Regulation of miR-126 and miR-122 Expression and Response of Imatinib Treatment on Its Expression in Chronic Myeloid Leukemia Patients

Background: MicroRNAs (miRNAs) have been observed to exhibit altered expression patterns in chronic myeloid leukemia (CML). Therefore, this study was aimed to evaluate the clinical importance of miR-126 and miR-122 expression in concert to imatinib response in CML patients. Methods: The present study included 100 CML and 100 healthy subjects. The expression of the 2 miRNAs was performed using TaqMan probe chemistry, and snU6 was used as internal control. Results: The expression of miR-126 and miR-122 was downregulated in CML patients, with a mean fold change +/- SD 0.20 +/- 0.33 and 0.22 +/- 0.37, respectively. While the expression of both miRNAs was analysed before and after imatinib treatment, it was observed that the expression levels of both were increased after imatinib treatment by 26.25-fold (5.33 against 0.20) and 13.95-fold (3.07 against 0.22) and the increase was statistically significant (p < 0.0001 and p < 0.0001, respectively). The expression of miR-126 was not conclusive when compared in different clinical stages of the CML disease as it showed a decreased expression in patients with accelerated phase compared to chronic phase (mean fold change = 0.03 and 0.27, respectively), but patients with chronic phase and blastic phase had comparable expression (mean fold change = 0.27 and 0.24, respectively). We also observed an increased expression of both miRNAs after imatinib therapy in each clinical phase. Conclusion: The study concludes that expression of miR-126 and miR-122 increases after imatinib treatment in CML patients and that miR-126 defines the good responders of imatinib therapy.

Automated summary

This study investigates the expression of miR-126 and miR-122 in chronic myeloid leukemia (CML) patients and their response to imatinib treatment. Results show that both miRNAs are downregulated in CML patients, but their expression levels increase significantly after imatinib therapy. Additionally, miR-126 is identified as a marker for defining good responders to imatinib therapy.