p120 and Kaiso dysregulation in intestinal tumorigenesis

p120 和 Kaiso 失调在肠道肿瘤发生中的作用

• 批准号: 8458185
• 负责人: Sarah Palmer Short
• 金额: $ 3.32万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-01 至 2014-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8458185
• 关键词: APC gene; Ablation; Accounting; Adenomatous Polyposis Coli; Adherens Junction; Alleles; Area; Attenuated; Automobile Driving; Binding; Biological Assay; Cancer Etiology; Cell Proliferation; Cells; Cessation of life; Colorectal Cancer; Data; Defect; Diagnosis; Effectiveness; Event; Genetic; Genetic Epistasis; Genetic Transcription; Goals; Growth; Intervention; Intestines; Lead; Malignant Neoplasms; Modeling; Molecular; Molecular Target; Mus; Mutate; Mutation; Nuclear; Outcome; Pathway interactions; Pharmacologic Substance; Phenotype; Play; Process; Proteins; Role; Signal Pathway; Signal Transduction; Stem cells; Tamoxifen; Therapeutic Intervention; Translating; Translations; Tumor Biology; Tumor Suppressor Proteins; United States; Up-Regulation; Villus; Work; adenoma; base; cell motility; design; in vivo; intestinal crypt; migration; mouse model; mutant mouse model; novel; prevent; promoter; research study; stem cell population; tumor; tumor initiation; tumorigenesis; tumorigenic

DESCRIPTION (provided by applicant): Colorectal cancer is the one of the most commonly diagnosed forms of cancer and the third leading cause of cancer-related deaths in the United States. Loss of the tumor suppressor adenomatous polyposis coli (APC) gene is the initiating mutation in ~80% of these cancers and the driving mutation behind familial adenomatous polyposis coli (FAP). Loss of the APC gene product (Apc) activates the Canonical Wnt signaling pathway, culminating in cell proliferation, transformation, and tumor formation. Using a variety of APC mutant mouse models, I have found that APC ablation coincides temporally and spatially with drastic upregulation of Kaiso, a nuclear binding partner of the adherens junction protein, p120-catenin (p120). Our previous data further show strong nuclear expression of Kaiso in all instances of Wnt activation, as Kaiso is naturally upregulated in the stem cell compartment of the intestinal crypt and aberrantly upregulated following either APC loss or -catenin activation. Work from our group and others further suggest that this upregulation of Kaiso may play a critical role in the tumor promoting events triggered by APC loss. Based on these observations, my working hypothesis is that Kaiso expression is directly or indirectly regulated by the canonical Wnt pathway. Additionally, I propose that constitutive upregulation of Kaiso may be a critical effector of the tumorigenic consequences of APC loss. The following aims seek to define the mechanism(s) of Kaiso upregulation and the molecular consequences of Kaiso ablation. In Aim 1, I will optimize an assay I have designed expressly to interrogate immediate physical and molecular consequences of APC ablation in vivo. This "Rapid Epistasis Assay" (hereafter, REA) will permit efficient analysis of the effects of APC ablation in the precise microenvironmental context of tumor formation. In Aim 2, I will identify the mechanism(s) of Kaiso upregulation following APC ablation. Alterations in Kaiso transcription, translation, and protein stability willbe determined with the goal of identifying means of blocking Kaiso upregulation. Finally, as Kaiso ablation in the ApcMin/+ model markedly delays tumor formation, Aim 3 will utilize the REA in combination with molecular and morphological readouts to clarify the mechanism(s) responsible for the tumor attenuating phenotype (e.g., reduced cell proliferation, rescued cell migration along the villus, reversal of dedifferentiation, etc.). Molecular effectors of the Kaiso ablation phenotype may ultimately provide novel targets for pharmaceutical intervention.

描述（由申请人提供）：结直肠癌是最常见的癌症形式之一，也是美国癌症相关死亡的第三大原因。抑癌腺瘤性结肠息肉病 (APC) 基因的缺失是约 80% 此类癌症的起始突变，也是家族性腺瘤性结肠息肉病 (FAP) 背后的驱动突变。 APC 基因产物 (Apc) 的丢失会激活 Canonical Wnt 信号通路，最终导致细胞增殖、转化和肿瘤形成。使用各种 在 APC 突变小鼠模型中，我发现 APC 消融在时间和空间上与 Kaiso 的急剧上调同时发生，Kaiso 是粘附连接蛋白 p120-连环蛋白 (p120) 的核结合伴侣。我们之前的数据进一步显示，Kaiso 在所有 Wnt 激活的情况下都有强烈的核表达，因为 Kaiso 在肠隐窝的干细胞区室中自然上调，并在 APC 丢失或 β-连环蛋白激活后异常上调。我们小组和其他人的工作进一步表明，Kaiso 的这种上调可能在 APC 丢失引发的肿瘤促进事件中发挥关键作用。基于这些观察，我的工作假设是 Kaiso 表达直接或间接受到经典 Wnt 通路的调节。此外，我认为 Kaiso 的组成性上调可能是 APC 丢失致瘤后果的关键效应器。以下目标旨在定义 Kaiso 上调的机制以及 Kaiso 消融的分子后果。在目标 1 中，我将优化我专门设计的一项测定，用于询问体内 APC 消融的直接物理和分子后果。这种“快速上位分析”（以下简称 REA）将允许在肿瘤形成的精确微环境背景下有效分析 APC 消融的影响。在目标 2 中，我将确定 APC 消融后 Kaiso 上调的机制。将确定 Kaiso 转录、翻译和蛋白质稳定性的改变，目的是确定阻断 Kaiso 上调的方法。最后，由于 ApcMin/+ 模型中的 Kaiso 消融显着延迟了肿瘤形成，Aim 3 将利用 REA 结合分子和形态学读数来阐明导致肿瘤减弱表型的机制（例如，减少细胞增殖、挽救肿瘤）细胞沿绒毛迁移、去分化逆转等）。 Kaiso 消融表型的分子效应器可能最终为药物干预提供新的靶点。