中文摘要：

目的探讨异甾体类生物碱药物环巴胺对胃癌细胞SGC-7901的生长抑制作用及对β-catenin和E-cadher-in基因表达水平的影响。方法体外培养人胃癌SGC-7901细胞,MTT法观察环巴胺在不同浓度及不同时间对细胞的生长抑制作用;AO/EB染色荧光显微镜下观察细胞凋亡形态学改变;应用流式细胞仪检测细胞周期各时相分布情况;采用RT-PCR法检测β-catenin、E-cadherin基因mRNA的表达情况。结果 MTT法显示环巴胺对SGC-7901细胞生长有显著抑制作用,其作用强度与剂量和作用时间呈正相关,且各组间比较差异有显著性（P〈0.05）。环巴胺作用24 h后,荧光显微镜下观察到典型的凋亡细胞形态改变。流式细胞分析结果显示环巴胺作用后G0/G1期细胞比例明显增高,S期细胞比例明显下降,细胞阻滞在G0/G1期,各组间比较差异显著（P〈0.05）。SGC-7901细胞中β-catenin mRNA呈高表达、E-cadherin呈低表达,环巴胺可下调β-catenin mRNA表达水平,上调E-cadherin mRNA表达水平,呈浓度依赖性（P〈0.05）。结论环巴胺可诱导SGC-7901细胞凋亡;SGC-7901细胞中β-catenin及E-cadherin存在异常表达,环巴胺抗肿瘤作用机制可能与下调Wnt信号通路的β-catenin表达、上调E-cadherin表达有关。

英文摘要：

Objective To explore the effect of cyclopamnie on cell proliferation and expression of β-catenin and E-cad- herin in human gastric cancer cell line SGC-7901. Methods SGC-7901 cells were cultured in vitro. MMT was used to examine the effect of cyclopamine on cell proliferation at different concentrations and different time points. The morphological changes of apoptosis were observed under AO / EB staining fluorescence microscopy. Alteration of cell cycle was analyzed by Flow cytome- try. Expression of β-catenin and E-cadherin mRNA were detected and quantified by RT-PCR. Results MTI＂ assay presented that cyclopamine inhibited the proliferation of SGC-7901 cells in dose-and time-dependent manners （ P 〈 0.05 ）. Different morphologi- cal changes of apoptosis had been found under fluorescence microscopes after treatment with cyclopamine for 24 h. Flow cytometry analysis showed that the percentage of cells in G0/G1 phase significantly increased, while percentage of S phase cells decreased. Cell cycle was arrested in G0/G1 phase （ P 〈 0.05 ）. Expression of 13-catenin mRNA was high, while that of E-cadherin mRNA was low in SGC-7901 cells. Cyclopamine could significantly down-regulate the expression of [3-catenin mRNA and up-regulate ex- pression of E-cadherin mRNA in a dose-dependent manner （ P 〈 0.05 ）. Conclusion Cyclopamine could induce apoptosis of hu- man gastric cancer cell SGC-7901.13-eatenin and E-cadherin all expressed abnormally in SGC-7901 cells. Cyclopamine played an- ticancer activity through down-regulating expression of β-catenin and up-regulating expression of E-cadherin.