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

• 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
• 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

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.

项目摘要 肠道干细胞程序的异常是结直肠癌的发病机理（CRC），A 2015年影响13万人的疾病。因此，进一步定义了调节的计划 基本干细胞过程可能导致新的热靶标。根据WNT信号 途径在维持肠道稳态和该途径中的破坏方面起着基本作用 与结肠癌的发展密不可分。 β-catenin是Wnt信号传导的关键效应子， 将信号转换为细胞核或作用于细胞膜的钙粘蛋白复合物的成分。 CRC中Wnt突变的优势最终增加了细胞内的β-catenin水平。然而， 到目前为止，靶向这一途径尚未产生治疗效率。 血管心外膜物质（BVE）是在cDNA中发现的紧密连接相关蛋白 发育中的心脏的屏幕。 BVE在CRC中被下调，BVE的过表达损害了肿瘤 生长，确定BVE在癌变中的肿瘤作用。 BVE也已显示出影响 Wnt活动。 BVE的表达降低了Wnt报告基因活性和炎症的小鼠模型 癌变，BVE-/ - 肿瘤的β-catenin水平升高。因为Wnt信令对于维护至关重要 肠道干细胞生态位BVE-/ - 小鼠也具有活化的干细胞程序。两者一起，是 假设BVE主要通过对β-catenin的影响调节Wnt信号传导。这个假设 将通过两个集中，机械和假设驱动的特定目标进行测试，以扩大我们 了解BVE如何调节Wnt信号。首先，BVE改变β-catenin的机制 水平将被确定。 BVE与Pr61α相互作用，Pr61α是一种蛋白质磷酸酶2a调节亚基，它是 假设通过这种相互作用，BVE调节β-catenin。或者，由于BVE可以本地化 膜，β-catenin活性可以通过膜隔离来控制。第二，一个BVE 将进行有条件的敲除小鼠模型，以确定肠道干细胞中BVE的损失是否 Wnt信号的随后改变会影响肠道加密动力学。新颖的3D肠道文化将是 用于扩展这些研究并进一步表征BVE的功能领域 调节依赖Wnt的表型。然后将这些研究转化为人类衍生的瘤 培养以确定恢复BVE功能是否可以调节肿瘤生长。我们提出的研究将定义 BVE在Wnt信号传导，肠道干细胞生物学和大肠癌中的作用。重要的是，澄清 BVE的作用可能阐明了针对这种阳光途径的新机制。