microRNA-21 Expression as Prognostic and Therapeutic Response Marker in Chronic Myeloid Leukaemia Patients.

Background: Chronic myeloid leukaemia (CML) is a myeloproliferative disorder categorized by malignant transformation of a single stem cell of hematopoietic cells. microRNAs (miRNAs) belong to transcription regulators in hematopoiesis and their altered expression associates with pathogenesis of CML. Aim: Current study aimed to access the miR-21 expression profile in CML patients and therapy response as well as its prognostic significance. Methods: 100 CML cases, 100 controls were included in study and miR-21 expression was analyzed. Overall 9.22 mean fold increased expression was observed in CML patients before treatment. Results: Patients with different CML phases such as chronic phase, accelerated phase and blast crisis showed 7.16, 10.30 and 13.20 fold increased expression respectively. Overall 3.57 mean fold expression was observed in imatinib treated patients suggested more than 5 fold decreased expression in CML patients. Prognostic significance was calculated and observed that miR-21 expression at 7.29 fold cutoff, 75% sensitivity and 50% specificity was observed (AUC=0.75, p<0.0001). Study observed miR-21 overexpression in CML patients as well as gradually increased expression with advancement of disease. Conclusion: miR-21 overexpression represented molecular prognostic marker and predictive tool enabling efficient monitoring of drug response and therapy outcomes in CML patients.