Troy, a Tumor Necrosis Factor Receptor Family Member, Interacts With Lgr5 to Inhibit Wnt Signaling in Intestinal Stem Cells
Troy, a Tumor Necrosis Factor Receptor Family Member, Interacts With Lgr5 to Inhibit Wnt Signaling in Intestinal Stem Cells
复制标题
DOI：
10.1053/j.gastro.2012.10.048
复制
发表时间：
2013-02-01
期刊：
影响因子：
29.4
通讯作者：
Korinek, Vladimir
中科院分区：
文献类型：
--
作者：
Fafilek, Bohumil;Krausova, Michaela;Korinek, Vladimir
背景与目的：Wnt信号通路是肠上皮维持所必需的；阻断这一途径会降低肠道干细胞的增殖能力。然而，异常的Wnt信号可导致肠癌。我们研究了Wnt通路在人类和小鼠肠上皮稳态和恶性转化过程中的作用。方法：我们采用染色质免疫沉淀（ChIP）和DNA微阵列分析（ChIP-on- ChIP）来鉴定人类结直肠癌细胞col320、DLD1、LS174T和SW480中受Wnt信号调控的基因。偶氮氧甲烷和硫酸葡聚糖诱导C57BL/6J小鼠肠道肿瘤形成。采用免疫组化和原位杂交的方法分析小鼠肠道组织以及Apc（+/Min）和Apc(CKO/CKO)/Lgr5-EGFP-IRES-CreERT2小鼠。结果：我们在4种不同的人类结直肠癌来源细胞系中鉴定了960个基因的启动子区域，这些基因与Wnt通路核效应t细胞因子4相互作用；其中18个启动子存在于所有染色质沉淀中。Wnt信号上调肿瘤坏死因子受体超家族成员TROY。在大肠腺瘤性息肉病（APC）基因缺失的人类细胞和受Wnt3a配体刺激的细胞中，TROY信使RNA水平升高。在小鼠肠道肿瘤发生过程中，Troy在肿瘤组织中的表达显著上调。谱系追踪实验显示，特洛伊是由快速循环的肠道干细胞特异性产生的。TROY与这些细胞的独特标记物——富含亮氨酸的重复g蛋白偶联受体（LGR）相关。在由肠隐窝建立的类器官中，Troy抑制了一种Wnt激动剂R-spondin介导的信号传导。结论：TROY在人类结直肠癌细胞系和小鼠肠道肿瘤中表达上调。它在lgr5阳性干细胞中作为Wnt通路的负调节因子。
BACKGROUND & AIMS: The Wnt signaling pathway is required for maintenance of the intestinal epithelia; blocking this pathway reduces the proliferative capacity of the intestinal stem cells. However, aberrant Wnt signaling leads to intestinal cancer. We investigated the roles of the Wnt pathway in homeostasis of the intestinal epithelium and during malignant transformation in human cells and mice. METHODS: We performed chromatin immunoprecipitation (ChIP) with DNA microarray analysis (ChIP-on-chip) to identify genes regulated by Wnt signaling in human colorectal cancer cells Colo320, DLD1, LS174T, and SW480. Formation of intestinal tumor was induced in C57BL/6J mice using azoxymethane and dextran sulfate. Intestinal tissues from these mice, as well as Apc(+/Min) and Apc(CKO/CKO)/Lgr5-EGFP-IRES-CreERT2 mice, were analyzed by immunohistochemistry and in situ hybridization. RESULTS: We identified promoter regions of 960 genes that interacted with the Wnt pathway nuclear effector T-cell factor 4 in 4 different human colorectal cancer-derived cell lines; 18 of these promoters were present in all chromatin precipitates. Wnt signaling up-regulated a member of the tumor necrosis factor receptor superfamily called TROY. Levels of TROY messenger RNA were increased in human cells with deficiencies in the adenomatous polyposis coli (APC) gene and in cells stimulated with the Wnt3a ligand. Expression of Troy was significantly up-regulated in neoplastic tissues from mice during intestinal tumorigenesis. Lineage tracing experiments revealed that Troy is produced specifically by fast-cycling intestinal stem cells. TROY associated with a unique marker of these cells, leucine-rich repeat-containing G-protein coupled receptor (LGR) 5. In organoids established from the intestinal crypts, Troy suppressed signaling mediated by R-spondin, a Wnt agonist. CONCLUSIONS: TROY is up-regulated in human colorectal cancer cell lines and in intestinal tumors in mice. It functions as a negative modulator of the Wnt pathway in LGR5-positive stem cells.