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

• 批准号: 10421293
• 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
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-20 至 2024-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10421293
• 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

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.

项目总结/文摘