The role of MIR-186 and ZNF545 in inhibiting the proliferation of multiple myeloma cells

Abstract

This study aimed to investigate the mechanism underlying the inhibitory effect of tumor suppressor gene miR-186 and zinc finger protein 545 (ZNF545) on the proliferation of multiple myeloma (MM) cells. CD138 magnetic beads were used to isolate different types of myeloma cell lines (KM3, U266, RPMI-8226, and H929), which were then infected by lentivirus carrying the miR-186 gene. Using uninfected myeloma cells as the control, MTT [3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide, Thiazolyl Blue Tetrazolium Bromide] assay was performed to calculate the rate of cell proliferation at different time points. In addition, the correlation between the expression of Jagged 1 and miR-186 was analyzed by real-time Polymerase Chain Reaction (PCR). Furthermore, the effect of 5-Aza-2-deoxycytidine and acetylase inhibitor Trichomycin A (TSA) on the expression of ZNF545 and proliferation/apoptosis of MM cells was investigated using Reverse Transcription-Polymerase Chain Reaction (RT-PCR), Western blotting (WB), MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] cell proliferation assay, and Annexin V-FITC/PI staining. Compared with the control group, the proliferation of miR-186-overexpressing U266 and RPMI-8226 cells was significantly decreased. In cell cloning experiments, miR-186 decreased the number of U266 and RPMI-8226 clones while reducing the protein expression of Jagged 1. The expression level of ZNF545 in myeloma patients was also reduced to some extent. ZNF545 protein also promoted the apoptosis of myeloma cells. By inhibiting the proliferation of myeloma cells, miR-186 gene and ZNF protein may be used as tumor suppressors in the treatment of myeloma.