中文摘要：

目的建立稳定过表达Cdx2基因的胃癌细胞株。方法使用阳离子脂质体分别将真核表达载体pCMV—Cdx2-HA或空载体pCMV—HA转染至人胃癌细胞MGC-803中，G418筛选出阳性克隆后扩大培养。RT—PCR和Western Blot技术检测各组胃癌细胞中Cdx2基因mRNA和蛋白的表达情况，将挑选出的稳定株命名为MGC-803／Cdx2细胞（转染组）和MGC-803／EV细胞（空载体组）；流式细胞仪检测MGC-803细胞（未转染组）、MGC-803／EV细胞和MGC-803／Cdx2细胞的细胞周期和凋亡情况。结果成功筛选出稳定过表达Cdx2基因的MGC-803胃癌细胞，即MGC-803／Cdx2细胞；与MGC-803细胞和MGC-803／EV细胞比较。MGC-803／Cdx2细胞中Cdx2基因mRNA和蛋白的表达明显增加（P〈0．05），而且细胞周期G0／G1期比例和凋亡率也明显增加（P〈0．05）。结论成功构建了稳定过表达Cdx2基因的胃癌细胞株，而且Cdx2过表达使细胞周期停滞、凋亡增加。

英文摘要：

Objective To establish a gastric cancer cell line with stable over - expression of Cdx2 gene. Methods The reeombined eukaryotic expression vector pCMV - Cdx2 - HA or empty vector pCMV - HA was transfected into gastric cancer MGC -803 cells by Lipofectamine. G418 -resistant colonies were selected by adding G418 to the medium. Cdx2 mRNA and protein expression was assessed by RT - PCR and Western blot. The cell cycle progression and apoptosis were assessed by flow cytometry. Results A gastric cancer cell line with stable over - expression of Cdx2 was established successfully, which was named MGC-803/Cdx2 cells. Cdx2 mRNA and protein in MGC -803/Cdx2 cells significantly increased, compared with those in MGC - 803 cells and MGC - 803/EV cells （ P 〈 0. 05 ）. The proportion of cells in G0/ G1 phase and the apoptotic rate in MGC - 803/Cdx2 cells were significantly higher than those in MGC - 803 cells and MGC - 803/EV cells （ P 〈 0. 05 ）. Conclusion Gastric cancer cell line with stable over - expression of Cdx2, which induces cell cycle arrest and cell apoptosis, is established.