MicroRNA Expression Analysis in Patients with Primary Myelofibrosis, Polycythemia vera and Essential Thrombocythemia.

MicroRNAs (miRNA) are small non-coding RNA molecules that play critical roles in cell differentiation, proliferation and apoptosis and thus regulate haematopoietic stem cells and committed progenitor cells. We analyzed expressions of miRNAs associated with hematopoietic transformation of myeloid, erythroid and megakaryocytic progenitor cells during haematopoiesis (mir155, mir181a, mir221, mir222, mir223, mir451), in patients with primary myelofibrosis (PMF) (n = 22), polycythemia vera (PV) (n = 33), essential thrombocythemia (ET) (n = 49) and in healthy controls (n = 40) by quantitate/real time polymerase chain reaction. RT-PCR testing was negative for BCR-ABL1 fusion gene in all the patients. Mir155 was expressed in higher levels in all 3 disorders (p < 0.05). Mir221 was higher especially in ET and PMF group (p < 0.05). Mir222 expression was lower in PV patients (p < 0.05) and higher in ET and PMF patients compared to control group. Mir223 expression was higher in ET and PMF group than control group (p > 0.05). Mir451 levels were lower in all three groups compared to control group (p < 0.05). There was no difference in expression levels of mir181a between groups. JAK2V617F positivity, co-morbidities, drugs, and gender did not affect miRNA expressions. This study holds promise for the future application of these molecules for differential diagnosis and as therapeutic targets in Philadelphia chromosome negative myeloproliferative neoplasms.