The effect of increasing the expression of miR-181b on the function of human breast cancer cells / 肿瘤

ABSTRACT

Objective: To investigate the effects of increasing the expression of miR-181b on the function of human breast cancer cell lines MDA-MB-231 and MCF-7, and to explore its possible target gene. Methods: miR-181b mimics were transfected into MDA-MB-231 and MCF-7 cells by LipofectAMINE 2000 and then the capabilities of proliferation and migration as well as the cell cycle distribution of MDA-MB-231 and MCF-7 cells were evaluated by MTT, Transwell and flow cytometry methods, respectively. Recombinant vector psiCHECK-2/cyclin- dependent kinase 8 (CDK8)-3'-untranslated region (3'-UTR) and miR-181b mimics were co-transfected into human embryonic kidney HEK293T cells and then the targeting of miR-181b combined with 3'-UTR of CDK8 gene was detected by dual luciferase report system. The expression of CDK8 in MDA-MB-231 and MCF-7 cells after transfection with miR-181b mimics was determined by Western blotting. Results: As compared with the miR-181b mimics-negative control (NC) tranfection group, the capabilities of proliferation and migration in MDA-MB-231 and MCF-7 cells after transfection with miR-181b mimics were significantly inhibited (P < 0.05), and the cell cycle was arrested at G0/G1 phase (P < 0.01). The luciferase activity of HEK293T cells after co-transfection with psiCHECK-2/CDK8-3'UTR and miR-181b mimics was reduced (P < 0.01), and it confirmed that miR-181b specifically targeted with CDK8 3'-UTR. As compared with the miR-181b mimics-NC transfection group, the expression level of CDK8 in MDA-MB-231 and MCF-7 cells after transfection with miR-181b mimics was down-regulated (P < 0.05). Conclusion: The up-regulation of miR-181b expression can inhibit the proliferation and migration of human breast cancer cells. This effect may be related to miR-181b targeting of the expression of CDK8. Copyright © 2014 by TUMOR.