P-糖蛋白、谷胱甘肽-s转移酶的表达与胃癌细胞耐药的关系研究

目的初步探索胃癌多药耐药细胞系SGC7901／VCR的耐药机制。方法间歇诱导法，胃癌细胞系SGC7901经长春新碱（VCR）短时间诱导后，对长春新碱产生耐药。MTT法检测对VCR、5-氟尿嘧啶、表阿霉索的耐药性。Western blot检测P-糖蛋白（P—glucoprotein，P—gp）、谷胱甘肽-s转移酶（ghtathione—s transferring enzyme，GST—s）的表达。结果耐药细胞SGC7901／VCR对长春新碱耐药提高16．56倍，此耐药株同时对5-氟尿嘧啶、表阿霉素呈交叉耐药，耐药指数分别达6．9、13．05。SGC7901／VCR的P—gP、GST—s出现表达增强。结论长春新碱短时间诱导后，SGC7901产生多药耐药性（multi—drug resistance，MDR），且P—gp、GST—s表达增强。反之，抑制P—gP、GsT—s蛋白的表达，则有可能降低细胞耐药从而逆转胃癌MDR。

Expression of P-glycoprotein and glutathione-S-transferases enzyme in gastric carcinoma cell line and their correlations with multidrug resistance

Objective To explore the mechanism of multi - drug resistance（MDR） in the human gastric carcinoma MDR subline SGC7901/VCR. Methods The density of vincristine（VCR） was increased gradually to induce the drug resistance of gastric carcinoma cell SGC7901. MTT assay was used to determine the lethal effect of anticarcinogens on tumor cells and Western blot assay was applied to determine the expression of P - gp and GST - s in tumor cells. Results The resistance of SGC7901/VCR cells to VCR, fluorouacil, and epirubicin were 16.56,2.69 and 13.05 times ,respectively,more than that of SGC7901 cells. Expressions of P - gp and GST - s in resting SGC7901/VCR cells were significantly higher than that in carcinogen - sensitive SGC7901 cells. Conclusion The density of vincristine（VCR）was increased gradually to induce the drug resistance of gastric carcinoma cell SGC7901. Expression of P - gp and GST - s in resting SGC7901/VCR cells was significantly more than that in carcinogen- sensitive SC, C＇7901 cells. On the contrary, Inhibiton of P-gp and GST- s may reverse drug resistance of SGC7901/VCR cells.