombotic events, and symptoms. Increased risk of mortality is mainly caused by thrombotic events and progression to post-polycythemia vera myelofibrosis (PPV-MF) or secondary acute myeloid leukemia (sAML). The most important prognostic factors include age and a history of thrombotic events, although recent evidence has indicated that leukocytosis and additional cytogenetic aberrations may also be of significant prognostic value. First-line therapies include aspirin and phlebotomies, which significantly reduce the incidence of thrombotic events and prolong survival. Cytoreductive treatment with hydroxyurea (approved) and conventional or pegylated interferon-α (effective, but not approved in many countries) is initiated for high-risk or inadequately controlled disease, e.g., uncontrolled hematocrit, leukocytosis, thrombocytosis, thrombotic events, splenomegaly, or symptoms. However, some patients may not receive initial benefit from first-line therapy or may become resistant or intolerant in due course. Although second-line treatment options are limited, clinical trials have shown the efficacy of ruxolitinib toward improving blood counts, enlarged spleen, and symptoms and potentially reducing thrombotic events. Identification of patients with uncontrolled PV is important for clinical care, as such patients have a high risk of complications, and future studies with JAK inhibitors or other agents alone or in combination are needed to test their potential to reduce rates of thrombotic events and transformation to PPV-MF or sAML.

  7. Manganese Vanadate Chemistry in Hydrothermal BaF 2 Brines: Ba 3 Mn 2 (V 2 O 7 ) 2 F 2 and Ba 7 Mn 8 O 2 (VO 4 ) 2 F 23

    DOE PAGES

    Sanjeewa, Liurukara D.; McMillen, Colin D.; McGuire, Michael A.; ...

    2016-12-05

    We synthesized manganese vanadate fluorides using high-temperature hydrothermal techniques with BaF 2 as a mineralizer. Ba 3Mn 2(V 2O 7) 2F 2 crystallizes in space group C2/c and consists of dimers built from edge-sharing MnO 4F 2 trigonal prisms with linking V 2O 7 groups. Ba 7Mn 8O 2(VO 4) 2F 23 crystallizes in space group Cmmm, with a manganese oxyfluoride network built from edge- and corner-sharing Mn 2+/3+(O,F) 6 octahedra. The resulting octahedra form alternating Mn 2+ and Mn 2+/3+ layers separated by VO 4 tetrahedra. This latter compound exhibits a canted antiferromagnetic order below TN = 25 K.

  8. The co-occurrence of driver mutations in chronic myeloproliferative neoplasms.

    PubMed

    Boddu, Prajwal; Chihara, Dai; Masarova, Lucia; Pemmaraju, Naveen; Patel, Keyur P; Verstovsek, Srdan

    2018-06-27

    Myeloproliferative neoplasms (MPNs) are clonal disorders characterized by proliferation of one or more elements of the myeloid lineage. Key genetic aberrations include the BCR-ABL1 gene rearrangement in Philadelphia chromosome-positive chronic myelogenous leukemia (CML) and JAK2/MPL/CALR aberrations in Philadelphia chromosome-negative MPNs. While thought to be mutually exclusive, occasional isolated reports of coexistence of BCR-ABL1 and JAK2, and JAK2 with MPL or CALR aberrations have been described. Given the paucity of data, clinical characteristics and outcome of patients harboring concurrent Philadelphia-positive and Philadelphia-negative mutations or dual Philadelphia-negative driver mutations have not been systematically evaluated, and their clinical relevance is largely unknown. It is difficult to determine the true relevance of co-existing driver mutations on outcomes given the rarity of its occurrence. In this case series, we describe those patients who had dual driver mutations detected at any point during the course of their disease and characterized their clinical and laboratory features, bone marrow pathology, and overall disease course.

  9. The JAK2 Inhibitor, AZD1480, Potently Blocks Stat3 Signaling and Oncogenesis in Solid Tumors

    PubMed Central

    Hedvat, Michael; Huszar, Dennis; Herrmann, Andreas; Gozgit, Joseph M.; Schroeder, Anne; Sheehy, Adam; Buettner, Ralf; Proia, David; Kowolik, Claudia M.; Xin, Hong; Armstrong, Brian; Bebernitz, Geraldine; Weng, Shaobu; Wang, Lin; Ye, Minwei; McEachern, Kristen; Chen, Huawei; Morosini, Deborah; Bell, Kirsten; Alimzhanov, Marat; Ioannidis, Stephanos; McCoon, Patricia; Cao, Zhu A.; Yu, Hua; Jove, Richard; Zinda, Michael

    2009-01-01

    Summary Persistent activation of Stat3 is oncogenic and is prevalent in a wide variety of human cancers. Chronic cytokine stimulation is associated with Stat3 activation in some tumors, implicating cytokine receptor-associated Jak family kinases. Using Jak2 inhibitors, we demonstrate a central role of Jaks in modulating basal and cytokine-induced Stat3 activation in human solid tumor cell lines. Inhibition of Jak2 activity is associated with abrogation of Stat3 nuclear translocation and tumorigenesis. The Jak2 inhibitor, AZD1480, suppresses the growth of human solid tumor xenografts harboring persistent Stat3 activity. We demonstrate the essential role of Stat3 downstream of Jaks by inhibition of tumor growth using shRNA targeting Stat3. Our data support a key role of Jak kinase activity in Stat3-dependent tumorigenesis. PMID:19962667

  10. Synthesis and characterization of new fluoride-containing manganese vanadates A2Mn2V2O7F2 (A=Rb, Cs) and Mn2VO4F

    NASA Astrophysics Data System (ADS)

    Sanjeewa, Liurukara D.; McGuire, Michael A.; Smith Pellizzeri, Tiffany M.; McMillen, Colin D.; Ovidiu Garlea, V.; Willett, Daniel; Chumanov, George; Kolis, Joseph W.

    2016-09-01

    Large single crystals of A2Mn2V2O7F2 (A=Rb, Cs) and Mn2VO4F were grown using a high-temperature (~600 °C) hydrothermal technique. Single crystal X-ray diffraction and powder X-ray diffraction were utilized to characterize the structures, which both possess MnO4F2 building blocks. The A2Mn2V2O7F2 series crystallizes as a new structure type in space group Pbcn (No. 60), Z=4 (Rb2Mn2V2O7F2: a=7.4389(17) Å, b=11.574(3) Å, c=10.914(2) Å; Cs2Mn2V2O7F2: a=7.5615(15) Å, b=11.745(2) Å, c=11.127(2) Å). The structure is composed of zigzag chains of edge-sharing MnO4F2 units running along the a-axis, and interconnected through V2O7 pyrovanadate groups. Temperature dependent magnetic susceptibility measurements on this interesting one-dimensional structural feature based on Mn2+ indicated that Cs2Mn2V2O7F2 is antiferromagnetic with a Neél temperature, TN=~3 K and a Weiss constant, θ, of -11.7(1) K. Raman and infrared spectra were also analyzed to identify the fundamental V-O vibrational modes in Cs2Mn2V2O7F2. Mn2(VO4)F crystalizes in the monoclinic space group of C2/c (no. 15), Z=8 with unit cell parameters of a=13.559(2) Å, b=6.8036(7) Å, c=10.1408(13) Å and β=116.16(3)°. The structure is associated with those of triplite and wagnerite. Dynamic fluorine disorder gives rise to complex alternating chains of five-and six-coordinate Mn2+. These interpenetrating chains are additionally connected through isolated VO4 tetrahedra to form the condensed structure.

  11. Congenital hypopituitarism due to POU1F1 gene mutation.

    PubMed

    Lee, Ni-Chung; Tsai, Wen-Yu; Peng, Shinn-Forng; Tung, Yi-Ching; Chien, Yin-Hsiu; Hwu, Wuh-Liang

    2011-01-01

    POU1F1 (Pit-1; Gene ID 5449) is an anterior pituitary transcriptional factor, and POU1F1 mutation is known to cause anterior pituitary hypoplasia, growth hormone and prolactin deficiency and various degree of hypothyroidism. We report here a patient who presented with growth failure and central hypothyroidism since early infancy. However, treatment with thyroxine gave no effect and he subsequently developed calf muscle pseudohypertrophy (Kocher-Debre-Semelaigne syndrome), elevation of creatinine kinase, dilated cardiomyopathy and pericardial effusion. Final diagnosis was made by combined pituitary function test and sequencing analysis that revealed POU1F1 gene C.698T > C (p.F233S) mutation. The rarity of the disease can result in delayed diagnosis and treatment. Copyright © 2011 Formosan Medical Association & Elsevier. Published by Elsevier B.V. All rights reserved.

  12. Causes of Adult Splanchnic Vein Thrombosis in the Mediterranean Area

    PubMed Central

    De Stefano, Valerio; Za, Tommaso; Ciminello, Angela; Betti, Silvia; Rossi, Elena

    2011-01-01

    The term splanchnic vein thrombosis encompasses Budd-Chiari syndrome (BCS), extrahepatic portal vein obstruction (EHPVO), and mesenteric vein thrombosis. Risk factors can be local or systemic. A local precipitating factor is rare in BCS, while it is common in patients with portal vein thrombosis. Chronic myeloproliferative neoplasms (MPN) are the leading systemic cause of splanchnic vein thrombosis, and are diagnosed in half BCS patients and one-third of EHPVO patients; the somatic mutation JAK2 V617F is detectable in a large majority of patients with overt MPN, and up to 40% of patients without overt MPN. Inherited thrombophilia is present in at least one-third of patients, and the factor V Leiden or the prothrombin G20210A mutations are the most common mutations found in BCS or EHPVO patients, respectively. Multiple factors are present in approximately one-third of patients with BCS and two- thirds of patients with portal vein thrombosis. In a few patient series from the Southern Mediterranean area the high prevalence of MPN and thrombophilia as underlying cause of BCS is confirmed, although the data should be considered preliminary. Peculiar risk factors present in the area are Behçet’s disease and hydatidosis; moreover, membraneous webs, typically found in Asian patients, are present in a significant portion of cases. PMID:22220260

  13. AVPR2 variants and mutations in nephrogenic diabetes insipidus: review and missense mutation significance.

    PubMed

    Spanakis, Elias; Milord, Edrice; Gragnoli, Claudia

    2008-12-01

    Almost 90% of nephrogenic diabetes insipidus (NDI) is due to mutations in the arginine-vasopressin receptor 2 gene (AVPR2). We retrospectively examined all the published mutations/variants in AVPR2. We planned to perform a comprehensive review of all the AVPR2 mutations/variants and to test whether any amino acid change causing a missense mutation is significantly more or less common than others. We performed a Medline search and collected detailed information regarding all AVPR2 mutations and variants. We performed a frequency comparison between mutated and wild-type amino acids and codons. We predicted the mutation effect or reported it based on published in vitro studies. We also reported the ethnicity of each mutation/variant carrier. In summary, we identified 211 AVPR2 mutations which cause NDI in 326 families and 21 variants which do not cause NDI in 71 NDI families. We described 15 different types of mutations including missense, frameshift, inframe deletion, deletion, insertion, nonsense, duplication, splicing and combined mutations. The missense mutations represent the 55.83% of all the NDI published families. Arginine and tyrosine are significantly (P = 4.07E-08 and P = 3.27E-04, respectively) the AVPR2 most commonly mutated amino acids. Alanine and glutamate are significantly (P = 0.009 and P = 0.019, respectively) the least mutated AVPR2 amino acids. The spectrum of mutations varies from rare gene variants or polymorphisms not causing NDI to rare mutations causing NDI, among which arginine and tyrosine are the most common missense. The AVPR2 mutations are spread world-wide. Our study may serve as an updated review, comprehensive of all AVPR2 variants and specific gene locations. J. Cell. Physiol. 217: 605-617, 2008. (c) 2008 Wiley-Liss, Inc.

  14. Pancreatic cancer-induced cachexia is Jak2-dependent in mice.

    PubMed

    Gilabert, Marine; Calvo, Ezequiel; Airoldi, Ana; Hamidi, Tewfik; Moutardier, Vincent; Turrini, Olivier; Iovanna, Juan

    2014-10-01

    Cancer cachexia syndrome is observed in 80% of patients with advanced-stage cancer, and it is one of the most frequent causes of death. Severe wasting accounts for more than 80% in patients with advanced pancreatic cancer. Here we wanted to define, by using an microarray approach and the Pdx1-cre;LSL-Kras(G12D) ;INK4a/arf(fl/fl) mice model, the pathways involved in muscle, liver, and white adipose tissue wasting. These mice, which develop systematically pancreatic cancer, successfully reproduced many human symptoms afflicted with this disease, and particularly cachexia. Using the profiling analysis of pancreatic cancer-dependent cachectic tissues we found that Jak2/Stat3 pathways, p53 and NFkB results activated. Thus, our interest was focused on the Jak2 pathways because it is pharmacologically targetable with low toxicity and FDA approved drugs are available. Therefore, Pdx1-cre;LSL-Kras(G12D) ;INK4a/arf(fl/fl) mice were treated with the Jak2 inhibitor AG490 compound daily starting at 7 weeks old and for a period of 3 weeks and animals were sacrificed at 10 weeks old. Body weight for control mice was 27.84 ± 2.14 g, for untreated Pdx1-cre;LSL-Kras(G12D) ;INK4a/arf(fl/fl) was 14.97 ± 1.99 g, whereas in animals treated with the AG490 compound the weight loss was significantly less to 24.53 ± 2.04 g. Treatment with AG490 compound was efficient since phosphorylation of Jak2 and circulating interleukin-6 (IL6) levels were significantly reduced in cachectic tissues and in mice respectively. In conclusion, we found that Jak2/Stat3-dependent intracellular pathway plays an essential role since its pharmacological inhibition strongly attenuates cachexia progression in a lethal transgenic pancreatic cancer model. © 2014 Wiley Periodicals, Inc.

  15. Synthesis and characterization of new fluoride-containing manganese vanadates A 2Mn 2V 2O 7F 2 (A=Rb, Cs) and Mn 2VO 4F

    DOE PAGES

    Sanjeewa, Liurukara D.; McGuire, Michael A.; Smith Pellizzeri, Tiffany M.; ...

    2016-05-10

    In large single crystals of A 2Mn 2V 2O 7F 2 (A=Rb, Cs) and Mn 2VO 4F were grown using a high-temperature (~600 °C) hydrothermal technique. We utilized single crystal X-ray diffraction and powder X-ray diffraction in order to characterize the structures, which both possess MnO 4F 2 building blocks. The A 2Mn 2V 2O 7F 2 series crystallizes as a new structure type in space group Pbcn (No. 60), Z=4 (Rb 2Mn 2V 2O 7F 2: a=7.4389(17) Å, b=11.574(3) Å, c=10.914(2) Å; Cs 2Mn 2V 2O 7F 2: a=7.5615(15) Å, b=11.745(2) Å, c=11.127(2) Å). The structure is composed ofmore » zigzag chains of edge-sharing MnO 4F 2 units running along the a-axis, and interconnected through V 2O 7 pyrovanadate groups. Temperature dependent magnetic susceptibility measurements on this interesting one-dimensional structural feature based on Mn 2+ indicated that Cs 2Mn 2V 2O 7F 2 is antiferromagnetic with a Neél temperature, TN=~3 K and a Weiss constant, θ, of -11.7(1) K. Raman and infrared spectra were also analyzed to identify the fundamental V–O vibrational modes in Cs 2Mn 2V 2O 7F 2. Mn 2(VO 4)F crystalizes in the monoclinic space group of C2/c (no. 15), Z=8 with unit cell parameters of a=13.559(2) Å, b=6.8036(7) Å, c=10.1408(13) Å and β=116.16(3)°. The structure is associated with those of triplite and wagnerite. Dynamic fluorine disorder gives rise to complex alternating chains of five-and six-coordinate Mn 2+. Our interpenetrating chains are additionally connected through isolated VO 4 tetrahedra to form the condensed structure.« less

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

    PubMed Central

    Zhong, Hai-Jing; Dong, Zhen-Zhen; Vellaisamy, Kasipandi; Lu, Jin-Jian; Chen, Xiu-Ping; Chiu, Pauline; Kwong, Daniel W. J.; Han, Quan-Bin; Ma, Dik-Lung

    2017-01-01

    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. PMID:28570563

  17. The novel complex allele [A238V;F508del] of the CFTR gene: clinical phenotype and possible implications for cystic fibrosis etiological therapies.

    PubMed

    Diana, Anna; Polizzi, Angela Maria; Santostasi, Teresa; Ratclif, Luigi; Pantaleo, Maria Giuseppina; Leonetti, Giuseppina; Iusco, Danila Rosa; Gallo, Crescenzio; Conese, Massimo; Manca, Antonio

    2016-06-01

    Few mutations in cis have been annotated for F508del homozygous patients. Southern Italy patients who at a first analysis appeared homozygous for the F508del mutation (n=63) or compound heterozygous for the F508del and another mutation in the cystic fibrosis transmembrane conductance regulator gene (n=155) were searched for the A238V mutation in exon 6. The allelic frequency of the complex allele [A238V;F508del] was 0.04. When the whole data set was used (comprised also of 56 F508del/F508del and 34 F508del/other mutation controls), no differences reached the statistical significance in the clinical parameters, except chloride concentrations which were lower in [A238V;F508del]/other mutation compared with F508del/other mutation (P=0.03). The two study groups presented less complications than the control groups. Within the minimal data set (34 F508del/F508del, 27 F508del/other mutation, 4 [A238V;F508del]/F508del cases and 5 [A238V;F508del]/other mutation cases); that is, presenting all the variables in each patient, forced expiratory volume in 1 s and forced vital capacity presented a trend to lower levels in the study groups in comparison with the F508del/F508del group, and C-reactive protein approximated statistically significant higher levels in the [A238V;F508del]/other mutation as compared with F508del/F508del patients (P=0.09). The analysis of statistical dependence among the variables showed a significant anticorrelation between chloride and body mass index in the [A238V;F508del]/other mutation group. In conclusion, the complex allele [A238V;F508del] seems to be associated with less general complications than in the control groups, on the other hand possibly giving a worse pulmonary phenotype and higher systemic/local inflammatory response. These findings have implications for the correct recruitment and clinical response of F508del patients in the clinical trials testing the new etiological drugs for cystic fibrosis.

  18. Inhibitors of JAK-family kinases: an update on the patent literature 2013-2015, part 2.

    PubMed

    Kettle, Jason G; Åstrand, Annika; Catley, Matthew; Grimster, Neil P; Nilsson, Magnus; Su, Qibin; Woessner, Richard

    2017-02-01

    Janus kinases (JAKs) are a family of four enzymes; JAK1, JAK2, JAK3 and tyrosine kinase 2 (TYK2) that are critical in cytokine signalling and are strongly linked to both cancer and inflammatory diseases. There are currently two launched JAK inhibitors for the treatment of human conditions: tofacitinib for Rheumatoid arthritis (RA) and ruxolitinib for myeloproliferative neoplasms including intermediate or high risk myelofibrosis and polycythemia vera. Areas covered: This review covers patents claiming activity against one or more JAK family members in the period 2013-2015 inclusive, and covers 95 patents from 42 applicants, split over two parts. The authors have ordered recent patents according to the primary applicant's name, with part 2 covering J through Z. Expert opinion: Inhibition of JAK-family kinases is an area of growing interest, catalysed by the maturity of data on marketed inhibitors ruxolitinib and tofacitinib in late stage clinical trials. Many applicants are pursuing traditional fast-follower strategies around these inhibitors, with a range of chemical strategies adopted. The challenge will be to show sufficient differentiation to the originator compounds, since dose limiting toxicities with such agents appear to be on target and mechanism-related and also considering that such agents may be available as generic compounds by the time follower agents reach market.

  19. Ketamine Corrects Stress-Induced Cognitive Dysfunction through JAK2/STAT3 Signaling in the Orbitofrontal Cortex

    PubMed Central

    Patton, Michael S; Lodge, Daniel J; Morilak, David A; Girotti, Milena

    2017-01-01

    Deficits in cognitive flexibility are prominent in stress-related psychiatric disorders, including depression. Ketamine has rapid antidepressant efficacy, but it is unknown if ketamine improves cognitive symptoms. In rats, 2 weeks chronic intermittent cold (CIC) stress impairs reversal learning, a form of cognitive flexibility mediated by the orbitofrontal cortex (OFC) that we have used previously to model cognitive dysfunction in depression. We have shown that activating JAK2/STAT3 signaling in the OFC rescued the CIC stress-induced reversal learning deficit. Thus, in the present study we determined whether ketamine also corrects the stress-induced reversal learning deficit, and if JAK2/STAT3 signaling is involved in this effect. A single injection of ketamine (10 mg/kg, i.p.) 24 h prior to testing rescued the CIC stress-induced reversal learning deficit. CIC stress decreased JAK2 phosphorylation in the OFC, and ketamine restored pJAK2 levels within 2 h post injection. The JAK2 inhibitor AG490 given systemically or into the OFC at the time of ketamine injection prevented its beneficial effect on reversal learning. We then tested the role of JAK2/STAT3 in ketamine-induced plasticity in the OFC. Ketamine depressed local field potentials evoked in the OFC by excitatory thalamic afferent stimulation, and this was prevented by JAK2 inhibition in the OFC. Further, in both the OFC and primary cortical neurons in culture, ketamine increased expression of the neural plasticity-related protein Arc, and this was prevented by JAK2 inhibition. These results suggest that the JAK2/STAT3 signaling pathway is a novel mechanism by which ketamine exerts its therapeutic effects on stress-induced cognitive dysfunction in the OFC. PMID:27748739

  20. Diabetes Insipidus in Mice with a Mutation in Aquaporin-2

    PubMed Central

    Lloyd, David J; Hall, Frank Wesley; Tarantino, Lisa M; Gekakis, Nicholas

    2005-01-01

    Congenital nephrogenic diabetes insipidus (NDI) is a disease characterized by failure of the kidney to concentrate urine in response to vasopressin. Human kindreds with nephrogenic diabetes insipidus have been found to harbor mutations in the vasopressin receptor 2 (Avpr2) gene or the vasopressin-sensitive water channel aquaporin-2 (Aqp2) gene. Development of a treatment is rendered difficult due to the lack of a viable animal model. Through forward genetic screening of ethylnitrosourea-mutagenized mice, we report the identification and characterization of a mouse model of NDI, with an F204V mutation in the Aqp2 gene. Unlike previously attempted murine models of NDI, our mice survive to adulthood and more exactly recapitulate the human disorder. Previous in vitro experiments using renal cell lines suggest recessive Aqp2 mutations result in improper trafficking of the mutant water pore. Using these animals, we have directly proven this hypothesis of improper AQP2 translocation as the molecular defect in nephrogenic diabetes insipidus in the intact organism. Additionally, using a renal cell line we show that the mutated protein, AQP2-F204V, is retained in the endoplasmic reticulum and that this abnormal localization can be rescued by wild-type protein. This novel mouse model allows for further mechanistic studies as well as testing of pharmacological and gene therapies for NDI. PMID:16121255

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

    PubMed

    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.

  2. How we treat myelofibrosis after failure of JAK inhibitors.

    PubMed

    Pardanani, Animesh; Tefferi, Ayalew

    2018-06-04

    The introduction of JAK inhibitors, leading to regulatory approval of ruxolitinib, represents a major therapeutic advance in myelofibrosis. Most patients experience reduction in splenomegaly and improved quality of life from symptom improvement. It is a paradox however that, despite inhibition of signaling downstream of disease-related driver mutations, JAK inhibitor treatment is not associated with consistent molecular or pathologic responses in myelofibrosis. Furthermore, there are important limitations to JAK inhibitor therapy including development of dose-limiting cytopenias and/or non-hematological toxicities such as neuropathy or opportunistic infections. Over half the patients discontinue treatment within three years of starting treatment. While data are sparse, clinical outcome after JAK inhibitor 'failure' is likely poor; consequently, it is important to understand patterns of failure to select appropriate salvage treatment(s). An algorithmic approach, particularly one that incorporates cytogenetics/molecular data, is most helpful in selecting stem cell transplant candidates. Treatment of transplant-ineligible patients relies on a problem-based approach that includes use of investigational drugs, or consideration of splenectomy or radiotherapy. Data from early-phase ruxolitinib combination studies, despite promising pre-clinical data, has not shown clear benefit over monotherapy thus far. Development of effective treatment strategies for myelofibrosis patients failing JAK inhibitors remains a major unmet need. Copyright © 2018 American Society of Hematology.

  3. Prolonged Response to Trastuzumab in a Patient With HER2-Nonamplified Breast Cancer With Elevated HER2 Dimerization Harboring an ERBB2 S310F Mutation.

    PubMed

    Chumsri, Saranya; Weidler, Jodi; Ali, Siraj; Balasubramanian, Sohail; Wallweber, Gerald; DeFazio-Eli, Lisa; Chenna, Ahmed; Huang, Weidong; DeRidder, Angela; Goicocheal, Lindsay; Perez, Edith A

    2015-09-01

    In the current genomic era, increasing evidence demonstrates that approximately 2% of HER2-negative breast cancers, by current standard testings, harbor activating mutations of ERBB2. However, whether patients with HER2-negative breast cancer with activating mutations of ERBB2 also experience response to anti-HER2 therapies remains unclear. This case report describes a patient with HER2-nonamplified heavily pretreated breast cancer who experienced prolonged response to trastuzumab in combination with pertuzumab and fulvestrant. Further molecular analysis demonstrated that her tumors had an elevated HER2 dimerization that corresponded to ERBB2 S310F mutation. Located in the extracellular domain of the HER2 protein, this mutation was reported to promote noncovalent dimerization that results in the activation of the downstream signaling pathways. This case highlights the fact that HER2-targeted therapy may be valuable in patients harboring an ERBB2 S310F mutation. Copyright © 2015 by the National Comprehensive Cancer Network.

  4. Th17 cytokine differentiation and loss of plasticity after SOCS1 inactivation in a cutaneous T-cell lymphoma.

    PubMed

    Ehrentraut, Stefan; Schneider, Björn; Nagel, Stefan; Pommerenke, Claudia; Quentmeier, Hilmar; Geffers, Robert; Feist, Maren; Kaufmann, Maren; Meyer, Corinna; Kadin, Marshall E; Drexler, Hans G; MacLeod, Roderick A F

    2016-06-07

    We propose that deregulated T-helper-cell (Th) signaling underlies evolving Th17 cytokine expression seen during progression of cutaneous T-cell lymphoma (CTCL). Accordingly, we developed a lymphoma progression model comprising cell lines established at indolent (MAC-1) and aggressive (MAC-2A) CTCL stages. We discovered activating JAK3 (V722I) mutations present at indolent disease, reinforced in aggressive disease by novel compound heterozygous SOCS1 (G78R/D105N) JAK-binding domain inactivating mutations. Though isogenic, indolent and aggressive-stage cell lines had diverged phenotypically, the latter expressing multiple Th17 related cytokines, the former a narrower profile. Importantly, indolent stage cells remained poised for Th17 cytokine expression, readily inducible by treatment with IL-2 - a cytokine which mitigates Th17 differentiation in mice. In indolent stage cells JAK3 expression was boosted by IL-2 treatment. Th17 conversion of MAC-1 cells by IL-2 was blocked by pharmacological inhibition of JAK3 or STAT5, implicating IL2RG - JAK3 - STAT5 signaling in plasticity responses. Like IL-2 treatment, SOCS1 knockdown drove indolent stage cells to mimic key aggressive stage properties, notably IL17F upregulation. Co-immunoprecipitation experiments showed that SOCS1 mutations abolished JAK3 binding, revealing a key role for SOCS1 in regulating JAK3/STAT5 signaling. Collectively, our results show how JAK/STAT pathway mutations contribute to disease progression in CTCL cells by potentiating inflammatory cytokine signaling, widening the potential therapeutic target range for this intractable entity. MAC-1/2A cells also provide a candidate human Th17 laboratory model for identifying potentally actionable CTCL markers or targets and testing their druggability in vitro.

  5. Implications of fALS Mutations on Sod1 Function and Oligomerization in Cell Models.

    PubMed

    Brasil, Aline A; Magalhães, Rayne S S; De Carvalho, Mariana D C; Paiva, Isabel; Gerhardt, Ellen; Pereira, Marcos D; Outeiro, Tiago F; Eleutherio, Elis C A

    2018-06-01

    Among the familial forms of amyotrophic lateral sclerosis (fALS), 20% are associated with the Cu,Zn-superoxide dismutase (Sod1). fALS is characterized by the accumulation of aggregated proteins and the increase in oxidative stress markers. Here, we used the non-invasive bimolecular fluorescence complementation (BiFC) assay in human H4 cells to investigate the kinetics of aggregation and subcellular localization of Sod1 mutants. We also studied the effect of the different Sod1 mutants to respond against oxidative stress by following the levels of reactive oxygen species (ROS) after treatment with hydrogen peroxide. Our results showed that only 30% of cells transfected with A4VSod1 showed no inclusions while for the other Sod1 mutants tested (L38V, G93A and G93C), this percentage was at least 70%. In addition, we found that 10% of cells transfected with A4VSod1 displayed more than five inclusions per cell and that A4V and G93A Sod1 formed inclusions more rapidly than L38V and G93C Sod1. Expression of WTSod1 significantly decreased the intracellular oxidation levels in comparison with expression of fALS Sod1 mutants, suggesting the mutations induce a functional impairment. All fALS mutations impaired nuclear localization of Sod1, which is important for maintaining genomic stability. Consistently, expression of WTSod1, but not of fALS Sod1 mutants, reduced DNA damage, as measured by the comet assay. Altogether, our study sheds light into the effects of fALS Sod1 mutations on inclusion formation, dynamics, and localization as well as on antioxidant response, opening novel avenues for investigating the role of fALS Sod1 mutations in pathogenesis.

  6. Combination of PIM and JAK2 inhibitors synergistically suppresses cell proliferation and overcomes drug resistance of myeloproliferative neoplasms

    PubMed Central

    Greco, Rita; Li, Zhifang; Sun, Fangxian; Barberis, Claude; Tabart, Michel; Patel, Vinod; Schio, Laurent; Hurley, Raelene; Chen, Bo; Cheng, Hong; Lengauer, Christoph; Pollard, Jack; Watters, James; Garcia-Echeverria, Carlos; Wiederschain, Dmitri; Adrian, Francisco; Zhang, JingXin

    2014-01-01

    Inhibitors of JAK2 kinase are emerging as an important treatment modality for myeloproliferative neoplasms (MPN). However, similar to other kinase inhibitors, resistance to JAK2 inhibitors may eventually emerge through a variety of mechanisms. Effective drug combination is one way to enhance therapeutic efficacy and combat resistance against JAK2 inhibitors. To identify potential combination partners for JAK2 compounds in MPN cell lines, we performed pooled shRNA screen targeting 5,000 genes in the presence or absence of JAK2 blockade. One of the top hits identified was MYC, an oncogenic transcription factor that is difficult to inhibit directly, but could be targeted by modulation of upstream regulatory elements such as kinases. We demonstrate herein that PIM kinase inhibitors efficiently suppress MYC protein levels in MPN cell lines. Overexpression of MYC restores the viability of PIM inhibitor-treated cells, revealing causal relationship between MYC down-regulation and cell growth inhibition by PIM compounds. Combination of various PIM inhibitors with a JAK2 inhibitor results in significant synergistic growth inhibition of multiple MPN cancer cell lines and induction of apoptosis. Mechanistic studies revealed strong downregulation of phosphorylated forms of S6 and 4EBP1 by JAK2/PIM inhibitor combination treatment. Finally, such combination was effective in eradicating in vitro JAK2 inhibitor-resistant MPN clones, where MYC is consistently up-regulated. These findings demonstrate that simultaneous suppression of JAK2 and PIM kinase activity by small molecule inhibitors is more effective than either agent alone in suppressing MPN cell growth. Our data suggest that JAK2 and PIM combination might warrant further investigation for the treatment of JAK2-driven hematologic malignancies. PMID:24830942

  7. Single molecule molecular inversion probes for targeted, high-accuracy detection of low-frequency variation

    PubMed Central

    Hiatt, Joseph B.; Pritchard, Colin C.; Salipante, Stephen J.; O'Roak, Brian J.; Shendure, Jay

    2013-01-01

    The detection and quantification of genetic heterogeneity in populations of cells is fundamentally important to diverse fields, ranging from microbial evolution to human cancer genetics. However, despite the cost and throughput advances associated with massively parallel sequencing, it remains challenging to reliably detect mutations that are present at a low relative abundance in a given DNA sample. Here we describe smMIP, an assay that combines single molecule tagging with multiplex targeted capture to enable practical and highly sensitive detection of low-frequency or subclonal variation. To demonstrate the potential of the method, we simultaneously resequenced 33 clinically informative cancer genes in eight cell line and 45 clinical cancer samples. Single molecule tagging facilitated extremely accurate consensus calling, with an estimated per-base error rate of 8.4 × 10−6 in cell lines and 2.6 × 10−5 in clinical specimens. False-positive mutations in the single molecule consensus base-calls exhibited patterns predominantly consistent with DNA damage, including 8-oxo-guanine and spontaneous deamination of cytosine. Based on mixing experiments with cell line samples, sensitivity for mutations above 1% frequency was 83% with no false positives. At clinically informative sites, we identified seven low-frequency point mutations (0.2%–4.7%), including BRAF p.V600E (melanoma, 0.2% alternate allele frequency), KRAS p.G12V (lung, 0.6%), JAK2 p.V617F (melanoma, colon, two lung, 0.3%–1.4%), and NRAS p.Q61R (colon, 4.7%). We anticipate that smMIP will be broadly adoptable as a practical and effective method for accurately detecting low-frequency mutations in both research and clinical settings. PMID:23382536

  8. ^2H(^18F,p)^19F Study at 6 MeV/u

    NASA Astrophysics Data System (ADS)

    Kozub, R. L.; Nesaraja, C. D.; Moazen, B. H.; Scott, J. P.; Bardayan, D. W.; Blackmon, J. C.; Gross, C. J.; Shapira, D.; Smith, M. S.; Batchelder, J. C.; Brune, C. R.; Champagne, A. E.; Sahin, L.; Cizewski, J. A.; Thomas, J. S.; Davinson, T.; Woods, P. J.; Greife, U.; Jewett, C.; Livesay, R. J.; Ma, Z.; Parker, P. D.

    2003-04-01

    The degree to which the (p,α) and (p,γ) reactions destroy ^18F at temperatures ˜1-4 x 10^8 K is important for understanding the synthesis of nuclei in nova explosions and for using ^18F as a monitor of nova mechanisms in gamma ray astronomy. The reactions are dominated by low-lying proton resonances near the ^18F+p threshold (E_x=6.411 MeV excitation energy in ^19Ne). To gain further information about these resonances, we have used the inverse ^18F(d,p)^19F neutron transfer reaction at the Holifield Radioactive Ion Beam Facility to selectively populate corresponding mirror states in ^19F. Proton angular distributions were measured for states in ^19F in the excitation energy range 0-9 MeV. Results and implications for the ^18F+p reactions and nuclear structure will be presented. ^1Supported by DOE. ^2ORNL is managed by UT-Battelle, LLC, for the USDOE.

  9. Epigenetic regulation of NFE2 overexpression in myeloproliferative neoplasms.

    PubMed

    Peeken, Jan C; Jutzi, Jonas S; Wehrle, Julius; Koellerer, Christoph; Staehle, Hans F; Becker, Heiko; Schoenwandt, Elias; Seeger, Thalia S; Schanne, Daniel H; Gothwal, Monika; Ott, Christopher J; Gründer, Albert; Pahl, Heike L

    2018-05-03

    The transcription factor "nuclear factor erythroid 2" (NFE2) is overexpressed in the majority of patients with myeloproliferative neoplasms (MPNs). In murine models, elevated NFE2 levels cause an MPN phenotype with spontaneous leukemic transformation. However, both the molecular mechanisms leading to NFE2 overexpression and its downstream targets remain incompletely understood. Here, we show that the histone demethylase JMJD1C constitutes a novel NFE2 target gene. JMJD1C levels are significantly elevated in polycythemia vera (PV) and primary myelofibrosis patients; concomitantly, global H3K9me1 and H3K9me2 levels are significantly decreased. JMJD1C binding to the NFE2 promoter is increased in PV patients, decreasing both H3K9me2 levels and binding of the repressive heterochromatin protein-1α (HP1α). Hence, JMJD1C and NFE2 participate in a novel autoregulatory loop. Depleting JMJD1C expression significantly reduced cytokine-independent growth of an MPN cell line. Independently, NFE2 is regulated through the epigenetic JAK2 pathway by phosphorylation of H3Y41. This likewise inhibits HP1α binding. Treatment with decitabine lowered H3Y41ph and augmented H3K9me2 levels at the NFE2 locus in HEL cells, thereby increasing HP1α binding, which normalized NFE2 expression selectively in JAK2 V617F -positive cell lines. © 2018 by The American Society of Hematology.

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

    PubMed

    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.

  11. Elevated serum erythropoietin in a patient with polycythaemia vera presenting with Budd-Chiari syndrome

    PubMed Central

    Jones, Catherine; Levy, Yair; Tong, Alex W

    2014-01-01

    Polycythaemia vera (PV) is a clonal disorder of bone marrow stem cells characterised by erythrocytosis. Diagnosis of PV requires exclusion of secondary causes of polycythaemia. It has been held that an elevated erythropoietin (Epo) level strongly indicates secondary erythrocytosis and excludes PV diagnosis, to the extent that the reduced serum Epo level is currently listed as a minor criterion in the WHO classification scheme for PV. However, patients with PV who co-present with Budd-Chiari syndrome have been documented with elevated serum Epo levels. For these patients, identification of the Janus kinase 2 (JAK2) V617F point mutation along with the transient nature of the Epo elevation provides certainty of PV diagnosis, as illustrated by the proband. In this case report, the patient's positive response to cytoreductive therapy (hydroxyurea 500 mg daily) and phlebotomy (750 mL over three phlebotomies) further supports validity of PV diagnosis with elevated Epo. The patient remains on rivaroxaban (Xarelto) for treatment of her portal vein thrombosis. PMID:25452296

  12. 5 CFR 831.617 - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false [Reserved] 831.617 Section 831.617 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE REGULATIONS (CONTINUED) RETIREMENT Survivor Annuities Elections at the Time of Retirement § 831.617 [Reserved] ...

  13. HER2 activating mutations are targets for colorectal cancer treatment.

    PubMed

    Kavuri, Shyam M; Jain, Naveen; Galimi, Francesco; Cottino, Francesca; Leto, Simonetta M; Migliardi, Giorgia; Searleman, Adam C; Shen, Wei; Monsey, John; Trusolino, Livio; Jacobs, Samuel A; Bertotti, Andrea; Bose, Ron

    2015-08-01

    The Cancer Genome Atlas project identified HER2 somatic mutations and gene amplification in 7% of patients with colorectal cancer. Introduction of the HER2 mutations S310F, L755S, V777L, V842I, and L866M into colon epithelial cells increased signaling pathways and anchorage-independent cell growth, indicating that they are activating mutations. Introduction of these HER2 activating mutations into colorectal cancer cell lines produced resistance to cetuximab and panitumumab by sustaining MAPK phosphorylation. HER2 mutants are potently inhibited by low nanomolar doses of the irreversible tyrosine kinase inhibitors neratinib and afatinib. HER2 gene sequencing of 48 cetuximab-resistant, quadruple (KRAS, NRAS, BRAF, and PIK3CA) wild-type (WT) colorectal cancer patient-derived xenografts (PDX) identified 4 PDXs with HER2 mutations. HER2-targeted therapies were tested on two PDXs. Treatment with a single HER2-targeted drug (trastuzumab, neratinib, or lapatinib) delayed tumor growth, but dual HER2-targeted therapy with trastuzumab plus tyrosine kinase inhibitors produced regression of these HER2-mutated PDXs. HER2 activating mutations cause EGFR antibody resistance in colorectal cell lines, and PDXs with HER2 mutations show durable tumor regression when treated with dual HER2-targeted therapy. These data provide a strong preclinical rationale for clinical trials targeting HER2 activating mutations in metastatic colorectal cancer. ©2015 American Association for Cancer Research.

  14. Analysis of the V2 Vasopressin Receptor (V2R) Mutations Causing Partial Nephrogenic Diabetes Insipidus Highlights a Sustainable Signaling by a Non-peptide V2R Agonist*

    PubMed Central

    Makita, Noriko; Sato, Tomohiko; Yajima-Shoji, Yuki; Sato, Junichiro; Manaka, Katsunori; Eda-Hashimoto, Makiko; Ootaki, Masanori; Matsumoto, Naoki; Nangaku, Masaomi; Iiri, Taroh

    2016-01-01

    Disease-causing mutations in G protein-coupled receptor (GPCR) genes, including the V2 vasopressin receptor (V2R) gene, often cause misfolded receptors, leading to a defect in plasma membrane trafficking. A novel V2R mutation, T273M, identified in a boy with partial nephrogenic diabetes insipidus (NDI), shows intracellular localization and partial defects similar to the two mutants we described previously (10). Although non-peptide V2R antagonists have been shown to rescue the membrane localization of V2R mutants, their level of functional rescue is weak. Interestingly, it has been reported that a non-peptide agonist, OPC51803, activates misfolded V2R mutants intracellularly without degradation, thus potentially serving as a therapeutic agent against NDI (14). In our current experiments, however, a peptide antagonist blocked arginine vasopressin (AVP)- or OPC51803-stimulated cAMP accumulation both in COS-7 and MDCK cells, suggesting that OPC51803 mainly stimulates cell surface V2R mutants. In addition, our analyses revealed that OPC51803 works not only as a non-peptide agonist that causes activation/β-arrestin-dependent desensitization of V2R mutants expressed at the plasma membrane but also as a pharmacochaperone that promotes the endoplasmic reticulum-retained mutant maturation and trafficking to the plasma membrane. The ratio of the pharmacochaperone effect to the desensitization effect likely correlates negatively with the residual function of the tested mutants, suggesting that OPC5 has a more favorable effect on the V2R mutants with a less residual function. We speculated that the canceling of the desensitization effect of OPC51803 by the pharmacochaperone effect after long-term treatment may produce sustainable signaling, and thus pharmacochaperone agonists such as OPC51803 may serve as promising therapeutics for NDI caused by misfolded V2R mutants. PMID:27601473

  15. Alzheimer’s Protective A2T Mutation Changes the Conformational Landscape of the Aβ1–42 Monomer Differently Than Does the A2V Mutation

    PubMed Central

    Das, Payel; Murray, Brian; Belfort, Georges

    2015-01-01

    The aggregation of amyloid-β (Aβ) peptides plays a crucial role in the etiology of Alzheimer’s disease (AD). Recently, it has been reported that an A2T mutation in Aβ can protect against AD. Interestingly, a nonpolar A2V mutation also has been found to offer protection against AD in the heterozygous state, although it causes early-onset AD in homozygous carriers. Since the conformational landscape of the Aβ monomer is known to directly contribute to the early-stage aggregation mechanism, it is important to characterize the effects of the A2T and A2V mutations on Aβ1–42 monomer structure. Here, we have performed extensive atomistic replica-exchange molecular dynamics simulations of the solvated wild-type (WT), A2V, and A2T Aβ1–42 monomers. Our simulations reveal that although all three variants remain as collapsed coils in solution, there exist significant structural differences among them at shorter timescales. A2V exhibits an enhanced double-hairpin population in comparison to the WT, similar to those reported in toxic WT Aβ1–42 oligomers. Such double-hairpin formation is caused by hydrophobic clustering between the N-terminus and the central and C-terminal hydrophobic patches. In contrast, the A2T mutation causes the N-terminus to engage in unusual electrostatic interactions with distant residues, such as K16 and E22, resulting in a unique population comprising only the C-terminal hairpin. These findings imply that a single A2X (where X = V or T) mutation in the primarily disordered N-terminus of the Aβ1–42 monomer can dramatically alter the β-hairpin population and switch the equilibrium toward alternative structures. The atomistically detailed, comparative view of the structural landscapes of A2V and A2T variant monomers obtained in this study can enhance our understanding of the mechanistic differences in their early-stage aggregation. PMID:25650940

  16. MET-oncogenic and JAK2-inactivating alterations are independent factors that affect regulation of PD-L1 expression in lung cancer.

    PubMed

    Saigi, Maria; Alburquerque-Bejar, Juan J; McLEER-Florin, Anne; Pereira, Carolina; Pros, Eva; Romero, Octavio A; Baixeras, Nuria; Esteve-Codina, Anna; Nadal, Ernest; Brambilla, Elisabeth; Sanchez-Cespedes, Montse

    2018-06-13

    The blockade of immune checkpoints such as PD-L1 and PD-1 is being exploited therapeutically in several types of malignancies. Here, we aimed to understand the contribution of the genetics of lung cancer (LC) to the ability of tumor cells to escape immunosurveillance checkpoints. Over 150 primary non-small cell lung cancers, including pulmonary sarcomatoid carcinomas, were tested for the levels of HLA-I complex, PD-L1, tumor-infiltrating CD8+ lymphocytes and alterations in main LC genes. Correlations were validated in cancer cell lines using appropriate treatments to activate or inhibit selected pathways. We also performed RNA sequencing to assess changes in gene expression after these treatments Results: MET-oncogenic activation tended to associate with positive PD-L1 immunostaining, whereas STK11 mutations were correlated with negative immunostaining. In MET-altered cancer cells, MET triggered a transcriptional increase of PD-L1 that was independent of the IFNγ-mediated JAK/STAT pathway. The activation of MET also up-regulated other immunosuppressive genes (PDCD1LG2 and SOCS1), and transcripts involved in angiogenesis (VEGFA and NRP1) and in cell proliferation. We also report recurrent inactivating mutations in JAK2 that co-occur with alterations in MET and STK11, which prevented the induction of immunoresponse-related genes following treatment with IFNγ. We show that MET activation promotes the expression of several negative checkpoint regulators of the immunoresponse, including PD-L1. In addition, we report inactivation of JAK2 in LC cells that prevented the response to IFNγ. These alterations are likely to facilitate tumor growth by enabling immune tolerance and may affect the response to immune checkpoint inhibitors. Copyright ©2018, American Association for Cancer Research.

  17. Responses to Cytokines and Interferons that Depend upon JAKs and STATs.

    PubMed

    Stark, George R; Cheon, HyeonJoo; Wang, Yuxin

    2018-01-02

    Many cytokines and all interferons activate members of a small family of kinases (the Janus kinases [JAKs]) and a slightly larger family of transcription factors (the signal transducers and activators of transcription [STATs]), which are essential components of pathways that induce the expression of specific sets of genes in susceptible cells. JAK-STAT pathways are required for many innate and acquired immune responses, and the activities of these pathways must be finely regulated to avoid major immune dysfunctions. Regulation is achieved through mechanisms that include the activation or induction of potent negative regulatory proteins, posttranslational modification of the STATs, and other modulatory effects that are cell-type specific. Mutations of JAKs and STATs can result in gains or losses of function and can predispose affected individuals to autoimmune disease, susceptibility to a variety of infections, or cancer. Here we review recent developments in the biochemistry, genetics, and biology of JAKs and STATs. Copyright © 2018 Cold Spring Harbor Laboratory Press; all rights reserved.

  18. Hyperactivation of JAK1 tyrosine kinase induces stepwise, progressive pruritic dermatitis

    PubMed Central

    Yasuda, Takuwa; Fukada, Toshiyuki; Nishida, Keigo; Nakayama, Manabu; Matsuda, Masashi; Miura, Ikuo; Fukuda, Shinji; Kabashima, Kenji; Nakaoka, Shinji; Bin, Bum-Ho; Kubo, Masato; Hasegawa, Takanori; Ohara, Osamu; Koseki, Haruhiko; Wakana, Shigeharu

    2016-01-01

    Skin homeostasis is maintained by the continuous proliferation and differentiation of epidermal cells. The skin forms a strong but flexible barrier against microorganisms as well as physical and chemical insults; however, the physiological mechanisms that maintain this barrier are not fully understood. Here, we have described a mutant mouse that spontaneously develops pruritic dermatitis as the result of an initial defect in skin homeostasis that is followed by induction of a Th2-biased immune response. These mice harbor a mutation that results in a single aa substitution in the JAK1 tyrosine kinase that results in hyperactivation, thereby leading to skin serine protease overexpression and disruption of skin barrier function. Accordingly, treatment with an ointment to maintain normal skin barrier function protected mutant mice from dermatitis onset. Pharmacological inhibition of JAK1 also delayed disease onset. Together, these findings indicate that JAK1-mediated signaling cascades in skin regulate the expression of proteases associated with the maintenance of skin barrier function and demonstrate that perturbation of these pathways can lead to the development of spontaneous pruritic dermatitis. PMID:27111231

  19. Hyperactivation of JAK1 tyrosine kinase induces stepwise, progressive pruritic dermatitis.

    PubMed

    Yasuda, Takuwa; Fukada, Toshiyuki; Nishida, Keigo; Nakayama, Manabu; Matsuda, Masashi; Miura, Ikuo; Dainichi, Teruki; Fukuda, Shinji; Kabashima, Kenji; Nakaoka, Shinji; Bin, Bum-Ho; Kubo, Masato; Ohno, Hiroshi; Hasegawa, Takanori; Ohara, Osamu; Koseki, Haruhiko; Wakana, Shigeharu; Yoshida, Hisahiro

    2016-06-01

    Skin homeostasis is maintained by the continuous proliferation and differentiation of epidermal cells. The skin forms a strong but flexible barrier against microorganisms as well as physical and chemical insults; however, the physiological mechanisms that maintain this barrier are not fully understood. Here, we have described a mutant mouse that spontaneously develops pruritic dermatitis as the result of an initial defect in skin homeostasis that is followed by induction of a Th2-biased immune response. These mice harbor a mutation that results in a single aa substitution in the JAK1 tyrosine kinase that results in hyperactivation, thereby leading to skin serine protease overexpression and disruption of skin barrier function. Accordingly, treatment with an ointment to maintain normal skin barrier function protected mutant mice from dermatitis onset. Pharmacological inhibition of JAK1 also delayed disease onset. Together, these findings indicate that JAK1-mediated signaling cascades in skin regulate the expression of proteases associated with the maintenance of skin barrier function and demonstrate that perturbation of these pathways can lead to the development of spontaneous pruritic dermatitis.

  20. Prevalence and prognostic impact of allelic imbalances associated with leukemic transformation of Philadelphia chromosome–negative myeloproliferative neoplasms

    PubMed Central

    Krug, Utz O.; Lee, Dhong Hyun Tony; Kawamata, Norihiko; Iwanski, Gabriela B.; Lasho, Terra; Weiss, Tamara; Nowak, Daniel; Koren-Michowitz, Maya; Kato, Motohiro; Sanada, Masashi; Shih, Lee-Yung; Nagler, Arnon; Raynaud, Sophie D.; Müller-Tidow, Carsten; Mesa, Ruben; Haferlach, Torsten; Gilliland, D. Gary; Tefferi, Ayalew; Ogawa, Seishi; Koeffler, H. Phillip

    2010-01-01

    Philadelphia chromosome–negative myeloproliferative neoplasms (MPNs) including polycythemia vera, essential thrombocythemia, and primary myelofibrosis show an inherent tendency for transformation into leukemia (MPN-blast phase), which is hypothesized to be accompanied by acquisition of additional genomic lesions. We, therefore, examined chromosomal abnormalities by high-resolution single nucleotide polymorphism (SNP) array in 88 MPN patients, as well as 71 cases with MPN-blast phase, and correlated these findings with their clinical parameters. Frequent genomic alterations were found in MPN after leukemic transformation with up to 3-fold more genomic changes per sample compared with samples in chronic phase (P < .001). We identified commonly altered regions involved in disease progression including not only established targets (ETV6, TP53, and RUNX1) but also new candidate genes on 7q, 16q, 19p, and 21q. Moreover, trisomy 8 or amplification of 8q24 (MYC) was almost exclusively detected in JAK2V617F− cases with MPN-blast phase. Remarkably, copy number–neutral loss of heterozygosity (CNN-LOH) on either 7q or 9p including homozygous JAK2V617F was related to decreased survival after leukemic transformation (P = .01 and P = .016, respectively). Our high-density SNP-array analysis of MPN genomes in the chronic compared with leukemic stage identified novel target genes and provided prognostic insights associated with the evolution to leukemia. PMID:20068225

  1. The role of JAK/STAT3 signaling pathway on apoptosis of lung adenocarcinoma cell line PC-9 induced by icotinib.

    PubMed

    Zhang, Yuping; Meng, Xia; Shi, Hongyang; Li, Wei; Ming, Zongjuan; Zhong, Yujie; Deng, Wenjing; Zhang, Qiuhong; Fan, Na; Niu, Zequn; Chen, Guo'an; Yang, Shuanying

    2016-01-01

    The aim of this study is to estimate the role of JAK/STAT3 signaling pathway on apoptosis of lung adenocarcinoma induced by icotinib. EGFR mutation was detected in lung adenocarcinoma cell line PC-9 by ARMS assay; The inhibitory rates of cell proliferation of PC-9 cells which were exposed to different concentrations of icotinib (0~100 μMol/L) for different time (24~72 h) respectively were evaluated by MTT assay; Apoptosis of PC-9 cells exposed to different concentrations of icotinib (0, 0.1, 1 and 10 μMol/L) for 48 h were evaluated by TUNEL assay; JAK2, STAT3, Bcl-2, Bax mRNA expressions were evaluated by Real-time PCR assay; The protein levels of P-STAT3 and IL-6 were evaluated by Western-blot assay. Human lung adenocarcinoma cell line PC-9 had an exon 19 deletion mutation in EGFR gene; Followed by treatment of icotinib, the proliferation of PC-9 cells were all inhibited significantly, especially in 48 and 72 h (P<0.01) in all concentrations; The inhibitory rates of cell proliferation in different treating time had statistical significance (P<0.01); Cell apoptosis in different concentrations were increased significantly (P<0.05); Along with the increasing concentrations, gene expression levels of JAK2, STAT3 and Bcl-2 decreased significantly (P<0.05), Bax increased significantly (P<0.05), JAK2/STAT3 ratios increased significantly (P<0.01), and Bcl-2/bax ratios decreased significantly (P<0.01); P-STAT3 and IL-6 protein levels were inhibited significantly in higher concentration. JAK/STAT3 signaling pathway participates in apoptosis of PC-9 cells induced by icotinib. The most likely mechanism is icotinib inhibited the gene expression levels of JAK2, STAT3 and Bcl-2, so with the P-STAT3 and IL-6 protein levels, and mediated gene Bax overexpression.

  2. The role of JAK/STAT3 signaling pathway on apoptosis of lung adenocarcinoma cell line PC-9 induced by icotinib

    PubMed Central

    Zhang, Yuping; Meng, Xia; Shi, Hongyang; Li, Wei; Ming, Zongjuan; Zhong, Yujie; Deng, Wenjing; Zhang, Qiuhong; Fan, Na; Niu, Zequn; Chen, Guo’an; Yang, Shuanying

    2016-01-01

    Objective: The aim of this study is to estimate the role of JAK/STAT3 signaling pathway on apoptosis of lung adenocarcinoma induced by icotinib. Methods: EGFR mutation was detected in lung adenocarcinoma cell line PC-9 by ARMS assay; The inhibitory rates of cell proliferation of PC-9 cells which were exposed to different concentrations of icotinib (0~100 μMol/L) for different time (24~72 h) respectively were evaluated by MTT assay; Apoptosis of PC-9 cells exposed to different concentrations of icotinib (0, 0.1, 1 and 10 μMol/L) for 48 h were evaluated by TUNEL assay; JAK2, STAT3, Bcl-2, Bax mRNA expressions were evaluated by Real-time PCR assay; The protein levels of P-STAT3 and IL-6 were evaluated by Western-blot assay. Results: Human lung adenocarcinoma cell line PC-9 had an exon 19 deletion mutation in EGFR gene; Followed by treatment of icotinib, the proliferation of PC-9 cells were all inhibited significantly, especially in 48 and 72 h (P<0.01) in all concentrations; The inhibitory rates of cell proliferation in different treating time had statistical significance (P<0.01); Cell apoptosis in different concentrations were increased significantly (P<0.05); Along with the increasing concentrations, gene expression levels of JAK2, STAT3 and Bcl-2 decreased significantly (P<0.05), Bax increased significantly (P<0.05), JAK2/STAT3 ratios increased significantly (P<0.01), and Bcl-2/bax ratios decreased significantly (P<0.01); P-STAT3 and IL-6 protein levels were inhibited significantly in higher concentration. Conclusions: JAK/STAT3 signaling pathway participates in apoptosis of PC-9 cells induced by icotinib. The most likely mechanism is icotinib inhibited the gene expression levels of JAK2, STAT3 and Bcl-2, so with the P-STAT3 and IL-6 protein levels, and mediated gene Bax overexpression. PMID:27186296

  3. Hierarchy of protein tyrosine kinases in interleukin-2 (IL-2) signaling: activation of syk depends on Jak3; however, neither Syk nor Lck is required for IL-2-mediated STAT activation.

    PubMed

    Zhou, Y J; Magnuson, K S; Cheng, T P; Gadina, M; Frucht, D M; Galon, J; Candotti, F; Geahlen, R L; Changelian, P S; O'Shea, J J

    2000-06-01

    Interleukin-2 (IL-2) activates several different families of tyrosine kinases, but precisely how these kinases interact is not completely understood. We therefore investigated the functional relationships among Jak3, Lck, and Syk in IL-2 signaling. We first observed that in the absence of Jak3, both Lck and Syk had the capacity to phosphorylate Stat3 and Stat5a. However, neither supported IL-2-induced STAT activation, nor did dominant negative alleles of these kinases inhibit. Moreover, pharmacological abrogation of Lck activity did not inhibit IL-2-mediated phosphorylation of Jak3 and Stat5a. Importantly, ligand-dependent Syk activation was dependent on the presence of catalytically active Jak3, whereas Lck activation was not. Interestingly, Syk functioned as a direct substrate of Jak1 but not Jak3. Additionally, Jak3 phosphorylated Jak1, whereas the reverse was not the case. Taken together, our data support a model in which Lck functions in parallel with Jak3, while Syk functions as a downstream element of Jaks in IL-2 signaling. Jak3 may regulate Syk catalytic activity indirectly via Jak1. However, IL-2-mediated Jak3/Stat activation is not dependent on Lck or Syk. While the essential roles of Jak1 and Jak3 in signaling by gammac-utilizing cytokines are clear, it will be important to dissect the exact contributions of Lck and Syk in mediating the effects of IL-2 and related cytokines.

  4. Impact of the A2V Mutation on the Heterozygous and Homozygous Aβ1-40 Dimer Structures from Atomistic Simulations.

    PubMed

    Nguyen, Phuong H; Sterpone, Fabio; Campanera, Josep M; Nasica-Labouze, Jessica; Derreumaux, Philippe

    2016-06-15

    The A2V mutation was reported to protect from Alzheimer's disease in its heterozygous form and cause an early Alzheimer's disease type dementia in its homozygous form. Experiments showed that the aggregation rate follows the order A2V > WT (wild-type) > A2V-WT. To understand the impact of this mutation, we carried out replica exchange molecular dynamics simulations of Aβ1-40 WT-A2V and A2V-A2V dimers and compared to the WT dimer. Our atomistic simulations reveal that the mean secondary structure remains constant, but there are substantial differences in the intramolecular and intermolecular conformations upon single and double A2V mutation. Upon single mutation, the intrinsic disorder is reduced, the intermolecular potential energies are reduced, the population of intramolecular three-stranded β-sheets is increased, and the number of all α dimer topologies is decreased. Taken together, these results offer an explanation for the reduced aggregation rate of the Aβ1-40 A2V-WT peptides and the protective effect of A2V in heterozygotes.

  5. A multiplex PCR for detection of knockdown resistance mutations, V1016G and F1534C, in pyrethroid-resistant Aedes aegypti.

    PubMed

    Saingamsook, Jassada; Saeung, Atiporn; Yanola, Jintana; Lumjuan, Nongkran; Walton, Catherine; Somboon, Pradya

    2017-10-10

    Mutation of the voltage-gated sodium channel (VGSC) gene, or knockdown resistance (kdr) gene, is an important resistance mechanism of the dengue vector Aedes aegypti mosquitoes against pyrethroids. In many countries in Asia, a valine to glycine substitution (V1016G) and a phenylalanine to cysteine substitution (F1534C) are common in Ae. aegypti populations. The G1016 and C1534 allele frequencies have been increasing in recent years, and hence there is a need to have a simple and inexpensive tool to monitor the alleles in large scale. A multiplex PCR to detect V1016G and F1534C mutations has been developed in the current study. This study utilized primers from previous studies for detecting the mutation at position 1016 and newly designed primers to detect variants at position 1534. The PCR conditions were validated and compared with DNA sequencing using known kdr mutant laboratory strains and field collected mosquitoes. The efficacy of this method was also compared with allele-specific PCR (AS-PCR). The results of our multiplex PCR were in complete agreement with sequencing data and better than the AS-PCR. In addition, the efficiency of two non-toxic DNA staining dyes, Ultrapower™ and RedSafe™, were evaluated by comparing with ethidium bromide (EtBr) and the results were satisfactory. Our multiplex PCR method is highly reliable and useful for implementing vector surveillance in locations where the two alleles co-occur.

  6. Impact of Molecular Genetics on Outcome in Myelofibrosis Patients after Allogeneic Stem Cell Transplantation.

    PubMed

    Kröger, Nicolaus; Panagiota, Victoria; Badbaran, Anita; Zabelina, Tatjana; Triviai, Ioanna; Araujo Cruz, Michelle Maria; Shahswar, Rabia; Ayuk, Francis; Gehlhaar, Marten; Wolschke, Christine; Bollin, Robin; Walter, Carolin; Dugas, Martin; Wiehlmann, Lutz; Lehmann, Ulrich; Koenecke, Christian; Chaturvedi, Anuhar; Alchalby, Haefaa; Stadler, Michael; Eder, Matthias; Christopeit, Max; Göhring, Gudrun; Koenigsmann, Michael; Schlegelberger, Brigitte; Kreipe, Hans-Heinrich; Ganser, Arnold; Stocking, Carol; Fehse, Boris; Thol, Felicitas; Heuser, Michael

    2017-07-01

    Molecular genetics may influence outcome for patients with myelofibrosis. To determine the impact of molecular genetics on outcome after allogeneic stem cell transplantation, we screened 169 patients with primary myelofibrosis (n = 110), post-essential thrombocythemia/polycythemia vera myelofibrosis (n = 46), and myelofibrosis in transformation (n = 13) for mutations in 16 frequently mutated genes. The most frequent mutation was JAK2V617F (n = 101), followed by ASXL1 (n = 49), calreticulin (n = 34), SRSF2 (n = 16), TET2 (n = 10), U2AF1 (n = 11), EZH2 (n = 7), MPL (n = 6), IDH2 (n = 5), IDH1 (n = 4), and CBL (n = 1). The cumulative incidence of nonrelapse mortality (NRM) at 1 year was 21% and of relapse at 5 years 25%. The 5-year rates progression-free (PFS) and overall survival (OS) were and 56%, respectively. In a multivariate analysis CALR mutation was an independent factor for lower NRM (HR, .415; P = .05), improved PFS (HR, .393; P = .01), and OS (HR, .448; P = .03). ASXL1 and IDH2 mutations were independent risk factors for lower PFS (HR, 1.53 [P = .008], and HR, 5.451 [P = .002], respectively), whereas no impact was observed for "triple negative" patients. Molecular genetics, especially CALR, IDH2, and ASXL1 mutations, may thus be useful to predict outcome independently from known clinical risk factors after allogeneic stem cell transplantation for myelofibrosis. Copyright © 2017 The American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

  7. Temporal frequency of knockdown resistance mutations, F1534C and V1016G, in Aedes aegypti in Chiang Mai city, Thailand and the impact of the mutations on the efficiency of thermal fogging spray with pyrethroids.

    PubMed

    Plernsub, Suriya; Saingamsook, Jassada; Yanola, Jintana; Lumjuan, Nongkran; Tippawangkosol, Pongsri; Walton, Catherine; Somboon, Pradya

    2016-10-01

    In Thailand, control of dengue outbreaks is currently attained by the use of space sprays, particularly thermal fogging using pyrethroids, with the aim of killing infected Aedes mosquito vectors in epidemic areas. However, the principal dengue vector, Aedes aegypti, is resistant to pyrethroids conferred mainly by mutations in the voltage-gated sodium channel gene, F1534C and V1016G, termed knockdown resistance (kdr). The objectives of this study were to determine the temporal frequencies of F1534C and V1016G in Ae. aegypti populations in relation to pyrethroid resistance in Chiang Mai city, and to evaluate the impact of the mutations on the efficacy of thermal fogging with the pyrethroid deltamethrin. Larvae and pupae were collected from several areas around Chiang Mai city during 2011-2015 and reared to adulthood for bioassays for deltamethrin susceptibility. These revealed no trend of increasing deltamethrin resistance during the study period (mortality 58.0-69.5%, average 62.8%). This corresponded to no overall change in the frequencies of the C1534 allele (0.55-0.66, average 0.62) and G1016 allele (0.34-0.45, average 0.38), determined using allele specific amplification. Only three genotypes of kdr mutations were detected: C1534 homozygous (VV/CC); G1016/C1534 double heterozygous (VG/FC); and G1016 homozygous (GG/FF) indicating that the F1534C and V1016G mutations occurred on separate haplotypic backgrounds and a lack of recombination between them to date. The F1 progeny females were used to evaluate the efficacy of thermal fogging spray with Damthrin-SP(®) (deltamethrin+S-bioallethrin+piperonyl butoxide) using a caged mosquito bioassay. The thermal fogging spray killed 100% and 61.3% of caged mosquito bioassay placed indoors and outdoors, respectively. The outdoor spray had greater killing effect on C1534 homozygous and had partially effect on double heterozygous mosquitoes, but did not kill any G1016 homozygous mutants living outdoors. As this selection

  8. JAK2 JH2 Fluorescence Polarization Assay and Crystal Structures for Complexes with Three Small Molecules.

    PubMed

    Newton, Ana S; Deiana, Luca; Puleo, David E; Cisneros, José A; Cutrona, Kara J; Schlessinger, Joseph; Jorgensen, William L

    2017-06-08

    A competitive fluorescence polarization (FP) assay is reported for determining binding affinities of probe molecules with the pseudokinase JAK2 JH2 allosteric site. The syntheses of the fluorescent 5 and 6 used in the assay are reported as well as K d results for 10 compounds, including JNJ7706621, NVP-BSK805, and filgotinib (GLPG0634). X-ray crystal structures of JAK2 JH2 in complex with NVP-BSK805, filgotinib, and diaminopyrimidine 8 elucidate the binding poses.

  9. JAK2 JH2 Fluorescence Polarization Assay and Crystal Structures for Complexes with Three Small Molecules

    PubMed Central

    2017-01-01

    A competitive fluorescence polarization (FP) assay is reported for determining binding affinities of probe molecules with the pseudokinase JAK2 JH2 allosteric site. The syntheses of the fluorescent 5 and 6 used in the assay are reported as well as Kd results for 10 compounds, including JNJ7706621, NVP-BSK805, and filgotinib (GLPG0634). X-ray crystal structures of JAK2 JH2 in complex with NVP-BSK805, filgotinib, and diaminopyrimidine 8 elucidate the binding poses. PMID:28626520

  10. Analysis of the V2 Vasopressin Receptor (V2R) Mutations Causing Partial Nephrogenic Diabetes Insipidus Highlights a Sustainable Signaling by a Non-peptide V2R Agonist.

    PubMed

    Makita, Noriko; Sato, Tomohiko; Yajima-Shoji, Yuki; Sato, Junichiro; Manaka, Katsunori; Eda-Hashimoto, Makiko; Ootaki, Masanori; Matsumoto, Naoki; Nangaku, Masaomi; Iiri, Taroh

    2016-10-21

    Disease-causing mutations in G protein-coupled receptor (GPCR) genes, including the V2 vasopressin receptor (V2R) gene, often cause misfolded receptors, leading to a defect in plasma membrane trafficking. A novel V2R mutation, T273M, identified in a boy with partial nephrogenic diabetes insipidus (NDI), shows intracellular localization and partial defects similar to the two mutants we described previously (10). Although non-peptide V2R antagonists have been shown to rescue the membrane localization of V2R mutants, their level of functional rescue is weak. Interestingly, it has been reported that a non-peptide agonist, OPC51803, activates misfolded V2R mutants intracellularly without degradation, thus potentially serving as a therapeutic agent against NDI (14). In our current experiments, however, a peptide antagonist blocked arginine vasopressin (AVP)- or OPC51803-stimulated cAMP accumulation both in COS-7 and MDCK cells, suggesting that OPC51803 mainly stimulates cell surface V2R mutants. In addition, our analyses revealed that OPC51803 works not only as a non-peptide agonist that causes activation/β-arrestin-dependent desensitization of V2R mutants expressed at the plasma membrane but also as a pharmacochaperone that promotes the endoplasmic reticulum-retained mutant maturation and trafficking to the plasma membrane. The ratio of the pharmacochaperone effect to the desensitization effect likely correlates negatively with the residual function of the tested mutants, suggesting that OPC5 has a more favorable effect on the V2R mutants with a less residual function. We speculated that the canceling of the desensitization effect of OPC51803 by the pharmacochaperone effect after long-term treatment may produce sustainable signaling, and thus pharmacochaperone agonists such as OPC51803 may serve as promising therapeutics for NDI caused by misfolded V2R mutants. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  11. V67L Mutation Fills an Internal Cavity To Stabilize RecA Mtu Intein

    DOE PAGES

    Zwarycz, Allison S.; Fossat, Martin; Akanyeti, Otar; ...

    2017-05-10

    Inteins mediate protein splicing, which has found extensive applications in protein science and biotechnology. In the Mycobacterium tuberculosis RecA mini–mini intein (ΔΔIhh), a single valine to leucine substitution at position 67 (V67L) dramatically increases intein stability and activity. However, crystal structures show that the V67L mutation causes minimal structural rearrangements, with a root-mean-square deviation of 0.2 Å between ΔΔIhh-V67 and ΔΔIhh-L67. Thus, the structural mechanisms for V67L stabilization and activation remain poorly understood. In this paper, we used intrinsic tryptophan fluorescence, high-pressure nuclear magnetic resonance (NMR), and molecular dynamics (MD) simulations to probe the structural basis of V67L stabilization ofmore » the intein fold. Guanidine hydrochloride denaturation monitored by fluorescence yielded free energy changes (ΔG f°) of -4.4 and -6.9 kcal mol –1 for ΔΔIhh-V67 and ΔΔIhh-L67, respectively. High-pressure NMR showed that ΔΔIhh-L67 is more resistant to pressure-induced unfolding than ΔΔIhh-V67 is. The change in the volume of folding (ΔV f) was significantly larger for V67 (71 ± 2 mL mol –1) than for L67 (58 ± 3 mL mol –1) inteins. The measured difference in ΔV f (13 ± 3 mL mol –1) roughly corresponds to the volume of the additional methylene group for Leu, supporting the notion that the V67L mutation fills a nearby cavity to enhance intein stability. In addition, we performed MD simulations to show that V67L decreases side chain dynamics and conformational entropy at the active site. Finally, it is plausible that changes in cavities in V67L can also mediate allosteric effects to change active site dynamics and enhance intein activity.« less

  12. V67L Mutation Fills an Internal Cavity To Stabilize RecA Mtu Intein

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zwarycz, Allison S.; Fossat, Martin; Akanyeti, Otar

    Inteins mediate protein splicing, which has found extensive applications in protein science and biotechnology. In the Mycobacterium tuberculosis RecA mini–mini intein (ΔΔIhh), a single valine to leucine substitution at position 67 (V67L) dramatically increases intein stability and activity. However, crystal structures show that the V67L mutation causes minimal structural rearrangements, with a root-mean-square deviation of 0.2 Å between ΔΔIhh-V67 and ΔΔIhh-L67. Thus, the structural mechanisms for V67L stabilization and activation remain poorly understood. In this paper, we used intrinsic tryptophan fluorescence, high-pressure nuclear magnetic resonance (NMR), and molecular dynamics (MD) simulations to probe the structural basis of V67L stabilization ofmore » the intein fold. Guanidine hydrochloride denaturation monitored by fluorescence yielded free energy changes (ΔG f°) of -4.4 and -6.9 kcal mol –1 for ΔΔIhh-V67 and ΔΔIhh-L67, respectively. High-pressure NMR showed that ΔΔIhh-L67 is more resistant to pressure-induced unfolding than ΔΔIhh-V67 is. The change in the volume of folding (ΔV f) was significantly larger for V67 (71 ± 2 mL mol –1) than for L67 (58 ± 3 mL mol –1) inteins. The measured difference in ΔV f (13 ± 3 mL mol –1) roughly corresponds to the volume of the additional methylene group for Leu, supporting the notion that the V67L mutation fills a nearby cavity to enhance intein stability. In addition, we performed MD simulations to show that V67L decreases side chain dynamics and conformational entropy at the active site. Finally, it is plausible that changes in cavities in V67L can also mediate allosteric effects to change active site dynamics and enhance intein activity.« less

  13. AURKA F31I Polymorphism and Breast Cancer Risk in BRCA1 and BRCA2 Mutation Carriers: A CIMBA study

    PubMed Central

    Couch, Fergus J.; Sinilnikova, Olga; Vierkant, Robert A; Pankratz, V. Shane; Fredericksen, Zachary S.; Stoppa-Lyonnet, Dominique; Coupier, Isabelle; Hughes, David; Hardouin, Agnès; Berthet, Pascaline; Peock, Susan; Cook, Margaret; Baynes, Caroline; Hodgson, Shirley; Morrison, Patrick J.; Porteous, Mary E.; Jakubowska, Anna; Lubinski, Jan; Gronwald, Jacek; Spurdle, Amanda B.; Schmutzler, Rita; Versmold, Beatrix; Engel, Christoph; Meindl, Alfons; Sutter, Christian; Horst, Jurgen; Schaefer, Dieter; Offit, Kenneth; Kirchhoff, Tomas; Andrulis, Irene L.; Ilyushik, Eduard; Glendon, Gordon; Devilee, Peter; Vreeswijk, Maaike P.G.; Vasen, Hans F.A.; Borg, Ake; Backenhorn, Katja; Struewing, Jeffery P.; Greene, Mark H.; Neuhausen, Susan L.; Rebbeck, Timothy R.; Nathanson, Katherine; Domchek, Susan; Wagner, Theresa; Garber, Judy E.; Szabo, Csilla; Zikan, Michal; Foretova, Lenka; Olson, Janet E.; Sellers, Thomas A.; Lindor, Noralane; Nevanlinna, Heli; Tommiska, Johanna; Aittomaki, Kristiina; Hamann, Ute; Rashid, Muhammad U.; Torres, Diana; Simard, Jacques; Durocher, Francine; Guenard, Frederic; Lynch, Henry T.; Isaacs, Claudine; Weitzel, Jeffrey; Olopade, Olufunmilayo I.; Narod, Steven; Daly, Mary B.; Godwin, Andrew K.; Tomlinson, Gail; Easton, Douglas F.; Chenevix-Trench, Georgia; Antoniouon, Antonis C.

    2009-01-01

    The AURKA oncogene is associated with abnormal chromosome segregation and aneuploidy and predisposition to cancer. Amplification of AURKA has been detected at higher frequency in tumors from BRCA1 and BRCA2 mutation carriers than in sporadic breast tumors, suggesting that overexpression of AURKA and inactivation of BRCA1 and BRCA2 co-operate during tumor development and progression. The F31I polymorphism in AURKA has been associated with breast cancer risk in the homozygous state in prior studies. We evaluated whether the AURKA F31I polymorphism modifies breast cancer risk in BRCA1 and BRCA2 mutation carriers from the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA). CIMBA was established to provide sufficient statistical power through increased numbers of mutation carriers to identify polymorphisms that act as modifiers of cancer risk and can refine breast cancer risk estimates in BRCA1 and BRCA2 mutation carriers. A total of 4935 BRCA1 and 2241 BRCA2 mutation carriers and 11 individuals carrying both BRCA1 and BRCA2 mutations were genotyped for F31I. Overall, homozygosity for the 31I allele was not significantly associated with breast cancer risk in BRCA1 and BRCA2 carriers combined (HR = 0.91; 95% CI 0.77-1.06). Similarly, no significant association was seen in BRCA1 (HR = 0.90; 95% CI 0.75-1.08) or BRCA2 carriers (HR = 0.93; 95% CI 0.67-1.29) or when assessing the modifying effects of either bilateral prophylactic oophorectomy or menopausal status of BRCA1 and BRCA2 carriers. In summary, the F31I polymorphism in AURKA is not associated with a modified risk of breast cancer in BRCA1 and BRCA2 carriers. PMID:17627006

  14. Identification of azabenzimidazoles as potent JAK1 selective inhibitors.

    PubMed

    Vasbinder, Melissa M; Alimzhanov, Marat; Augustin, Martin; Bebernitz, Geraldine; Bell, Kirsten; Chuaqui, Claudio; Deegan, Tracy; Ferguson, Andrew D; Goodwin, Kelly; Huszar, Dennis; Kawatkar, Aarti; Kawatkar, Sameer; Read, Jon; Shi, Jie; Steinbacher, Stefan; Steuber, Holger; Su, Qibin; Toader, Dorin; Wang, Haixia; Woessner, Richard; Wu, Allan; Ye, Minwei; Zinda, Michael

    2016-01-01

    We have identified a class of azabenzimidazoles as potent and selective JAK1 inhibitors. Investigations into the SAR are presented along with the structural features required to achieve selectivity for JAK1 versus other JAK family members. An example from the series demonstrated highly selective inhibition of JAK1 versus JAK2 and JAK3, along with inhibition of pSTAT3 in vivo, enabling it to serve as a JAK1 selective tool compound to further probe the biology of JAK1 selective inhibitors. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. A mouse model for the cystic fibrosis delta F508 mutation.

    PubMed Central

    van Doorninck, J H; French, P J; Verbeek, E; Peters, R H; Morreau, H; Bijman, J; Scholte, B J

    1995-01-01

    Most cystic fibrosis (CF) patients produce a mutant form (delta F508) of the cystic fibrosis transmembrane conductance regulator (CFTR), which is not properly processed in normal cells but is active as a chloride channel in several experimental systems. We used a double homologous recombination ('Hit and Run') procedure to generate a mouse model for the delta F508 mutation. Targeted embryonic stem (ES) cells (Hit clones) were found; of these either 80 or 20% of the clones had lost the delta F508 mutation, depending on the distance between the linearization site in the targeting construct and the delta F508 mutation. Correctly targeted clones underwent a second selection step resulting in ES cell clones (Run clones) heterozygous for the delta F508 mutation with an efficiency of 2-7%. Chimeric mice were generated and offspring homozygous for the delta F508 mutation showed electrophysiological abnormalities in nasal epithelium, gallbladder and in the intestine, and histological abnormalities in the intestine, typical of CF. Our data suggest that the delta F508 mice have residual delta F508 CFTR activity which would explain the mild pathology of the delta F508 mice. The delta F508 mouse may provide a useful model for the study of the processing defect of delta F508 CFTR and for the development of novel therapeutic approaches based on circumvention of the processing block. Images PMID:7556083

  16. First somatic mutation of E2F1 in a critical DNA binding residue discovered in well-differentiated papillary mesothelioma of the peritoneum

    PubMed Central

    2011-01-01

    Background Well differentiated papillary mesothelioma of the peritoneum (WDPMP) is a rare variant of epithelial mesothelioma of low malignancy potential, usually found in women with no history of asbestos exposure. In this study, we perform the first exome sequencing of WDPMP. Results WDPMP exome sequencing reveals the first somatic mutation of E2F1, R166H, to be identified in human cancer. The location is in the evolutionarily conserved DNA binding domain and computationally predicted to be mutated in the critical contact point between E2F1 and its DNA target. We show that the R166H mutation abrogates E2F1's DNA binding ability and is associated with reduced activation of E2F1 downstream target genes. Mutant E2F1 proteins are also observed in higher quantities when compared with wild-type E2F1 protein levels and the mutant protein's resistance to degradation was found to be the cause of its accumulation within mutant over-expressing cells. Cells over-expressing wild-type E2F1 show decreased proliferation compared to mutant over-expressing cells, but cell proliferation rates of mutant over-expressing cells were comparable to cells over-expressing the empty vector. Conclusions The R166H mutation in E2F1 is shown to have a deleterious effect on its DNA binding ability as well as increasing its stability and subsequent accumulation in R166H mutant cells. Based on the results, two compatible theories can be formed: R166H mutation appears to allow for protein over-expression while minimizing the apoptotic consequence and the R166H mutation may behave similarly to SV40 large T antigen, inhibiting tumor suppressive functions of retinoblastoma protein 1. PMID:21955916

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

    PubMed

    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.

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

    PubMed

    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.

  19. Postconditioning inhibits myocardial apoptosis during prolonged reperfusion via a JAK2-STAT3-Bcl-2 pathway

    PubMed Central

    2011-01-01

    Background Postconditioning (PostC) inhibits myocardial apoptosis after ischemia-reperfusion (I/R) injury. The JAK2-STAT3 pathway has anti-apoptotic effects and plays an essential role in the late protection of preconditioning. Our aim was to investigate the anti-apoptotic effect of PostC after prolonged reperfusion and the role of the JAK2-STAT3 pathway in the anti-apoptotic effect of PostC. Methods Wistar rats were subjected to 30 minutes ischemia and 2 or 24 hours (h) reperfusion, with or without PostC (three cycles of 10 seconds reperfusion and 10 seconds reocclusion at the onset of reperfusion). Separate groups of rats were treated with a JAK2 inhibitor (AG490) or a PI3K inhibitor (wortmannin) 5 minutes before PostC. Immunohistochemistry was used to analyze Bcl-2 protein levels after reperfusion. mRNA levels of Bcl-2 were detected by qRT-PCR. TTC staining was used to detect myocardial infarction size. Myocardial apoptosis was evaluated by TUNEL staining. Western-blot was used to detect p-STAT3 and p-Akt levels after reperfusion. Results There was more myocardial apoptosis at 24 h vs 2 h after reperfusion in all groups. PostC significantly reduced myocardial apoptosis and elevated Bcl-2 levels at both 2 and 24 hours after reperfusion. PostC increased p-STAT3 and p-Akt levels after reperfusion. Administration of AG490 reduced p-STAT3 and p-Akt levels and attenuated the anti-apoptotic effect of PostC. Wortmannin also reduced p-Akt levels and attenuated the anti-apoptotic effect of PostC but had no effect on p-STAT3 levels. AG490 abrogated the up-regulation of Bcl-2 by PostC. Conclusion PostC may reduce myocardial apoptosis during prolonged reperfusion via a JAK2-STAT3-Bcl-2 pathway. As a downstream target of JAK2 signaling, activation of PI3K/Akt pathway may be necessary in the protection of PostC. PMID:21810244

  20. Origin and migration of an Afrikaner founder mutation FHAfrikaner-2 (V408M) causing familial hypercholesterolemia.

    PubMed

    Defesche, J C; Van Diermen, D E; Hayden, M R; Kastelein, J P

    1996-04-01

    Of the three major Afrikaner founder mutations, responsible for more than 95% of Familial Hypercholesterolemia cases among South African Afrikaners, one mutation called V408M or FHAfrikaner-2 was identified in the Netherlands. Subsequent analysis of a group of Canadian patients of Dutch origin with Familial Hypercholesterolemia revealed the presence of this mutation in western Canada. The founder of the Canadian family, suffering from Familial Hypercholesterolemia caused by V408M, was traced back to Andijk, a small village in the northwestern part of the Netherlands, a region from where the first settlers to South Africa departed in the 17th and 18th century. Further genealogical investigation demonstrated that the mutation must have been introduced in the Netherlands by an individual from northern Germany. Haplotype analysis resulted in the identification of the common haplotypes TaqI-, StuI+, AvaII+, NcoI+ in Canadian as well as Dutch patients with V408M. The results of this study further support the hypothesis that Dutch settlers introduced this Afrikaner founder mutation in the Afrikaner population in South Africa. After a recombinational event in the mutated gene, the mutation was also introduced in western Canada.

  1. The JAK2/STAT5 signaling pathway as a potential therapeutic target in canine mastocytoma

    PubMed Central

    Keller, Alexandra; Wingelhofer, Bettina; Peter, Barbara; Bauer, Karin; Berger, Daniela; Gamperl, Susanne; Reifinger, Martin; Cerny-Reiterer, Sabine; Moriggl, Richard; Willmann, Michael; Valent, Peter; Hadzijusufovic, Emir

    2018-01-01

    Background Mastocytoma are frequently diagnosed cutaneous neoplasms in dogs. In non-resectable mastocytoma patients, novel targeted drugs are often applied. The transcription factor STAT5 has been implicated in the survival of human neoplastic mast cells (MC). Our study evaluated the JAK2/STAT5 pathway as a novel target in canine mastocytoma. Materials and Methods We employed inhibitors of JAK2 (R763, TG101348, AZD1480, ruxolitinib) and STAT5 (pimozide, piceatannol) and evaluated their effects on 2 mastocytoma cell lines, C2 and NI-1. Results Activated JAK2 and STAT5 were detected in both cell lines. The drugs applied were found to inhibit proliferation and survival in these cells with the following rank-order of potency: R763 > TG101348 > AZD1480 > pimozide > ruxolitinib > piceatannol. Moreover, synergistic anti-neoplastic effects were obtained by combining pimozide with KIT-targeting drugs (toceranib, masitinib, nilotinib, midostaurin) in NI-1 cells. Conclusion The JAK2/STAT5 pathway is a novel potential target of therapy in canine mastocytoma. PMID:28397975

  2. Gα73B is a downstream effector of JAK/STAT signalling and a regulator of Rho1 in Drosophila haematopoiesis.

    PubMed

    Bausek, Nina; Zeidler, Martin P

    2014-01-01

    JAK/STAT signalling regulates many essential developmental processes including cell proliferation and haematopoiesis, whereas its inappropriate activation is associated with the majority of myeloproliferative neoplasias and numerous cancers. Furthermore, high levels of JAK/STAT pathway signalling have also been associated with enhanced metastatic invasion by cancerous cells. Strikingly, gain-of-function mutations in the single Drosophila JAK homologue, Hopscotch, result in haemocyte neoplasia, inappropriate differentiation and the formation of melanised haemocyte-derived 'tumour' masses; phenotypes that are partly orthologous to human gain-of-function JAK2-associated pathologies. Here we show that Gα73B, a novel JAK/STAT pathway target gene, is necessary for JAK/STAT-mediated tumour formation in flies. In addition, although Gα73B does not affect haemocyte differentiation, it does regulate haemocyte morphology and motility under non-pathological conditions. We show that Gα73B is required for constitutive, but not injury-induced, activation of Rho1 and for the localisation of Rho1 into filopodia upon haemocyte activation. Consistent with these results, we also show that Rho1 interacts genetically with JAK/STAT signalling, and that wild-type levels of Rho1 are necessary for tumour formation. Our findings link JAK/STAT transcriptional outputs, Gα73B activity and Rho1-dependent cytoskeletal rearrangements and cell motility, therefore connecting a pathway associated with cancer with a marker indicative of invasiveness. As such, we suggest a mechanism by which JAK/STAT pathway signalling may promote metastasis.

  3. Cardiomyopathy mutation (F88L) in troponin T abolishes length dependency of myofilament Ca2+ sensitivity.

    PubMed

    Reda, Sherif M; Chandra, Murali

    2018-05-18

    Recent clinical studies have revealed a new hypertrophic cardiomyopathy-associated mutation (F87L) in the central region of human cardiac troponin T (TnT). However, despite its implication in several incidences of sudden cardiac death in young and old adults, whether F87L is associated with cardiac contractile dysfunction is unknown. Because the central region of TnT is important for modulating the muscle length-mediated recruitment of new force-bearing cross-bridges (XBs), we hypothesize that the F87L mutation causes molecular changes that are linked to the length-dependent activation of cardiac myofilaments. Length-dependent activation is important because it contributes significantly to the Frank-Starling mechanism, which enables the heart to vary stroke volume as a function of changes in venous return. We measured steady-state and dynamic contractile parameters in detergent-skinned guinea pig cardiac muscle fibers reconstituted with recombinant guinea pig wild-type TnT (TnT WT ) or the guinea pig analogue (TnT F88L ) of the human mutation at two different sarcomere lengths (SLs): short (1.9 µm) and long (2.3 µm). TnT F88L increases pCa 50 (-log [Ca 2+ ] free required for half-maximal activation) to a greater extent at short SL than at long SL; for example, pCa 50 increases by 0.25 pCa units at short SL and 0.17 pCa units at long SL. The greater increase in pCa 50 at short SL leads to the abolishment of the SL-dependent increase in myofilament Ca 2+ sensitivity (ΔpCa 50 ) in TnT F88L fibers, ΔpCa 50 being 0.10 units in TnT WT fibers but only 0.02 units in TnT F88L fibers. Furthermore, at short SL, TnT F88L attenuates the negative impact of strained XBs on force-bearing XBs and augments the magnitude of muscle length-mediated recruitment of new force-bearing XBs. Our findings suggest that the TnT F88L -mediated effects on cardiac thin filaments may lead to a negative impact on the Frank-Starling mechanism. © 2018 Reda and Chandra.

  4. Inhibition of cerebral ischemia/reperfusion injury-induced apoptosis: nicotiflorin and JAK2/STAT3 pathway.

    PubMed

    Hu, Guang-Qiang; Du, Xi; Li, Yong-Jie; Gao, Xiao-Qing; Chen, Bi-Qiong; Yu, Lu

    2017-01-01

    Nicotiflorin is a flavonoid extracted from Carthamus tinctorius. Previous studies have shown its cerebral protective effect, but the mechanism is undefined. In this study, we aimed to determine whether nicotiflorin protects against cerebral ischemia/reperfusion injury-induced apoptosis through the JAK2/STAT3 pathway. The cerebral ischemia/reperfusion injury model was established by middle cerebral artery occlusion/reperfusion. Nicotiflorin (10 mg/kg) was administered by tail vein injection. Cell apoptosis in the ischemic cerebral cortex was examined by hematoxylin-eosin staining and terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Bcl-2 and Bax expression levels in ischemic cerebral cortex were examined by immunohistochemial staining. Additionally, p-JAK2, p-STAT3, Bcl-2, Bax, and caspase-3 levels in ischemic cerebral cortex were examined by western blot assay. Nicotiflorin altered the shape and structure of injured neurons, decreased the number of apoptotic cells, down-regulates expression of p-JAK2, p-STAT3, caspase-3, and Bax, decreased Bax immunoredactivity, and increased Bcl-2 protein expression and immunoreactivity. These results suggest that nicotiflorin protects against cerebral ischemia/reperfusion injury-induced apoptosis via the JAK2/STAT3 pathway.

  5. Cancer genes mutation profiling in calcifying epithelial odontogenic tumour.

    PubMed

    de Sousa, Sílvia Ferreira; Diniz, Marina Gonçalves; França, Josiane Alves; Fontes Pereira, Thaís Dos Santos; Moreira, Rennan Garcias; Santos, Jean Nunes Dos; Gomez, Ricardo Santiago; Gomes, Carolina Cavalieri

    2018-03-01

    To identify calcifying epithelial odontogenic tumour (CEOT) mutations in oncogenes and tumour suppressor genes. A panel of 50 genes commonly mutated in cancer was sequenced in CEOT by next-generation sequencing. Sanger sequencing was used to cover the region of the frameshift deletion identified in one sample. Missense single nucleotide variants (SNVs) with minor allele frequency (MAF) <1% were detected in PTEN , MET and JAK3 . A frameshift deletion in CDKN2A occurred in association with a missense mutation in the same gene region, suggesting a second hit in the inactivation of this gene. APC, KDR, KIT, PIK3CA and TP53 missense SNVs were identified; however, these are common SNVs, showing MAF >1%. CEOT harbours mutations in the tumour suppressor PTEN and CDKN2A and in the oncogenes JAK3 and MET . As these mutations occurred in only one case each, they are probably not driver mutations for these tumours. © 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.

  6. Prognostication in Philadelphia Chromosome Negative Myeloproliferative Neoplasms: a Review of the Recent Literature.

    PubMed

    Zhou, Amy; Afzal, Amber; Oh, Stephen T

    2017-10-01

    The prognosis for patients with Philadelphia chromosome (Ph)-negative myeloproliferative neoplasms (MPNs) is highly variable. All Ph-negative MPNs carry an increased risk for thrombotic complications, bleeding, and leukemic transformation. Several clinical, biological, and molecular prognostic factors have been identified in recent years, which provide important information in guiding management of patients with Ph-negative MPNs. In this review, we critically evaluate the recent published literature and discuss important new developments in clinical and molecular factors that impact survival, disease transformation, and thrombosis in patients with polycythemia vera, essential thrombocythemia, and primary myelofibrosis. Recent studies have identified several clinical factors and non-driver mutations to have prognostic impact on Ph-negative MPNs independent of conventional risk stratification and prognostic models. In polycythemia vera (PV), leukocytosis, abnormal karyotype, phlebotomy requirement on hydroxyurea, increased bone marrow fibrosis, and mutations in ASXL1, SRSF2, and IDH2 were identified as additional adverse prognostic factors. In essential thrombocythemia (ET), JAK2 V617F mutation, splenomegaly, and mutations in SH2B3, SF3B1, U2AF1, TP53, IDH2, and EZH2 were found to be additional negative prognostic factors. Bone marrow fibrosis and mutations in ASXL1, SRSF2, EZH2, and IDH1/2 have been found to be additional prognostic factors in primary myelofibrosis (PMF). CALR mutations appear to be a favorable prognostic factor in PMF, which has not been clearly demonstrated in ET. The prognosis for patients with PV, ET, and PMF is dependent upon the presence or absence of several clinical, biological, and molecular risk factors. The significance of additional risk factors identified in these recent studies will need further validation in prospective studies to determine how they may be best utilized in the management of these disorders.

  7. Eriodictyol Attenuates Myocardial Ischemia-Reperfusion Injury through the Activation of JAK2

    PubMed Central

    Li, Defang; Lu, Ning; Han, Jichun; Chen, Xiaoyu; Hao, Wenjin; Xu, Wenjuan; Liu, Xiaona; Ye, Lei; Zheng, Qiusheng

    2018-01-01

    Myocardial ischemia-reperfusion (I/R) injury remains the leading risk factor of disability and mortality worldwide. In this study, the myocardial protective effect of eriodictyol (EDT) and the underlying mechanism in an ex vivo model of global myocardial I/R was investigated. After treatment with different concentrations of EDT, the decreased hemodynamic parameters induced by myocardial I/R injury were significantly attenuated by EDT. The elevated levels of IL-6, CRP, IL-8, and TNF-α were effectively reduced by EDT treatment. EDT also remarkably suppressed the levels of Bax and cleaved Caspase-3, and up-regulated the level of Bcl-2 in cardiac tissues from EDT-treated groups. Further studies showed that EDT could increase the levels of p-JAK2 and p-STAT3 in cardiac tissues. Meanwhile, treatment of AG490, a specific inhibitor of JAK2, abolished the protective effect of EDT on hemodynamic parameters, myocardial inflammation and myocardial cell apoptosis induced by I/R injury. These results demonstrated that EDT could protect against myocardial I/R injury through the activation of JAK2, providing a potential treatment with EDT during myocardial I/R injury. PMID:29441020

  8. Synthesis and characterization of new fluoride-containing manganese vanadates A{sub 2}Mn{sub 2}V{sub 2}O{sub 7}F{sub 2} (A=Rb, Cs) and Mn{sub 2}VO{sub 4}F

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sanjeewa, Liurukara D.; McGuire, Michael A.; Smith Pellizzeri, Tiffany M.

    2016-09-15

    Large single crystals of A{sub 2}Mn{sub 2}V{sub 2}O{sub 7}F{sub 2} (A=Rb, Cs) and Mn{sub 2}VO{sub 4}F were grown using a high-temperature (~600 °C) hydrothermal technique. Single crystal X-ray diffraction and powder X-ray diffraction were utilized to characterize the structures, which both possess MnO{sub 4}F{sub 2} building blocks. The A{sub 2}Mn{sub 2}V{sub 2}O{sub 7}F{sub 2} series crystallizes as a new structure type in space group Pbcn (No. 60), Z=4 (Rb{sub 2}Mn{sub 2}V{sub 2}O{sub 7}F{sub 2}: a=7.4389(17) Å, b=11.574(3) Å, c=10.914(2) Å; Cs{sub 2}Mn{sub 2}V{sub 2}O{sub 7}F{sub 2}: a=7.5615(15) Å, b=11.745(2) Å, c=11.127(2) Å). The structure is composed of zigzag chains ofmore » edge-sharing MnO{sub 4}F{sub 2} units running along the a-axis, and interconnected through V{sub 2}O{sub 7} pyrovanadate groups. Temperature dependent magnetic susceptibility measurements on this interesting one-dimensional structural feature based on Mn{sup 2+} indicated that Cs{sub 2}Mn{sub 2}V{sub 2}O{sub 7}F{sub 2} is antiferromagnetic with a Neél temperature, T{sub N}=~3 K and a Weiss constant, θ, of −11.7(1) K. Raman and infrared spectra were also analyzed to identify the fundamental V–O vibrational modes in Cs{sub 2}Mn{sub 2}V{sub 2}O{sub 7}F{sub 2}. Mn{sub 2}(VO{sub 4})F crystalizes in the monoclinic space group of C2/c (no. 15), Z=8 with unit cell parameters of a=13.559(2) Å, b=6.8036(7) Å, c=10.1408(13) Å and β=116.16(3)°. The structure is associated with those of triplite and wagnerite. Dynamic fluorine disorder gives rise to complex alternating chains of five-and six-coordinate Mn{sup 2+}. These interpenetrating chains are additionally connected through isolated VO{sub 4} tetrahedra to form the condensed structure. - Graphical abstract: New vanadate fluorides A{sub 2}Mn{sub 2}V{sub 2}O{sub 7}F{sub 2} (A=Rb, Cs) and Mn{sub 2}(VO{sub 4})F have been synthesized hydrothermally. Upon cooling, the one-dimensional Mn(II) substructure results in

  9. Prevalence, mutation patterns, and effects on protease inhibitor susceptibility of the L76V mutation in HIV-1 protease.

    PubMed

    Young, Thomas P; Parkin, Neil T; Stawiski, Eric; Pilot-Matias, Tami; Trinh, Roger; Kempf, Dale J; Norton, Michael

    2010-11-01

    Patterns of HIV-1 protease inhibitor (PI) resistance-associated mutations (RAMs) and effects on PI susceptibility associated with the L76V mutation were studied in a large database. Of 20,501 sequences with ≥1 PI RAM, 3.2% contained L76V; L76V was alone in 0.04%. Common partner mutations included M46I, I54V, V82A, I84V, and L90M. L76V was associated with a 2- to 6-fold decrease in susceptibility to lopinavir, darunavir, amprenavir, and indinavir and a 7- to 8-fold increase in susceptibility to atazanavir and saquinavir.

  10. Selective JAK inhibitors in development for rheumatoid arthritis.

    PubMed

    Norman, Peter

    2014-08-01

    The JAK kinases are a family of four tyrosine receptor kinases that play a pivotal role in cytokine receptor signalling pathways via their interaction with signal transducers and activators of transcription proteins. Selective inhibitors of JAK kinases are viewed as of considerable potential as disease-modifying anti-inflammatory drugs for the treatment of rheumatoid arthritis. This article provides a review of the clinical development and available clinical results for those JAK inhibitors currently under investigation. Phase II data for four JAK inhibitors (baricitinib, decernotinib, filgotinib and INCB-039110) are contrasted with that reported for the recently approved JAK inhibitor tofacitinib. The preclinical data on these, in addition to peficitinib, ABT-494, INCB-047986 and AC-410 are also discussed, as are some of the inhibitors in preclinical development. JAK inhibitors are effective in the treatment of rheumatoid arthritis as evidenced by several inhibitors enabling the majority of treated patients to achieve ACR20 responses, with baricitinib and INCB-039110 both effective when administered once daily. JAK inhibitors differ in isoform specificity profiles, with good efficacy achievable by selective inhibition of either JAK1 (filgotinib or INCB-039110) or JAK3 (decernotinib). It remains to be seen what selectivity provides the optimal side-effect profile and to what extent inhibition of JAK2 should be avoided.

  11. JAK3 as an Emerging Target for Topical Treatment of Inflammatory Skin Diseases.

    PubMed

    Alves de Medeiros, Ana Karina; Speeckaert, Reinhart; Desmet, Eline; Van Gele, Mireille; De Schepper, Sofie; Lambert, Jo

    2016-01-01

    The recent interest and elucidation of the JAK/STAT signaling pathway created new targets for the treatment of inflammatory skin diseases (ISDs). JAK inhibitors in oral and topical formulations have shown beneficial results in psoriasis and alopecia areata. Patients suffering from other ISDs might also benefit from JAK inhibition. Given the development of specific JAK inhibitors, the expression patterns of JAKs in different ISDs needs to be clarified. We aimed to analyze the expression of JAK/STAT family members in a set of prevalent ISDs: psoriasis, lichen planus (LP), cutaneous lupus erythematosus (CLE), atopic dermatitis (AD), pyoderma gangrenosum (PG) and alopecia areata (AA) versus healthy controls for (p)JAK1, (p)JAK2, (p)JAK3, (p)TYK2, pSTAT1, pSTAT2 and pSTAT3. The epidermis carried in all ISDs, except for CLE, a strong JAK3 signature. The dermal infiltrate showed a more diverse expression pattern. JAK1, JAK2 and JAK3 were significantly overexpressed in PG and AD suggesting the need for pan-JAK inhibitors. In contrast, psoriasis and LP showed only JAK1 and JAK3 upregulation, while AA and CLE were characterized by a single dermal JAK signal (pJAK3 and pJAK1, respectively). This indicates that the latter diseases may benefit from more targeted JAK inhibitors. Our in vitro keratinocyte psoriasis model displayed reversal of the psoriatic JAK profile following tofacitinib treatment. This direct interaction with keratinocytes may decrease the need for deep skin penetration of topical JAK inhibitors in order to exert its effects on dermal immune cells. In conclusion, these results point to the important contribution of the JAK/STAT pathway in several ISDs. Considering the epidermal JAK3 expression levels, great interest should go to the investigation of topical JAK3 inhibitors as therapeutic option of ISDs.

  12. Wide spetcrum mutational analysis of metastatic renal cell cancer: a retrospective next generation sequencing approach

    PubMed Central

    Fiorentino, Michelangelo; Gruppioni, Elisa; Massari, Francesco; Giunchi, Francesca; Altimari, Annalisa; Ciccarese, Chiara; Bimbatti, Davide; Scarpa, Aldo; Iacovelli, Roberto; Porta, Camillo; Virinder, Sarhadi; Tortora, Giampaolo; Artibani, Walter; Schiavina, Riccardo; Ardizzoni, Andrea; Brunelli, Matteo; Knuutila, Sakari; Martignoni, Guido

    2017-01-01

    Renal cell cancer (RCC) is characterized by histological and molecular heterogeneity that may account for variable response to targeted therapies. We evaluated retrospectively with a next generation sequencing (NGS) approach using a pre-designed cancer panel the mutation burden of 32 lesions from 22 metastatic RCC patients treated with at least one tyrosine kinase or mTOR inhibitor. We identified mutations in the VHL, PTEN, JAK3, MET, ERBB4, APC, CDKN2A, FGFR3, EGFR, RB1, TP53 genes. Somatic alterations were correlated with response to therapy. Most mutations hit VHL1 (31,8%) followed by PTEN (13,6%), JAK3, FGFR and TP53 (9% each). Eight (36%) patients were wild-type at least for the genes included in the panel. A genotype concordance between primary RCC and its secondary lesion was found in 3/6 cases. Patients were treated with Sorafenib, Sunitinib and Temsirolimus with partial responses in 4 (18,2%) and disease stabilization in 7 (31,8%). Among the 4 partial responders, 1 (25%) was wild-type and 3 (75%) harbored different VHL1 variants. Among the 7 patients with disease stabilization 2 (29%) were wild-type, 2 (29%) PTEN mutated, and single patients (14% each) displayed mutations in VHL1, JAK3 and APC/CDKN2A. Among the 11 non-responders 7 (64%) were wild-type, 2 (18%) were p53 mutated and 2 (18%) VHL1 mutated. No significant associations were found among RCC histotype, mutation variants and response to therapies. In the absence of predictive biomarkers for metastatic RCC treatment, a NGS approach may address single patients to basket clinical trials according to actionable molecular specific alterations. PMID:27741505

  13. Allele-Specific Polymerase Chain Reaction for the Imatinib-Resistant KIT D816V and D816F Mutations in Mastocytosis and Acute Myelogenous Leukemia

    PubMed Central

    Corless, Christopher L.; Harrell, Patina; Lacouture, Mario; Bainbridge, Troy; Le, Claudia; Gatter, Ken; White, Clifton; Granter, Scott; Heinrich, Michael C.

    2006-01-01

    Oncogenic mutations of the receptor tyrosine kinase KIT contribute to the pathogenesis of gastrointestinal stromal tumors, systemic mastocytosis (SM), and some cases of acute myelogenous leukemia (AML). The D816V substitution in the activation loop of KIT results in relative resistance to the kinase inhibitor imatinib (Gleevec). Because this mutation occurs in 80 to 95% of adult SM, its detection has diagnostic and predictive significance. Unfortunately, the fraction of mutation-positive cells in clinical SM samples is often below the 20 to 30% threshold needed for detection by direct DNA sequencing. We have developed an allele-specific polymerase chain reaction assay using a mutation-specific primer combined with a wild-type blocking oligonucleotide that amplifies D816V at the level of 1% mutant allele in DNA extracted from formalin-fixed, paraffin-embedded tissue. There were no amplifications among 64 KIT wild-type tumors and cell lines, whereas all D816V-mutant samples (eight AML and 11 mast cell disease) were positive. Other D816 substitutions associated with resistance to imatinib in vitro are rare in SM. Among these D816F was detectable with the assay whereas D816H, D816Y, and D816G did not amplify. Nine biopsies (bone marrow, skin, or colon) with suspected SM were negative by denaturing high performance liquid chromatography and/or DNA sequencing but positive by allele-specific polymerase chain reaction. Thus, the assay may be useful in confirming the diagnosis of SM. PMID:17065430

  14. F4-related mutation and expression analysis of the aminopeptidase N gene in pigs.

    PubMed

    Goetstouwers, T; Van Poucke, M; Nguyen, V U; Melkebeek, V; Coddens, A; Deforce, D; Cox, E; Peelman, L J

    2014-05-01

    Intestinal infections with F4 enterotoxigenic Escherichia coli (ETEC) are worldwide an important cause of diarrhea in neonatal and recently weaned pigs. Adherence of F4 ETEC to the small intestine by binding to specific receptors is mediated by F4 fimbriae. Porcine aminopeptidase N (ANPEP) was recently identified as a new F4 receptor. In this study, 7 coding mutations and 1 mutation in the 3' untranslated region (3' UTR)were identified in ANPEP by reverse transcriptase (RT-) PCR and sequencing using 3 F4 receptor-positive (F4R+) and 2 F4 receptor-negative (F4R-) pigs, which were F4 phenotyped based on the MUC4 TaqMan, oral immunization, and the in vitro villous adhesion assay. Three potential differential mutations (g.2615C > T, g.8214A > G, and g.16875C > G) identified by comparative analysis between the 3 F4R+ and 2 F4R- pigs were genotyped in 41 additional F4 phenotyped pigs. However, none of these 3 mutations could be associated with F4 ETEC susceptibility. In addition, the RT-PCR experiments did not reveal any differential expression or alternative splicing in the small intestine of F4R+ and F4R- pigs. In conclusion, we hypothesize that the difference in F4 binding to ANPEP is due to modifications in its carbohydrate moieties.

  15. JAK2-binding long noncoding RNA promotes breast cancer brain metastasis

    PubMed Central

    Wang, Shouyu; Liang, Ke; Hu, Qingsong; Li, Ping; Song, Jian; Yang, Yuedong; Yao, Jun; Mangala, Lingegowda Selanere; Li, Chunlai; Park, Peter K.; Hawke, David H.; Zhou, Jianwei; Zhou, Yan; Xia, Weiya; Hung, Mien-Chie; Marks, Jeffrey R.; Gallick, Gary E.; Lopez-Berestein, Gabriel; Flores, Elsa R.; Sood, Anil K.; Huang, Suyun; Yu, Dihua; Yang, Liuqing

    2017-01-01

    Conventional therapies for breast cancer brain metastases (BCBMs) have been largely ineffective because of chemoresistance and impermeability of the blood-brain barrier. A comprehensive understanding of the underlying mechanism that allows breast cancer cells to infiltrate the brain is necessary to circumvent treatment resistance of BCBMs. Here, we determined that expression of a long noncoding RNA (lncRNA) that we have named lncRNA associated with BCBM (Lnc-BM) is prognostic of the progression of brain metastasis in breast cancer patients. In preclinical murine models, elevated Lnc-BM expression drove BCBM, while depletion of Lnc-BM with nanoparticle-encapsulated siRNAs effectively treated BCBM. Lnc-BM increased JAK2 kinase activity to mediate oncostatin M– and IL-6–triggered STAT3 phosphorylation. In breast cancer cells, Lnc-BM promoted STAT3-dependent expression of ICAM1 and CCL2, which mediated vascular co-option and recruitment of macrophages in the brain, respectively. Recruited macrophages in turn produced oncostatin M and IL-6, thereby further activating the Lnc-BM/JAK2/STAT3 pathway and enhancing BCBM. Collectively, our results show that Lnc-BM and JAK2 promote BCBMs by mediating communication between breast cancer cells and the brain microenvironment. Moreover, these results suggest targeting Lnc-BM as a potential strategy for fighting this difficult disease. PMID:29130936

  16. Triazolopyridines as selective JAK1 inhibitors: from hit identification to GLPG0634.

    PubMed

    Menet, Christel J; Fletcher, Stephen R; Van Lommen, Guy; Geney, Raphael; Blanc, Javier; Smits, Koen; Jouannigot, Nolwenn; Deprez, Pierre; van der Aar, Ellen M; Clement-Lacroix, Philippe; Lepescheux, Liên; Galien, René; Vayssiere, Béatrice; Nelles, Luc; Christophe, Thierry; Brys, Reginald; Uhring, Muriel; Ciesielski, Fabrice; Van Rompaey, Luc

    2014-11-26

    Janus kinases (JAK1, JAK2, JAK3, and TYK2) are involved in the signaling of multiple cytokines important in cellular function. Blockade of the JAK-STAT pathway with a small molecule has been shown to provide therapeutic immunomodulation. Having identified JAK1 as a possible new target for arthritis at Galapagos, the compound library was screened against JAK1, resulting in the identification of a triazolopyridine-based series of inhibitors represented by 3. Optimization within this chemical series led to identification of GLPG0634 (65, filgotinib), a selective JAK1 inhibitor currently in phase 2B development for RA and phase 2A development for Crohn's disease (CD).

  17. Profile of the Roche cobas® EGFR mutation test v2 for non-small cell lung cancer.

    PubMed

    Malapelle, Umberto; Sirera, Rafael; Jantus-Lewintre, Eloísa; Reclusa, Pablo; Calabuig-Fariñas, Silvia; Blasco, Ana; Pisapia, Pasquale; Rolfo, Christian; Camps, Carlos

    2017-03-01

    The discovery of driver mutations in non-small cell lung cancer (NSCLC) has led to the development of genome-based personalized medicine. Fifteen to 20% of adenocarcinomas harbor an epidermal growth factor receptor (EGFR) activating mutation associated with responses to EGFR tyrosine kinase inhibitors (TKIs). Individual laboratories' expertise and the availability of appropriate equipment are valuable assets in predictive molecular pathology, although the choice of methods should be determined by the nature of the samples to be tested and whether the detection of only well-characterized EGFR mutations or rather, of all detectable mutations, is required. Areas covered: The EGFR mutation testing landscape is manifold and includes both screening and targeted methods, each with their own pros and cons. Here we review one of these companion tests, the Roche cobas® EGFR mutation test v2, from a methodological point of view, also exploring its liquid-biopsy applications. Expert commentary: The Roche cobas® EGFR mutation test v2, based on real time RT-PCR, is a reliable option for testing EGFR mutations in clinical practice, either using tissue-derived DNA or plasma-derived cfDNA. This application will be valuable for laboratories with whose purpose is purely diagnostic and lacking high-throughput technologies.

  18. CXCL12/CXCR4 pathway is activated by oncogenic JAK2 in a PI3K-dependent manner

    PubMed Central

    Abdelouahab, Hadjer; Zhang, Yanyan; Wittner, Monika; Oishi, Shinya; Fujii, Nobutaka; Besancenot, Rodolphe; Plo, Isabelle; Ribrag, Vincent; Solary, Eric; Vainchenker, William; Barosi, Giovanni; Louache, Fawzia

    2017-01-01

    JAK2 activation is the driver mechanism in BCR-ABL-negative myeloproliferative neoplasms (MPN). These diseases are characterized by an abnormal retention of hematopoietic stem cells within the bone marrow microenvironment and their increased trafficking to extramedullary sites. The CXCL12/CXCR4 axis plays a central role in hematopoietic stem cell/ progenitor trafficking and retention in hematopoietic sites. The present study explores the crosstalk between JAK2 and CXCL12/CXCR4 signaling pathways in MPN. We show that JAK2, activated by either MPL-W515L expression or cytokine stimulation, cooperates with CXCL12/CXCR4 signaling to increase the chemotactic response of human cell lines and primary CD34+ cells through an increased phosphatidylinositol-3-kinase (PI3K) signaling. Accordingly, primary myelofibrosis (MF) patient cells demonstrate an increased CXCL12-induced chemotaxis when compared to controls. JAK2 inhibition by knock down or chemical inhibitors decreases this effect in MPL-W515L expressing cell lines and reduces the CXCL12/CXCR4 signaling in some patient primary cells. Taken together, these data indicate that CXCL12/CXCR4 pathway is overactivated in MF patients by oncogenic JAK2 that maintains high PI3K signaling over the threshold required for CXCR4 activation. These results suggest that inhibition of this crosstalk may contribute to the therapeutic effects of JAK2 inhibitors. PMID:28903325

  19. Sevoflurane postconditioning protects the myocardium against ischemia/reperfusion injury via activation of the JAK2–STAT3 pathway

    PubMed Central

    Wu, Jianjiang; Yu, Jin; Xie, Peng; Maimaitili, Yiliyaer; Wang, Jiang; Yang, Long; Ma, Haiping; Zhang, Xing; Yang, Yining

    2017-01-01

    Background Sevoflurane postconditioning (S-post) has similar cardioprotective effects as ischemic preconditioning. However, the underlying mechanism of S-post has not been fully elucidated. Janus kinase signaling transduction/transcription activator (JAK2–STAT3) plays an important role in cardioprotection. The purpose of this study was to determine whether the cardioprotective effects of S-post are associated with activation of the JAK2–STAT3 signal pathway. Methods An adult male Sprague–Dawley (SD) rat model of myocardial ischemia/reperfusion (I/R) injury was established using the Langendorff isolated heart perfusion apparatus. At the beginning of reperfusion, 2.4% sevoflurane alone or in combination with AG490 (a JAK2 selective inhibitor) was used as a postconditioning treatment. The cardiac function indicators, myocardial infarct size, lactic dehydrogenase (LDH) release, mitochondrial ultrastructure, mitochondrial reactive oxygen species (ROS) generation rates, ATP content, protein expression of p-JAK, p-STAT3, Bcl-2 and Bax were measured. Results Compared with the I/R group, S-post significantly increased the expression of p-JAK, p-STAT3 and Bcl-2 and reduced the protein expression of Bax, which markedly decreased the myocardial infarction areas, improved the cardiac function indicators and the mitochondrial ultrastructure, decreased the mitochondrial ROS and increased the ATP content. However, the cardioprotective effects of S-post were abolished by treatment with a JAK2 selective inhibitor (p < 0.05). Conclusion This study demonstrates that the cardioprotective effects of S-post are associated with the activation of JAK2–STAT3. The mechanism may be related to an increased expression of p-JAK2 and p-STAT3 after S-post, which reduced mitochondrial ROS generation and increased mitochondrial ATP content, thereby reducing apoptosis and myocardial infarct size. PMID:28392989

  20. Association of common JAK2 variants with body fat, insulin sensitivity and lipid profile

    PubMed Central

    Ge, Dongliang; Gooljar, Sakina B; Kyriakou, Theodosios; Collins, Laura J; Swaminathan, Ramasamyiyer; Snieder, Harold; Spector, Tim D; O'Dell, Sandra D

    2007-01-01

    The leptin signal is transduced via the JAK2-STAT3 pathway at the leptin receptor. JAK2 also phosphorylates IRS, integral to insulin and leptin action and is required for optimum ABCA1-dependent transport of lipids from cells to apoA-I. We hypothesised that common variation in the JAK2 gene may be associated with body fat, insulin sensitivity and modulation of the serum lipid profile in the general population. Ten tagging SNPs spanning the gene were genotyped in 2760 Caucasian female twin subjects (mean age 47.3±12.6 years) from the St Thomas' UK Adult Twin Registry (Twins UK). Minor allele frequencies were between 0.170 and 0.464. The major allele of rs7849191 was associated with higher central fat (P=0.030), % central fat (P=0.014) and waist circumference (P=0.027) and the major allele of rs3780378 with higher serum apoA (P=0.026), total cholesterol (P=0.014) and LDL cholesterol (P=0.012) and lower triglyceride (P=0.023). However, no associations were significant at a level which took account of multiple testing. Although JAK2 is a critical element in leptin and insulin signalling and has a role in cellular cholesterol transport, we failed to establish associations of common SNPs with relevant phenotypes in this human study. PMID:18239666

  1. Prevalence, Mutation Patterns, and Effects on Protease Inhibitor Susceptibility of the L76V Mutation in HIV-1 Protease▿ †

    PubMed Central

    Young, Thomas P.; Parkin, Neil T.; Stawiski, Eric; Pilot-Matias, Tami; Trinh, Roger; Kempf, Dale J.; Norton, Michael

    2010-01-01

    Patterns of HIV-1 protease inhibitor (PI) resistance-associated mutations (RAMs) and effects on PI susceptibility associated with the L76V mutation were studied in a large database. Of 20,501 sequences with ≥1 PI RAM, 3.2% contained L76V; L76V was alone in 0.04%. Common partner mutations included M46I, I54V, V82A, I84V, and L90M. L76V was associated with a 2- to 6-fold decrease in susceptibility to lopinavir, darunavir, amprenavir, and indinavir and a 7- to 8-fold increase in susceptibility to atazanavir and saquinavir. PMID:20805393

  2. 44Sc-PSMA-617 for radiotheragnostics in tandem with 177Lu-PSMA-617-preclinical investigations in comparison with 68Ga-PSMA-11 and 68Ga-PSMA-617.

    PubMed

    Umbricht, Christoph A; Benešová, Martina; Schmid, Raffaella M; Türler, Andreas; Schibli, Roger; van der Meulen, Nicholas P; Müller, Cristina

    2017-12-01

    The targeting of the prostate-specific membrane antigen (PSMA) is of particular interest for radiotheragnostic purposes of prostate cancer. Radiolabeled PSMA-617, a 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetic acid (DOTA)-functionalized PSMA ligand, revealed favorable kinetics with high tumor uptake, enabling its successful application for PET imaging ( 68 Ga) and radionuclide therapy ( 177 Lu) in the clinics. In this study, PSMA-617 was labeled with cyclotron-produced 44 Sc (T 1/2  = 4.04 h) and investigated preclinically for its use as a diagnostic match to 177 Lu-PSMA-617. 44 Sc was produced at the research cyclotron at PSI by irradiation of enriched 44 Ca targets, followed by chromatographic separation. 44 Sc-PSMA-617 was prepared under standard labeling conditions at elevated temperature resulting in a radiochemical purity of >97% at a specific activity of up to 10 MBq/nmol. 44 Sc-PSMA-617 was evaluated in vitro and compared to the 177 Lu- and 68 Ga-labeled match, as well as 68 Ga-PSMA-11 using PSMA-positive PC-3 PIP and PSMA-negative PC-3 flu prostate cancer cells. In these experiments it revealed similar in vitro properties to that of 177 Lu- and 68 Ga-labeled PSMA-617. Moreover, 44 Sc-PSMA-617 bound specifically to PSMA-expressing PC-3 PIP tumor cells, while unspecific binding to PC-3 flu cells was not observed. The radioligands were investigated with regard to their in vivo properties in PC-3 PIP/flu tumor-bearing mice. 44 Sc-PSMA-617 showed high tumor uptake and a fast renal excretion. The overall tissue distribution of 44 Sc-PSMA-617 resembled that of 177 Lu-PSMA-617 most closely, while the 68 Ga-labeled ligands, in particular 68 Ga-PSMA-11, showed different distribution kinetics. 44 Sc-PSMA-617 enabled distinct visualization of PC-3 PIP tumor xenografts shortly after injection, with increasing tumor-to-background contrast over time while unspecific uptake in the PC-3 flu tumors was not observed. The in vitro characteristics and in vivo

  3. Association between Three Mutations, F1565C, V1023G and S996P, in the Voltage-Sensitive Sodium Channel Gene and Knockdown Resistance in Aedes aegypti from Yogyakarta, Indonesia

    PubMed Central

    Rochmijati Wuliandari, Juli; Lee, Siu Fai; White, Vanessa Linley; Tantowijoyo, Warsito; Hoffmann, Ary Anthony; Endersby-Harshman, Nancy Margaret

    2015-01-01

    Mutations in the voltage-sensitive sodium channel gene (Vssc) have been identified in Aedes aegypti and some have been associated with pyrethroid insecticide resistance. Whether these mutations cause resistance, alone or in combination with other alleles, remains unclear, but must be understood if mutations are to become markers for resistance monitoring. We describe High Resolution Melt (HRM) genotyping assays for assessing mutations found in Ae. aegypti in Indonesia (F1565C, V1023G, S996P) and use them to test for associations with pyrethroid resistance in mosquitoes from Yogyakarta, a city where insecticide use is widespread. Such knowledge is important because Yogyakarta is a target area for releases of Wolbachia-infected mosquitoes with virus-blocking traits for dengue suppression. We identify three alleles across Yogyakarta putatively linked to resistance in previous research. By comparing resistant and susceptible mosquitoes from bioassays, we show that the 1023G allele is associated with resistance to type I and type II pyrethroids. In contrast, F1565C homozygotes were rare and there was only a weak association between individuals heterozygous for the mutation and resistance to a type I pyrethroid. As the heterozygote is expected to be incompletely recessive, it is likely that this association was due to a different resistance mechanism being present. A resistance advantage conferred to V1023G homozygotes through addition of the S996P allele in the homozygous form was suggested for the Type II pyrethroid, deltamethrin. Screening of V1023G and S996P should assist resistance monitoring in Ae. aegypti from Yogyakarta, and these mutations should be maintained in Wolbachia strains destined for release in this city to ensure that these virus-blocking strains of mosquitoes are not disadvantaged, relative to resident populations. PMID:26463408

  4. Association between Three Mutations, F1565C, V1023G and S996P, in the Voltage-Sensitive Sodium Channel Gene and Knockdown Resistance in Aedes aegypti from Yogyakarta, Indonesia.

    PubMed

    Wuliandari, Juli Rochmijati; Lee, Siu Fai; White, Vanessa Linley; Tantowijoyo, Warsito; Hoffmann, Ary Anthony; Endersby-Harshman, Nancy Margaret

    2015-07-23

    Mutations in the voltage-sensitive sodium channel gene (Vssc) have been identified in Aedes aegypti and some have been associated with pyrethroid insecticide resistance. Whether these mutations cause resistance, alone or in combination with other alleles, remains unclear, but must be understood if mutations are to become markers for resistance monitoring. We describe High Resolution Melt (HRM) genotyping assays for assessing mutations found in Ae. aegypti in Indonesia (F1565C, V1023G, S996P) and use them to test for associations with pyrethroid resistance in mosquitoes from Yogyakarta, a city where insecticide use is widespread. Such knowledge is important because Yogyakarta is a target area for releases of Wolbachia-infected mosquitoes with virus-blocking traits for dengue suppression. We identify three alleles across Yogyakarta putatively linked to resistance in previous research. By comparing resistant and susceptible mosquitoes from bioassays, we show that the 1023G allele is associated with resistance to type I and type II pyrethroids. In contrast, F1565C homozygotes were rare and there was only a weak association between individuals heterozygous for the mutation and resistance to a type I pyrethroid. As the heterozygote is expected to be incompletely recessive, it is likely that this association was due to a different resistance mechanism being present. A resistance advantage conferred to V1023G homozygotes through addition of the S996P allele in the homozygous form was suggested for the Type II pyrethroid, deltamethrin. Screening of V1023G and S996P should assist resistance monitoring in Ae. aegypti from Yogyakarta, and these mutations should be maintained in Wolbachia strains destined for release in this city to ensure that these virus-blocking strains of mosquitoes are not disadvantaged, relative to resident populations.

  5. The role of the JAK/STAT signal pathway in rheumatoid arthritis

    PubMed Central

    Malemud, Charles J.

    2018-01-01

    Proinflammatory cytokine activation of the Janus kinase/signal transducers and activators of transcription (JAK/STAT) signal transduction pathway is a critical event in the pathogenesis and progression of rheumatoid arthritis. Under normal conditions, JAK/STAT signaling reflects the influence of negative regulators of JAK/STAT, exemplified by the suppressor of cytokine signaling and protein inhibitor of activated STAT. However, in rheumatoid arthritis (RA) both of these regulators are dysfunctional. Thus, continuous activation of JAK/STAT signaling in RA synovial joints results in the elevated level of matrix metalloproteinase gene expression, increased frequency of apoptotic chondrocytes and most prominently ‘apoptosis resistance’ in the inflamed synovial tissue. Tofacitinib, a JAK small molecule inhibitor, with selectivity for JAK2/JAK3 was approved by the United States Food and Drug Administration (US FDA) for the therapy of RA. Importantly, tofacitinib has demonstrated significant clinical efficacy for RA in the post-US FDA-approval surveillance period. Of note, the success of tofacitinib has spurred the development of JAK1, JAK2 and other JAK3-selective small molecule inhibitors, some of which have also entered the clinical setting, whereas other JAK inhibitors are currently being evaluated in RA clinical trials. PMID:29942363

  6. Low-burden TP53 mutations in chronic phase of myeloproliferative neoplasms: association with age, hydroxyurea administration, disease type and JAK2 mutational status

    PubMed Central

    Kubesova, B; Pavlova, S; Malcikova, J; Kabathova, J; Radova, L; Tom, N; Tichy, B; Plevova, K; Kantorova, B; Fiedorova, K; Slavikova, M; Bystry, V; Kissova, J; Gisslinger, B; Gisslinger, H; Penka, M; Mayer, J; Kralovics, R; Pospisilova, S; Doubek, M

    2018-01-01

    The multistep process of TP53 mutation expansion during myeloproliferative neoplasm (MPN) transformation into acute myeloid leukemia (AML) has been documented retrospectively. It is currently unknown how common TP53 mutations with low variant allele frequency (VAF) are, whether they are linked to hydroxyurea (HU) cytoreduction, and what disease progression risk they carry. Using ultra-deep next-generation sequencing, we examined 254 MPN patients treated with HU, interferon alpha-2a or anagrelide and 85 untreated patients. We found TP53 mutations in 50 cases (0.2–16.3% VAF), regardless of disease subtype, driver gene status and cytoreduction. Both therapy and TP53 mutations were strongly associated with older age. Over-time analysis showed that the mutations may be undetectable at diagnosis and slowly increase during disease course. Although three patients with TP53 mutations progressed to TP53-mutated or TP53-wild-type AML, we did not observe a significant age-independent impact on overall survival during the follow-up. Further, we showed that complete p53 inactivation alone led to neither blast transformation nor HU resistance. Altogether, we revealed patient's age as the strongest factor affecting low-burden TP53 mutation incidence in MPN and found no significant age-independent association between TP53 mutations and hydroxyurea. Mutations may persist at low levels for years without an immediate risk of progression. PMID:28744014

  7. Somatic mutations of GUCY2F, EPHA3, and NTRK3 in human cancers.

    PubMed

    Wood, Laura D; Calhoun, Eric S; Silliman, Natalie; Ptak, Janine; Szabo, Steve; Powell, Steve M; Riggins, Gregory J; Wang, Tian-Li; Yan, Hai; Gazdar, Adi; Kern, Scott E; Pennacchio, Len; Kinzler, Kenneth W; Vogelstein, Bert; Velculescu, Victor E

    2006-10-01

    Tyrosine kinases are major regulators of signal transduction cascades involved in cellular proliferation and have important roles in tumorigenesis. We have recently analyzed the tyrosine kinase gene family for alterations in human colorectal cancers and identified somatic mutations in seven members of this gene family. In this study we have used high-throughput sequencing approaches to further evaluate this subset of genes for genetic alterations in other human tumors. We identified somatic mutations in GUCY2F, EPHA3, and NTRK3 in breast, lung, and pancreatic cancers. Our results implicate these tyrosine kinase genes in the pathogenesis of other tumor types and suggest that they may be useful targets for diagnostic and therapeutic intervention in selected patients.

  8. Epilepsy-causing mutations in Kv7.2 C-terminus affect binding and functional modulation by calmodulin.

    PubMed

    Ambrosino, Paolo; Alaimo, Alessandro; Bartollino, Silvia; Manocchio, Laura; De Maria, Michela; Mosca, Ilaria; Gomis-Perez, Carolina; Alberdi, Araitz; Scambia, Giovanni; Lesca, Gaetan; Villarroel, Alvaro; Taglialatela, Maurizio; Soldovieri, Maria Virginia

    2015-09-01

    Mutations in the KCNQ2 gene, encoding for voltage-gated Kv7.2K(+) channel subunits, are responsible for early-onset epileptic diseases with widely-diverging phenotypic presentation, ranging from Benign Familial Neonatal Seizures (BFNS) to epileptic encephalopathy. In the present study, Kv7.2 BFNS-causing mutations (W344R, L351F, L351V, Y362C, and R553Q) have been investigated for their ability to interfere with calmodulin (CaM) binding and CaM-induced channel regulation. To this aim, semi-quantitative (Far-Western blotting) and quantitative (Surface Plasmon Resonance and dansylated CaM fluorescence) biochemical assays have been performed to investigate the interaction of CaM with wild-type or mutant Kv7.2 C-terminal fragments encompassing the CaM-binding domain; in parallel, mutation-induced changes in CaM-dependent Kv7.2 or Kv7.2/Kv7.3 current regulation were investigated by patch-clamp recordings in Chinese Hamster Ovary (CHO) cells co-expressing Kv7.2 or Kv7.2/Kv7.3 channels and CaM or CaM1234 (a CaM isoform unable to bind Ca(2+)). The results obtained suggest that each BFNS-causing mutation prompts specific biochemical and/or functional consequences; these range from slight alterations in CaM affinity which did not translate into functional changes (L351V), to a significant reduction in the affinity and functional modulation by CaM (L351F, Y362C or R553Q), to a complete functional loss without significant alteration in CaM affinity (W344R). CaM overexpression increased Kv7.2 and Kv7.2/Kv7.3 current levels, and partially (R553Q) or fully (L351F) restored normal channel function, providing a rationale pathogenetic mechanism for mutation-induced channel dysfunction in BFNS, and highlighting the potentiation of CaM-dependent Kv7.2 modulation as a potential therapeutic approach for Kv7.2-related epilepsies. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Mutation profiling of 19 candidate genes in acute myeloid leukemia suggests significance of DNMT3A mutations.

    PubMed

    Shin, Sang-Yong; Lee, Seung-Tae; Kim, Hee-Jin; Cho, Eun Hae; Kim, Jong-Won; Park, Silvia; Jung, Chul Won; Kim, Sun-Hee

    2016-08-23

    We selected 19 significantly-mutated genes in AMLs, including FLT3, DNMT3A, NPM1, TET2, RUNX1, CEBPA, WT1, IDH1, IDH2, NRAS, ASXL1, SETD2, PTPN11, TP53, KIT, JAK2, KRAS, BRAF and CBL, and performed massively parallel sequencing for 114 patients with acute myeloid leukemias, mainly including those with normal karyotypes (CN-AML). More than 80% of patients had at least one mutation in the genes tested. DNMT3A mutation was significantly associated with adverse outcome in addition to conventional risk stratification such as the European LeukemiaNet (ELN) classification. We observed clinical usefulness of mutation testing on multiple target genes and the association with disease subgroups, clinical features and prognosis in AMLs.

  10. The novel c.247_249delTTC (p.F83del) GJB2 mutation in a family with prelingual sensorineural deafness.

    PubMed

    Petersen, Michael B; Grigoriadou, Maria; Koutroumpe, Maria; Kokotas, Haris

    2012-07-01

    Non-syndromic hearing loss is one of the most common hereditary determined diseases in human, and the disease is a genetically heterogeneous disorder. Mutations in the GJB2 gene, encoding connexin 26 (Cx26), are a major cause of non-syndromic recessive hearing impairment in many countries and are largely dependent on ethnic groups. Due to the high frequency of the c.35delG GJB2 mutation in the Greek population, we have previously suggested that Greek patients with sensorineural, non-syndromic deafness should be tested for the c.35delG mutation and the coding region of the GJB2 gene should be sequenced in c.35delG heterozygotes. Here we present on the clinical and molecular genetic evaluation of a family suffering from prelingual, sensorineural, non-syndromic deafness. A novel c.247_249delTTC (p.F83del) GJB2 mutation was detected in compound heterozygosity with the c.35delG GJB2 mutation in the proband and was later confirmed in the father, while the mother was homozygous for the c.35delG GJB2 mutation. We conclude that compound heterozygosity of the novel c.247_249delTTC (p.F83del) and the c.35delG mutations in the GJB2 gene was the cause of deafness in the proband and his father. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  11. Calreticulin mutation-specific immunostaining in myeloproliferative neoplasms: pathogenetic insight and diagnostic value

    PubMed Central

    Vannucchi, A M; Rotunno, G; Bartalucci, N; Raugei, G; Carrai, V; Balliu, M; Mannarelli, C; Pacilli, A; Calabresi, L; Fjerza, R; Pieri, L; Bosi, A; Manfredini, R; Guglielmelli, P

    2014-01-01

    Mutations in the gene calreticulin (CALR) occur in the majority of JAK2- and MPL-unmutated patients with essential thrombocythemia (ET) and primary myelofibrosis (PMF); identifying CALR mutations contributes to the diagnostic pathway of ET and PMF. CALR mutations are heterogeneous spanning over the exon 9, but all result in a novel common protein C terminus. We developed a polyclonal antibody against a 17-amino-acid peptide derived from mutated calreticulin that was used for immunostaining of bone marrow biopsies. We show that this antibody specifically recognized patients harboring different types of CALR mutation with no staining in healthy controls and JAK2- or MPL-mutated ET and PMF. The labeling was mostly localized in megakaryocytes, whereas myeloid and erythroid cells showed faint staining, suggesting a preferential expression of calreticulin in megakaryocytes. Megakaryocytic-restricted expression of calreticulin was also demonstrated using an antibody against wild-type calreticulin and by measuring the levels of calreticulin RNA by gene expression analysis. Immunostaining using an antibody specific for mutated calreticulin may become a rapid, simple and cost-effective method for identifying CALR-mutated patients complementing molecular analysis; furthermore, the labeling pattern supports the preferential expansion of megakaryocytic cell lineage as a result of CALR mutation in an immature hematopoietic stem cell. PMID:24618731

  12. Genomic characterization of pediatric T-cell acute lymphoblastic leukemia reveals novel recurrent driver mutations

    PubMed Central

    Spinella, Jean-François; Cassart, Pauline; Richer, Chantal; Saillour, Virginie; Ouimet, Manon; Langlois, Sylvie; St-Onge, Pascal; Sontag, Thomas; Healy, Jasmine; Minden, Mark D.; Sinnett, Daniel

    2016-01-01

    T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematologic malignancy with variable prognosis. It represents 15% of diagnosed pediatric ALL cases and has a threefold higher incidence among males. Many recurrent alterations have been identified and help define molecular subgroups of T-ALL, however the full range of events involved in driving transformation remain to be defined. Using an integrative approach combining genomic and transcriptomic data, we molecularly characterized 30 pediatric T-ALLs and identified common recurrent T-ALL targets such as FBXW7, JAK1, JAK3, PHF6, KDM6A and NOTCH1 as well as novel candidate T-ALL driver mutations including the p.R35L missense mutation in splicesome factor U2AF1 found in 3 patients and loss of function mutations in the X-linked tumor suppressor genes MED12 (frameshit mutation p.V167fs, splice site mutation g.chrX:70339329T>C, missense mutation p.R1989H) and USP9X (nonsense mutation p.Q117*). In vitro functional studies further supported the putative role of these novel T-ALL genes in driving transformation. U2AF1 p.R35L was shown to induce aberrant splicing of downstream target genes, and shRNA knockdown of MED12 and USP9X was shown to confer resistance to apoptosis following T-ALL relevant chemotherapy drug treatment in Jurkat leukemia cells. Interestingly, nearly 60% of novel candidate driver events were identified among immature T-ALL cases, highlighting the underlying genomic complexity of pediatric T-ALL, and the need for larger integrative studies to decipher the mechanisms that contribute to its various subtypes and provide opportunities to refine patient stratification and treatment. PMID:27602765

  13. Secretion pathway of liver IGF-1 via JAK2/STAT3 in chick embryo under the monochromatic light.

    PubMed

    Wang, Tuanjie; Dong, Yulan; Wang, Zixu; Cao, Jing; Chen, Yaoxing

    2016-02-01

    This study reveals mechanism of monochromatic light on the IGF-1 secretion of chick embryo liver. The chick embryos were incubated and exposed to continuous red, green, blue light or a dark environment. Compared to other light-treated groups, green light increased IGF-1 and melatonin concentrations both in plasma and liver, and Mel1a, Mel1b and Mel1c receptors expressions in liver but decreased p-JAK2, p-STAT3 and ROS in liver. IGF-1 had a positive correlation with melatonin, but a negative relevance with p-JAK2 and p-STAT3. In vitro, the IGF-1 level in the hepatocyte supernatant was enhanced by melatonin with lower p-JAK2/p-STAT3 and ROS levels, which was suppressed by Mel1c antagonist but not Mel1a/Mel1b or Mel1b antagonists. AG490 (JAK/STAT inhibitor) promoted role of melatonin-Mel1c modulated IGF-1 secretion. These results suggest the antioxidant effect of melatonin mediated the green light-enhanced IGF-1 secretion of chick embryo liver through Mel1c receptor to inhibit the JAK2/STAT3 pathway.

  14. Structure-based design of oxygen-linked macrocyclic kinase inhibitors: discovery of SB1518 and SB1578, potent inhibitors of Janus kinase 2 (JAK2) and Fms-like tyrosine kinase-3 (FLT3)

    NASA Astrophysics Data System (ADS)

    Poulsen, Anders; William, Anthony; Blanchard, Stéphanie; Lee, Angeline; Nagaraj, Harish; Wang, Haishan; Teo, Eeling; Tan, Evelyn; Goh, Kee Chuan; Dymock, Brian

    2012-04-01

    Macrocycles from our Aurora project were screened in a kinase panel and were found to be active on other kinase targets, mainly JAKs, FLT3 and CDKs. Subsequently these compounds became leads in our JAK2 project. Macrocycles with a basic nitrogen in the linker form a salt bridge with Asp86 in CDK2 and Asp698 in FLT3. This residue is conserved in most CDKs resulting in potent pan CDK inhibition. One of the main project objectives was to achieve JAK2 potency with 100-fold selectivity against CDKs. Macrocycles with an ether linker have potent JAK2 activity with the ether oxygen forming a hydrogen bond to Ser936. A hydrogen bond to the equivalent residues of JAK3 and most CDKs cannot be formed resulting in good selectivity for JAK2 over JAK3 and CDKs. Further optimization of the macrocyclic linker and side chain increased JAK2 and FLT3 activity as well as improving DMPK properties. The selective JAK2/FLT3 inhibitor 11 (Pacritinib, SB1518) has successfully finished phase 2 clinical trials for myelofibrosis and lymphoma. Another selective JAK2/FLT3 inhibitor, 33 (SB1578), has entered phase 1 clinical development for the non-oncology indication rheumatoid arthritis.

  15. Cryptochromes regulate IGF-1 production and signaling through control of JAK2-dependent STAT5B phosphorylation

    PubMed Central

    Chaudhari, Amol; Gupta, Richa; Patel, Sonal; Velingkaar, Nikkhil; Kondratov, Roman

    2017-01-01

    Insulin-like growth factor (IGF) signaling plays an important role in cell growth and proliferation and is implicated in regulation of cancer, metabolism, and aging. Here we report that IGF-1 level in blood and IGF-1 signaling demonstrates circadian rhythms. Circadian control occurs through cryptochromes (CRYs)—transcriptional repressors and components of the circadian clock. IGF-1 rhythms are disrupted in Cry-deficient mice, and IGF-1 level is reduced by 80% in these mice, which leads to reduced IGF signaling. In agreement, Cry-deficient mice have reduced body (∼30% reduction) and organ size. Down-regulation of IGF-1 upon Cry deficiency correlates with reduced Igf-1 mRNA expression in the liver and skeletal muscles. Igf-1 transcription is regulated through growth hormone–induced, JAK2 kinase–mediated phosphorylation of transcriptional factor STAT5B. The phosphorylation of STAT5B on the JAK2-dependent Y699 site is significantly reduced in the liver and skeletal muscles of Cry-deficient mice. At the same time, phosphorylation of JAK2 kinase was not reduced upon Cry deficiency, which places CRY activity downstream from JAK2. Thus CRYs link the circadian clock and JAK-STAT signaling through control of STAT5B phosphorylation, which provides the mechanism for circadian rhythms in IGF signaling in vivo. PMID:28100634

  16. Expression analysis revealing destabilizing mutations in phosphomannomutase 2 deficiency (PMM2-CDG): expression analysis of PMM2-CDG mutations.

    PubMed

    Vega, Ana Isabel; Pérez-Cerdá, Celia; Abia, David; Gámez, Alejandra; Briones, Paz; Artuch, Rafael; Desviat, Lourdes R; Ugarte, Magdalena; Pérez, Belén

    2011-08-01

    Deficiency of phosphomannomutase (PMM2, MIM#601785) is the most common congenital disorder of glycosylation. Herein we report the genetic analysis of 22 Spanish PMM2 deficient patients and the functional analysis of 14 nucleotide changes in a prokaryotic expression system in order to elucidate their molecular pathogenesis. PMM2 activity assay revealed the presence of six protein changes with no enzymatic activities (p.R123Q, p.R141H, p.F157S, p.P184T, p.F207S and p.D209G) and seven mild protein changes with residual activities ranging from 16 to 54% (p.L32R, p.V44A p.D65Y, p.P113L p.T118S, p.T237M and p.C241S) and also one variant change with normal activity (p.E197A). The results obtained from Western blot analysis, degradation time courses of 11 protein changes and structural analysis of the PMM2 protein, suggest that the loss-of-function of most mutant proteins is based on their increased susceptibility to degradation or aggregation compared to the wild type protein, considering PMM2 deficiency as a conformational disease. We have identified exclusively catalytic protein change (p.D209G), catalytic protein changes affecting protein stability (p.R123Q and p.R141H), two protein changes disrupting the dimer interface (p.P113L and p.T118S) and several misfolding changes (p.L32R, p.V44A, p.D65Y, p.F157S, p.P184T, p.F207S, p.T237M and p.C241S). Our current work opens a promising therapeutic option using pharmacological chaperones to revert the effect of the characterized misfolding mutations identified in a wide range of PMM2 deficient patients.

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

    PubMed

    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 (p<0.0001) and the minor venous events were significantly elevated (p<0.0001) after the diagnosis. Major hemorrhagic complications were found in 25 and transformation in 26 cases. Our registry allows to collect and evaluate the features of patients with polycythemia 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.

  18. Tricyclic Covalent Inhibitors Selectively Target Jak3 through an Active Site Thiol*

    PubMed Central

    Goedken, Eric R.; Argiriadi, Maria A.; Banach, David L.; Fiamengo, Bryan A.; Foley, Sage E.; Frank, Kristine E.; George, Jonathan S.; Harris, Christopher M.; Hobson, Adrian D.; Ihle, David C.; Marcotte, Douglas; Merta, Philip J.; Michalak, Mark E.; Murdock, Sara E.; Tomlinson, Medha J.; Voss, Jeffrey W.

    2015-01-01

    The action of Janus kinases (JAKs) is required for multiple cytokine signaling pathways, and as such, JAK inhibitors hold promise for treatment of autoimmune disorders, including rheumatoid arthritis, inflammatory bowel disease, and psoriasis. However, due to high similarity in the active sites of the four members (Jak1, Jak2, Jak3, and Tyk2), developing selective inhibitors within this family is challenging. We have designed and characterized substituted, tricyclic Jak3 inhibitors that selectively avoid inhibition of the other JAKs. This is accomplished through a covalent interaction between an inhibitor containing a terminal electrophile and an active site cysteine (Cys-909). We found that these ATP competitive compounds are irreversible inhibitors of Jak3 enzyme activity in vitro. They possess high selectivity against other kinases and can potently (IC50 < 100 nm) inhibit Jak3 activity in cell-based assays. These results suggest irreversible inhibitors of this class may be useful selective agents, both as tools to probe Jak3 biology and potentially as therapies for autoimmune diseases. PMID:25552479

  19. Tricyclic Covalent Inhibitors Selectively Target Jak3 through an Active Site Thiol

    DOE PAGES

    Goedken, Eric R.; Argiriadi, Maria A.; Banach, David L.; ...

    2014-12-31

    The action of Janus kinases (JAKs) is required for multiple cytokine signaling pathways, and as such, JAK inhibitors hold promise for treatment of autoimmune disorders, including rheumatoid arthritis, inflammatory bowel disease, and psoriasis. However, due to high similarity in the active sites of the four members (Jak1, Jak2, Jak3, and Tyk2), developing selective inhibitors within this family is challenging. In this paper, we have designed and characterized substituted, tricyclic Jak3 inhibitors that selectively avoid inhibition of the other JAKs. This is accomplished through a covalent interaction between an inhibitor containing a terminal electrophile and an active site cysteine (Cys-909). Wemore » found that these ATP competitive compounds are irreversible inhibitors of Jak3 enzyme activity in vitro. They possess high selectivity against other kinases and can potently (IC 50 < 100 nM) inhibit Jak3 activity in cell-based assays. Finally, these results suggest irreversible inhibitors of this class may be useful selective agents, both as tools to probe Jak3 biology and potentially as therapies for autoimmune diseases.« less

  20. Tricyclic Covalent Inhibitors Selectively Target Jak3 through an Active Site Thiol

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Goedken, Eric R.; Argiriadi, Maria A.; Banach, David L.

    The action of Janus kinases (JAKs) is required for multiple cytokine signaling pathways, and as such, JAK inhibitors hold promise for treatment of autoimmune disorders, including rheumatoid arthritis, inflammatory bowel disease, and psoriasis. However, due to high similarity in the active sites of the four members (Jak1, Jak2, Jak3, and Tyk2), developing selective inhibitors within this family is challenging. In this paper, we have designed and characterized substituted, tricyclic Jak3 inhibitors that selectively avoid inhibition of the other JAKs. This is accomplished through a covalent interaction between an inhibitor containing a terminal electrophile and an active site cysteine (Cys-909). Wemore » found that these ATP competitive compounds are irreversible inhibitors of Jak3 enzyme activity in vitro. They possess high selectivity against other kinases and can potently (IC 50 < 100 nM) inhibit Jak3 activity in cell-based assays. Finally, these results suggest irreversible inhibitors of this class may be useful selective agents, both as tools to probe Jak3 biology and potentially as therapies for autoimmune diseases.« less

  1. A targeted mutational landscape of angioimmunoblastic T-cell lymphoma

    PubMed Central

    Odejide, Oreofe; Weigert, Oliver; Lane, Andrew A.; Toscano, Dan; Lunning, Matthew A.; Kopp, Nadja; Kim, Sunhee; van Bodegom, Diederik; Bolla, Sudha; Schatz, Jonathan H.; Teruya-Feldstein, Julie; Hochberg, Ephraim; Louissaint, Abner; Dorfman, David; Stevenson, Kristen; Rodig, Scott J.; Piccaluga, Pier Paolo; Jacobsen, Eric; Pileri, Stefano A.; Harris, Nancy L.; Ferrero, Simone; Inghirami, Giorgio; Horwitz, Steven M.

    2014-01-01

    The genetics of angioimmunoblastic T-cell lymphoma (AITL) are very poorly understood. We defined the mutational landscape of AITL across 219 genes in 85 cases from the United States and Europe. We identified ≥2 mutations in 34 genes, nearly all of which were not previously implicated in AITL. These included loss-of-function mutations in TP53 (n = 4), ETV6 (n = 3), CCND3 (n = 2), and EP300 (n = 5), as well as gain-of-function mutations in JAK2 (n = 2) and STAT3 (n = 4). TET2 was mutated in 65 (76%) AITLs, including 43 that harbored 2 or 3 TET2 mutations. DNMT3A mutations occurred in 28 (33%) AITLs; 100% of these also harbored TET2 mutations (P < .0001). Seventeen AITLs harbored IDH2 R172 substitutions, including 15 with TET2 mutations. In summary, AITL is characterized by high frequencies of overlapping mutations in epigenetic modifiers and targetable mutations in a subset of cases. PMID:24345752

  2. Philadelphia chromosome-negative classical myeloproliferative neoplasms: revised management recommendations from European LeukemiaNet.

    PubMed

    Barbui, Tiziano; Tefferi, Ayalew; Vannucchi, Alessandro M; Passamonti, Francesco; Silver, Richard T; Hoffman, Ronald; Verstovsek, Srdan; Mesa, Ruben; Kiladjian, Jean-Jacques; Hehlmann, Rȕdiger; Reiter, Andreas; Cervantes, Francisco; Harrison, Claire; Mc Mullin, Mary Frances; Hasselbalch, Hans Carl; Koschmieder, Steffen; Marchetti, Monia; Bacigalupo, Andrea; Finazzi, Guido; Kroeger, Nicolaus; Griesshammer, Martin; Birgegard, Gunnar; Barosi, Giovanni

    2018-05-01

    This document updates the recommendations on the management of Philadelphia chromosome-negative myeloproliferative neoplasms (Ph-neg MPNs) published in 2011 by the European LeukemiaNet (ELN) consortium. Recommendations were produced by multiple-step formalized procedures of group discussion. A critical appraisal of evidence by using Grades of Recommendation, Assessment, Development and Evaluation (GRADE) methodology was performed in the areas where at least one randomized clinical trial was published. Seven randomized controlled trials provided the evidence base; earlier phase trials also informed recommendation development. Key differences from the 2011 diagnostic recommendations included: lower threshold values for hemoglobin and hematocrit and bone marrow examination for diagnosis of polycythemia vera (PV), according to the revised WHO criteria; the search for complementary clonal markers, such as ASXL1, EZH2, IDH1/IDH2, and SRSF2 for the diagnosis of myelofibrosis (MF) in patients who test negative for JAK2V617, CALR or MPL driver mutations. Regarding key differences of therapy recommendations, both recombinant interferon alpha and the JAK1/JAK2 inhibitor ruxolitinib are recommended as second-line therapies for PV patients who are intolerant or have inadequate response to hydroxyurea. Ruxolitinib is recommended as first-line approach for MF-associated splenomegaly in patients with intermediate-2 or high-risk disease; in case of intermediate-1 disease, ruxolitinib is recommended in highly symptomatic splenomegaly. Allogeneic stem cell transplantation is recommended for transplant-eligible MF patients with high or intermediate-2 risk score. Allogeneic stem cell transplantation is also recommended for transplant-eligible MF patients with intermediate-1 risk score who present with either refractory, transfusion-dependent anemia, blasts in peripheral blood > 2%, adverse cytogenetics, or high-risk mutations. In these situations, the transplant procedure should be

  3. Janus-kinase-2 relates directly to portal hypertension and to complications in rodent and human cirrhosis.

    PubMed

    Klein, Sabine; Rick, Johanna; Lehmann, Jennifer; Schierwagen, Robert; Schierwagen, Irela Gretchen; Verbeke, Len; Hittatiya, Kanishka; Uschner, Frank Erhard; Manekeller, Steffen; Strassburg, Christian P; Wagner, Kay-Uwe; Sayeski, Peter P; Wolf, Dominik; Laleman, Wim; Sauerbruch, Tilman; Trebicka, Jonel

    2017-01-01

    Angiotensin II (AngII) activates via angiotensin-II-type-I receptor (AT1R) Janus-kinase-2 (JAK2)/Arhgef1 pathway and subsequently RHOA/Rho-kinase (ROCK), which induces experimental and probably human liver fibrosis. This study investigated the relationship of JAK2 to experimental and human portal hypertension. The mRNA and protein levels of JAK2/ARHGEF1 signalling components were analysed in 49 human liver samples and correlated with clinical parameters of portal hypertension in these patients. Correspondingly, liver fibrosis (bile duct ligation (BDL), carbon tetrachloride (CCl 4 )) was induced in floxed-Jak2 knock-out mice with SM22-promotor (SM22 Cre+ -Jak2 f/f ). Transcription and contraction of primary myofibroblasts from healthy and fibrotic mice and rats were analysed. In two different cirrhosis models (BDL, CCl 4 ) in rats, the acute haemodynamic effect of the JAK2 inhibitor AG490 was assessed using microsphere technique and isolated liver perfusion experiments. Hepatic transcription of JAK2/ARHGEF1 pathway components was upregulated in liver cirrhosis dependent on aetiology, severity and complications of human liver cirrhosis (Model for End-stage Liver disease (MELD) score, Child score as well as ascites, high-risk varices, spontaneous bacterial peritonitis). SM22 Cre+ - Jak2 f/f mice lacking Jak2 developed less fibrosis and lower portal pressure (PP) than SM22 Cre- -Jak2 f/f upon fibrosis induction. Myofibroblasts from SM22 Cre+ -Jak2 f/f mice expressed less collagen and profibrotic markers upon activation. AG490 relaxed activated hepatic stellate cells in vitro. In cirrhotic rats, AG490 decreased hepatic vascular resistance and consequently the PP in vivo and in situ. Hepatic JAK2/ARHGEF1/ROCK expression is associated with portal hypertension and decompensation in human cirrhosis. The deletion of Jak2 in myofibroblasts attenuated experimental fibrosis and acute inhibition of JAK2 decreased PP. Thus, JAK2 inhibitors, already in clinical use for other

  4. Painful Charcot-Marie-Tooth neuropathy type 2E/1F due to a novel NEFL mutation.

    PubMed

    Doppler, Kathrin; Kunstmann, Erdmute; Krüger, Stefan; Sommer, Claudia

    2017-05-01

    Charcot-Marie-Tooth neuropathy (CMT) 2E/1F is caused by mutations in the neurofilament light-chain polypeptide (NEFL) gene. Giant axons are a histological hallmark frequently seen in nerves of patients with CMT2E. We describe the case of a 43-year-old patient with a painful, predominantly sensory neuropathy. The patient's sural nerve biopsy showed multiple giant axons. Genetic sequencing of the NEFL gene revealed that the patient was heterozygous for an altered sequence of the gene, c.816C>G, p.Asn272Lys, which has not yet been described in CMT2E/1F. In contrast to other cases of CMT2E/1F, where motor symptoms are predominant, pain was the most disabling symptom in this patient. Muscle Nerve 55: 752-755, 2017. © 2016 Wiley Periodicals, Inc.

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

    PubMed

    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.

  6. V2R mutations and nephrogenic diabetes insipidus.

    PubMed

    Bichet, Daniel G

    2009-01-01

    Nephrogenic diabetes insipidus (NDI), which can be inherited or acquired, is characterized by an inability to concentrate urine despite normal or elevated plasma concentrations of the antidiuretic hormone, arginine vasopressin (AVP). Polyuria, with hyposthenuria, and polydipsia are the cardinal clinical manifestations of the disease. Nephrogenic failure to concentrate urine maximally may be due to a defect in vasopressin-induced water permeability of the distal tubules and collecting ducts, to insufficient buildup of the corticopapillary interstitial osmotic gradient, or to a combination of these two factors. Thus, the broadest definition of the term NDI embraces any antidiuretic hormone-resistant urinary-concentrating defect, including medullary disease with low interstitial osmolality, renal failure, and osmotic diuresis. About 90% of patients with congenital NDI are males with X-linked recessive NDI (OMIM 304800)(1) and have mutations in the AVP receptor 2 (AVPR2) gene that codes for the vasopressin V(2) receptor; the gene is located in chromosome region Xq28. In about 10% of the families studied, congenital NDI has an autosomal recessive or autosomal dominant mode of inheritance (OMIM 222000 and 125800)(1). Mutations have been identified in the aquaporin-2 gene (AQP2, OMIM 107777)(1), which is located in chromosome region 12q13 and codes for the vasopressin-sensitive water channel. NDI is clinically distinguishable from neurohypophyseal diabetes insipidus (OMIM 125700(1); also referred to as central or neurogenic diabetes insipidus) by a lack of response to exogenous AVP and by plasma levels of AVP that rise normally with increase in plasma osmolality. Hereditary neurohypophyseal diabetes insipidus is secondary to mutations in the gene encoding AVP (OMIM 192340)(1). Neurohypophyseal diabetes insipidus is also a component of autosomal recessive Wolfram syndrome 1 or DIDMOAD syndrome (diabetes insipidus, diabetes mellitus, optic atrophy, and deafness) (OMIM

  7. The dimeric [V{sub 2}O{sub 2}F{sub 8}]{sup 4−} anion: Structural characterization of a magnetic basic-building-unit

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Lu, Hongcheng, E-mail: hchlu@northwestern.edu; State Key Laboratory of Solidification Processing, School of Material Science and Engineering, Northwestern Polytechnical University, 127 Youyixilu Road, Xi'an 710072; Gautier, Romain, E-mail: r-gautier@northwestern.edu

    2013-04-15

    New materials built from the [V{sub 2}O{sub 2}F{sub 8}]{sup 4−} anionic basic-building-unit (BBU) exhibit interesting magnetic properties owing to the proximity of the two d{sup 1} V(IV) cations and the orbital interactions of fluoride and oxide ligands. In our search to target such materials, the vanadium oxide–fluoride compound [dpaH{sub 2}]{sub 2}[V{sub 2}O{sub 2}F{sub 8}] in which a dimeric anion [V{sub 2}O{sub 2}F{sub 8}]{sup 4−} is isolated in a hydrogen bond network was hydrothermally synthesized (dpa=2,2′-dipyridylamine). This hydrogen bond network is able to stabilize the highly ionic species [V{sub 2}O{sub 2}F{sub 8}]{sup 4−} as demonstrated with bond valence calculations. The coordinationmore » of the O{sup 2−}/F{sup −} ordered ligands was investigated and antiferromagnetic coupling of the isolated BBU was measured. - The new hybrid compound [dpaH{sub 2}]{sub 2}[V{sub 2}O{sub 2}F{sub 8}] built from the interesting [V{sub 2}O{sub 2}F{sub 8}]{sup 4−} magnetic basic-building-unit (BBU) was synthesized by the hydrothermal method. The coordination of the O{sup 2−}/F{sup −} ordered ligands was investigated by BVS calculations and antiferromagnetic coupling was measured. Highlights: ► A new vanadium oxyfluoride was synthesized by hydrothermal method. ► The Dimeric [V{sub 2}O{sub 2}F{sub 8}]{sup 4−} basic building unit is isolated in the hydrogen bond networks. ► The coordination of [V{sub 2}O{sub 2}F{sub 8}]{sup 4−} units to the extended structure is investigated. ► Isolated [V{sub 2}O{sub 2}F{sub 8}]{sup 4−} units exhibit antiferromagnetic coupling.« less

  8. Functional interaction of CCAAT/enhancer-binding-protein-α basic region mutants with E2F transcription factors and DNA.

    PubMed

    Kowenz-Leutz, Elisabeth; Schuetz, Anja; Liu, Qingbin; Knoblich, Maria; Heinemann, Udo; Leutz, Achim

    2016-07-01

    The transcription factor CCAAT/enhancer-binding protein α (C/EBPα) regulates cell cycle arrest and terminal differentiation of neutrophils and adipocytes. Mutations in the basic leucine zipper domain (bZip) of C/EBPα are associated with acute myeloid leukemia. A widely used murine transforming C/EBPα basic region mutant (BRM2) entails two bZip point mutations (I294A/R297A). BRM2 has been discordantly described as defective for DNA binding or defective for interaction with E2F. We have separated the two BRM2 mutations to shed light on the intertwined reciprocity between C/EBPα-E2F-DNA interactions. Both, C/EBPα I294A and R297A retain transactivation capacity and interaction with E2F-DP. The C/EBPα R297A mutation destabilized DNA binding, whereas the C/EBPα I294A mutation enhanced binding to DNA. The C/EBPα R297A mutant, like BRM2, displayed enhanced interaction with E2F-DP but failed to repress E2F-dependent transactivation although both mutants were readily suppressed by E2F1 for transcription through C/EBP cis-regulatory sites. In contrast, the DNA binding enhanced C/EBPα I294A mutant displayed increased repression of E2F-DP mediated transactivation and resisted E2F-DP mediated repression. Thus, the efficient repression of E2F dependent S-phase genes and the activation of differentiation genes reside in the balanced DNA binding capacity of C/EBPα. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Non-syndromic hearing loss caused by the dominant cis mutation R75Q with the recessive mutation V37I of the GJB2 (Connexin 26) gene.

    PubMed

    Kim, Juwon; Jung, Jinsei; Lee, Min Goo; Choi, Jae Young; Lee, Kyung-A

    2015-06-19

    GJB2 alleles containing two cis mutations have been rarely found in non-syndromic hearing loss. Herein, we present a Korean patient with non-syndromic hearing loss caused by the R75Q cis mutation with V37I, which arose de novo in the father and was inherited by the patient. Biochemical coupling and hemichannel permeability assays were performed after molecular cloning and transfection of HEK293T cells. Student's t-tests or analysis of variance followed by Tukey's multiple comparison test was used as statistical analysis. Biochemical coupling was significantly reduced in connexin 26 (Cx26)-R75Q- and Cx26-V37I-transfected cells, with greater extent in Cx26-R75Q and Cx26-R75Q+V37I cells. Interestingly, our patient and his father with the mutations had more residual hearing compared with patients with the dominant mutation alone. Although the difference in hemichannel activity between R75Q alone and R75Q in combination with V37I failed to reach significance, it is of note that there is a possibility that V37I located upstream of R75Q might have the ability to ameliorate R75Q expression. Our study emphasizes the importance of cis mutations with R75Q, as the gene effect of R75Q can be modulated depending on the type of additional mutation.

  10. JAK2 rs10758669 polymorphisms and susceptibility to ulcerative colitis and Crohn's disease: a meta-analysis.

    PubMed

    Zhang, Ji-Xiang; Song, Jia; Wang, Jun; Dong, Wei-Guo

    2014-06-01

    In this meta-analysis, we aimed to clarify the impact of Janus kinase 2 (JAK2) rs10758669 polymorphisms on ulcerative colitis (UC) and Crohn's disease (CD) risk. Data were extracted, and pooled odd ratios (ORs) as well as 95% confidence intervals (95%CIs) were calculated. Eleven studies with 7009 CD patients, 7929 UC patients, and 19235 controls were included. The results showed that JAK2 rs10758669 polymorphism was associated with CD (AC vs. AA, OR = 1.16, 95%CI, 1.08-1.24; CC vs. AA, OR = 1.29, 95%CI, 1.17-1.43; AC + CC vs. AA, OR = 1.19, 95%CI, 1.11-1.27; CC vs. AA + AC, OR = 1.19, 95%CI, 1.09-1.31; C vs. A, OR = 1.14, 95%CI, 1.09-1.20) and UC susceptibility (AC vs. AA, OR = 1.14, 95%CI, 1.06-1.22; CC vs. AA, OR = 1.33, 95%CI, 1.20-1.47; AC + CC vs. AA, OR = 1.18, 95%CI, 1.10-1.27; CC vs. AA + AC, OR = 1.24, 95%CI, 1.12-1.36; C vs. A, OR = 1.15, 95%CI, 1.10-1.21). But no significant association was found between JAK2 rs10758669 polymorphism with CD in Asian. Either in adult-onset group or multi-age group, hospital-based group or population-based group, JAK2 rs10758669 polymorphism was associated with CD and UC susceptibility. This meta-analysis indicated that JAK2 rs10758669 polymorphism was a risk factor both for CD and UC, especially in Caucasian. The differences in age of onset and study design did not influence the associations obviously. Gene-gene and gene-environment interactions should be investigated in the future.

  11. A Drosophila model of myeloproliferative neoplasm reveals a feed-forward loop in the JAK pathway mediated by p38 MAPK signalling

    PubMed Central

    Pérez, Lidia; Bray, Sarah J.

    2017-01-01

    ABSTRACT Myeloproliferative neoplasms (MPNs) of the Philadelphia-negative class comprise polycythaemia vera, essential thrombocythaemia and primary myelofibrosis (PMF). They are associated with aberrant numbers of myeloid lineage cells in the blood, and in the case of overt PMF, with development of myelofibrosis in the bone marrow and failure to produce normal blood cells. These diseases are usually caused by gain-of-function mutations in the kinase JAK2. Here, we use Drosophila to investigate the consequences of activation of the JAK2 orthologue in haematopoiesis. We have identified maturing haemocytes in the lymph gland, the major haematopoietic organ in the fly, as the cell population susceptible to induce hypertrophy upon targeted overexpression of JAK. We show that JAK activates a feed-forward loop, including the cytokine-like ligand Upd3 and its receptor, Domeless, which are required to induce lymph gland hypertrophy. Moreover, we present evidence that p38 MAPK signalling plays a key role in this process by inducing expression of the ligand Upd3. Interestingly, we also show that forced activation of the p38 MAPK pathway in maturing haemocytes suffices to generate hypertrophic organs and the appearance of melanotic tumours. Our results illustrate a novel pro-tumourigenic crosstalk between the p38 MAPK pathway and JAK signalling in a Drosophila model of MPNs. Based on the shared molecular mechanisms underlying MPNs in flies and humans, the interplay between Drosophila JAK and p38 signalling pathways unravelled in this work might have translational relevance for human MPNs. PMID:28237966

  12. Mutational landscape of MCPyV-positive and MCPyV-negative Merkel cell carcinomas with implications for immunotherapy.

    PubMed

    Goh, Gerald; Walradt, Trent; Markarov, Vladimir; Blom, Astrid; Riaz, Nadeem; Doumani, Ryan; Stafstrom, Krista; Moshiri, Ata; Yelistratova, Lola; Levinsohn, Jonathan; Chan, Timothy A; Nghiem, Paul; Lifton, Richard P; Choi, Jaehyuk

    2016-01-19

    Merkel cell carcinoma (MCC) is a rare but highly aggressive cutaneous neuroendocrine carcinoma, associated with the Merkel cell polyomavirus (MCPyV) in 80% of cases. To define the genetic basis of MCCs, we performed exome sequencing of 49 MCCs. We show that MCPyV-negative MCCs have a high mutation burden (median of 1121 somatic single nucleotide variants (SSNVs) per-exome with frequent mutations in RB1 and TP53 and additional damaging mutations in genes in the chromatin modification (ASXL1, MLL2, and MLL3), JNK (MAP3K1 and TRAF7), and DNA-damage pathways (ATM, MSH2, and BRCA1). In contrast, MCPyV-positive MCCs harbor few SSNVs (median of 12.5 SSNVs/tumor) with none in the genes listed above. In both subgroups, there are rare cancer-promoting mutations predicted to activate the PI3K pathway (HRAS, KRAS, PIK3CA, PTEN, and TSC1) and to inactivate the Notch pathway (Notch1 and Notch2). TP53 mutations appear to be clinically relevant in virus-negative MCCs as 37% of these tumors harbor potentially targetable gain-of-function mutations in TP53 at p.R248 and p.P278. Moreover, TP53 mutational status predicts death in early stage MCC (5-year survival in TP53 mutant vs wild-type stage I and II MCCs is 20% vs. 92%, respectively; P = 0.0036). Lastly, we identified the tumor neoantigens in MCPyV-negative and MCPyV-positive MCCs. We found that virus-negative MCCs harbor more tumor neoantigens than melanomas or non-small cell lung cancers (median of 173, 65, and 111 neoantigens/sample, respectively), two cancers for which immune checkpoint blockade can produce durable clinical responses. Collectively, these data support the use of immunotherapies for virus-negative MCCs.

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

    PubMed Central

    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

  14. Mutation and polymorphism analysis of the human homogentisate 1, 2-dioxygenase gene in alkaptonuria patients.

    PubMed Central

    Beltrán-Valero de Bernabé, D; Granadino, B; Chiarelli, I; Porfirio, B; Mayatepek, E; Aquaron, R; Moore, M M; Festen, J J; Sanmartí, R; Peñalva, M A; de Córdoba, S R

    1998-01-01

    Alkaptonuria (AKU), a rare hereditary disorder of phenylalanine and tyrosine catabolism, was the first disease to be interpreted as an inborn error of metabolism. AKU patients are deficient for homogentisate 1,2 dioxygenase (HGO); this deficiency causes homogentisic aciduria, ochronosis, and arthritis. We cloned the human HGO gene and characterized two loss-of-function mutations, P230S and V300G, in the HGO gene in AKU patients. Here we report haplotype and mutational analysis of the HGO gene in 29 novel AKU chromosomes. We identified 12 novel mutations: 8 (E42A, W97G, D153G, S189I, I216T, R225H, F227S, and M368V) missense mutations that result in amino acid substitutions at positions conserved in HGO in different species, 1 (F10fs) frameshift mutation, 2 intronic mutations (IVS9-56G-->A, IVS9-17G-->A), and 1 splice-site mutation (IVS5+1G-->T). We also report characterization of five polymorphic sites in HGO and describe the haplotypic associations of alleles at these sites in normal and AKU chromosomes. One of these sites, HGO-3, is a variable dinucleotide repeat; IVS2+35T/A, IVS5+25T/C, and IVS6+46C/A are intronic sites at which single nucleotide substitutions (dimorphisms) have been detected; and c407T/A is a relatively frequent nucleotide substitution in the coding sequence, exon 4, resulting in an amino acid change (H80Q). These data provide insight into the origin and evolution of the various AKU alleles. PMID:9529363

  15. Discovery of a Highly Selective JAK2 Inhibitor, BMS-911543, for the Treatment of Myeloproliferative Neoplasms

    PubMed Central

    2015-01-01

    JAK2 kinase inhibitors are a promising new class of agents for the treatment of myeloproliferative neoplasms and have potential for the treatment of other diseases possessing a deregulated JAK2-STAT pathway. X-ray structure and ADME guided refinement of C-4 heterocycles to address metabolic liability present in dialkylthiazole 1 led to the discovery of a clinical candidate, BMS-911543 (11), with excellent kinome selectivity, in vivo PD activity, and safety profile. PMID:26288683

  16. JAK-STAT and G-protein-coupled receptor signaling pathways are frequently altered in epitheliotropic intestinal T-cell lymphoma

    PubMed Central

    Nairismägi, M-L; Tan, J; Lim, J Q; Nagarajan, S; Ng, C C Y; Rajasegaran, V; Huang, D; Lim, W K; Laurensia, Y; Wijaya, G C; Li, Z M; Cutcutache, I; Pang, W L; Thangaraju, S; Ha, J; Khoo, L P; Chin, S T; Dey, S; Poore, G; Tan, L H C; Koh, H K M; Sabai, K; Rao, H-L; Chuah, K L; Ho, Y-H; Ng, S-B; Chuang, S-S; Zhang, F; Liu, Y-H; Pongpruttipan, T; Ko, Y H; Cheah, P-L; Karim, N; Chng, W-J; Tang, T; Tao, M; Tay, K; Farid, M; Quek, R; Rozen, S G; Tan, P; Teh, B T; Lim, S T; Tan, S-Y; Ong, C K

    2016-01-01

    Epitheliotropic intestinal T-cell lymphoma (EITL, also known as type II enteropathy-associated T-cell lymphoma) is an aggressive intestinal disease with poor prognosis and its molecular alterations have not been comprehensively characterized. We aimed to identify actionable easy-to-screen alterations that would allow better diagnostics and/or treatment of this deadly disease. By performing whole-exome sequencing of four EITL tumor-normal pairs, followed by amplicon deep sequencing of 42 tumor samples, frequent alterations of the JAK-STAT and G-protein-coupled receptor (GPCR) signaling pathways were discovered in a large portion of samples. Specifically, STAT5B was mutated in a remarkable 63% of cases, JAK3 in 35% and GNAI2 in 24%, with the majority occurring at known activating hotspots in key functional domains. Moreover, STAT5B locus carried copy-neutral loss of heterozygosity resulting in the duplication of the mutant copy, suggesting the importance of mutant STAT5B dosage for the development of EITL. Dysregulation of the JAK-STAT and GPCR pathways was also supported by gene expression profiling and further verified in patient tumor samples. In vitro overexpression of GNAI2 mutants led to the upregulation of pERK1/2, a member of MEK-ERK pathway. Notably, inhibitors of both JAK-STAT and MEK-ERK pathways effectively reduced viability of patient-derived primary EITL cells, indicating potential therapeutic strategies for this neoplasm with no effective treatment currently available. PMID:26854024

  17. JAK-STAT and G-protein-coupled receptor signaling pathways are frequently altered in epitheliotropic intestinal T-cell lymphoma.

    PubMed

    Nairismägi, M-L; Tan, J; Lim, J Q; Nagarajan, S; Ng, C C Y; Rajasegaran, V; Huang, D; Lim, W K; Laurensia, Y; Wijaya, G C; Li, Z M; Cutcutache, I; Pang, W L; Thangaraju, S; Ha, J; Khoo, L P; Chin, S T; Dey, S; Poore, G; Tan, L H C; Koh, H K M; Sabai, K; Rao, H-L; Chuah, K L; Ho, Y-H; Ng, S-B; Chuang, S-S; Zhang, F; Liu, Y-H; Pongpruttipan, T; Ko, Y H; Cheah, P-L; Karim, N; Chng, W-J; Tang, T; Tao, M; Tay, K; Farid, M; Quek, R; Rozen, S G; Tan, P; Teh, B T; Lim, S T; Tan, S-Y; Ong, C K

    2016-06-01

    Epitheliotropic intestinal T-cell lymphoma (EITL, also known as type II enteropathy-associated T-cell lymphoma) is an aggressive intestinal disease with poor prognosis and its molecular alterations have not been comprehensively characterized. We aimed to identify actionable easy-to-screen alterations that would allow better diagnostics and/or treatment of this deadly disease. By performing whole-exome sequencing of four EITL tumor-normal pairs, followed by amplicon deep sequencing of 42 tumor samples, frequent alterations of the JAK-STAT and G-protein-coupled receptor (GPCR) signaling pathways were discovered in a large portion of samples. Specifically, STAT5B was mutated in a remarkable 63% of cases, JAK3 in 35% and GNAI2 in 24%, with the majority occurring at known activating hotspots in key functional domains. Moreover, STAT5B locus carried copy-neutral loss of heterozygosity resulting in the duplication of the mutant copy, suggesting the importance of mutant STAT5B dosage for the development of EITL. Dysregulation of the JAK-STAT and GPCR pathways was also supported by gene expression profiling and further verified in patient tumor samples. In vitro overexpression of GNAI2 mutants led to the upregulation of pERK1/2, a member of MEK-ERK pathway. Notably, inhibitors of both JAK-STAT and MEK-ERK pathways effectively reduced viability of patient-derived primary EITL cells, indicating potential therapeutic strategies for this neoplasm with no effective treatment currently available.

  18. Controlling nuclear JAKs and STATs for specific gene activation by IFNγ.

    PubMed

    Noon-Song, Ezra N; Ahmed, Chulbul M; Dabelic, Rea; Canton, Johnathan; Johnson, Howard M

    2011-07-08

    We previously showed that gamma interferon (IFNγ) and its receptor subunit, IFNGR1, interacted with the promoter region of IFNγ-activated genes along with transcription factor STAT1α. Recent studies have suggested that activated Janus kinases pJAK2 and pJAK1 also played a role in gene activation by phosphorylation of histone H3 on tyrosine 41. This study addresses the question of the role of activated JAKs in specific gene activation by IFNγ. We carried out chromatin immunoprecipitation (ChIP) followed by PCR in IFNγ treated WISH cells and showed association of pJAK1, pJAK2, IFNGR1, and STAT1 on the same DNA sequence of the IRF-1 gene promoter. The β-actin gene, which is not activated by IFNγ, did not show this association. The movement of activated JAK to the nucleus and the IRF-1 promoter was confirmed by the combination of nuclear fractionation, confocal microscopy and DNA precipitation analysis using the biotinylated GAS promoter. Activated JAKs in the nucleus was associated with phosphorylated tyrosine 41 on histone H3 in the region of the GAS promoter. Unphosphorylated JAK2 was found to be constitutively present in the nucleus and was capable of undergoing activation in IFNγ treated cells, most likely via nuclear IFNGR1. Association of pJAK2 and IFNGR1 with histone H3 in IFNγ treated cells was demonstrated by histone H3 immunoprecipitation. Unphosphorylated STAT1 protein was associated with histone H3 of untreated cells. IFNγ treatment resulted in its disassociation and then re-association as pSTAT1. The results suggest a novel role for activated JAKs in epigenetic events for specific gene activation. Copyright © 2011 Elsevier Inc. All rights reserved.

  19. A novel heterozygous intronic mutation in POU1F1 is associated with combined pituitary hormone deficiency.

    PubMed

    Takagi, Masaki; Kamasaki, Hotaka; Yagi, Hiroko; Fukuzawa, Ryuji; Narumi, Satoshi; Hasegawa, Tomonobu

    2017-02-27

    POU class 1 homeobox 1 (POU1F1) regulates pituitary cell-specific gene expression of somatotropes, lactotropes, and thyrotropes. In humans, two POU1F1 isoforms (long and short isoform), which are generated by the alternative use of the splice acceptor site for exon 2, have been identified. To date, more than 30 POU1F1 mutations in patients with combined pituitary hormone deficiency (CPHD) have been described. All POU1F1 variants reported to date affect both the short and long isoforms of the POU1F1 protein; therefore, it is unclear at present whether a decrease in the function of only one of these two isoforms is sufficient for disease onset in humans. Here, we described a sibling case of CPHD carrying a heterozygous mutation in intron 1 of POU1F1. In vitro experiments showed that this mutation resulted in exon 2-skipping of only in the short isoform of POU1F1, while the long isoform remained intact. This result strongly suggests the possibility, for the first time, that isolated mutations in the short isoform of POU1F1 could be sufficient for induction of POU1F1-related CPHD. This finding improves our understanding of the molecular mechanisms, and developmental course associated with mutations in POU1F1.

  20. miR-122-SOCS1-JAK2 axis regulates allergic inflammation and allergic inflammation-promoted cellular interactions

    PubMed Central

    Kim, Hanearl; Kim, Hyuna; Byun, Jaehwan; Park, Yeongseo; Lee, Hansoo; Lee, Yun Sil; Choe, Jongseon; Kim, Young Myeong; Jeoung, Dooil

    2017-01-01

    The regulatory role of suppressor of cytokine signaling 1 (SOCS1) in inflammation has been reported. However, its role in allergic inflammation has not been previously reported. SOCS1 mediated in vitro and in vivo allergic inflammation. Histone deacetylase-3 (HDAC3), a mediator of allergic inflammation, interacted with SOCS1, and miR-384 inhibitor, a positive regulator of HDAC3, induced features of allergic inflammation in an SOCS1-dependent manner. miRNA array analysis showed that the expression of miR-122 was decreased by antigen-stimulation. TargetScan analysis predicted the binding of miR-122 to the 3′-UTR of SOCS1. miR-122 inhibitor induced in vitro and in vivo allergic features in SOCS1-dependent manner. SOCS1 was necessary for allergic inflammation-promoted enhanced tumorigenic and metastatic potential of cancer cells. SOCS1 and miR-122 regulated cellular interactions involving cancer cells, mast cells and macrophages during allergic inflammation. SOCS1 mimetic peptide, D-T-H-F-R-T-F-R-S-H-S-D-Y-R-R-I, inhibited in vitro and in vivo allergic inflammation, allergic inflammation-promoted enhanced tumorigenic and metastatic potential of cancer cells, and cellular interactions during allergic inflammation. Janus kinase 2 (JAK2) exhibited binding to SOCS1 mimetic peptide and mediated allergic inflammation. Transforming growth factor- Δ1 (TGF-Δ1) was decreased during allergic inflammation and showed an anti-allergic effect. SOCS1 and JAK2 regulated the production of anti-allergic TGF-Δ1. Taken together, our results show that miR-122-SOCS1 feedback loop can be employed as a target for the development of anti-allergic and anti-cancer drugs. PMID:28968979

  1. 48 CFR 617.105 - Policy.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 4 2011-10-01 2011-10-01 false Policy. 617.105 Section 617.105 Federal Acquisition Regulations System DEPARTMENT OF STATE CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Multiyear Contracting 617.105 Policy. ...

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

    PubMed

    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.

  3. Gradual Loss of ACTH Due to a Novel Mutation in LHX4: Comprehensive Mutation Screening in Japanese Patients with Congenital Hypopituitarism

    PubMed Central

    Takagi, Masaki; Ishii, Tomohiro; Inokuchi, Mikako; Amano, Naoko; Narumi, Satoshi; Asakura, Yumi; Muroya, Koji; Hasegawa, Yukihiro; Adachi, Masanori; Hasegawa, Tomonobu

    2012-01-01

    Mutations in transcription factors genes, which are well regulated spatially and temporally in the pituitary gland, result in congenital hypopituitarism (CH) in humans. The prevalence of CH attributable to transcription factor mutations appears to be rare and varies among populations. This study aimed to define the prevalence of CH in terms of nine CH-associated genes among Japanese patients. We enrolled 91 Japanese CH patients for DNA sequencing of POU1F1, PROP1, HESX1, LHX3, LHX4, SOX2, SOX3, OTX2, and GLI2. Additionally, gene copy numbers for POU1F1, PROP1, HESX1, LHX3, and LHX4 were examined by multiplex ligation-dependent probe amplification. The gene regulatory properties of mutant LHX4 proteins were characterized in vitro. We identified two novel heterozygous LHX4 mutations, namely c.249-1G>A, p.V75I, and one common POU1F1 mutation, p.R271W. The patient harboring the c.249-1G>A mutation exhibited isolated growth hormone deficiency at diagnosis and a gradual loss of ACTH, whereas the patient with the p.V75I mutation exhibited multiple pituitary hormone deficiency. In vitro experiments showed that both LHX4 mutations were associated with an impairment of the transactivation capacities of POU1F1 andαGSU, without any dominant-negative effects. The total mutation prevalence in Japanese CH patients was 3.3%. This study is the first to describe, a gradual loss of ACTH in a patient carrying an LHX4 mutation. Careful monitoring of hypothalamic–pituitary -adrenal function is recommended for CH patients with LHX4 mutations. PMID:23029363

  4. Factor V Leiden mutation in pregnancy.

    PubMed

    Cohen, Susan Murphy

    2004-01-01

    Normal maternal adaptation to pregnancy significantly increases the risk for thrombus formation. Inherited thrombophilias further increase risk for deep venous thrombosis and adverse outcome in pregnancy. Factor V Leiden mutation is the most common inherited thrombophilia, occurring in approximately 5% of the White and 1% of the Black populations. Nurses should be knowledgeable about screening for and diagnosis of factor V Leiden mutation, risk reduction counseling, recommended care of the affected patient, and implications of anticoagulant therapy during the perinatal period.

  5. Frequency of V1016I and F1534C mutations in the voltage-gated sodium channel gene in Aedes aegypti in Venezuela.

    PubMed

    Alvarez, Leslie C; Ponce, Gustavo; Saavedra-Rodriguez, Karla; Lopez, Beatriz; Flores, Adriana E

    2015-06-01

    The V1016I and F1534C mutations in the voltage-gated sodium channel gene have been associated with resistance to pyrethroids and DDT in Aedes aegypti mosquitoes. A study was carried out to determine the frequency of I1016 and C1534 by real-time PCR in five natural populations of Ae. aegypti in Venezuela during 2008, 2010 and 2012, as well as in a strain selected with 0.14 µg of deltamethrin for 15 generations. In natural populations, frequencies of I1016 varied between 0.01 and 0.37, and frequencies of C1534 between 0.35 and 1.0. In the Pampanito strain, the frequency of I1016 increased from 0.02 in F1 up to 0.5 in F15 and from 0.35 up to fixation for C1534 after selection with deltamethrin. The results showed that C1534 frequencies are higher than I1016 frequencies in natural populations of Ae. aegypti in Venezuela, and that deltamethrin selected the C1534 more rapidly than I1016. © 2014 Society of Chemical Industry.

  6. BRAF V600 Mutation Profile of Metastatic Melanoma in the Thrace Region of Turkey.

    PubMed

    Can, Nuray; Taştekin, Ebru; Deniz Yalta, Tülin; Süt, Necdet; Korkmaz, Selma; Usta, Ufuk; Öz Puyan, Fulya; Genç, Ezgi; Cezik, Mert; Binboğa Tutuğ, Busem; Köstek, Osman; Tozkir, Hilmi

    2018-02-08

    BRAF is the most common mutation in melanoma. The most common subtype is BRAF V600E, followed by V600K. Initially, the authors aimed to investigate whether clinicopathological features of melanoma are associated with BRAF mutations. We then aimed to present the relationships between the clinicopathological features and the mutated subtype (V600E vs V600K). 61 patients with metastatic malignant melanoma (affecting the lymph node or other distant sites) were selected. Patient data regarding age at the time of diagnosis, sex, metastatic site (lymph node, distant metastasis or both) and primary tumour site were obtained from the hospital's database. Tissue samples containing at least 30% tumour cells were isolated from the specimens of 61 patients (24 samples from primary tumours and 37 from metastatic foci) for BRAF analysis. Comparisons between the BRAF V600 mutation and clinicopathological and histopathological features were performed. BRAF V600 mutation was detected in 34 (55.7%) patients. The subtype was BRAF V600E in 22 (64.7%) patients, BRAF V600K in 11(32.4%) patients and BRAF V600R in 1(2.9%) patient. The crucial results of the present study may be summarized as follows: i) BRAF V600 mutation was more common in older patients and tumors with BRAF V600 mutation revealed necrosis and LVI more commonly than wild-type tumors, ii) BRAF V600K mutation was more common in older patients and BRAF V600K mutated tumors exhibited ulceration more commonly than tumors with BRAF V600E mutation (close to significant). The BRAF V600 mutation may have interactions with prognostic clinicoptahological features of melanoma including necrosis and lymphovascular invasion. V600K mutation may be more common than expected and may have different associations with properties of the tumor such as tumor ulceration and patient age. Investigation of the mutated subtype of the BRAF gene may therefore reveal more detailed data about the management of melanoma and may also prevent missing of

  7. 48 CFR 617.602 - Policy.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 4 2011-10-01 2011-10-01 false Policy. 617.602 Section 617.602 Federal Acquisition Regulations System DEPARTMENT OF STATE CONTRACTING METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Management and Operating Contracts 617.602 Policy. The Assistant...

  8. Patient characteristics and outcomes in adolescents and young adults with classical Philadelphia chromosome-negative myeloproliferative neoplasms.

    PubMed

    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.

  9. Jak2 and Ca2+/calmodulin are key intermediates for bradykinin B2 receptor-mediated activation of Na+/H+ exchange in KNRK and CHO cells.

    PubMed

    Lefler, David; Mukhin, Yurii V; Pettus, Tobiah; Leeb-Lundberg, L M Fredrik; Garnovskaya, Maria N; Raymond, John R

    2003-04-01

    Na(+)/H(+) exchangers are ubiquitous in mammalian cells, carrying out key functions, such as cell volume defense, acid-base homeostasis, and regulation of the cytoskeleton. We used two screening technologies (FLIPR and microphysiometry) to characterize the signal transduction pathway used by the bradykinin B(2) receptor to activate Na(+)/H(+) exchange in two cell lines, KNRK and CHO. In both cell types, B(2) receptor activation resulted in rapid increases in the rate of proton extrusion that were sodium-dependent and could be blocked by the Na(+)/H(+) exchange inhibitors EIPA and MIA or by replacing extracellular sodium with TMA. Activation of Na(+)/H(+) exchange by bradykinin was concentration-dependent and could be blocked by the selective B(2) receptor antagonist HOE140, but not by the B(1) receptor antagonist des-Arg10-HOE140. Inhibitors of Jak2 tyrosine kinase (genistein and AG490) and of CAM (W-7 and calmidazolium) attenuated bradykinin-induced activation of Na(+)/H(+) exchange. Bradykinin induced formation of a complex between CAM and Jak2, supporting a regulatory role for Jak2 and CAM in the activation of Na(+)/H(+) exchange in KNRK and CHO cells. We propose that this pathway (B(2) receptor --> Jak2 --> CAM --> Na(+)/H(+) exchanger) is a fundamental regulator of Na(+)/H(+) exchange activity.

  10. Myeloproliferative Neoplasms in Children.

    PubMed

    Hofmann, Inga

    2015-09-01

    Myeloproliferative neoplasms (MPN) are a group of clonal hematopoietic stem cell disorders characterized by aberrant proliferation of one or more myeloid lineages often with increased immature cells in the peripheral blood. The three classical BCR-ABL-negative MPNs are: 1) polycythemia vera (PV), 2) essential thrombocythemia (ET), and 3) primary myelofibrosis (PMF), which are typically disorders of older adults and are exceedingly rare in children. The diagnostic criteria for MPNs remain largely defined by clinical, laboratory and histopathology assessments in adults, but they have been applied to the pediatric population. The discovery of the JAK2 V617F mutation, and more recently, MPL and CALR mutations, are major landmarks in the understanding of MPNs. Nevertheless, they rarely occur in children, posing a significant diagnostic challenge given the lack of an objective, clonal marker. Therefore, in pediatric patients, the diagnosis must rely heavily on clinical and laboratory factors, and exclusion of secondary disorders to make an accurate diagnosis of MPN. This review focuses on the clinical presentation, diagnostic work up, differential diagnosis, treatment and prognosis of the classical BCR-ABL-negative MPNs (PV, ET and PMF) in children and highlights key differences to the adult diseases. Particular attention will be given to pediatric PMF, as it is the only disorder of this group that is observed in infants and young children, and in many ways appears to be a unique entity compared to adult PMF.

  11. Preventing structural degradation from Na3V2(PO4)3 to V2(PO4)3: F-doped Na3V2(PO4)3/C cathode composite with stable lifetime for sodium ion batteries

    NASA Astrophysics Data System (ADS)

    Chen, Yanjun; Xu, Youlong; Sun, Xiaofei; Zhang, Baofeng; He, Shengnan; Li, Long; Wang, Chao

    2018-02-01

    A prospective NASICON-type F-doped Na3V2(PO4)2.93F0.07/C (F-0.07-NVP/C) composite is synthesized by a solid-state reaction method. F-doping can restrain the structural degradation from Na3V2(PO4)3 to V2(PO4)3 and enhance the structural stability. Meanwhile, it can decrease the particle size to diminish the pathway of Na+ diffusion, which can increase ionic conductivity efficiently. The kinetic behavior is significantly improved and it is beneficial to reinforcing the electrochemical performance of F-doping composites. Compared with Undoped-NVP/C sample, F-0.07-NVP/C composite delivers a 113 mAh g-1 discharge capacity at 10 mA g-1, which is very close to the theoretical capacity (117 mAh g-1). As for cycle performance, a reversible capacity of 97.8 mAh g-1 can be obtained and it retains 86% capacity after 1000 cycles at 200 mA g-1. F-0.07-NVP/C composite presents the highest DNa+ (2.62 × 10-15 cm2s-1), two orders of magnitude higher than the undoped sample (4.8 × 10-17 cm2s-1). This outstanding electrochemical performance is ascribed to the synergetic effect from improved kinetic behavior and enhanced structural stability due to F-doping. Hence, the F-doped composite would be a promising cathode material in SIB for energy storage and conversion.

  12. BRCA2, EGFR, and NTRK mutations in mismatch repair-deficient colorectal cancers with MSH2 or MLH1 mutations.

    PubMed

    Deihimi, Safoora; Lev, Avital; Slifker, Michael; Shagisultanova, Elena; Xu, Qifang; Jung, Kyungsuk; Vijayvergia, Namrata; Ross, Eric A; Xiu, Joanne; Swensen, Jeffrey; Gatalica, Zoran; Andrake, Mark; Dunbrack, Roland L; El-Deiry, Wafik S

    2017-06-20

    Deficient mismatch repair (MMR) and microsatellite instability (MSI) contribute to ~15% of colorectal cancer (CRCs). We hypothesized MSI leads to mutations in DNA repair proteins including BRCA2 and cancer drivers including EGFR. We analyzed mutations among a discovery cohort of 26 MSI-High (MSI-H) and 558 non-MSI-H CRCs profiled at Caris Life Sciences. Caris-profiled MSI-H CRCs had high mutation rates (50% vs 14% in non-MSI-H, P < 0.0001) in BRCA2. Of 1104 profiled CRCs from a second cohort (COSMIC), MSH2/MLH1-mutant CRCs showed higher mutation rates in BRCA2 compared to non-MSH2/MLH1-mutant tumors (38% vs 6%, P < 0.0000001). BRCA2 mutations in MSH2/MLH1-mutant CRCs included 75 unique mutations not known to occur in breast or pancreatic cancer per COSMIC v73. Only 5 deleterious BRCA2 mutations in CRC were previously reported in the BIC database as germ-line mutations in breast cancer. Some BRCA2 mutations were predicted to disrupt interactions with partner proteins DSS1 and RAD51. Some CRCs harbored multiple BRCA2 mutations. EGFR was mutated in 45.5% of MSH2/MLH1-mutant and 6.5% of non-MSH2/MLH1-mutant tumors (P < 0.0000001). Approximately 15% of EGFR mutations found may be actionable through TKI therapy, including N700D, G719D, T725M, T790M, and E884K. NTRK gene mutations were identified in MSH2/MLH1-mutant CRC including NTRK1 I699V, NTRK2 P716S, and NTRK3 R745L. Our findings have clinical relevance regarding therapeutic targeting of BRCA2 vulnerabilities, EGFR mutations or other identified oncogenic drivers such as NTRK in MSH2/MLH1-mutant CRCs or other tumors with mismatch repair deficiency.

  13. 20 CFR 617.46 - Travel allowance.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Travel allowance. 617.46 Section 617.46... FOR WORKERS UNDER THE TRADE ACT OF 1974 Relocation Allowances § 617.46 Travel allowance. (a) Computation. The amount of travel allowance (including lodging and meals) payable under § 617.45(a)(1) shall...

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

    PubMed

    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.

  15. In Japanese patients with papillary thyroid carcinoma, TERT promoter mutation is associated with poor prognosis, in contrast to BRAF V600E mutation.

    PubMed

    Nasirden, Almira; Saito, Tsuyoshi; Fukumura, Yuki; Hara, Kieko; Akaike, Keisuke; Kurisaki-Arakawa, Aiko; Asahina, Miki; Yamashita, Atsushi; Tomomasa, Ran; Hayashi, Takuo; Arakawa, Atsushi; Yao, Takashi

    2016-12-01

    The prognostic value of BRAF V600E and TERT promoter mutation in papillary thyroid carcinoma (PTC) is controversial. We examined alterations in BRAF V600E and TERT promoter by PCR-direct sequencing in PTC of 144 Japanese patients. Alternative lengthening of telomeres was examined as another mechanism of telomere maintenance by immunohistochemical staining for ATRX and DAXX. Of the clinicopathological characteristics, regional lymph node metastasis, extra-thyroid extension, multifocality/intrathyroidal spread, and advanced stage (III/V) were associated with shorter disease-free survival rate (DFSR). TERT promoter mutation was found in eight patients (6 %), and this was significantly associated with total thyroidectomy, multifocality/intrathyroidal spread, lymph node metastasis and advanced stage. The BRAF V600E mutation was found in 53 patients (38.2 %) but was not associated with any clinicopathological factors. TERT mutations were not correlated with BRAF V600E mutation status. TERT mutation-positive tumors (TERT+) showed lower DFSR than BRAF V600E -mutation-positive tumors (BRAF V600E +), and TERT+/BRAF V600E + tumors showed lower DFSR than BRAF V600E + tumors. No cases showed loss of ATRX/DAXX expression by immunohistochemistry. TERT promoter mutations showed a lower prevalence in our series and appeared to be associated with aggressive behavior. In PTCs, telomerase activation by TERT promoter mutation might be more important than alternative lengthening of telomeres.

  16. Activating HER2 mutations in HER2 gene amplification negative breast cancer

    PubMed Central

    Bose, Ron; Kavuri, Shyam M.; Searleman, Adam C.; Shen, Wei; Shen, Dong; Koboldt, Daniel C.; Monsey, John; Goel, Nicholas; Aronson, Adam B.; Li, Shunqiang; Ma, Cynthia X.; Ding, Li; Mardis, Elaine R.; Ellis, Matthew J.

    2012-01-01

    Data from eight breast cancer genome sequencing projects identified 25 patients with HER2 somatic mutations in cancers lacking HER2 gene amplification. To determine the phenotype of these mutations, we functionally characterized thirteen HER2 mutations using in vitro kinase assays, protein structure analysis, cell culture and xenograft experiments. Seven of these mutations are activating mutations, including G309A, D769H, D769Y, V777L, P780ins, V842I, and R896C. HER2 in-frame deletion 755-759, which is homologous to EGFR exon 19 in-frame deletions, had a neomorphic phenotype with increased phosphorylation of EGFR or HER3. L755S produced lapatinib resistance, but was not an activating mutation in our experimental systems. All of these mutations were sensitive to the irreversible kinase inhibitor, neratinib. These findings demonstrate that HER2 somatic mutation is an alternative mechanism to activate HER2 in breast cancer and they validate HER2 somatic mutations as drug targets for breast cancer treatment. PMID:23220880

  17. Controlling nuclear JAKs and STATs for specific gene activation by IFN{gamma}

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Noon-Song, Ezra N.; Ahmed, Chulbul M.; Dabelic, Rea

    2011-07-08

    Highlights: {yields} Gamma interferon (IFN{gamma}) and its receptor subunit, IFNGR1, interact with the promoter region of IFN{gamma}-associated genes along with transcription factor STAT1{alpha}. {yields} We show that activated Janus kinases pJAK2 and pJAK1 also associate with IFNGR1 in the nucleus. {yields} The activated Janus kinases are responsible for phosphorylation of tyrosine 41 on histone H3, an important epigenetic event for specific gene activation. -- Abstract: We previously showed that gamma interferon (IFN{gamma}) and its receptor subunit, IFNGR1, interacted with the promoter region of IFN{gamma}-activated genes along with transcription factor STAT1{alpha}. Recent studies have suggested that activated Janus kinases pJAK2 andmore » pJAK1 also played a role in gene activation by phosphorylation of histone H3 on tyrosine 41. This study addresses the question of the role of activated JAKs in specific gene activation by IFN{gamma}. We carried out chromatin immunoprecipitation (ChIP) followed by PCR in IFN{gamma} treated WISH cells and showed association of pJAK1, pJAK2, IFNGR1, and STAT1 on the same DNA sequence of the IRF-1 gene promoter. The {beta}-actin gene, which is not activated by IFN{gamma}, did not show this association. The movement of activated JAK to the nucleus and the IRF-1 promoter was confirmed by the combination of nuclear fractionation, confocal microscopy and DNA precipitation analysis using the biotinylated GAS promoter. Activated JAKs in the nucleus was associated with phosphorylated tyrosine 41 on histone H3 in the region of the GAS promoter. Unphosphorylated JAK2 was found to be constitutively present in the nucleus and was capable of undergoing activation in IFN{gamma} treated cells, most likely via nuclear IFNGR1. Association of pJAK2 and IFNGR1 with histone H3 in IFN{gamma} treated cells was demonstrated by histone H3 immunoprecipitation. Unphosphorylated STAT1 protein was associated with histone H3 of untreated cells. IFN

  18. 45 CFR 617.10 - Mediation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Mediation. 617.10 Section 617.10 Public Welfare... OF AGE IN PROGRAMS OR ACTIVITIES RECEIVING FEDERAL FINANCIAL ASSISTANCE FROM NSF § 617.10 Mediation. (a) NSF will refer to the Federal Mediation and Conciliation Service all complaints that fall within...

  19. Inflammation as a Driver of Clonal Evolution in Myeloproliferative Neoplasm

    DTIC Science & Technology

    2017-10-01

    ligation due to a defect in the negative regulatory feedback loop which normally serves to dampen TNF production . We have localized this defect to a...excessive inflammatory cytokine production in MPN. 15. SUBJECT TERMS Myeloproliferative neoplasm, JAK2V617F, IL-10, TNF, inflammation 16. SECURITY...4 4. Impact…………………………...……………………………………9 5. Changes/Problems...….………………………………………………11 6. Products …………………………………….……….….…………….12 7

  20. JAK inhibitors in autoinflammation.

    PubMed

    Hoffman, Hal M; Broderick, Lori

    2018-06-11

    Interferonopathies are a subset of autoinflammatory disorders with a prominent type I IFN gene signature. Treatment of these patients has been challenging, given the lack of response to common autoinflammatory therapeutics including IL-1 and TNF blockade. JAK inhibitors (Jakinibs) are a family of small-molecule inhibitors that target the JAK/STAT signaling pathway and have shown clinical efficacy, with FDA and European Medicines Agency (EMA) approval for arthritic and myeloproliferative syndromes. Sanchez and colleagues repurposed baricitinib to establish a significant role for JAK inhibition as a novel therapy for patients with interferonopathies, demonstrating the power of translational rare disease research with lifesaving effects.