Effects of astragalin on the cell proliferation and cell cycle of prostate cancer cells through up-regulating miRNA-513 expression / 肿瘤研究与临床

ABSTRACT

Objective:To investigate the effects of astragalin on the cell proliferation and cell cycle of prostate cancer cell line C4-2B through up-regulating the expression of miRNA-513 (miR-513).Methods:Prostate cancer cell line C4-2B cells were taken and treated with 125 μg/L of astragalin for 48 h (astragalin group), and untreated C4-2B cells were set as the control group. The methyl thiazolyl tetrazolium (MTT) method was used to detect the proliferation ability of C4-2B cells in the two groups, and cell cycle was detected by using flow cytometry. The miRNAMap prediction software was used to predict that the targeted gene of miR-513 was the forkhead box protein R2 (FOXR2), and the dual luciferase gene reporter assay was used to verify it. Real-time fluorescent quantitative polymerase chain reaction (qRT-PCR) was used to detect the relative expression levels of miR-513 and FOXR2 mRNA in the two groups of cells. Western blotting was used to detect the expressions of FOXR2, cyclin-dependent kinase 7 (CDK7), β-actin and cyclin H in the two groups of C4-2B cells.Results:Compared with the control group, the proliferation activity of C4-2B cells in the astragalin group was decreased from day 2 to day 5 (all P < 0.05). The proportions of S-phase cells in the control group and the astragalin group were (48.1±3.2)% and (36.0±2.1)%, respectively. The proportion of S-phase cells in the astragalin group was decreased ( t = 3.12, P = 0.021); the proportions of G 2-phase cells were (24.9±3.3)% and (11.8±2.4)%, respectively. The proportion of G 2-phase cells in the astragalin group was decreased ( t = 3.18, P = 0.019). The relative expression levels of miR-513 in C4-2B cells of the control group and the astragalin group were 1.01±0.22 and 6.55±0.61, respectively. The relative expression levels of miR-513 in C4-2B cells in the astragalin group was increased ( t = 7.70, P < 0.01). The dual luciferase reporter gene assay verified that FOXR2 was the targeted gene of miR-513. The relative expression level of FOXR2 mRNA in C4-2B cells of the control group and the astragalin group was 1.04±0.14 and 0.19±0.06, respectively, and the difference was statistically significant ( t = 5.53, P = 0.002), suggesting that after astragalin promoted the expression of miR-513, the FOXR2 mRNA expression was decreased. The relative expression levels of FOXR2, CDK7 and cyclin H protein in C4-2B cells in the astragalin group were all decreased compared with those in the control group. Conclusions:Astragalin inhibits the proliferation of prostate cancer C4-2B cells and induces cell cycle arrest by up-regulating the expression of miR-513.