Mechanisms of microRNA-19b on osteosarcoma cell proliferation and apoptosis by Targeting Krueppel-like factor 13

Abstract

Objective To investigate the mechanisms of microRNA-19b on osteosarcoma cell proliferation and apoptosis by Targeting Krueppel-like factor 13 (KLF13). Methods The expression of miR-19b and KLF13 was detected by quantitative Real-time polymerase chain reaction in three human osteosarcoma cell lines (MG-63, US-OS and Saos-2) and one normal human osteoblast cell line (hFOB 1.19). KLF13 as a potential target of miR-19b was predicted by sequence analysis. The viability and apoptosis effects of miR-19 inhibitor on MG-63 cell was assessed by Cell Proliferation Assay and flow cytometry. Luciferase assay and Western blotting were used to examine the regulatory effect. Results The relative expression of miR-19b and KLF13 in osteosarcoma cells (665.66±39.74, 517.75±26.82, 564.88±41.20) were significantly higher than that in normal human osteoblast cell (16.09±4.80) (both P<0.05). Luciferase reporter vector system confirmed that KLF13 was one of the target genes of miR-19b. The absorbance (A) of experiment groups and control group was 0.424±0.021, 0.265±0.016 and 0.783±0.053 respectively by Western blotting. 3-(4, 5-Dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay and flow cytometry demonstrated that miR-19b inhibitor significantly inhibited proliferation and promoted apoptosis of MG-63 cell (both P<0.01). Moreover, the anti-proliferation and pro-apoptotic effect by miR-19b inhibitor could be consolidate d by KLF13 knock down. Conclusion Suppression the expression of miR-19b can effectively inhibit the proliferation and promote apoptosis of osteosarcoma cells. miR-19b may become a new target for the regulation of gene expression in osteosarcoma. Key words: Osteosarcoma; MicroRNA-19b; Krueppel-like factor 13; Cell proliferation; Apoptosis