Combination Effect of MicroRNA-۱۵a and MicroRNA-۱۶-۱ on Chemosensitivity of the Leukemia Cells

Background: Down-regulation of miRNA-۱۵a and miRNA-۱۶-۱ is associated with Bcl-۲ and Mcl-۱ expression and chemoresistance in tumor cells. In this study, the combined effect of miRNA-۱۵a and miRNA-۱۶-۱ on apoptosis and sensitivity of the chronic lymphocytic leukemia (CLL) cells to fludarabine and ABT-۱۹۹ was investigated. Materials and Methods: The experiment groups were as follows: ABT-۱۹۹, negative control (NC) miRNA, miRNA-۱۵a, miRNA-۱۶, miRNA-۱۵a+miRNA-۱۶, NC miRNA+ABT-۱۹۹, miRNA-۱۵a+miRNA-۱۶+ABT-۱۹۹, erlotinib blank control, miRNA blank control and combination blank control. The expression levels of Bcl-۲ and Mcl-۱ were measured using quantitative real-time PCR (qRT-PCR). The effect of treatments on cell growth and survival was measured by trypan blue staining and MTT (۳-[۴, ۵ dimethylthiazol-۲-yl]-۲, ۵ diphenyltetrazolium bromide) assay, respectively. Apoptosis was measured using caspase-۳ activity and ELISA cell death assays. Results: Transfection of miRNA-۱۵a or miRNA-۱۶-۱ significantly suppressed the expression of Bcl-۲ and Mcl-۱ in a time-dependent manner (P<۰.۰۵ versus negative control miRNA or blank control). Other experiments showed that up-regulation of miRNA-۱۵a or miRNA-۱۶-۱ decreased cell growth, induced apoptosis, and synergistically lowered the IC۵۰ value of fludarabine and ABT-۱۹۹ in CLL cells. Moreover, co-transfection of two miRNAs showed a more significant effect on cell survival, apoptosis, and drug sensitivity than single transfection. Conclusion: Our study shows that miRNA-۱۵a and miRNA-۱۶-۱ can effectively enhance the anticancer effects of fludarabine and ABT-۱۹۹ in CLL cells and may offer a new promising therapeutic strategy for CLL-resistant patients.

کلیدواژه ها:

ABT-۱۹۹ ، fludarabine ، Mcl-۱ ، miRNA-۱۵a ، miRNA-۱۶-۱