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）：结直肠癌是美国最常见的癌症形式之一，也是美国与癌症相关死亡的第三大主要原因。肿瘤抑制腺瘤性息肉病（APC）基因的丧失是这些癌症中约80％的启动突变，是家族性腺瘤性息肉大肠杆菌（FAP）背后的驱动突变。 APC基因产物（APC）的丧失激活了规范的Wnt信号通路，最终导致细胞增殖，转化和肿瘤形成。使用各种 APC突变体模型，我发现APC消融在时间和空间上与粘附蛋白P120-catenin（P120）的核结合伴侣Kaiso的急剧上调相吻合。我们先前的数据进一步显示了Kaiso在Wnt激活的所有情况下的强核表达，因为Kaiso在肠道隐窝的干细胞室中自然上调，并且在APC损失或-Catenin激活后异常上调。我们小组和其他人的工作进一步表明，Kaiso的这种上调可能在促进APC损失触发的事件的肿瘤中起关键作用。基于这些观察结果，我的工作假设是Kaiso表达直接或间接地受到规范WNT途径的调节。另外，我建议Kaiso的构型上调可能是APC损失后果的关键效应因子。以下目的旨在定义Kaiso上调的机制和Kaiso消融的分子后果。在AIM 1中，我将优化我明确设计的一种测定法，以询问体内APC消融的直接物理和分子后果。这种“快速的上毒测定法”（以下简介）将允许对APC消融在肿瘤形成的精确微环境环境中的影响有效分析。在AIM 2中，我将确定APC消融后Kaiso上调的机制。 Kaiso转录，翻译和蛋白质稳定性的改变将以识别阻塞Kaiso上调的方法的确定。最后，随着APCMIN/+模型中的Kaiso消融显着地延迟了肿瘤的形成，AIM 3将利用REA与分子和形态学读数结合使用，以阐明负责肿瘤减弱表型的机制（例如，降低的细胞增殖，营救细胞的迁移，沿着村庄的vellus of Dedififififferferentiation。 Kaiso消融表型的分子效应子最终可能为药物干预提供新的靶标。