Oxymatrine inhibits proliferation and apoptosis of human breast cancer cells through the regulation of miRNA-140-5P

Objective: Oxymatrine has shown strong anti-cancer ability, but its mechanism is not well-studied.

Methods: The inhibitory rates of oxymatrine with various concentrations (0, 1, 2, 4, 6, 8, 16, 32 mg/ml) on MCF-7 cells were detected by CCK-8. The effects of oxymatrine on the expression of miRNA-140-5P in MCF-7 cells were detected by real-time fluorescent quantitative PCR (RT-PCR). miRNA-140-5P mimics or NC mimics were transfected into cells using Lipofectamine 2000. Eventually, the cells were divided into control-group, drug-group, miRNA-140-5P mimics group, NC mimics group, and miRNA-140-5P mimics + drug group. Cell viability was detected by CCK-8 assay and apoptosis rate of each group were measured by using Flow cytometry. Western blot was carried out to detect the protein expression of TGFBR1 and FGF9.

Results: Oxymatrine at various concentrations had conspicuous inhibitory effect on the proliferation of MCF-7 cells (P<0.05), and the inhibitory effect of oxymatrine on MCF-7 cells showed both dose- and time-dependent manners. The relative expression of miRNA-140-5P in MCF cells was remarkably lower than that in MCF-10A. Oxymatrine could effectively promote the expression of miRNA-140-5P in MCF-7 cells, and the relative expression of miRNA-140-5P increased significantly with the increased dose of oxymatrine (P<0.05). Both transfection of miRNA-140-5P mimics and oxymatrine treatment could reduce the proliferation of MCF-7 cells (P<0.05), and the proliferation of cells in miRNA-140-5P mimics + drug-group was significantly lower than that of other groups (P<0.05). Compared with the control-group, the protein expressions of TGFbR1 and FGF9 in low-dose, medium-dose and high-dose groups were dramatically decreased (P<0.05), in a dose-dependent manner (P<0.05).

Conclusion: Oxymatrine inhibits proliferation and promotes cell apoptosis of breast cancer MCF-7 cells. The mechanism may contribute to the regulation of miRNA-140-5p and its target genes.