MiRNA-Mediated Knock-Down of Bcl-2 and Mcl-1 Increases Fludarabine-Sensitivity in CLL-CII Cells

• DOI: 10.31557/apjcp.2021.22.7.2191
• Publication Date: 2021-07-28T13:31:51Z
• Authors: Nooshin Ashofteh; Razieh Amini; Neda Molaee; Hadi Karami; Maryam Baazm
• Keywords: 0301 basic medicine; Antineoplastic Agents; Apoptosis; Leukemia, Lymphocytic, Chronic, B-Cell; 3. Good health; MicroRNAs; 03 medical and health sciences; Proto-Oncogene Proteins c-bcl-2; Drug Resistance, Neoplasm; Tumor Cells, Cultured; Myeloid Cell Leukemia Sequence 1 Protein; Apoptosis Regulatory Proteins; Vidarabine; Research Article; Cell Proliferation

Over-expression of anti-apoptotic proteins such as Bcl-2 and Mcl-1 is associated with resistance to chemotherapeutic agents such as fludarabine. Moreover, an inverse relationship between miRNA-15a levels with Bcl-2 and Mcl-1 expression has been observed in CLL patients. In this study, the effect of miRNA-15a on apoptosis and sensitivity of the CLL cells to fludarabine was investigated.After treatments, the Mcl-1 and Bcl-2 expression levels were quantified by RT-qPCR. Trypan blue assay was used to explore the effects of miRNA-15a and fludarabine on cell proliferation. The cytotoxicity was measured using MTT assay and combination index analysis. Cell death was determined using cell death detection ELISA assay and caspase-3 activity assay Kits.Results showed that miRNA-15a clearly decreased the mRNA levels of Bcl-2 and Mcl-1 in a time dependent manner, which led to CLL-II cell proliferation inhibition and enhancement of apoptosis (p < 0.05, relative to control). Transfection of the miRNA-15a synergistically reduced the cell survival rate and lowered the IC50 value of fludarabine. Furthermore, miRNA-15a significantly enhanced the apoptotic effect of fludarabine.Our data propose that suppression of Bcl-2 and Mcl-1 by miRNA-15a can effectively inhibit the cell proliferation and sensitize CLL cells to fludarabine. Therefore, miRNA-15a can be considered as a potential therapeutic target in CLL resistant patients.