Correlation analysis on JAK2V617F mutation and clinical features in patients with myeloproliferative neoplasms and its clinical significance / 吉林大学学报(医学版)

Objective: To investigate the distribution of JAK2V617F mutation in the patients with myeloproliferative neoplasms (MPN), to explore the association between JAK2V617F mutation and the clinical features of MPN, and to clarify its clinical significance in the diagnosis and treatment of the MPN patients. Methods: A total of 170 patients with MPN were selected as the subjects and divided into true polycythemia (PV) group (n=68), primary thrombocytopenia (ET) group (n=88) and primary myelofibrosis (PMF) group (n=14). The JAK2V617F mutations in 170 patients with MPN were detected by allele-specific PCR (AS-PCR). The differences in gender, age, white blood cell count, hemoglobin, platelet count, prothrombin time (PT), activated partial thromboplastin time (APTT), D-dimer, whether complicated with splenomegaly and thromboembolism of the JAK2V617F mutant-type and wild-type patients in each group were analyzed. Results: The total mutation rate of JAK2V617F mutation in 170 patients with MPN was 68. 2% (116/170), and the mutation rates in PV, ET, and PMF groups were 72. 1% (49/68), 68. 1% (60/88), and 50. 0% (7/14), respectively. The JAK2V617F mutation rate in PV group was higher than those in the other two groups, but there were no statistical differences (P = 0. 281). Compared with wild type group, the age of onset, the white blood cell and platelet counts of the PV patients with JAK2V617F mutation were significantly increased (P

Association of JAK2V617F mutation with thrombosis in Indian patients with Philadelphia negative chronic myeloproliferative neoplasms

Background: It is still a matter of debate regarding the association of JAK2V617F mutation with thrombosis in BCR-ABL negative CMPN patients. The role of JAK2V617F mutation in increasing the thrombotic risk in CMPNs is yet unequivocal. Aims: To clarify the contribution of JAK2V617F mutation in thrombosis in CMPN patients. Settings and Design: This retrospective study was done to evaluate role of JAK2V617F mutation in thrombosis in CMPNs. Materials and Methods: 65 CMPN patients (PV, ET and PMF) were analyzed for JAK2V617F mutation using ARMS-PCR and detailed history of thrombosis was recorded in these patients. Statistical Analysis: P values were 2 tailed, and statistical significance was set at P < 0.05. Results: 46/65 were males and 19/65 were females [M: F: 2.4:1] with median age 46 years [range, 14-80 years]. Patients had median Hb 15.6 g/dl [range, 5.1-20.3], median TLC 10.7 × 109/l [range 2.4-216] and platelet count 360 × 109/l [range, 20-1859]. 32 were JAK2V617F positive and 33 were negative for this mutation. On comparing the prevalence of thrombosis in JAK2V617F positive patients with JAK2V617F negative patients, we observed that 20/32 (62.5%) JAK2V617F positive patients had thrombosis as compared to 16/33 (48%) in JAK2V617F negative patients (P = 0.04). We observed significant association of JAK2V617F mutation with thrombosis, however no association of this mutation with thrombosis was observed among the JAK2V617F negative patients. Conclusion: Our study suggests that JAK2V617F mutation may increase the risk of thrombosis in CMPNs. This finding could lead to risk stratification, setting up the treatment strategy in CMPNs.

Expression of socs1 and shp1 in JAK2V617F mutation positive myeloproliferative neoplasms and regulation effect of ruxolitinib / 第二军医大学学报

Objective To analyze the relationship between the JAK2V617F mutation and the expressions of phosphorylated Janus kinase 2 (p-JAK2), suppressor of cytokine signaling 1 (SOCS1), and SH2-containing protein tyrosine phosphatase 1 (SHP1) in JAK2V617F mutation positive myeloproliferative neoplasm (MPN) tissues, and to investigate the effects of JAK2 inhibitor ruxolitinib on regulating the proliferation of JAK2V617F mutation positive human erythroleukemia cell lines HEL and the expressions of SOCS1 and SHP1 in HEL cells. Methods A total of 48 patients with JAK2V617F mutation positive MPN (MPN group) and 24 patients with anemia (control group) in Hebei General Hospital and The First People’s Hospital of Baoding from Jul. 2012 to Aug. 2016 were enrolled in this study. The protein expressions of p-JAK2, SOCS1 and SHP1 in bone marrow biopsies (BMBs) were detected by immunohistochemistry. The correlations between JAK2V617F mutation level and the protein expressions of SOCS1 and SHP1 were analyzed by Spearman rank correlation analysis. HEL cells were treated with ruxolitinib at different concentrations (50, 100, 250, 500 and 1 000 nmol/L), and the viability of cells was determined by CCK-8 assay. The JAK2V617F mutation levels in MPN tissues and HEL cells and the mRNA expressions of JAK2, SOCS1 and SHP1 in HEL cells were detected by qPCR. The protein expressions of JAK2, SOCS1 and SHP1 in HEL cells were detected by Western blotting analysis. Results The ratio of JAK2V617F/JAK2 was (57.33±20.82)% in the MPN group and was zero in the control group. The protein expressions of p-JAK2, SOCS1 and SHP1 in BMBs of MPN patients were significantly different from those in the control group (all P0.01). The protein expressions of SOCS1 and SHP1 were negatively correlated with the mutation level of JAK2V617F (r＝－0.648, －0.692; P0.05). The expressions of SOCS1 and SHP1 in MPN patients with JAK2V617F/JAK250% were significantly higher than those in MPN patients with JAK2V617F/JAK2≥50% (P0.01), while the expression of p-JAK2 was significantly lower than that in MPN patients with JAK2V617F/JAK2≥50% (P0.01). After treatment with 250 nmol/L ruxolitinib for 24 h, 48 h, and 72 h, the viabilities of HEL cells were (60.06±3.87)%, (52.05±2.88)%, and (36.43±2.01)%, respectively. With the increase of ruxolitinib concentrations, the mRNA and protein expressions of JAK2 and the protein expression of p-JAK2 were gradually decreased (P0.01, P0.05), while the mRNA and protein expressions of SOCS1 and SHP1 were gradually increased (all P0.01). Conclusion Ruxolitinib can inhibit the expressions of JAK and the phosphorylation of JAK in HEL cells, enhance the expressions of SOCS1 and SHP1, and reduce the viability of HEL cells.

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

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.

Clinical significances of JAK2 mutation in patients with polycythemia vera / 中国肿瘤临床

Polycythemia vera (PV) is a myeloproliferative neoplasm (MPN) characterized by overproduction of red blood cells. The pathogenesis of PV is not completely understood. However, studies report that it may be associated with the gain-of-function somatic mutation of JAK2 and that the JAK2 mutation provides a molecular diagnostic standard for PV. JAK2 mutation and allele mutation bur-den are useful for predicting clinical features and courses. The discovery of JAK2 mutation has promoted the development of molecu-lar-targeted therapy, such as the JAK2 inhibitor, ruxolitinib, a drug with superior therapeutic effect and safety that is used in clinical practice. The JAK2 allele mutation burden is closely associated with leukocytosis and progression to myelofibrosis (MF). A high JAK2 al-lele mutation burden may be a risk factor for poor prognosis. This article briefly reviews the clinical significance of the JAK2 mutation in patients with PV.

The Prevalence of JAK2-V617F Mutation in Sudanese Patients with Chronic Myeloproliferative Neoplasms.

Myeloproliferative neoplasms (MPNs) are clonal malignant diseases that represent a group of conditions including polycythemia vera (PV), essential thrombocythemia (ET), and myelofibrosis (MF). The JAK2-V617F mutation has been described as a frequent genetic event in majority of patients with MPNs. The aim of this study was to determine the frequency of JAK2-V617Fmutation in Sudanese patients with myeloproliferative disorders referred to Isotope Center, and to investigate the differences of laboratory parameters between patients with JAK2-V617F positive myeloproliferative neoplasms (MPNs) and JAK2 wild type MPNs. A total of 259 patients with MPNs; 159 with polycythemia vera (PV), 55 with essential thrombocytosis (ET) and 45 with primary myelofibrosis (PMF), and11 healthy adult individuals were enrolled in this study from March 2013 to November 2015. DNA was isolated from peripheral blood leukocytes by innuPREP kit, and JAK2-V617F mutation gene detected by allele specific PCR. The JAK2-V617F mutation was detected in 71% (184/259) patients with MPNs. The prevalence of the mutation was 81.7% in PV, 56.4% inET, and 51.1% in PMF. Mutation was not detected in 11 healthy adult people. The presence of JAK2-V617F was not associated with Hb level, Hct, or the platelet count for PV and ET, whoever the mutation positively correlated with high Hb (P=.039), Hct (P=.04) in PMF patients, and with high erythrocytes count in PV. The JAK2-V617F mutation can be frequently detected in the Sudanese patients with MPNs.

The relationship between JAK2 V617F mutation and coagulation function in patients with essential thrombocythemia / 白血病·淋巴瘤

Objective To investigate the frequency of JAK2 V617F mutation and JAK2 V617F mutation allele burden in patients with essential thrombocythemia (ET), and explore the relationship between mutation and hematological parameters and coagulation function. Methods The clinical and laboratory parameters of 90 ET patients were analyzed. JAK2 V617F mutation was detected by AS-PCR and the mutation allele burden of JAK2 V617F was detected by qPCR. The correlation between mutation frequency and mutation burden of JAK2 V617F and blood laboratory parameters were investigated in ET. Results JAK2 V617F mutation was found in 50 patients (55.6 %). RBC [(4.67±0.89)×109/L vs (4.04±0.99)×109/L, P =0.003], WBC (11.64±5.20)×109/L vs (9.11±4.11)×109/L, P = 0.014], HCT (0.41±0.07) vs (0.36±0.07), P =0.005) in the JAK2 V617F mutated group were higher than those in the wild-type group. PT in mutated patients was longer than that in wild-type group [(13.18±1.63) s vs (12.02±1.24) s, P = 0.000]. The JAK2 V617F mutation allele burden was (29.91 ±18.63) %. No significant correlation was found between JAK2 V617F mutation allele burden and hematological parameters such as WBC, RBC and Plt (all P>0.05), but the JAK2 V617F mutation allele burden had a significant correlation with FDP (r = 0.456, P = 0.001). Conclusions JAK2 V617F mutation occurs in significant percentage patients with ET. Detection of JAK2 V617F mutation allele burden at diagnosis may play an important role in the early prevention of vascular events.

Myeloproliferative neoplasms and the JAK/STAT signaling pathway: an overview

ABSTRACTMyeloproliferative neoplasms are caused by a clonal proliferation of a hematopoietic progenitor. First described in 1951 as 'Myeloproliferative Diseases' and reevaluated by the World Health Organization classification system in 2011, myeloproliferative neoplasms include polycythemia vera, essential thrombocythemia and primary myelofibrosis in a subgroup called breakpoint cluster region-Abelson fusion oncogene-negative neoplasms. According to World Health Organization regarding diagnosis criteria for myeloproliferative neoplasms, the presence of the JAK2 V617F mutation is considered the most important criterion in the diagnosis of breakpoint cluster region-Abelson fusion oncogene-negative neoplasms and is thus used as a clonal marker. The V617F mutation in the Janus kinase 2(JAK2) gene produces an altered protein that constitutively activates the Janus kinase/signal transducers and activators of transcription pathway and other pathways downstream as a result of signal transducers and activators of transcription which are subsequently phosphorylated. This affects the expression of genes involved in the regulation of apoptosis and regulatory proteins and modifies the proliferation rate of hematopoietic stem cells.

Effect of interferon on HEL cell apoptosis and JAK2 V617F mutation gene expression / 实用医学杂志

Objective To observe the effect of Interferon-α2b on HEL cells (human erythroleukemia cell line) growth, apoptosis and JAK2 V617F mutation gene expression. Methods HEL cells were placed in RPMI1640 containing 10% FBS and incubated in a cell incubator. Cells in the logarithmic growth phasem were collected, adjusting the cell density to 1 × 105/mL for experimental research. The interferon concentration in five groups were 0, 5 × 105, 10 × 105, 50 × 105, 100 × 105 U/L, with different incubation time (0, 24, 72, 120 h), respectively. The cell growth status in different groups was observed in the inverted optical microscope; MTT was used to detect the inhibition of interferon on HEL cell proliferation. Cell apoptosis was detected by flow cytometry. Fluorescence quantitative PCR was used to detect the mutation gene of JAK2 V617F expression. Results Inhibition rates of Interferon on the HEL cell proliferation in 5 × 105 U/L, 10 × 105 U/L, 50 × 105 U/L, 100 × 105 U/L groups were 18.57%, 25.10%, 42.10%, 57.00%, respectively. JAK2 V617F/GAPDH by fluorescence quantitative was 1.556, 1.213, 0.870 respectively under the concentration of interferon 100 × 105 U/L for 24, 72, 120 h. Conclusions Interferon-α2b can inhibit HEL cells proliferation and induce HEL cells apoptosis. Increasing concentration of interferon increases HEL cell apoptosis rate. Interferon can inhibit JAK2 V617F expression of HEL cells in a dose-dependent manner.

Correlati on between JAK2V617F mutation and clinical characteristics in patients with myeloproliferative neoplasm / 白血病·淋巴瘤

Objective To investigate the correlation between JAK2V617F mutation and clinical characteristics in patients with myeloproliferative neoplasm(MPN) in Xinjiang area.Methods The correlation between JAK2V617F mutation and clinical characteristics about gender,age,nationality,leukocyte counts,platelet counts,hemoglobin and LDH levels,complications of thrombosis,bleeding and vascular disease in 134patients with MPN were analyzed. Results 73.1％ (98/134) JAK2V617F mutation was found in patients (51with PV,66 with ET, 17 with IMF). Compared with negtive mutation, the rata of ≥60 years was significantly higher in positive group [78.6 ％(77/98)vs25.0 ％(9/36)(χ2=32.867,P＜0.001)]. Patients harboring JAK2V617F mutation have higher leukocyte counts[(15.9±8.2)×109/L vs (9.6±5.3)×109 L,t=4.296,P＜0.001],hemoglobin levels [(156.4 ±44.9)g/L vs (133.8 ±44.1)g/L,t=2.590,P =0.011],incidence of thrombosis [73.5 ％(72/98)vs22.2 ％(8/36),χ2=28.740,P＜0.001)] and vascular diseas [81.6 ％(80/98)vs25.0 ％(9/36),χ2=37.859,P＜0.001)]. There was no significant difference in gender, nationality, platelet counts, LDH levels and bleeding complications between JAK2V617F positive and negative patients. Conclusion There is a correlation between JAK2V617F mutation in MPN and age,leukocyte counts,hemoglobin levels,thrombosis and vascular disease complications.

A Case of Pulmonary Thromboembolism with JAK2 Mutation / 결핵및호흡기질환

The incidence of pulmonary thromboembolism increases with age. The risk factors of pulmonary thromboembolism include surgery, malignancy, obesity, lupus anticoagulants, and vascular conditions such as deep vein thrombosis. Thromboembolism in younger patients or in unusual locations, the possibility of primary thrombophilic conditions should be considered. Primary thrombophilic states include myeloproliferative disorders (MPD). JAK2 V617F mutation is found commonly in patients diagnosed with MPD, in 90~95% of polycythemia vera (PV) and in 50~60% of essential thrombocytosis (ET) patients. Sometimes the JAK2 V617F mutation is found in cases without MPD. The relationship between JAK2 V617F mutation and thrombosis has not been defined. Recently, clinical evidence suggests that this mutation may be variably associated with thrombosis. We present one case of pulmonary thromboembolism in a young patient, who was positive for the JAK2 V617F mutation and did not have MPD.

The Janus Kinase 2 (JAK2) V617F mutation in hematological malignancies in México / La mutación V617F del gen de la cinasa JAK2 en padecimientos hematológicos malignos en México

A new mutation (V617F) affecting the JAK2 gene has been recently described as acquired in patients with myeloproliferative disorders and other myeloid malignancies. Using an amplification refractory mutation system, we investigated this mutation in 70 Mexican mestizo patients with hematological malignancies: 28 cases of acute lymphoblastic leukemia, 17 cases of Phi-positive chronic myelogenous leukemia, 8 patients with acute myelogenous leukemia, 6 patients with chronic lymphocytic leukemia, 6 patients with polycythemia vera (PV), two patients with essential thrombocythemia (ET), one patient with hypereosinophilic syndrome one patient with primary myelofibrosis (MF) and one patient with chronic myelomonocytic leukemia. The mutation was identified in 4 of 6 patients with PV, in one of 2 patients with ET and in the patient with MF. Our data add to the observation that the JAK2 V617F mutation seems to be rather uncommon in myeloid malignancies other than the classic BCR/ABL negative MPD.

Se ha descrito una nueva mutación (V617F) que afecta al gen de la cinasa JAK2 en pacientes con padecimientos mieloproliferativos y otras neoplasias mieloides. Empleando un sistema de amplificación de mutaciones refractarias y reacción en cadena de la polimerasa, investigamos esta mutación en 70 pacientes mestizos mexicanos con neoplasias hematológicas malignas: 28 casos de leucemia aguda linfoblástica, 17 casos de leucemia granulocítica crónica BCR/ABL (+), ocho casos de leucemia aguda mieloblástica, seis casos de leucemia linfocítica crónica, seis casos de policitemia vera (PV), dos casos de trombocitosis primaria (TP), un caso de síndrome hipereosinofílico primario y un caso de mielofibrosis primaria (MF) y un caso de leucemia mielomonocítica crónica. La mutación se identificó en cuatro de seis pacientes con PV, en uno de dos pacientes con TP y en el paciente con MF. Estos datos confirman que esta mutación es infrecuente en neoplasias hematológicas mieloides diferentes a los síndromes mieloproliferativos malignos negativos al BCR/ABL; es probable que esta mutación se convierta en el marcador molecular de la PV.