Biology of EGFR and P53 in esophageal epithelial cells

描述（由申请人提供）：食管癌是一种高度侵袭性的恶性肿瘤，是全球第六大癌症死亡原因。食管癌有两种主要类型，食管鳞状细胞癌（ESCC）和腺癌。本项目的重点是阐明食管鳞状上皮恶性转化早期事件的分子机制。表皮生长因子受体（EGFR）过表达和p53突变是食管鳞癌发生发展过程中常见的基因改变。然而，EGFR和突变的p53对食管癌发生作用的分子基础仍不清楚。为此，将在体外和体内确定EGFR过表达和p53突变的生物学作用和功能后果。我们提出的研究将使用食管上皮细胞和小鼠模型，在食管中靶向过表达EGFR和突变型p53，以确定这些遗传改变在ESCC中的作用。我们的基本假设是EGFR的配体活化诱导细胞反应，促进基底细胞室中的过度增殖，并诱导这些细胞迁移到基底上室而不分化。虽然这些过程是必要的，但它们不足以导致癌症，因此需要其他遗传事件，如p53突变。这一假设将通过以下相互关联的具体目的来实现：目的1：评估食管上皮细胞中EGFR过表达和p53失活的组合的后果。当在单层、三维基质胶和器官型培养中生长时，将表征过表达EGFR和四种不同突变p53的食管上皮细胞。研究将测试对增殖，迁移和入侵能力的影响以及对关键信号分子的影响。目标二：利用食管中表达EGFR和突变型p53的小鼠（cre-lox系统）了解EGFR和突变型p53的协同作用在体内的作用。研究将试图通过在食管中特异性表达人EGFR和突变型p53来产生两种新的ESCC体内模型。去年，美国诊断出超过14，000例新的食管癌病例。据估计，超过90%的确诊患者将死于这种疾病。该研究旨在为EGFR过表达和p53失活在ESCC发展中的生物学作用提供新的见解。最终，这些可能转化为更新的诊断和治疗方式。

DESCRIPTION (provided by applicant): Esophageal cancer is a highly aggressive malignancy and is the sixth leading cause of cancer death worldwide. There are two main types of esophageal cancer, esophageal squamous cell carcinoma (ESCC) and adenocarcinoma. This project focuses upon the elucidation of molecular mechanisms underlying early events in malignant transformation in the esophageal squamous epithelium. Epidermal growth factor receptor (EGFR) overexpression and p53 mutation are frequent genetic alterations in the premalignant stages of esophageal squamous cell carcinogenesis. Yet, the molecular basis for EGFR's and mutated p53's contributions to esophageal carcinogenesis remains unclear. To that end, the biological roles and functional consequences of EGFR overexpression and p53 mutation will be determined in vitro and in vivo. Our proposed studies will use esophageal epithelial cells and mouse models with targeted overexpresssion of EGFR and mutant p53 in the esophagus to determine the role of these genetic alterations in ESCC. Our fundamental hypothesis is that ligand activation of EGFR induces cellular responses that facilitate hyperproliferation in the basal cell compartment and induction of migration of such cells into the suprabasal compartment without commitment to differentiation. Although, these processes are necessary they are not sufficient to cause cancer, and thus, other genetic events, such as p53 mutation, are required. This hypothesis will be pursued by the following interrelated Specific Aims: Aim 1: To assess the consequences of the combination of EGFR overexpression and p53 inactivation in esophageal epithelial cells. Esophageal epithelial cells overexpressing EGFR and four diffent mutant p53s will be characterized when grown in monolayer, and three-dimesional Matrigel and organotypic culture. Studies will test effects on proliferation, migration and invasion capabilities as well as effects on key signaling molecules. Aim 2: To understand the in vivo roles of the cooperation of EGFR and mutant p53 using mice (cre-lox system) expressing EGFR and mutant p53 in the esophagus. Studies will attempt to generate two novel in vivo models of ESCC by expressing human EGFR and mutant p53 specifically in the esophagus. Over 14,000 new cases of esophageal cancer were diagnosed in the United States last year. It is estimated that more than 90% of those diagnosed will die of their disease. The proposed studies aim to provide novel insights into the biological roles of EGFR overexpression and p53 inactivation in the development of ESCC. Ultimately, these may translate into newer diagnostic and therapeutic modalities.