多药耐药相关蛋白在肝癌耐药细胞系HepG2/Oxal中的作用机制研究

Role of multi-drug resistance proteins in drug resistance cell line HepG2/Oxal of hepatocellular carcinoma

目的:探讨多药耐药(multi-drug resistance,MDR)相关蛋白在肝癌细胞系HepG2及不同浓度耐奥沙利铂(oxaliplatin,Oxal)亚系中的表达及参与肝癌对Oxal耐药的机制。方法:以浓度递增法诱导肝癌细胞系HepG2,建立2.5、5.0μg/ml的Oxal耐药亚系,以半定量RT-PCR法测定MDR、多药耐药相关蛋白(multi-drug resistance related protein,MRP)和乳腺癌耐药蛋白(breast cancer resistance protein,BCRP)在亲代和不同耐药亚系中的mRNA表达,并在蛋白水平以Western blot法验证基因表达的差异性。结果:成功建立了IC50值为15和25倍亲代细胞的Oxal耐药亚系(HepG2/Oxal);在mRNA和蛋白水平,BCRP的表达与HepG2的耐药性呈正相关,而MDR、MRP的表达在耐药的早期升高不明显,随着耐药程度的增加其表达增加。结论:BCRP在HepG2对Oxal获得性耐药中起着重要作用,MDR和MRP在HepG2/Oxal耐药过程中早期起的作用不明显,随着耐药浓度的增加,表达越来越高。

Objective：To investigate the expression of multi-drug resistance-associated proteins（MDR） in Hepatocellular cancer cell line HepG2 and in different concentrations of sub-cell line of oxaliplatin（Oxal）,and to study the mechanism of their resistance to Oxal.Methods：HepG2 multi-drug resistance sub-cell line was induced by increasing the concentration of Oxal progressively,and the drug resistance cell line 2.5 μg/ml HepG2/Oxal and 5.0 μg/ml HepG2/Oxal was successfully established.The mRNA expression of the MDR,the expression of multi-drug resistance related protein（MRP） and breast cancer resistance protein（BCRP） in the cell lines（HepG2/Oxal） of 2.5 μg/ml HepG2/Oxal and 5.0 μg/ml HepG2/Oxal were detected using RT-PCR,and the variability of the gene expression was verified by Western blot.Results：HepG2/Oxal drug resistance cell subseries with IC50 value of 15 and 25 times were successfully constructed.BCRP expression was positively correlated with HepG2 drug resistance at mRNA and the protein level.But MDR and MRP did not display significant high expression in the prophase drug resistance subseries;the expression of MDR and MRP increased along with the rise of drug resistance level.Conclusions：BCRP plays an important role in the acquired character resistance of HepG2 cell line to Oxal;the expression of MDR and MRP is not obvious at the prophase of the resistance,but increases with the rise of the resistance level.