BVES modulation of intestinal homeostasis and tumorigenesis via regulation of Wnt signaling

BVES 通过调节 Wnt 信号传导调节肠道稳态和肿瘤发生

基本信息

批准号：
9190648
负责人：
Joshua James Thompson
金额：
$ 2.82万
依托单位：
VANDERBILT UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-09-01 至 2020-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9190648
关键词：
Accounting Affect Anchorage-Independent Growth Animal Model Attenuated Automobile Driving Blood Vessels Cadherins Cancer cell line Cancerous Cell Adhesion Molecules Cell Communication Cell Nucleus Cell Proliferation Cell membrane Cell physiology Cells Clonal Expansion Colon Carcinoma Colorectal Cancer Competence Complementary DNA Complex Data Development Diagnosis Disease Dominant-Negative Mutation Epithelial Gene Targeting Goals Growth Heart Homeostasis Human Individual Inflammatory Intervention Intestines Knockout Mice Laboratories Lead Link Literature Maintenance Malignant Neoplasms Membrane Mesenchymal Molecular Mus Mutation Neoplasm Metastasis Nuclear Oncogenic Pathogenesis Pathway interactions Phenotype Play Population Protein phosphatase Proteins Regulation Reporter Research Role Rotation Signal Pathway Signal Transduction Stem cells Testing Tight Junctions Translating Treatment Efficacy Tumor Biology Up-Regulation beta catenin c-myc Genes cancer diagnosis carcinogenesis cell growth cell motility human disease intestinal crypt intestinal homeostasis molecular targeted therapies monolayer mouse model new therapeutic target novel overexpression programs protein phosphatase 2A regulatory subunit 65 kDa research study stem cell biology stem cell niche stem cell population trait tumor tumor growth tumorigenesis tumorigenic

项目摘要

Project Summary Abnormalities in intestinal stem cell programs underlie the pathogenesis of colorectal cancer (CRC), a disease that affected over 130,000 individuals in 2015. Therefore, further defining programs that regulate fundamental stem cell processes may lead to novel therapeutic targets. Accordingly, the Wnt signaling pathway plays a fundamental role in maintaining intestinal homeostasis and disruptions in this pathway are inextricably linked to the development of colon cancer. β-catenin is the key effector of Wnt signaling, transducing signals to the nucleus or acting as a component of the cadherin complex at the cell membrane. The preponderance of Wnt mutations in CRC ultimately increase levels of β-catenin within the cell. However, targeting this pathway has, as of yet, not yielded therapeutic efficacy. Blood vessel epicardial substance (BVES) is a tight junction-associated protein discovered in a cDNA screen of the developing heart. BVES is downregulated in CRC and overexpression of BVES impairs tumor growth, identifying a tumor suppressive role for BVES in carcinogenesis. BVES has also been shown to affect Wnt activity. BVES expression reduces Wnt reporter activity and in mouse models of inflammatory carcinogenesis, Bves-/- tumors have increased levels of β-catenin. As Wnt signaling is critical in maintenance of the intestinal stem cell niche, Bves-/- mice also have activated stem cell programs. Taken together, it is hypothesized that BVES modulates Wnt signaling, principally through an effect on β-catenin. This hypothesis will be tested via two focused, mechanistic, and hypothesis driven specific aims that will expand our understanding of how BVES regulates Wnt signaling. First, the mechanism by which BVES alters β-catenin levels will be determined. BVES interacts with PR61α, a protein phosphatase 2A regulatory subunit, and it is hypothesized that through this interaction BVES modulates β-catenin. Alternatively, as BVES can localize to the membrane, β-catenin activity may be controlled through membrane sequestration. Second, a BVES conditional knockout mouse model will be employed to determine if loss of BVES in intestinal stem cells and subsequent alterations in Wnt signaling affect intestinal crypt dynamics. Novel 3D enteroid cultures will be employed to expand these studies and further characterize the functional domain of BVES responsible for modulating Wnt dependent phenotypes. These studies will then be translated into human derived tumoroid cultures to determine if restoring BVES function can modulate tumor growth. Our proposed studies will define the role of BVES in Wnt signaling, intestinal stem cell biology, and colorectal cancer. Importantly, clarifying the role of BVES may elucidate novel mechanisms to target this pro-tumorigenic pathway.

项目概要肠道干细胞程序异常是结直肠癌 (CRC) 发病机制的基础，结直肠癌是一种 2015 年，该疾病影响了超过 130,000 人。因此，进一步制定监管计划基本的干细胞过程可能会产生新的治疗靶标。该途径在维持肠道稳态中发挥着重要作用，该途径的破坏是 β-连环蛋白是 Wnt 信号传导的关键效应子，与结肠癌的发展密切相关。将信号转导至细胞核或充当细胞膜上钙粘蛋白复合物的组成部分。 CRC 中 Wnt 突变的优势最终会增加细胞内 β-连环蛋白的水平。迄今为止，针对该途径尚未产生治疗效果。血管心外膜物质 (BVES) 是一种在 cDNA 中发现的紧密连接相关蛋白 BVES 在 CRC 中下调，BVES 过度表达会损害肿瘤。生长，确定 BVES 在致癌作用中的肿瘤抑制作用也被证明会影响。 BVES 表达可降低 Wnt 报告基因活性并在小鼠炎症模型中发挥作用。在致癌过程中，Bves-/- 肿瘤的 β-连环蛋白水平升高，因为 Wnt 信号传导对于维持 Bves-/- 肿瘤至关重要。肠道干细胞生态位，Bves-/-小鼠也具有激活的干细胞程序。促进 BVES 主要通过对 β-catenin 的影响来调节 Wnt 信号传导。将通过两个有重点的、机械的和假设驱动的具体目标进行测试，这些目标将扩展我们的了解 BVES 如何调节 Wnt 信号传导首先，BVES 改变 β-catenin 的机制。 BVES 与蛋白磷酸酶 2A 调节亚基 PR61α 相互作用。通过这种相互作用，BVES 可以调节 β-连环蛋白，或者，BVES 可以定位到。在膜上，β-连环蛋白活性可以通过膜隔离来控制。条件性基因敲除小鼠模型将用于确定肠道干细胞中 BVES 的缺失和 Wnt 信号传导的后续变化将影响新型 3D 肠样培养物的动力学。用于扩展这些研究并进一步表征 BVES 的功能域，负责这些研究随后将转化为人源性肿瘤样物质。培养以确定恢复 BVES 功能是否可以调节肿瘤生长。 BVES 在 Wnt 信号传导、肠道干细胞生物学和结直肠癌中的作用。 BVES 的作用可能阐明针对这一促肿瘤发生途径的新机制。