EZH2过表达在MCF-7获得性耐药中的作用

The effect of EZH2 overexpression on acquired drug resistance in MCF - 7 cells

目的探讨EZH2过表达在MCF-7／ADR获得性耐药中的作用。方法应用荧光定量PCR技术和Westernblot技术分别检测EZH2在MCF-7和MCF-7／ADR中的mRNA和蛋白的相对表达量。将带有报告基因eGFP的EZH2shRNA、EZH2shRNA—scramble质粒分别转染MCF-7／ADR细胞后，用G418筛选获得稳转细胞株，应用荧光定量PCR技术验证EZH2shRNA组EZH2mRNA表达是否被抑制。采用WST-1方法检测EZH2shRNA、EZH2shRNA—scramNe和阴性对照组细胞对阿霉素敏感性的变化情况。结果MCF-7／ADR中EZH2mRNA相对表达量约为MCF-7的2．52±1．523倍，MCF-7／ADR中EZH2蛋白相对表达量约为MCF-7的1．58±0．58倍，差异均有统计学意义（P〈0．05）。EZH2shRNA组稳转的细胞株EZH2mRNA的抑制率约为84％（P〈0．05），加入阿霉素后细胞增殖能力约下降25％（P〈0．05），而EZH2shRNA—scramble组和阴性对照组加入阿霉素后细胞增殖能力无明显变化。结论在MCF-7／ADR细胞中EZH2mRNA和蛋白的相对表达量较MCF-7细胞高。沉默EZH2的表达有可能逆转MCF-7／ADR细胞对阿霉素的耐药性。

Objective To explore the effect of EZH2 overexpression on acquired drug resistance in MCF - 7 cells. Methods The relative expressions of EZH2 mRNA and protein of MCF - 7 and MCF - 7/ADR were detected respectively by real time fluorescence quantitative PCR （RTFQPCR） and Western - blot. After EZH2 shRNA and EZI-I2 shRNA - scramble plasmid vectors with reporter gene EGFP were transfected into MCF - 7/ ADR cells ,the stable cell line was screened by G418. RTFQPCR was used to validate whether the EZH2 mRNA in EZH2 shRNA group was supressed. The differences of the effect of adriamycin on cell proliferation were evaluated among EZH2 shRNA goup, EZH2 shRNA - scramble group and negative control groups using WST - 1 assays. Results The EZH2 mRNA and protein expression levels in MCF -7/ADR cells were 2.52 ~ 1. 523 and 1.58 ＋ O. 58 folds of those in MCF - 7cells. The differences were significant（ P 〈 O. 05 ）. After the EZH2 shRNA plasmid was stably expressed in MCF - 7/ADR cells, the expressions of EZH2 mRNA were decreased by 84% （ P 〈 0.05 ） and the cell proliferation was decreased by 25 % after adriamycin （P 〈 O. 05 ）, However there were no significant changes of cell proliferation in EZH2 shRNA - scramble group and negative control groups after adriamycin. Conclusion EZH2 was overexpressed in MCF -7/ADR cells compared with MCF -7 cells. Silencing EZH2 may effectively reverse the resistance of MCF -7/ADR cells to adriamycin.