Quantitative Determination Of JAK2V617F Mutation And P-STAT5in The Patients With Myeloproliferative Neoplasm And Their Relations With Clinic Features

Objective:This study was aimed to quantitatively detect the proportion of JAK2V617F mutation and p-STAT5in patients with myeloproliferative neoplasm (MPN), and investigate the correlation of p-STAT5intensity and proportion of JAK2V617F mutation and their relations with clinical characteristics, further confirm the significance of JAK2V617F mutation and its downstream signal pathways in the cause of MPN to provide a theoretically basis for clinical diagnosis and target therapy.Methods:According to the latest revision of WHO diagnostic criteria, we enrolled45MPN patients who were confirmed with BCR-ABL (-) and15healthy adults from the provincial hospital affiliated to Shandong university as the research object. We collected5ml peripheral blood of every patient and abstracted the mononuclear cells. These cells were divided into two parts, one part is used to quantitative detect the JAK2V617F gene mutation proportion by real-time fluorescence quantitative polymerase chain reaction(Real-time fluorescent PCR), and another part is used to check the expression of p-STAT5proteins by Western blot combined with UVP grey value analyzer. The quantitative outcomes were statistic by Logistic regression analysis. In addition, we also analysis the relationship between JAK2V617F mutation and patients’ clinical features, including gender, age, white blood cell and platelet counts, hemoglobin, red blood cells deposited, bone marrow cytology results, pathological results, chromosome karyotype, liver and spleen under ultrasound examination, hemorrhage and thromboembolism events. We used SPSS15.0as the statistical software and considered p<0.05are statistically significant.Results:Our experiment results show that BCR-ABL-negative MPN patients has high JAK2V617F mutation rate(73.3%,33/45), which including83.3%(20/24) in PV,68.8%(11/16) in ET and40.0%(2/5) in IMF. The mutation proportion of JAK2V617F in PV, ET and IMF patients was0.472±0.245,0.216±0.162, and0.435±0.239respectively; While the corresponding Gray value of p-STAT5protein was1.396±0.758,0.760±0.623, and0.792±0.612. From the result we can see, the higher JAK2V617F mutation rate, the higher p-STAT5protein grey value, which showed a linear correlation (P<0.05). In correlation analysis of JAK2V617F mutation and the clinical characteristics, we found that PV patients with higher JAK2V617F mutation proportion had higher hematocrit, hemoglobin and white blood cell count, but had lower platelet; ET patients who with higher mutation proportion showed older in age and higher hemoglobin, hematocrit count and white blood cell count. IMF patients who has higher JAK2V617F mutation rate showed lower platelet count, hemoglobin, hematocrit count and white blood cells count. Patients with JAK2V617F (+) were more likely to develop to thrombotic, bleeding events and splenomegaly.Conclusion:1、BCR-ABL-negative MPN patients has high JAK2V617F mutation rate. Therefore, JAK2V617F is one of the important indices for MPN disease diagnosis;2、JAK2V617F mutation proportion and expression of downstream p-STAT5proteins were significantly linear correlated. The discovery further confirmed that Jak2V617F mutation is the most important pathogenesis of MPN which can lead to the abnormality in downstream signaling pathway. These provided a new thought for targeted therapy of MPN;3、JAK2V617F mutation proportion observably correlated with the patients’ clinical characteristics. Patients with higher mutation rate have higher risk of complications such as splenomegaly and thrombotic events, thus providing theoretical basis for application of quantitatively detection of JAK2V617F in MPN’s diagnosis, treatment effect evaluation and prognostic prediction.