维生素E琥珀酸酯对人大肠癌细胞的生长抑制和凋亡诱导作用(英文)

Growth inhibition and apoptosis of human colon cancer cells induced by vitamin Esuccinate

目的:检测维生素E琥珀酸酯(VES)对人大肠癌细胞的生长抑制和凋亡诱导作用并分析此种作用的可能机制。方法:VES分别以5、10和20 mg/L浓度作用于人大肠癌细胞株LS174T,12、24以及48 h后应用MTT法检测VES对大肠癌细胞的生长抑制作用。应用流式细胞仪分析不同浓度VES处理48 h后大肠癌细胞的细胞周期并计算凋亡率;以Western蛋白印迹法和流式细胞术检测VES处理后肿瘤细胞Fas蛋白水平和细胞表面Fas表达的变化。结果:VES能够显著抑制人大肠癌细胞的增殖并表现为剂量和时间依赖关系。以5、10和20 mg/L VES作用48 h后,肿瘤细胞的凋亡率由0.9%分别升高至15.9%、46.7%和64.5%。Fas中和性抗体能够明显阻断VES介导的凋亡。VES处理后,细胞Fas蛋白水平升高。流式细胞仪检测细胞表面Fas平均荧光强度由5.43升高至9.88、13.21和18.0。结论:VES能够诱导人大肠癌细胞的生长抑制和凋亡。调控凋亡诱导分子Fas的表达是主要机制之一。其作用主要与肿瘤细胞表面Fas分子表达的上调有关。

Objective： To investigate the growth inhibition and apoptosis induction effect of vitamin E succinate （VES） on human colon cancer cells and to analyze the modulation of apoptosis-mediator Fas expression in this process. Methods： Human colon cancer cell line LS174T was treated with VES for 12 h, 24 h and 48 h at the concentrations of 5 mg/L, 10 mg/L and 20mg/L. 1-（4,5-dimethylthiazo-2-yl）-3,5-diphenylformazan （MTT） assay was employed to detect the inhibitory effect of VES on the growth of colon cancer cells. Flow cytometry was then used to analyze the cell cycle of the colon cancer cells after being treated with VES and the apoptotic rate was calculated at the same time. To find out whether the Fas protein expression was modulated in this process, Western blotting assay and flow cytometry were used to detect the Fas protein level in whole cell lystates and on cell surface. Results： VES exhibited a significant inhibitory effect on the growth of human colon cancer cells in a doseand time-dependent manner. After being treated with VES at 5 mg/L, 10 mg/L and 20 mg/L for 48 h, the apoptotic rate of LS174T cells rose from 0.90% to 15.9%, 46.7% and 64.5%, respectively. Fas neutralizing antibody can significantly block VES-induced apoptosis. After the administration of VES, total Fas protein in whole-cell extracts increased in a dose-dependent manner. The flow cytometry showed that the mean fluorescence intensity rose from 5.43 to 9.88, 13.21 and 18.0 after being treated with VES. Conclusion： VES can induce significant growth inhibition and apoptosis in human colon cancer cells. The modulation of Fas expression is one of the mechanisms involved in this process and may be related to the upregulation of Fas molecule on the cancer cell surface.