摘要目的:探讨紫云英苷上调miRNA-513（miR-513）对前列腺癌细胞株C4-2B细胞增殖能力及细胞周期的影响。方法:选取前列腺癌细胞株C4-2B，采用125 μg/L紫云英苷作用48 h者为紫云英苷组，未处理者为对照组。采用四甲基偶氮唑盐（MTT）法检测两组C4-2B细胞增殖能力，流式细胞术检测细胞周期。采用miRNAMap预测软件预测miR-513的靶基因为叉头框蛋白R2（FOXR2），并采用双荧光素酶报告基因实验进行验证。实时荧光定量聚合酶链反应（qRT-PCR）检测两组细胞miR-513和FOXR2 mRNA的相对表达水平，蛋白质印迹法检测两组细胞中FOXR2、细胞周期蛋白依赖性激酶7（CDK7）、β-actin和细胞周期蛋白H（cyclin H）的表达。结果:与对照组比较，培养第2、3、4、5天紫云英苷组C4-2B细胞增殖活力均降低（均 P<0.05）。对照组和紫云英苷组S期细胞比例分别为（48.1±3.2）%和（36.0±2.1）%，紫云英苷组S期细胞比例降低（ t=3.12， P=0.021）；G 2期细胞比例分别为（24.9±3.3）%和（11.8±2.4）%，紫云英苷组G 2期细胞比例降低（ t=3.18， P=0.019）。对照组和紫云英苷组C4-2B细胞中miR-513的相对表达水平分别为1.01±0.22和6.55±0.61，紫云英苷组C4-2B细胞中miR-513的相对表达水平升高（ t=7.70， P<0.01）。双荧光素酶报告基因实验验证FOXR2为miR-513的靶基因。对照组和紫云英苷组C4-2B细胞中FOXR2 mRNA相对表达水平分别为1.04±0.14和0.19±0.06，差异有统计学意义（ t=5.53， P=0.002），提示紫云英苷促进miR-513表达后，FOXR2 mRNA表达降低。紫云英苷组C4-2B细胞FOXR2、CDK7和cyclin H蛋白相对表达水平较对照组均降低。 结论:紫云英苷可能通过上调miR-513的表达，抑制前列腺癌C4-2B细胞增殖，诱导细胞周期停滞。

abstractsObjective: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.