Wnt Signaling in intestinal stem cells, homeostasis, and cancer

肠道干细胞、体内平衡和癌症中的 Wnt 信号转导

基本信息

批准号：
10170338
负责人：
Xi He
金额：
$ 52.14万
依托单位：
BOSTON CHILDREN'S HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-08-20 至 2023-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10170338
关键词：
APC gene Address Adult Area Binding Biology Cancer Biology Cell Communication Cell Surface Receptors Cells ChIP-seq Chromatin Chromosomal translocation Colorectal Cancer Complex Congenital Abnormality DNA Binding Data Degenerative Disorder Development Doctor of Philosophy Elements Embryonic Development Enhancers Epithelial Evaluation Event Exhibits Expression Library Family GTP-Binding Proteins Gastrointestinal Diseases Gastrointestinal tract structure Gene Activation Gene Expression Gene Mutation Genes Genetic Transcription Government Homeostasis Human Integral Membrane Protein Intestines Investigation LDL-Receptor Related Proteins Leucine-Rich Repeat Link Malignant Neoplasms Malignant neoplasm of gastrointestinal tract Mediating Mus Mutant Strains Mice Mutation Natural regeneration Organoids Pathogenesis Pathway interactions Patients Persons Play Population Process Proteins Regulation Research Role Signal Pathway Signal Transduction Simple Epithelium Syndrome TCF Transcription Factor TCF7L2 gene Techniques Therapeutic Tissues Transcription Coactivator Transcriptional Regulation Ubiquitination WNT Signaling Pathway Zinc Fingers beta catenin cDNA Expression cDNA Library cancer cell cell behavior colon cancer cell line colorectal cancer treatment epithelial stem cell experimental study gain of function mutation gastrointestinal genetic signature genome-wide in vivo insight intestinal crypt intestinal epithelium intestinal homeostasis loss of function mutation member novel programs promoter receptor self-renewal stem cell biology stem cell expansion stem cell genes stem cell homeostasis stem cells therapeutic target transcription factor transcriptome sequencing tumor ubiquitin-protein ligase

项目摘要

Project Summary/Abstract Signaling by the Wnt family of secreted proteins through transcription coactivator β-catenin (the Wnt/β-catenin pathway) plays central roles in regulation of intestinal stem cells (ISCs) and homeostasis of the gastrointestinal (GI) tract. R-spondin (Rspo) proteins are secreted molecules that enhance Wnt/β-catenin signaling through stabilizing Wnt receptors, and they exhibit potent stimulation effect on self-renewal and proliferation of ISCs. Anomaly of Wnt/Rspo signaling leads to GI diseases including colorectal cancer (CRC). Wnt/β-catenin signaling controls ISCs through an ISC-specific gene expression program, which is driven by the DNA-bound TCF/LEF (T cell factor/Lymphoid enhancer factor) family of transcription factors in complex with β- catenin. TCF/β-catenin-mediated transcriptional regulation has been a cornerstone for our understanding of the Wnt/β-catenin pathway including in ISC regulation and CRC pathogenesis. To better understand Wnt/Rspo signaling and search for additional potential therapeutic target for CRC treatment, we performed a functional cDNA expression screen and identified a Zinc-finger (Znf) transcription factor as a potent stimulators of TCF/β-catenin-dependent transcription. Our preliminary data suggest that this Znf is required for (i) Wnt/Rspo stimulation of ISC expansion in mouse intestinal organoids; (ii) for TCF/β- catenin-mediated Wnt target genes/stem cell signature genes in human CRC cell lines; and (iii) for proliferation of CRC cell lines. Our preliminary data further suggest that the Znf binds to TCF, and co-occupies with TCF/β- catenin on enhancers/promoters of Wnt target genes in chromatin. Our preliminary findings identify a novel critical component of Wnt/Rspo signaling in ISCs and CRC cells, and reveal an unappreciated complexity in the mechanism by which TCF/β-catenin-mediated gene activation is achieved. We propose three specific aims in this application to investigate the Znf in Wnt/Rspo signaling in ISC regulation and CRC pathogenesis. In Aim 1 we will define the Znf requirement in TCF/β-catenin-driven transcription via genome-wide RNA-seq and CHIP-seq techniques, thereby addressing whether this factor is required for all or a subset of TCF/β-catenin target genes; In Aim 2 we will examine the Znf requirement in human intestinal organoids and primary CRC organoids, attempting to validate its critical role in human GI and cancer biology; and in Aim 3 we will generate conditional Znf deletion mutant mice, thereby studying its role in intestinal tissue homeostasis and tumor formation in vivo.

项目概要/摘要 Wnt 分泌蛋白家族通过转录共激活因子 β-连环蛋白（Wnt/β-连环蛋白）发出信号途径）在肠道干细胞（ISC）的调节和胃肠道稳态中发挥核心作用 (GI) 道。R-spondin (Rspo) 蛋白是通过增强 Wnt/β-连环蛋白信号传导的分泌分子。稳定Wnt受体，并对ISC的自我更新和增殖表现出有效的刺激作用。 Wnt/Rspo 信号异常会导致胃肠道疾病，包括结直肠癌 (CRC)。 Wnt/β-连环蛋白信号通过 ISC 特异性基因表达程序控制 ISC，该程序由 DNA 结合的 TCF/LEF（T 细胞因子/淋巴增强因子）转录因子家族与 β- 复合物 TCF/β-连环蛋白介导的转录调控一直是我们理解的基石。 Wnt/β-catenin 通路包括 ISC 调节和 CRC 发病机制。更好地了解 Wnt/Rspo 信号传导并寻找 CRC 的其他潜在治疗靶点治疗后，我们进行了功能性 cDNA 表达筛选并鉴定了锌指 (Znf) 转录我们的初步数据表明，该因子是 TCF/β-连环蛋白依赖性转录的有效刺激剂。 (i) Wnt/Rspo 刺激小鼠肠道类器官 ISC 扩张需要 Znf；(ii) TCF/β- 人类 CRC 细胞系中连环蛋白介导的 Wnt 靶基因/干细胞特征基因；以及 (iii) 用于增殖；我们的初步数据进一步表明 Znf 与 TCF 结合，并与 TCF/β- 共占据。我们的初步研究结果确定了染色质中 Wnt 靶基因增强子/启动子的连环蛋白。 ISC 和 CRC 细胞中 Wnt/Rspo 信号传导的关键组成部分，并揭示了 TCF/β-连环蛋白介导的基因激活的机制。我们在此应用中提出了三个具体目标，以研究 ISC 调节中 Wnt/Rspo 信号传导中的 Znf 在目标 1 中，我们将通过 TCF/β-连环蛋白驱动的转录来定义 Znf 需求。全基因组 RNA-seq 和 CHIP-seq 技术，解决该因素是否是所有或 TCF/β-连环蛋白目标基因的子集；在目标 2 中，我们将检查人类肠道对 Znf 的需求类器官和初级 CRC 类器官，试图验证其在人类胃肠道和癌症生物学中的关键作用；在目标3中，我们将生成条件性Znf缺失突变小鼠，从而研究其在肠道组织中的作用体内稳态和肿瘤形成。