糖皮质激素对人肝癌细胞系增殖的抑制作用

目的 探讨糖皮质激素在体外环境下对肝癌细胞增殖的影响及可能机制.方法 以不同浓度(0.1、0.01、1×10-3、1×10-4、1×10-5、1×10～mmol/L,均为终浓度)的地塞米松(Dex)在体外作用于人肝癌细胞系Bel7402、H7402和Hep G2细胞,计算细胞生长抑制率.再以Bel7402细胞为对象,分别加入1×10-4 mmol/L的Dex(Dex组)、1×10-4mmol/L的Ru486(Ru486组)、Dex和Ru486(浓度均为1×10-4mmol/L,Dex+Ru486组),并设加人培养液的阴性对照组,计算各组细胞生长抑制率,流式细胞仪测定各组的细胞周期分布,Western免疫印迹法检测Bel7402细胞的P21蛋白的表达;报告基因法检测Dex和Ru486对Bel7402细胞的核因子κB(NF-κB)启动子的影响.结果 各浓度Dex对3种肝癌细胞的增殖均有抑制作用,且呈浓度依赖性.Dex组Bel7402细胞的增殖受到抑制,其G0/G1期细胞增多,S期细胞减少,其细胞内的P21蛋白表达上调,NF-κB启动子的激活受到抑制,而加入Ru486后(Dex+Ru486组),Dex的这些作用被逆转.结论 Dex可以抑制Bel7402细胞的增殖,并使细胞周期停滞在G上/G1,期,其机制可能包括上调P21蛋白的表达和抑制NF-κB的表达,这种作用由糖皮质激素胞内受体介导.

Inhibitory effect of glucocorticoid on proliferation of human hepatoma carcinoma cell line in vitro

Objective To illustrate the role of glucocorticoids in growth regulation of human hepatoma cells and the possible mechanism. Methods The human hepatoma carcinoma cell lines Be17402, H7402 and Hep G2 were treated with different concentrations of dexamethasones (Dex) (0.1, 0.01, 1×10-3, 1×10-4, 1×10-5, and 1×10-6 mmol/L). The inhibition rate was calculated. Be17402 cells were treated with Dex (1×10-4 mmol/L, Dex group), or RU486 (1×10-4 mmol/L, RU486 group) or both (both concentrations were 1×10-4 mmol/L, Dex+ Ru486 group), or medium as negative control group. The inhibition rate was calculated, and the cycle progression was measured by flow cytometry. Western blot was used to detect the expression of P21 protein, and the reporter genes were employed to detect the effect of Dex and Ru486 on promoter of NF-kappa B in Be17402 cells. Results Dex could significantly inhibit the proliferation of these cells in a dose-dependent manner. Dex inhibited the growth of Be17402, and induced G0/G1 arrest. Dex increased the expression of P21, and suppressed the promoter of NF-kappa B. Ru486 could reverse these effects. Conclusion Up-regulation of P21/WAF1 expression and suppression of promoter of NF-κB may contribute to the growth inhibition and G0/G1 arrest induced by glucocorticoid in human hepatoma carcinoma cells. These effects may be mediated by GR.