全反式维甲酸诱导食管癌细胞凋亡的实验研究

目的探讨全反式维甲酸(ATRA)诱导食管癌EC9706细胞凋亡的作用及其机制。方法用不同浓度的ATRA处理EC9706细胞,采用四甲基偶氮唑盐(MTT)法检测ATRA对EC9706细胞的增殖抑制效应;采用流式细胞仪和原位末端标记(TUNEL)法检测细胞周期的变化和凋亡率;采用免疫组化S-P法,检测凋亡相关基因caspase-3和bcl-2的蛋白表达,并用病理图像分析软件进行半定量分析。结果ATRA对EC9706细胞有增殖抑制和诱导凋亡的作用;流式细胞仪检测显示,在G1期之前可出现Sub-G1峰,凋亡率最高为(32.6±0.4)%,并有浓度和时间依赖性;TUNEL法显示凋亡小体形成;EC9706细胞在凋亡过程中,凋亡相关基因caspase-3的蛋白表达增强,bcl-2的蛋白表达减弱。结论ATRA作用于食管癌EC9706细胞后将引起细胞凋亡的增加,这主要与ATRA能促进caspase-3的活化,并下调bcl-2的蛋白表达有关。

Apoptosis in esophageal cancer cells induced by all-trans retinoic acid

Objective To study the anti-tumor effects of all-trans retinoic acid (ATRA) and mechanisms of its action. Methods Human esophageal carcinoma cell line EC9706 cells were treated with ATRA at different concentration. The proliferation inhibition was examined by MTT assay. Morphological examination, TUNEL method and flow cytometry were used to detect the apoptosis and changes of cell cycle. Immunohistochemical method was used to detect the expression of apoptosis-related genes caspase-3 and bcl-2. The semi-quantification of protein expression was analyzed by pathological image analysis. Results ATRA inhibited the proliferation of EC9706 cells moderately. Apoptosis in EC9706 cells was induced by ATRA treatment. The morphology of EC9706 cells showed changes such as nuclear chromatin condensation and fragmentation. Sub-G1 peak was found by flow cytometry. The maximal apoptosis rate was 32.6%. The expression of caspase-3 gene was enhanced. The expression of bcl-2 gene was decreased. All these effects were presented in a dose-dependent and time-depend manner. Conclusion Apoptosis is one of the key mechanisms of ATRA action on EC9706 cells.