中文摘要：

目的：建立人结直肠癌裸鼠肝转移瘤模型，探讨干扰尾型同源盒基因2（caudal-related homeobox 2，CDX2）基因表达对结直肠癌肝转移瘤的影响。方法：通过慢病毒载体将CDX2-shRNA体外转染人结直肠癌细胞SW480、HT29，筛选建立稳定干扰 CDX2基因表达细胞株和阴性病毒细胞株；将稳定干扰CDX2基因表达的结直肠癌细胞（SW480-KD、HT29-KD）、空白对照细胞（SW480-CON、HT29-CON）和阴性对照细胞（SW480-NC、HT29-NC）接种到裸鼠脾下极包膜内，建立裸鼠结直肠癌肝转移瘤模型，每天称量裸鼠体质量并观察其摄食、活动及精神情况；50 d后处死裸鼠，分别从大体水平以及镜下观察肝转移瘤情况。结果：成功构建裸鼠结直肠癌肝转移模型，H-E染色确认为结直肠癌肝转移。各细胞干扰组（SW480-KD、HT29-KD）裸鼠体质量明显低于相应空白对照组和阴性对照组[SW480-KD：（15.02±2.00） vs （18.00±2.48）、（18.03±2.05） g；F=3.761，P〈0.05；HT29-KD：（15.39±2.16） vs （17.96±2.48） 、（18.30±1.87） g；F=3.721，P〈0.05]。SW480-KD组肝转移瘤数目明显多于SW480-CON组和SW480-NC组[（57.83±22.56）vs （29.50±16.90）、（28.20±15.40）个；F=4.197，P〈0.05]; HT29-KD组肝转移瘤数目明显多于HT29-CON组和HT29-NC组[（56.83±29.16） vs （26.40±12.76）、（2100±11.50）个; F=4.467，P〈0.05）]。结论：脾注射法裸鼠肝转移模型可作为体内研究基因功能的理想模型；干扰CDX2基因表达可促进结直肠癌SW480和HT29细胞在体内的转移。

英文摘要：

Objective：To establish a liver metastasis model of human colorectal cancer in nude mice,and to investigate the effect of interfering CDX2 gene on the metastasis of colorectal cancer in vivo. Methods： Lentiviral vector particles were used to infect human colorectal cancer HT29 and SW480 cells; CDX2 gene interfering cell lines （SW480-KD、HT29-KD） and negative shRNA were screened and established; cell lines with CDX2 gene interfering （SW480-KD,HT29-KD）,cell lines with negative shRNA （SW480-NC, HT29-NC） and blank control cells （SW480-CON, HT29-CON） were injected into the spleen of nude mice, respectively; the ingestion, movement and mental status of the mice were observed everyday and the weight of nude mice were measured every days. The nude mice were sacrificed on D50 to observe the liver metastasis by visual and microscopic observation. Results：The liver metastasis model of human colorectal cancer in nude mice was successfully constructed and confirmed by H-E staining. The weight of rats in knockdown group （SW480-KD, HT29-KD） was significantly lower than that of the blank control group （SW480-CON, HT29-CON） and negative control group （SW480-NC, HT29-NC）（SW480：[15.02±2.00] g vs [18.00±2.48] g, [18.03±2.05] g, F=3.761, P〈0.05; HT29： [15.39±2.16] g vs [17.96±2.48] g, [18.30±1.87] g, F=3.721, P〈0.05）. The number of liver metastatic tumors in SW480-KD group was significantly more than that of the SW480-CON group and SW480-NC group （[5783±22.56] vs [29.50±16.90], [28.20±15.40], F=4.197, P〈0.05）. The number of liver metastatic tumors in HT29-KD group was significantly more than that of the HT29-CON group and HT29-NC group （[56.83±2916] vs [2640±12.76] , [21.00±11.50], F=4.467,P〈0.05）. Conclusion： The liver metastasis model in nude mice established by the spleen injection was an ideal model to study the geng function in vivo; the CDX2