中文摘要：

目的探讨人结肠癌细胞系SW480上皮-间质转化现象与其在化疗药物及靶向药物耐药中的作用。方法西妥昔单抗（cetuximab,C225）、5-氟尿嘧啶（5-Fu）以及二者联合处理人结肠癌细胞系SW480,观察细胞形态,免疫荧光化学方法检测处理前后SW480细胞骨架改变以及E-钙粘素（E-cardherin）、波形蛋白（vinmentin）表达差异,Western blot方法检测实验组与对照组SW480细胞E-cardherin、Vinmentin以及多药耐药蛋白（MRP）、P-糖蛋白（P-gp）表达差异;体外药物敏感试验（cell Counting Kit-8,CCK-8比色法）分别检测实验组与对照组SW480细胞存活能力。结果 SW480细胞经C225、5-Fu以及二者联合处理后细胞形态由上皮细胞向间质细胞转化;细胞免疫荧光显示处理前后SW480细胞骨架改变,微丝蛋白排列极性增强,E-cardherin表达下降,Vinmentin表达升高,同时伴随MRP、P-gp表达增高。SW480细胞经C225与5-Fu联合处理较单独应用2个药物细胞存活率明显降低（P〈0.05）。结论 SW480细胞经单独使用靶向药物或化疗药物以及两者联合应用可诱导细胞发生EMT,且此EMT对肿瘤细胞耐药有影响。

英文摘要：

Objective To discuss the epithelial-mesenchymal transition（EMT） of human colon cancer cell line SW480 and its effect on tumor drug resistance to chemotherapy drugs and targeted drugs.Methods SW480 cells were treated with cetuximab（C225）,5-fluorouracil（5-FU）,and C225 and 5-Fu combination,separately.Cell morphology was observed.Immunofluorescence assay was employed to detect the cytoskeleton changes as well as the expression difference of E-cadherin and vimentin before and after treatment.Western blotting was used to inspect the expression of E-cadherin,vimentin,multidrug resistance-associated protein（MRP）,and P-glycoprotein（P-gp） of SW480 cells in an experimental group（C225 and 5-FU treated）,a negative control group（untreated）,and a positive control group（TGF-β1 induced）.In-vitro drug susceptibility test（by cell counting kit-8,CCK-8 colorimetry） was adopted to examine the survival of SW480 cells with or without drug treatment.Results The cell morphology of SW480 cells after separate treatment with C225,5-FU,and C225 and 5-FU combination showed EMT.Immunofluorescence assay results indicated changes in SW480 cell cytoskeleton and an arrangement polarity increase of filamin,E-cadherin downregulation,and vimentin upregulation,accompanied by upregulation of both MRP and P-gp.The SW480 cells treated with C225 and 5-FU combination possessed a significantly reduced survival rate as compared with those treated with C225 or 5-FU separately（P0.05）.Conclusion Combined or separate application of targeted drugs and chemotherapy drugs on SW480 cells can induce EMT that influences tumor drug resistance.