Snail促进乳腺癌MCF-7细胞移植瘤对多柔比星的耐药及其机制

Snail increases resistance of breast cancer MCF-7 cell transplanted tumors to doxorubicin and its mechanism

目的:探讨Snail在乳腺癌MCF-7细胞移植瘤对多柔比星耐药中的作用及其可能的机制。方法:构建Snail基因真核表达载体pcDNA3.1-Snail,转染至MCF-7细胞,筛选稳定表达Snail的MCF-7/Snail细胞,以转染空质粒pcDNA3.1的MCF-7细胞(MCF-7/pcDNA)为对照。构建小鼠MCF-7/Snail及MCF-7/pcDNA细胞移植瘤模型,注射多柔比星,观测移植瘤生长,计算抑瘤率。免疫组织化学方法检测移植瘤组织中Snail、多药耐药基因-1(multidrug resistance-1,MDR-1)和基质金属蛋白酶-9(matrix metalloproteinase-9,MMP-9)的表达。结果:成功构建pcDNA3.1-Snail表达载体,转染MCF-7细胞后获得MCF-7/Snail和MCF-7/pcDNA细胞,并制备小鼠移植瘤。多柔比星治疗后,MCF-7/Snail细胞移植瘤的瘤重明显高于MCF-7/pcDNA细胞移植瘤[(1.413±0.674)g vs(1.257±0.576)g,P<0.05],多柔比星对MCF-7/Snail移植瘤抑瘤率明显低于MCF-7/pcDNA移植瘤(18.42%vs30.18%,P<0.05),MCF-7/Snail细胞移植瘤的组织中Snail、MDR-1、MMP-9的表达均显著高于MCF-7/pcDNA移植瘤(408.08±20.39vs67.67±16.56,363.50±26.56vs55.08±12.23,396.25±16.03vs56.92±7.35;均P<0.01),且Snail与MDR-1和MMP-9的表达均呈正相关(r1=0.89,P<0.01;r2=0.81,P<0.01)。结论:Snail促进乳腺癌MCF-7细胞移植瘤对多柔比星的耐药,其机制与增强MDR-1和MM9-9表达有关。

Objective：To study the effect of Snail on resistance of breast cancer MCF-7 cell transplanted tumors to doxorubicin and its possible mechanism. Methods：Snail eukaryotic expression vector pcDNA3.1-Snail was constructed and transfected into MCF-7 cells,and MCF-7 cells with stable Snail expression （MCF-7/Snail cells） were screened. MCF-7 cells transfected with blank pcDNA3.1 （MCF-7/pcDNA cells） were used as control. MCF-7/Snail-and MCF-7/pcDNA-cell transplanted tumor models were established. After doxorubicin injection,the growth of transplanted tumors was observed,and the inhibitory rate of doxorubicin was calculated. The expressions of Snail,MDR-1 and MMP-9 in transplanted tumor tissues were examined by immunohistochemistry. Results：pcDNA3.1-Snail expression vector was successfully constructed,and MCF-7/Snail and MCF-7/pcDNA cells were obtained. After doxorubicin therapy,the transplanted tumor weight in MCF-7/Snail group was significantly higher than that in the MCF-7/pcDNA group （[1.413±0.674]g vs [1.257±0.576]g,P〈0.05）,and the inhibitory rate of doxorubicin was significantly lower （18.42% vs 30.18%,P〈0.05）. The expressions of Snail,MDR-1 and MMP-9 in transplanted tumor tissues were significantly higher than those in MCF-7/pcDNA group （408.08±20.39 vs 67.67±16.56,363.50±26.56 vs 55.08±12.23,396.25±16.03 vs 56.92±7.35,all P〈0.05）,and the expression of Snail was positively correlated with that of MDR-1 and MMP-9 （r1=0.89,P〈0.01; r2=0.81,P〈0.01）. Conclusion：Snail can increase resistance of breast cancer MCF-7 cell transplanted tumors to doxorubicin,which might be related with the increased expressions of MDR-1 and MMP-9 in breast cancer MCF-7 transplanted tumors.