MRP1介导肿瘤的多药耐药

MRP1- mediated tumor multidrug resistance

目的:探讨多药耐药相关蛋白基因MRP1介导肿瘤耐药机制,寻找逆转耐药的方法。方法:建立肝细胞癌单基因耐药细胞株Hep G2/MRP1,体外转录合成目的 siRNA片断,脂质体介导转染单基因肝细胞癌耐药细胞株,MTT法检测细胞对化疗药的敏感性,流式细胞仪检测药物浓度及细胞表面MRP1蛋白表达。结果:成功建立多药耐药细胞株,并筛选出靶向MRP1基因高效的siRNA分子。转染Hep G2/MRP1细胞后,MRP1 mRNA及MRP1表达水平明显下调,细胞内DNR蓄积量增加,对ADM的IC50下调,相对逆转率达90%。转染前后细胞对化疗药敏感性、细胞内药物浓度、细胞表面MRP1蛋白质表达均有显著差异。结论:肿瘤多药耐药与MRP1高表达密切相关,RNAi技术能有效逆转由MRP1介导的肿瘤细胞的多药耐药。

Objective： To investigate the suppression of MRP1 and MRP1 induced by small interfering RNA and the restoration of sensitivity to chemotherapeutic drugs in the multidrug- resistant hepatocellular carcinoma cell lines Hep G2 / MRP1. Methods： MRP1- targeted small interfering RNA duplexes were designed,composed and introduced into multidrug- resistant hepatocellular carcinoma cell lines Hep G2 / MRP1. The suppression of MRP1 mRNA and its gene product MRP1 was examined by RT- PCR and flow cytometry（ FCM） respectively. MTT assay was performed to measure the reverse effect of small interfering RNA based on the results of IC50. Results： The overexpression of MRP1 mRNA and MRP1 was suppressed,by the introduction of small interfering RNAs,which caused sequence- specific gene silence. The level of MRP1 mRNA in the transfected Hep G2 / MRP1 cells reduced to（ 86. 36 ± 2. 76） % and MRP1 to（ 89. 38 ± 3. 76） % compared with those of the controls. The resistance to ADR was reversed by five folds,which indicated the restoration of sensitivity to drugs. Conclusion： The multidrug resistance of tumors were closely related to the high expression of MRP1. Small interfering RNA can inhibit MRP1 expression and reverse the multidrug resistance mediated by MRP1.