miR-125b-1增强乳腺癌SKBR-3细胞对紫杉醇的药物敏感性

MiR-125b-1 enhances the chemosensitivy of SKBR-3 breast cancer cells to the paclitaxel

目的探讨miR-125b-1增强紫杉醇对乳腺癌SKBR-3细胞化疗敏感性的影响,及其对靶基因Her2蛋白表达的影响。方法合成miR-125b-1并通过LipofectamineTM2000转染SKBR-3细胞,将实验分为空白对照组(脂质体转染SKBR-3细胞株)、阴性对照组(siRNA转染SKBR-3细胞株)、miR-125b-1组(miR-125-1转染SKBR-3细胞株)3组。分别用RT-PCR和蛋白质印迹法检测Her2 mRNA和蛋白质表达水平的变化;流式细胞仪检测细胞周期;MTT法检测miR-125b-1对紫杉醇作用于SKBR-3细胞化疗敏感性的影响。结果 miR-125b-1转染后的SKBR-3细胞中Her2 mRNA和蛋白质水平显著下降;流式细胞仪检测结果显示,转染miRNA-125b-1的SKBR-3细胞G2M期细胞比例显著高于其他组(P=0.000),而空白对照组与阴性对照组比较差异无统计学意义(P=0.094)。三组之间比较,G0-G1期、S期比例差异无统计学意义;用miR-125b-1处理组细胞的IC50与未处理组相比下降2.69倍,差异有统计学意义(P<0.05)。结论 miR-125b-1可增强乳腺癌SKBR-3细胞对紫杉醇的化疗敏感性,下调Her2可能是其作用机制之一。

Objective To identify the effect of miR-125b-1 on the chemosensitivity of SKBR-3 breast cancer ceils to paclitaxel and its influence on the Her2 protein level. Methods A recombinant miR-125b-1 was introduced by LipofectamineTM 2000 mediated gene transfection into cultured SKBR-3 cells. The transfected cell clones were collected and analyzed by RT-PCR to determine the level of Her2 mRNA. The protein level of Her2 was detected by Western blot. The cell cycle were determined by cytometry （FCM）. The effect of miR-125b-1 on the chemosensitivy of SKBR-3 breast cancer cells was measured by MTY assay. Results In the miR-125b-1 transfected group, both the mRNA and protein expression levels of Her2 gene were reduced significantly. FCM analysis revealed that most of the transfected SKBR-3 ceils were blocked in G2M phase. The results were greater than the other groups （P=0.000）. When comparing the blank control group with the negative group, there was no statistical difference （P=0.094）. There was no different in the G0-G1 phase and S phase in these three groups. The ICs0 of miR-125b-1 transfected cells was 2.69 times lower than the control group （P〈0.05）. Conclusion miR- 125b-1 can increase the chemosensitivity of SKBR-3 breast cancer cells to paclitaxel. And the downregulation of Her2 may be the cause of increasing in drug sensitivity.