JAK2V617F mRNA metabolism in myeloproliferative neoplasm cell lines.

Abstract

Myeloproliferative neoplasms (MPNs) are a heterogeneous group of leukemias with defective regulation of myeloid stem cell proliferation. They include four distinct diseases: chronic myeloid leukemia, polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF).1, 2 In 2005, four independent studies have concurred to the identification in MPN patients of a specific mutation in the Janus kinase 2 (JAK2) protein (1849 G→T in exon 14; 617Val→Phe) in the majority of MPNs.1, 2 Indeed, this JAK2V617F variant was identified in 95% of PV, 55% of ET and 65% of PMF patients. The amino-acid change triggers a constitutive activation of the JAK2 protein, independently of cytokines. Whether JAK2V617F is the initiating event in these MPNs remains under debate; however, JAK2V617F seems to drive the phenotype of the disease.