Song Jia, Zhang Jixiang, Wang Jing, Wang Jun, Guo Xufeng, Dong Weiguo
Department of Gastroenterology, Renmin Hospital of Wuhan University, 99 Zhi-Dong Zhang Road, Wuhan, 430060, Hubei Province, People's Republic of China.
Tumour Biol. 2015 Mar;36(3):2013-21. doi: 10.1007/s13277-014-2808-x. Epub 2014 Nov 12.
β1 integrin (ITGB1) is the major expressed integrin protein of normal cells and tumor-associated cells. It is often up-regulated in human malignancies and is involved in many developmental processes, such as tumor progression and metastasis. However, little is known about the function of ITGB1 in colorectal cancer. We constructed lentiviral vectors expressing ITGB1 or ITGB1-specific RNA interference (RNAi) and an unrelated control vector. After infecting HT29 cells in vitro, proliferation and migration were evaluated by Cell Counting Kit 8 (CCK-8) assays, transwell invasion assays, and Western blots. The influence of lentivirus infection on the tumor development capacity of HT29 cells in vivo was examined by xenografting the tumor cells. The expression of ITGB1 in the xenografted tumor cells was analyzed by immunohistochemistry. The up-regulation of ITGB1 significantly increased the proliferation in HT29 cells in vitro. Moreover, we found that the overexpression of ITGB1 up-regulated sonic hedgehog (Shh) while down-regulating Gli1 and SuFu in HT29-ITGB1 cells compared to controls. Moreover, the levels of c-myc and cyclin D1 proteins were up-regulated. Transwell assays showed that the number of migrating HT29-RNAi cells was lower than that in the other cell groups, indicating that ITGB1 significantly enhances the invasive ability of HT29 cells. In addition to these in vitro results, ITGB1 was found to be a significantly effective growth factor in a xenografted tumor mouse model. These results suggest that ITGB1 induces growth and invasion in a human colorectal cancer cell line through the hedgehog (Hh) signaling pathway in vitro and in vivo.
β1整合素（ITGB1）是正常细胞和肿瘤相关细胞中主要表达的整合素蛋白。它在人类恶性肿瘤中常上调，并参与许多发育过程，如肿瘤进展和转移。然而，关于ITGB1在结直肠癌中的功能知之甚少。我们构建了表达ITGB1或ITGB1特异性RNA干扰（RNAi）的慢病毒载体以及一个无关的对照载体。在体外感染HT29细胞后，通过细胞计数试剂盒8（CCK-8）检测、Transwell侵袭检测和蛋白质印迹法评估细胞增殖和迁移情况。通过将肿瘤细胞异种移植来检测慢病毒感染对HT29细胞体内肿瘤发展能力的影响。通过免疫组织化学分析异种移植肿瘤细胞中ITGB1的表达。ITGB1的上调显著增加了体外HT29细胞的增殖。此外，我们发现与对照组相比，HT29-ITGB1细胞中ITGB1的过表达上调了音猬因子（Shh），同时下调了Gli1和SuFu。此外，c-myc和细胞周期蛋白D1蛋白水平上调。Transwell检测表明，迁移的HT29-RNAi细胞数量低于其他细胞组，这表明ITGB1显著增强了HT29细胞的侵袭能力。除了这些体外结果外，在异种移植肿瘤小鼠模型中发现ITGB1是一种显著有效的生长因子。这些结果表明，ITGB1在体外和体内通过刺猬（Hh）信号通路诱导人结肠癌细胞系的生长和侵袭。
