Molecular Mechanisms Underlying Barrett's Esophagus

描述(申请人提供)：Barrett‘s食道是指食道的鳞状上皮向肠型转化。化生组织是癌前病变，并通过一个发育不良的中间阶段的逐步过渡进展为腺癌。食管腺癌的发病率正在增加，但人们对Barrett‘s食道的分子机制知之甚少，Barrett’s食道是最早的病变。为了了解转化为化生的过程，有必要研究事件发生时所涉及的基因。这项提案中概述的研究重点是巴雷特食道诱导基因的鉴定和特征。我们的假设是，这些基因的阐明对于理解Barrett‘s食道的分子发病机制以及它对腺癌的易感性是基础的。 目标1：通过比较鳞状上皮和Barrett‘s食道，通过微阵列分析确定在Barrett’s食道中诱导表达的基因。被选中进行进一步评估的基因将是那些可能对细胞分化和增殖起重要作用的基因。初步研究已经确定了16个符合这些标准的基因。对这些基因和其他已鉴定基因的进一步分析将包括：用于验证阵列结果的定量聚合酶链式反应，以及通过免疫组织化学或原位杂交来定位组织中的基因表达。目的2：确定特定目的基因的功能意义1.将表达目的基因的逆转录病毒感染的食道器官培养物进行繁殖。将分析培养物的形态和基因表达的变化。预计这些研究结果将为我们理解Barrett‘s食道形成的分子机制奠定基础。有了这些知识，就有可能进一步研究转基因小鼠的基因，以更好地阐明这些基因在体内系统中的意义。了解Barrett‘s食道的基本性质，特别是启动分子事件，将有助于开发更好的诊断、治疗和化学预防策略，以便在早期阶段针对化生转化为癌症的过程。

DESCRIPTION (provided by applicant): Barrett's esophagus is the transformation of the squamous epithelium of the esophagus to an intestinal type. The metaplastic tissue is preneoplastic and progresses to adenocarcinoma through a stepwise transition with a dysplastic intermediate stage. Esophageal adenocarcinoma is increasing in incidence yet little is known about the molecular mechanisms underlying the development of Barrett's esophagus, the earliest lesion. To understand the transformation to metaplasia it is necessary to investigate the genes that are involved at the initiation of the events. The research outlined in this proposal focuses on the identification and characterization of genes induced in Barrett's esophagus. It is our hypothesis that the elucidation of these genes is fundamental to the understanding of the molecular pathogenesis of Barrett's esophagus as well as its predilection to adenocarcinoma. The following interrelated specific aims will be pursued: Aim 1: To determine the genes that are induced in Barrett's esophagus through microarray analysis by comparing squamous epithelium to Barrett's esophagus. The genes selected for further evaluation will be those that may be important in cellular differentiation and proliferation. Preliminary studies have identified sixteen genes that meet these criteria. Further analysis of these genes and others identified will include: quantitative PCR for validation of the array results and localization of gene expression in tissue by either immunohistochemistry or in situ hybridization. Aim 2: To determine the functional significance of the genes identified in Specific Aim 1. Esophageal organotypic cultures will be propagated that are infected with retroviruses expressing the genes of interest. The cultures will be analyzed for changes in morphology and gene expression. It is anticipated that the results of these studies will lay the foundation for our understanding of the molecular mechanisms, which underlie the development of Barrett's esophagus. With this knowledge it will be possible to further study the genes in transgenic mice to better elucidate the significance of the genes in an in vivo system. The understanding of the fundamental properties of Barrett's esophagus, specifically the initiating molecular events, will allow for the development of better diagnostic, treatment and chemoprevention strategies to target the metaplasia to cancer process at an early stage.