Inflammatory and oncogenic signaling converge in disease evolution of BCR-ABL-negative myeloproliferative neoplasms, clonal hematopoietic stem cell disorders characterized by gain-of-function mutation in JAK2 kinase (JAK2V617F), with highest prevalence in patients with polycythemia vera (PV).
By real-time PCR, we showed that, upon exposure to ITF2357, JAK2(V617F) mRNA was not modified in granulocytes from PV patients while the expression of the PRV-1 gene, a known target of JAK2, was rapidly downmodulated.
These exon 12 mutants constituted 50% of PVJAK2V617F-negative group and 4.4% (out of 90) of all PV patients (JAK2V617F-positive and JAK2V617F-negative).
The positive rate of JAK2V617F in polycythaemia vera (PV), essential thrombocythaemia (ET) and primary myelofibrosis (PMF) was 82.0%, 36.6% and 51.1% respectively.
The most common mutation-cytogenetic combinations in myeloproliferative neoplasm (MPN) were mutations of JAK2 or ASXL1 with del(20q) and were more common in patients with PMF and PV than in patients with ET.
Finally, a significant correlation between JAK2V617F mutational status and hematocrit (Ht), white blood cell and platelet counts in PV patients, and Ht values in ET cases, was observed by AS-PCR.
In vitro expansion of PV erythroid progenitors and differentiated dendritic cells resulted in a decrease of the frequency of JAK2(V617F) allele compared with granulocytes or CD235(+) erythroid progenitors.
The JAK2(V617F) mutation occurred in 27% of SP patients diagnosed according to the Polycythemia Vera Study Group or World Health Organization 2001 criteria.
Polycythemia vera is a relatively common myeloproliferative neoplasm (MPN) molecularly defined by the presence of mutations in the janus kinase (JAK2) gene.
We show that transplantation of JAK2(V617F)-transduced bone marrow into BALB/c mice induces MPD reminiscent of human PV, characterized by erythrocytosis, granulocytosis, extramedullary hematopoiesis, and bone marrow fibrosis, but not thrombocytosis.
Therefore, in a patient with acquired erythrocytosis, it is reasonable to begin the diagnostic work-up with JAK2 mutation analysis to distinguish PV from secondary erythrocytosis.
Therefore, in a patient with acquired erythrocytosis, it is reasonable to begin the diagnostic work-up with peripheral blood JAK2 mutation analysis and serum Epo measurement to distinguish PV from secondary erythrocytosis.
In polycythemia vera (PV) and essential thrombocythemia (ET) specific JAK2 mutations constitutively activate the JAK-STAT pathway, explaining biologic findings such as endogenous erythroid colony (EECs) growth or PRV-1 RNA overexpression.
Here we isolated and characterized hematopoietic stem cells (HSC) and myeloid progenitors from 16 PV patient samples and 14 normal individuals, testing whether the JAK2 mutation could be found at the level of stem or progenitor cells and whether the JAK2 V617F-positive cells had altered differentiation potential.
"The significance of bone marrow biopsy and JAK2V617F mutation in the differential diagnosis between the ""early"" prepolycythemic phase of polycythemia vera and essential thrombocythemia."
The JAK2V617F somatic mutation is present in the majority of patients with myeloproliferative cancer (polycythaemia vera, essential thrombocytosis, and primary myelofibrosis).
Our understanding of the genetic basis of myeloproliferative neoplasms began in 2005, when the JAK2 (V617F) mutation was identified in polycythemia vera, essential thrombocythemia, and primary myelofibrosis.