西罗莫司对肝癌HepG2细胞中HIF-1α表达影响

THE EFFECT OF SIROLIMUS ON THE EXPRESSION OF HYPOXIA-INDUCIBLE FACTOR-1 ALPHA IN HEPATOCELLULAR CARCINOMA HEPG2 CELLS

目的研究西罗莫司对氯化钴(CoCl2)诱导的肝癌HepG2细胞中缺氧诱导因子-1α(HIF-1α)表达的影响。方法用CoCl2诱导细胞模拟缺氧微环境,并根据CoCl2浓度不同分为0、50、100、200及400μmol/L组;选择CoCl2浓度为200μmol/L来模拟肿瘤内缺氧微环境,同时分别联合0、10、20、30、40nmol/L的西罗莫司作用于细胞24h。应用逆转录-聚合酶链反应检测HIF-1αmRNA的表达。结果随CoCl2浓度提高,HIF-1αmRNA的表达升高(F=103.67,q=4.83～24.15,P<0.05),其中CoCl2浓度为200和400μmol/L两组比较差异无显著性(q=0.69,P>0.05);西罗莫司可使HepG2细胞HIF-1αmRNA的表达降低并呈剂量依赖性(F=127.90,q=4.24～28.28,P<0.05)。结论缺氧微环境可以促进HepG2细胞中HIF-1αmRNA的表达,HIF-1α可能通过在细胞缺氧调控中起作用而参与了肿瘤的发生发展。西罗莫司可以抑制HIF-1αmRNA的表达,这可能是其抗肿瘤的机制之一。

Objective To investigate the effect of sirolimus on the expression of hypoxia-inducible factor-1 alpha （HIF-1α） in human hepatocellular carcinoma HepG2 cells induced by cobalt chloride. Methods Cobalt chloride was used to mimic the cell hypoxic microenvironment, and HepG2 ceils were divided into five groups according to different concentrations of cobalt chloride, i.e. 0-, 50-, 100-, 200-, and 400 μmol/L groups. The concentration of 200μmol/L of cobalt chloride was chosen to mimic tumor hypoxic microenvironment, and, at the same time, different concentrations of sirolimus （0, 10, 20, 30, and 40 nmol/L） were applied to treat the cells for 24 h. The expression of HIF-1α mRNA was detected by semi-quantitative reverse transcriptionpolymerase chain reaction （RT-PCR）. Results With increasing of concentration of cobalt chloride, the expression of HIF-1α mRNA increased （F=103.67,q=4.83-24. 15 ,P〈0.05）, and there was no significant difference between 200 μmol/L group and 400μmol/L group. The expression of HIF-1α mRNA of HepG2 cells induced by cobalt chloride was degressive with the effect of sirolimus, and became dose-dependent （F=127.90,q=4.24-28. 28,P〈0.05）. Conclusion The expression of HIF-1α mRNA of HepG2 cells can be elevated by hypoxic microenvironment, and HIF-1α may play an important role in the cell hypoxic regulation to participate in the tumorous growth. Sirolimus can inhibit the expression of HIF-1α mRNA, which may be one of its antineoplastie mechanisms.