中文摘要：

目的观察Cdx2基因过表达的重组逆转录病毒载体（pLXSN-Cdx2）对裸鼠人胃癌皮下瘤生长的影响。方法构建重组逆转录病毒载体pLXSN-Cdx2,建立裸鼠人胃癌皮下瘤模型,将30只裸鼠随机分为pLXSN-Cdx2组、空载体逆转录病毒颗粒pLXSN组和对照组,每组10只。向3组动物肿瘤内分别注射pLXSN-Cdx2、pLXSN或生理盐水0.2 mL,共7次,测量各组肿瘤体积的大小;15 d后处死裸鼠,显微镜下观察移植瘤组织形态变化,应用RT-PCR检测肿瘤中Cdx2基因mRNA的表达,TUNEL检测细胞凋亡指数。结果 pLXSN-Cdx2构建成功;与对照组和pLXSN组比较,pLXSN-Cdx2组的肿瘤生长速度明显减慢（P〈0.05）;pLXSN-Cdx2组肿瘤体积为（14.15±2.17）mm3,明显低于pLXSN组和对照组的肿瘤体积（P〈0.05）;pLXSN-Cdx2组Cdx2 mR NA的表达量为（2.71±0.65）,高于pLXSN组和对照组（P〈0.05）。pLXSN-Cdx2组的凋亡指数（14.4±5.3）%显著高于pLXSN组（7.6±2.2）%和生理盐水组（7.7±2.3）%（P〈0.05）。结论重组逆转录病毒载体pLXSN-Cdx2瘤内注射可抑制裸鼠人胃癌皮下瘤的生长。

英文摘要：

【Objective】 To study the effects of the recombinant retroviral vector with Cdx2 overexpression on growth of subcutaneous tumor of human gastric cancer in nude mice.【Methods】 The recombinant retroviral vector pLXSN-Cdx2 was constructed.Nude mice were inoculated subcutaneously with MGC-803 cells to establish the subcutaneous tumor model of gastric carcinoma.pLXSN-Cdx2,pLXSN or NS（0.2 mL per time） was injected individually every two days.The volume of tumor was measured and after HE staining,histopathological characteristics of subcutaneous tumor were observed under microscope;the expression of Cdx2 was detected by semi-quantitative reverse transcription polymerase chain reaction（RT-PCR）.The apoptosis of tumor xerographs was measured by in situ end labeling technique（TUNEL）.【Results】 The recombinant retroviral vector pLXSN-Cdx2 was constructed successfully.The mean rate of tumor growth in pLXSN-Cdx2 group was much slower than that in pLXSN group and control group（P〈0.05）.The mean volume of tumor in pLXSN-Cdx2 group was（14.15±2.17） mm3,which was lower than that in pLXSN group and control group（P〈0.05）.Compared with that in pLXSN group and control group,Cdx2 mRNA was increased in pLXSN-Cdx2 group（P〈0.05）.The apoptotic rate in the pLXSN-E2F-1 treatment group was（14.4±5.3） %,significantly higher than that in the other two groups [（7.6±2.2） % for pLXSN and（7.7±2.3） % for NS（P〈0.05）].【Conclusion】 Intra-tumor injection of pLXSN-Cdx2 has significantly inhibitory effect on growth of subcutaneous tumor of human gastric cancer in nude mice.