二甲双胍联合紫杉醇对人乳腺癌细胞增殖抑制作用及其机制

Inhibitory effect of metformin combined with paclitaxel on human breast cancer cell proliferation and its mechanism

目的:探讨二甲双胍联合紫杉醇对人乳腺癌细胞增殖抑制作用及其机制。方法:将人乳腺癌细胞MCF-7分为对照组、二甲双胍组、紫杉醇组、二甲双胍组+紫杉醇联合组,MTT法检测各组人乳腺癌细胞MCF-7活力,实时荧光定量逆转录法测定miR-34a的表达水平,酶联免疫吸附法测定Ki-67、cyc D1、β-catenin、VEGF蛋白水平。结果:(1)二甲双胍组、紫杉醇组、联合组的OD值、存活率均低于对照组(P<0.05);联合组OD值、存活率低于二甲双胍组、紫杉醇组(P<0.05);二甲双胍组OD值、存活率与紫杉醇组比较无明显差异(P>0.05);(2)二甲双胍组、紫杉醇组、联合组miR-34a表达水平均高于对照组(P<0.05);联合组miR-34a表达水平高于二甲双胍组、紫杉醇组(P<0.05);二甲双胍组miR-34a表达水平与紫杉醇组比较无明显差异(P>0.05);(3)二甲双胍组、紫杉醇组、联合组Ki-67、cyc D1、β-catenin、VEGF蛋白水平均低于对照组(P<0.05);联合组Ki-67、cyc D1、β-catenin、VEGF蛋白水平低于二甲双胍组、紫杉醇组(P<0.05);二甲双胍组Ki-67、cyc D1、β-catenin、VEGF蛋白水平与紫杉醇组比较无明显差异(P>0.05);miR-34a表达水平与存活率、Ki-67、cyc D1、β-catenin、VEGF蛋白呈明显负相关关系(P<0.05)。结论:二甲双胍与紫杉醇组联合作用能明显抑制人乳腺癌细胞MCF-7的增殖和转移,其机制与miR-34a介导抑制细胞周期、Wnt-β-catenin信号通路、VEGF有关。

Objective: To investigate the inhibitory effect of metformin combined with paclitaxel on human breast cancer cell proliferation and its mechanism. Methods: Human breast cancer cells MCF-7 were divided into three groups: control group, metformin group, paclitaxel group, combined group. MCF-7 activity of human breast cancer cells were detected by MTT assay, and the expression of miR-34a was measured by real-time fluorescence quantitative reverse transcriptase assay. The level of Ki-67,cyc D 1, β-catenin,VEGF, protein was determined by enzyme linked immunosorbent assay(ELISA). Results:(1) The OD and survival rate of the metformin group, the paclitaxel group and the combination group were significantly lower than those of the control group(t=10.46, 13.76, 12.15, 10.48, 13.14, 13.33, P<0. 05). The OD value and survival rate of the combined group were significantly lower than those of the metformin group and the paclitaxel group(P<0.05). The OD value and survival rate in metformin group were similar to those in the paclitaxel group, and there was no significant difference between them(t=1.13,0.98, P>0. 05).(2) The expression of miR-34a in the metformin group, the paclitaxel group and the combination group was significantly higher than that in the control group(P<0. 05). The expression of miR-34a in the combination group was higher than that in the metformin group and the paclitaxel group(P<0.05). The expression of miR-34a in the metformin group was similar to that in the paclitaxel group(t=1.16,P>0 05).(3) the protein levels of Ki-67,cyc D1 and β-catenin,VEGF in the metformin group, the paclitaxel group and the combination group were significantly lower than those in the control group(P<0.05);The protein levels of Ki-67,cyc D1 and β-catenin,VEGF in the combined group were significantly lower than those in the the metformin group and the paclitaxel group(P<0.05). The levels of Ki-67,cyc D 1, β-catenin,VEGF protein in the metformin group were similar to those in the paclitaxel group, and there was no significant difference between them. The expression level of miR-34a was negatively correlated with survival rate, Ki-67,cyc D1, β-catenin,VEGF protein, and the difference was statistically significant(P<0.05). Conclusion: The combination of metformin and paclitaxel can significantly inhibit the proliferation and metastasis of MCF-7 cells. The mechanism is related to the inhibition of cell cycle, Wnt-β-catenin signaling pathway and VEGF by miR-34a.