T细胞因子4对结直肠癌细胞结缔组织生长因子启动子的靶向调控  

Direct regulation of connective tissue growth factor promoter by T cell factor 4 in colorectal cancer cells

作　　者：孙政[1] 曹杰[1] 杨平[1] 张伟健[1] 唐伟镖[1] 

机构地区：[1]广州医学院附属广州市第一人民医院胃肠外科,510180

出　　处：《中华实验外科杂志》2012年第10期2006-2008,共3页Chinese Journal of Experimental Surgery

基　　金：广州市医药卫生科技项目重点项目（2009-ZDi-08）;广东省社会发展领域科技计划项目（93077）

摘　　要：目的探讨结缔组织生长因子（CTGF）是否为T细胞因子4（TCF4）的靶基因，参与调控结直肠癌细胞wnL／β-连环蛋白（β-catenin）通路。方法构建CTGF启动子质粒pGL3-CTGF，联合TCF4显性负性突变体表达质粒pcDNA3-dnTCF4，转染结肠癌细胞株SW480，双荧光素酶实验分析CTGF启动子转录活性，染色质免疫共沉淀（ChIP）法验证CTGF启动子区与TCF4的相互作用。结果SW480转染pGL3-CTGF质粒后荧光素酶活性（0．78±0．04）显著高于对照组转染空白质粒（0．01±0．00）（P〈0．01）；同时转染阻断β-catenin／TCF4信号通路的pcDNA3-dnTCF4质粒和pGL3-CTGF质粒，SW480细胞的荧光素酶活性（0．26±0．03）比单纯转染pGL3-CTGF质粒显著下降（P〈0．05）。ChIP-聚合酶链反应（PCR）证实CTGF为TCF4的直接作用靶基因。结论CTGF是β—cmenin—TCF4信号通路的下游靶基因，TCF4直接结合于CTGF启动子区。Objective To investigate whether connective tissue growth factor （CTGF）, which is involved in the regulation of Wnt/β-catenin signaling pathway, is the target gene of T cell factor-4 （TCF4） in colorectal cancer （CRC） cells. Methods The promoter vector of CTGF （pGL3-CTGF） was construc- ted and transfected into CRC cell lines SW480, together with or without dominant negative TCF4 vector （pcDNA3-dnTCF4）. Then the promoter activity of CTGF was detected using dual luciferase reporter assays. Chromatin immunoprecipitation （CHIP） was used to determine the interaction between TCF4 and CTGF promoter in SW480 cells. Results The luciferase activities of SW480 cells transfected with pGL3-CTGF were significantly higher than the blank control （0. 78 ± 0. 04 versus 0. 01 ±0, P 〈 0. 01 ）. Cells co-transfected with pcDNA3-dnTCF4 could lead to significant suppression of the luciferase activity, comparing to the cells transfected with pGL3-CTGF alone （0. 26 ± 0.03 versus 0. 78± 0. 04, P 〈 0. 05 ）. Furthermore, ChIP-PCR showed direct interaction between TCF4 and CTGF promoter. Conclusion Our study identifies CTGF as a novel target geneI of β-catenin-TCF4 signaling pathway, and TCF4 direct targets the promoter of CTGF.

关 键 词：结直肠癌 结缔组织生长因子 T细胞因子4 

分 类 号：R735.3[医药卫生—肿瘤]