绒癌耐药细胞系的建立及获得性耐药机制的研究

目的 :采用目前治疗绒癌最常用的药物诱导建立绒癌的耐药细胞系 ,比较不同药物引起耐药机制的差异。方法 :采用浓度梯度递增法和间歇诱导法 ,分别用 5 FU ,MTX ,VP 16诱导绒癌细胞系JEG 3,建立相应耐药细胞系 ,采用MTT法测定耐药细胞系对5 FU、MTX、KSM、VP 16和Taxol的耐药指数 ,用RT PCR测定亲本细胞及各耐药细胞系耐药相关基因如肺耐药蛋白 (LRP)、多药耐药相关蛋白 (MRP)、谷胱甘肽转移酶 (GST π)、二氢叶酸还原酶 (DHFR)和多药耐药基因 (MDR 1)的mRNA表达 ,比较各种细胞生长曲线 ,细胞群体倍增时间。结果 :JEG 3细胞系在诱导耐药细胞前即有LRP、MRP、GST π、DHFR的共表达 ,诱导耐药后上述各基因的表达无明显变化。诱导耐药前JEG 3细胞无MDR1的表达 ,用VP 16、5 FU间歇诱导的方法诱导形成的耐药细胞系有MDR 1表达 ,且耐药指数增加。结论 :JEG 3耐药细胞系耐药性的产生与MRP、LRP、GST π、DHFR表达的关系不密切 ,而与MDR1的表达有关。

The establishment of the drug resistant cell lines and the study on the mechanism of acquired drug resistance in choriocarcinoma.

Objective:To establish the drug resistant cell lines of choriocarcinoma and study the mechanism of the acquired drug resistance.Methods:The resistant cell lines were established by stepwise or pulse exposure choriocarcinoma cell line JEG-3 to 5-FU,MTX and VP-16 for 10 months.The expressions of MDR1,MRP,LRP,DHFR and GST-π mRNA were analyzed by RT-PCR.The chemosensitivity of the cell lines to MTX,VP-16,KSM,Taxol and 5-FU was determined by MTT cytotoxicity assay.Results:The resistant cell lines showed resistance to drugs which used to induce drug resistance and showed cross resistance to other drugs.JEG-3 cell co-expressed MRP,LRP,DHFR and GST-π before induction of drug resistance.However,there were no changes of expression of these genes in drug resistant choriocarcinoma cell lines.JEG-3 cell showed no expression of MDR1 mRNA before induction,but the resistant cell lines induced by VP-16 and 5-FU expressed MDR1.Conclusion:The mechanism of the drug resistance of induced choriocarcinoma cell line is related to MDR1 mRNA expression.