人类皮层肌动蛋白基因siRNA干预结肠癌细胞侵袭能力的研究

Interference of invasion and metastasis of colorectal cancer cells by EMSI-siRNA encoded by a recombinant lentiviral vector

目的探讨通过慢病毒载体介导的人类皮层肌动蛋白基因（EMS1）siRNA沉默皮层肌动蛋白（Cortactin）的表达对结肠癌细胞侵袭能力的影响。方法构建针对Cortactin的编码基因EMS1的siRNA慢病毒载体转染结肠癌细胞HCT8，分为3组：EMS1-siRNA转染组、空载体组，以及未转染组。Western blot检测3组Cortactin蛋白的表达：采用Transwell小室．观察3组癌细胞的侵袭能力的变化。取4～6周龄的裸鼠共30只，随机分成3组。每组10只。通过尾静脉分别注射上述3种细胞，6周后处死并观察这3组动物的肺转移灶形成情况。结果EMS1-siRNA转染细胞的Cortactin表达以及其侵袭能力较另外两组细胞明显降低（P〈0．05）。转染组、空载体组和未转染组裸鼠的肺转移率分别为20％、80％和80％，转染组肺转移率明显下降（P〈0．05）。结论Cortactin的表达减少可以降低结肠癌细胞的侵袭能力．并能降低肿瘤在动物体内器官转移的能力。

Objective To explore the effect of Cortactin on invasion and metastasis of human colorectal cancer calls through silencing the expression of Cortactin by transfecting colorectal cancer cells with EMSI-siRNA encoded by a recombinant lentiviral vector. Methods EMSI-siRNA lentiviral vector and negative control lentiviral vector were both transfected into HCT8 cells after virus packing, then the expression of Cortaetion of the cells was examined by Western blot to determine the inhibited level of Cortactin. The cells were defined as three groups：EMSl-siRNA transfecting cells, negative control transfecting ceils and untransfecting cells. Cell invasion was evaluated with Transwe11 body. In addition, cells metastasis was observed in animal models. Thirty nude mice were evenly divided into three groups and all the mice were injected through tail vein with 1×10^7 cells/0.2 ml per animal for each group with the three kinds of cells. The mice were sacrificed 6 weeks after injection and examined for lung metastases development. Results The expression of Cortactin and the ability of invasion of the EMSI-siRNA transfecting cells were all decreased. Lung metastasis rates of EMSI-siRNA transfeting group, negative control group and untransfecting group were 20%, 80% and 80%, respectively. Conclusion siRNA silencing of Cortactin expression can decrease the colorectal cancer cells invasion, and can also decrease the cells＇ implantation metastasis in animals.