Understanding and Controlling p120 Dysfunction in CRC

了解和控制 CRC 中的 p120 功能障碍

• 批准号: 7245694
• 负责人: MARY Kay WASHINGTON
• 金额: $ 25.91万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-05-01 至 2012-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7245694
• 关键词: Ablation; Adhesions; Adverse effects; Affect; Biology; Cadherins; Cancer Center; Cancer Model; Cancer cell line; Carcinoma; Cell Line; Cell surface; Cell-Cell Adhesion; Cells; Cellular Morphology; Chemicals; Chronic; Clinic; Clinical; Collaborations; Colon; Colon Carcinoma; Colorectal Cancer; Complex; Contact Inhibition; Cytoplasm; Data; Databases; Defect; Down-Regulation; E-Cadherin; Elements; Epigenetic Process; Event; Exhibits; Functional disorder; Genetic; Genus Cola; Head; Human; In Vitro; Individual; Inflammation; Institutes; Intervention; Knock-out; Lead; Letters; Link; Localized; Malignant Neoplasms; Mammals; Mediating; Messenger RNA; Meta-Analysis; Metastasis Suppression; Mismatch Repair; Modeling; Molecular; Mutation; N-terminal; Neoplasm Metastasis; Outcome; PTGS2 gene; Pathway interactions; Pattern; Pharmacologic Substance; Phosphotransferases; Principal Investigator; Progress Reports; Proteins; Regulation; Role; Running; Sampling; Serum; Signal Pathway; Signal Transduction; Small Intestines; Staging; Staurosporine; Testing; Time; Work; adenoma; base; cell growth; cell type; chemical genetics; cohort; concept; design; falls; follow-up; high throughput screening; in vivo; inhibitor/antagonist; innovation; mRNA Expression; mouse model; mutant; novel; outcome forecast; programs; rho; small molecule; tumor; tumor growth; tumor progression

Tumor progression in colorectal cancer (CRC) involves accumulation of genetic and epigenetic changes that ultimately lead to malignancy. E-cadherin downregulation occurs frequently and is widely believed to be a pivotal event in the transition to metastasis. In the majority of E-cadherin-deficient CRCs, p120 localizes aberrantly to the cytoplasm, and E-cadherin-loss / cytoplasmic p120 is strongly associated poor prognosis. p120 itself is downregulated in a subset of CRC but the significance is not yet clear. We have found that p120 ablation in vitro and in vivo destabilizes E-cadherin (and associated catenins) causing severe defects in cell morphology and adhesion. Interestingly, in vitro p120-ablation in many cell types induces constitutive activation of Rho, cell growth in the absence of serum, and loss of contact inhibition. In vivo, similar effects lead to cell autonomous activation of a ROCK/NFKB/COX-2 signaling cascade and chronic inflammation, an observation of potential relevance to the efficacy of NSAIDS and COX-2 inhibitors in CRC. Our data suggest novel co-dependent interactions between p120 and E-cadherin that act through regulation of Rho to suppress metastasis and inflammation. The progress report describes these effects, along with a novel molecular explanation for the relationship between Rho, p120, and E-cadherin. The aims (below) seek to apply our findings to tumor progression and clinical intervention in CRC. In aim 1, we will evaluate a simplified p120 KO mouse model to ascertain whether pharmaceutical intervention at the level of pathways activated by p120 (or E-cadherin) downregulation can suppress tumor progression, tumor growth, or metastasis. Aim 2 explores two separate hypotheses based on novel observations. First, to examine implied relationships between p120 loss, mismatch repair (MMR) deficient CRC, and defects in TGF0IIR signaling, we will perform a head-to-head comparison between well-annotated groups of MMR-deficient and proficient tumors. Second, we will follow up on novel observations of p120 downregulation at the mRNA level in advanced CRC. We will determine whether mRNA levels fall at early stages of CRC progression, whether this phenomenon is associated at any level with tumor type or outcome, and the significance at the molecular level with respect to cause and effect. Finally, in aim 3 we will use chemical genetics to interrogate a well characterized but as yet unknown signaling pathway associated with p120-dependant inactivation of E-cadherin. In collaboration with the Beauchamp lab (project 2) and the Vanderbilt Institute for Chemical Biology (VICB) high throughput screening facility, we have developed a high throughput small molecule screen (HTS) to identify novel compounds that rescue E-cadherin function in CRC model cell lines. The application of HTS represents an innovative approach to delineating signaling pathways that control p1207E-cadherin function, and could lead to identification of novel compounds capable of suppressing tumor progression or metastasis.

结直肠癌 (CRC) 的肿瘤进展涉及遗传和表观遗传的积累 最终导致恶性肿瘤的变化。 E-钙粘蛋白下调频繁发生且广泛 被认为是向转移转变的关键事件。在大多数 E-钙粘蛋白缺陷的 CRC 中， p120 异常定位于细胞质，E-钙粘蛋白丢失/细胞质 p​​120 密切相关 预后不良。 p120 本身在 CRC 的一部分中下调，但其意义尚不清楚。我们 发现 p120 的体外和体内消融会破坏 E-钙粘蛋白（和相关联蛋白）的稳定性，从而导致 细胞形态和粘附的严重缺陷。有趣的是，许多细胞类型中的体外 p120 消除 诱导 Rho 的组成型激活、无血清条件下的细胞生长以及接触抑制的丧失。在 在体内，类似的效应导致 ROCK/NFKB/COX-2 信号级联的细胞自主激活，并且 慢性炎症，与 NSAIDS 和 COX-2 抑制剂功效潜在相关性的观察 在CRC中。我们的数据表明 p120 和 E-钙粘蛋白之间新的相互依赖的相互作用，通过 Rho 的调节抑制转移和炎症。进度报告描述了这些影响， 以及对 Rho、p120 和 E-钙粘蛋白之间关系的新颖分子解释。目标 （下）寻求将我们的发现应用于结直肠癌的肿瘤进展和临床干预。在目标 1 中，我们将 评估简化的 p120 KO 小鼠模型，以确定药物干预是否达到 p120（或 E-钙粘蛋白）下调激活的途径可以抑制肿瘤进展、肿瘤生长、 或转移。目标 2 基于新颖的观察结果探索两个独立的假设。首先，要检查 p120 丢失、错配修复 (MMR) 缺陷 CRC 和 TGF0IIR 缺陷之间的隐含关系 信号，我们将在注释良好的 MMR 缺陷组和 精通肿瘤。其次，我们将跟进 mRNA 水平上 p120 下调的新观察结果 在高级 CRC 中。我们将确定 mRNA 水平是否在 CRC 进展的早期阶段下降，是否 这种现象在任何水平上都与肿瘤类型或结果相关，并且其重要性 分子水平上的因果关系。最后，在目标 3 中，我们将使用化学遗传学来 探究与 p120 依赖性相关的已明确表征但迄今未知的信号通路 E-钙粘蛋白失活。与 Beauchamp 实验室（项目 2）和范德比尔特研究所合作 化学生物学（VICB）高通量筛选设备，我们开发了高通量小型 分子筛选 (HTS)，用于鉴定可挽救 CRC 模型细胞系中 E-钙粘蛋白功能的新型化合物。 HTS 的应用代表了一种描述控制信号通路的创新方法。 p1207E-钙粘蛋白功能，并可能导致鉴定能够抑制肿瘤的新型化合物 进展或转移。