The Analysis Of JAK2V617F In Myeloproliferative Neoplasms And Its Correlation With MPL

Objective: In this study, we investigate the proportion of JAK2V617F gene mutationin patients with myeloproliferative neoplasms (MPNs), and its role in MPNs diagnosis.We also detect the expression level of thrombopoietin receptor (MPL/TPOR/c-MPL)in the MPNs patients with JAK2V617F mutation, and its relationship with JAK2V617F as well as its potential role in the pathogenesis of MPNs.Methods： JAK2V617F gene mutation was examed by amplification refractorymutation PCR (ARMS-PCR) from bone marrow or peripheral blood in111patientsdiagnosed with polycythemia vera (PV, n=15), essential thrombocythemia (ET, n=35),chronic myeloid leukemia (CML, n=24), primary myelofibrosis (PMF, n=13) andunclassified MPNs (n=24).The real-time fluorescence quantitative PCR (Real-time PCR) was used to detectthe MPL gene expression in MPN patients with JAK2V617F mutation.Results：60cases of JAK2V617F mutation (54.05%) were detected in111patients;including11cases of PV (18.33%),24cases of ET (40.00%),19cases of unclassfiedMPNs (31.67%). The ARMS-PCR and the gel electrophoresis data showed that thepositive rate of JAK2V617F mutation was73.33%(11/15) in PV,68.57%(24/35) inET,46.15%(6/13) in PMF,0%in CML and79.17%(19/24) in unclassfied MPNs.43cases were heterozygosis mutation and17cases were homozygous mutation. Therewas a significant difference between these groups (Chi-Square Test, x~2=39.87,P<0.05). Only CML group showed significant lower rate compared with otherdiseases (P <0.05), there was no significant difference between any other groups (P<0.05). There was no statistical difference between women and men of these patients.Patients in mutation group were older than the patients of wild type.0.8%agarose gel electrophoresis was used to detect the total RNA. The band of5s rRNA,18s rRNA and28s rRNA can be clearly identified, indicating that the qualityof RNA extraction was good enough. The amplification curve of MPL gene and theinternal reference gene ABL was better in the real-time fluorescence quantitative PCR.The results of the relative quantification of MPL which calculate by2-△ctwasstatistical difference by using the variance of the single factor method (P<0.05).Conclusion：In China, JAK2V617F mutation in MPNs patients is correlated with age. Mutation isfrequently found in older patients.In the MPNs with JAK2V617F (+), MPL expression is lower than normal, whichpossibly can be used as one index of MPNs with JAK2V617F mutation.