大豆异黄酮在缺氧条件下诱导食管癌细胞凋亡及对HIF-1α表达的影响

Induction of apoptosis and influence of HIF-1α expression on esophageal carcinoma cell ECa109 by soybean isoflavone during hypoxia

目的研究在缺氧条件下大豆异黄酮(soybeanisoflavone)对人食管癌细胞株ECa109生长抑制作用及可能机制。方法运用产气袋法(GasPaK)制造缺氧条件,实验分为对照组、大豆异黄酮组、缺氧对照组、缺氧大豆异黄酮组,用MTT法检测常氧和缺氧条件下药物效应。流式细胞仪分析各组细胞周期分布,透射电镜观察细胞超微形态的改变,S-P免疫组化法检测各组细胞HIF-1α和Fas的表达。结果不同浓度大豆异黄酮不同氧条件下对人食管癌细胞株ECa109生长均有抑制作用,并呈剂量-效应关系。缺氧条件下大豆异黄酮对人食管癌细胞株ECa109生长抑制作用增加。常氧和缺氧条件下大豆异黄酮处理后细胞均滞留于G2/M期,缺氧大豆异黄酮组凋亡率增加。透射电镜观察常氧下及缺氧条件下大豆异黄酮处理后细胞出现凋亡和坏死细胞的形态学改变。大豆异黄酮不同氧条件下均上调Fas表达,并能下调因缺氧表达增加的缺氧诱导因子-1α(hypoxia-induciblefactor-1α,HIF-1α)的表达。结论大豆异黄酮对人食管癌细胞生长有抑制作用,其抑制作用可能通过阻抑细胞周期进程,上调Fas蛋白表达,从而诱导食管癌细胞凋亡而实现的。缺氧条件下大豆异黄酮抑制作用增强,抑制HIF-1α的表达可能是其重要机制。

Objective To study the mechanisms and effect of soybean isoflavone on esophageal carcinoma cell ECa109 during the normoxia and hypoxia. Methods The environment of hypoxia was established by GasPak method. The ECa109 cells were assigned into normal control group, soybean isoflavones group, hypoxia group, and soybean isoflavones plus hypoxia group. The effect of soybean isoflavones was determined by MTT, and FCM was used for detecting the apoptosis and cell cycle of ECa109. Electron microscope was used to observe the ultrastructural changes of ECa109 induced by soybean isoflavone. Immunohistochemistry was used to detect the changes of HIF-1α and Fas. Results Soybean isoflavone could inhibit significantly the growth of ECa109 cells in a concentration-dependent manner, and arrest the cells in G2/M phase during normoxia and hypoxia. The inhibitory effect was elevated significantly during hypoxia, and the cell apoptosis and necrosis were observed by electron microscope. The Fas expression was elevated by soybean isoflavone during the normoxia and hypoxia, and the HIF-1α expression was down-regulated during hypoxia. Conclusion Soybean isoflavone can inhibit ECa109 cells growth by delaying the progress of cell cycle, up-regulating the Fas expression. Soybean isoflavone can inhibit the expression of HIF-1α that was increased during hypoxia, which may be the mechanism that the inhibitory effect was enhanced significantly during hypoxia.