中文摘要：

目的体外构建胶质瘤耐甲磺酸伊玛替尼多药耐药细胞株，并研究其生物学特性。方法采用逐渐增加培养基中伊玛替尼药物浓度的方法诱导构建耐甲磺酸伊玛替尼的人脑胶质瘤U251细胞株（命名为U251AR）；CCK8法检测U25IAR、U251对多种化疗药物的IC50和耐药指数；QRT-PCR法检测耐药相关基因ABCC1、ABCB1、ABCB4、ABCG2mRNA的表达，流式细胞术检测ABCG2蛋白的表达。结果体外培养12个月后建立了稳定耐药的细胞株U251AR，与亲代细胞相比异形性不显著。U251和U251AR对化疗药物的IC50相比较差异均有统计学意义（P〈0．05），U251AR对甲磺酸伊玛替尼、阿霉素、顺铂的耐药指数分别为20．41、5．06、10．28，表现出多药耐药特征。QRT-PCR检测结果显示耐药细胞株U251AR中ABCC1、ABCB1、ABCB4、ABCG2mRNA的表达明显高于亲代U251细胞，流式细胞术检测结果显示U251AR中ABCG2蛋白的表达强于亲代U251细胞，差异均有统计学意义（P〈0．05）。结论成功建立多药耐药的胶质瘤细胞株U251AR，其多药耐药与ABCCl、ABCB1、ABCB4、ABCG2mRNA及ABCG2蛋白的表达上调相关。

英文摘要：

Objective To establish the imatinib （STI-571）-resistant subline in vitro and investigate its biological characteristics. Methods Human gliobLastoma multiform drug-resistant cell line （named U251AR） was established in vitro by successively increasing the concentration of imatinib in a cell culture medium. The 50% inhibitory dose （IC50） values and the resistance indexes （[IC50 U251/STI-571 ]/[IC50 U251 ]） for other chemotherapeutic agents were evaluated using cell counting kit-8 assays. Expressions of acquired multidrug resistance P-glycoprotein （MDR1, ABCB 1; MDR3, ABCB4）, breast cancer resistance protein （BCRP, ABCG2） and multidrug resistance-associated protein 1 （MRP1, ABCC1） were detected by QRT-PCR. Flow cytometry was employed to detect the protein expression of ABCG2. Results The U251AR was developed after culture for 12 months and similar morphologies of U251 and U251/STI-571 cells were determined. The resistance coefficient of U251AR cells to imatinib was 20.41 times more than that of the parent cells, and U251AR cells showed cross-resistance to many anti-tumor agents （P〈0.05）. The resistance coefficients of U251AR cell line to doxorubicin and cisplatin were 5.06 and 10.28 times, respectively, more than those of U251 cells （P〈0.05）. QRT-PCR indicated that the mRNA levels ofMDR1, MRP1, BCRPandABCB4 （P-g4） in the U251/STI571 resistant cells were significantly higher than those in the U251 cells （P〈0.05）. The protein expression of ABCG2 in U251AR cell line was significantly increased as compared with that in the parent cells （P〈0.05）.Conclusion We have successfully established multidrug resistant cell line U251AR, and the drug resistance of U251/STI571 is associated with over-expressions of A BCC1, A BCB1, A BCB4, and A BCG2 mRNA, and ABCG2 protein.