Inhibition of MicroRNA miR-222 with LNA Inhibitor Can Reduce Cell Proliferation in B Chronic Lymphoblastic Leukemia.

MicroRNAs (miRNAs) are small regulatory molecules that negatively regulate gene expression by base-pairing with their target mRNAs. miRNAs have contribute significantly to cancer biology and recent studies have demonstrated the oncogenic or tumor-suppressing role in cancer cells. In many tumors up-regulation miRNAs has been reported especially miR-222 has been shown to be up-regulated in B chronic lymphocytic leukemia (B-CLL). In this study we assessed the effected inhibition of miR-222 in cell viability of B-CLL. We performed inhibition of mir-222 in B-CLL cell line (183-E95) using locked nucleic acid (LNA) antagomir. At different time points after LNA-anti-mir-222 transfection, miR-222 quantitation and cell viability were assessed by qRT-real time polymerase chain reaction and MTT assays. The data were analyzed by independent t test and one way ANOVA. Down-regulation of miR-222 in B-CLL cell line (183-E95) with LNA antagomir decreased cell viability in B-CLL. Cell viability gradually decreased over time as the viability of LNA-anti-mir transfected cells was <47 % of untreated cells at 72 h post-transfection. The difference in cell viability between LNA-anti-miR and control groups was statistically significant (p < 0.042). Based on our findings, the inhibition of miR-222 speculate represent a potential novel therapeutic approach for treatment of B-CLL.