【摘要】 目的探讨缺氧环境下人肝癌细胞中多药耐药相关基因和缺氧诱导因子1α(HIF1α)的表达和意义,从而部分阐明肝细胞癌发生多药耐药的机制,为逆转肝癌耐药提供新的分子靶点。方法将人肝癌细胞系HepG2细胞分别行不同时间低氧培养和转染HIF1α/PCDNA3质粒;应用荧光定量聚合酶链反应技术和蛋白免疫印迹技术分别检测每组HepG2细胞中多药耐药相关基因(mdr1)、多药耐药相关蛋白1(MRP1)和肺耐药相关蛋白(LRP)在mRNA和蛋白水平的表达。结果在缺氧组,随着缺氧时间的延长HepG2细胞中多药耐药相关基因mdr1、MRP1和LRP的表达均逐渐增高,且以MRP1变化更为显著;而且这些多药耐药相关基因的表达升高与缺氧诱导因子1α的表达呈同步化改变。在HIF1α/PCDNA3质粒转染细胞中这些多药耐药相关基因的表达亦明显升高。结论缺氧可通过核转录因子HIF1α上调肝癌细胞内mdr1,LRP、MRP1等多药耐药相关基因的表达,从而使肝细胞癌获得多药耐药性。生长局部微环境的缺氧是诱导肝癌产生多药耐药性的重要原因之一。核转录因子HIF1α和这些多药耐药相关基因将可能成为逆转肝癌耐药的新的分子靶点。更多还原

【Abstract】 Objective To explore the mechanism of multidrug resistance of hepatocellular carcinoma induced by hypoxia and the potential role of hypoxia-inducible factor-1α (HIF-1α) and multidrug resistance related genes. Methods Human hepatocarcinoma cell lines HepG2 cells were exposed to hypoxia and were transfected by plasmid HIF-1α/PCDNA3, respectively. The expressions of multidrug resistance gene (mdr1), multidrug resistance protein(MRP1), and lung resistance protein (LRP) gene at the mRNA and the protein levels in the above two groups were respectively analyzed by real-time fluorescent quantitative PCR and Western-blot technique. Results In the hypoxia group, the expressions of mdr1, MRP1 and LRP were stepped up correlating to the degree of hypoxia, especially the prominent increase in the expression of MRP1. Furthermore, they were synchronous with the changes of the expression of HIF-1α. Also the increased expression of mdr1, MRP1, and LRP gene was observed in transfected HepG2 cells by plasmid HIF-1α/PCDNA3. Conclusions Resistance of hepatocellular carcinoma to chemotherapeutics could be induced by hypoxia. HIF-1α may be critical to the upregulation of the expression of the related multidrug resistance genes induced by hypoxia. HIF-1α and these related multidrug resistance genes could be potential molecular targets for reversing multidrug resistance of hepatocellular carcinoma.更多还原