姜黄素阻断NF-κB信号通路促进食管鳞癌细胞凋亡的体外研究

Curcumin Promotes Apoptosis of Esophageal Squamous Carcinoma Cell Lines Through Inhibition of NF-κB Signaling Pathway

背景与目的:活化的核转录因子-kappa B(nuclear factor-kappa B,NF-κB)信号通路参与调控多种与炎症、抗凋亡、肿瘤形成和转化有关的基因表达。但在食管鳞癌中的作用尚不清楚。姜黄素具有抗感染、抗氧化等多种药理作用。本研究将探讨姜黄素是否能够通过阻断NF-κB信号通路对食管鳞癌细胞增殖、抗凋亡产生影响。方法:Western blot法检测EC9706和Eca109细胞中加入姜黄素(50μmol/L)培养不同时间后,pIκBα和抗凋亡蛋白Bcl-2的表达情况。在EC9706和Eca109细胞中加入姜黄素培养72h,流式细胞仪检测凋亡细胞情况。MTT法检测姜黄素单独或与5-FU联合对细胞增殖的影响。结果:Western blot的结果显示,在姜黄素作用下EC9706和Eca109细胞中pIκBα和Bcl-2蛋白的表达水平随着时间的延长逐渐下降。在单独使用姜黄素后,就可促进EC9706和Eca109细胞的凋亡(P<0.05);当与5-FU联合使用时,可明显提高EC9706和Eca109细胞对化疗药物的敏感性,凋亡细胞显著增加(P<0.05)。姜黄素与5-FU联合应用48h和72h,可明显抑制EC9706和Eca109细胞的增殖,与单独使用姜黄素或5-FU组相比,细胞存活率显著降低,差异有统计学意义(P<0.05)。结论:姜黄素可以通过抑制IκBα的磷酸化阻断NF-κB信号通路,促进细胞凋亡,抑制细胞增殖,增加细胞对5-FU的敏感性。

BACKGRAND＆ OBJECTIVE： Activation of NF-κB signaling pathway plays a critical role in the initiation and progression of carcinogenesis. However, the role of NF-κB pathway in esophageal squamous cell carcinoma （ESCC） has not been fully elucidated. Studies have shown that curcumin possesses anti-infection and anti-oxidation effects. This study was to evaluate whether curcumin could induce apoptosis through inhibition of NF-κB signaling pathway in ESCC cells. METHODS： Expressions of pIκBα and Bcl-2 were detected using Western blott after incubation of ESCC cells with curcumin （50 μmol/L） at different time points. Apoptosis and the number of viable ESCC cells were analyzed using flow cytometry and MTT, respectively, after the treatment of curcumin, 5-FU, or the combination of curcumin and 5-FU. RESULTS： In two ESCC cell lines, EC9706 and Eca109, curcumin inhibited IκBα phosphorylation and Bcl-2 in a time-dependent manner~ curcumin alone increased cell apoptosis （P〈0.05）, and the effect became more prominent when it was combined with 5-FU （P〈0.05）; curcumin plus 5-FU exerted a stronger inhibition effect on cell proliferation than curcumin alone （P〈0.05） or 5-FU alone （P〈0.05）. CONCLUSION： Curcumin inhibits the phosphorylation of IκBα, leading to suppression of proliferation, induction of apoptosis and an increase of the sensitivity of ESCC cell lines towards 5-FU.