Establishment of human glioblastoma multiform multidrug resistant cell line in vitro and identification of its biological characteristics / 中华神经医学杂志

ABSTRACT

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 ([IC50U251/STI-571]/[IC50 U251]) for other chemotherapeutic agents were evaluated using cell counting kit-8 assays. Expressions of acquired multidrug resistance P-glycoprotein (MDR 1, 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 of MDR1, 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 ABCC1, ABCB1, ABCB4, and ABCG2 mRNA, and ABCG2 protein.