Influence of acid reflux on stromal epithelial interaction in Barrett?s esophagus

描述(申请人提供)：巴雷特食道(BE)是食管腺癌的重要危险因素。十二指肠胃反流导致慢性炎症和BE的发展1，2。慢性炎症可以激活成纤维细胞，通过分泌生长因子促进胃肠道的癌变4。肌成纤维细胞衍生的生长因子已知促进上皮性肿瘤的增殖5-7。尽管酸和胆汁促进Barrett‘s上皮的增殖，控制反流抑制增殖并促进分化，控制酸反流与降低BE-9异型增生的风险有关，但确切的机制、需要的反流控制程度以及酸反流对BE间质的影响尚不清楚。基于这些概念，我们的假设是胃十二指肠反流会导致间质成纤维细胞的激活，从而通过分泌生长因子来促进肿瘤的发生。这项建议的第一个目标将是比较已知的无发育不良的BE患者的间质激活，这些患者有控制的和持续的胃酸反流。无异型增生的BE患者将接受内窥镜活检和24小时pH研究，以了解质子泵抑制剂(PPI)的治疗情况。然后，患者将被分成A组(GER)：有胃酸反流(特征是胃镜检查有食管炎(根据洛杉矶分类)10，和/或标准11定义的PH值阳性；B组(NGER)：有受控的胃酸反流(胃镜检查阴性，治疗时有PH值研究)。我们将比较肌成纤维细胞的存在和COX-2的表达，通过免疫组织化学方法评估两组之间的差异。我们还将评估酸和胆汁对体外培养的食道成纤维细胞增殖和凋亡的影响。这项应用的第二个目的将是使用免疫组织化学和定量PCR来评估和比较基质衍生生长因子(EGF、HGF)及其受体(EGF的EGFR、HER2和HGF的c-Met)在持续性和可控性酸反流患者的BE活检组织中的存在。此外，我们还将使用共培养模型评估BE中基质上皮的相互作用，并试图通过使用基质衍生生长因子的抑制剂来阻断这种相互作用。我们的研究计划的目标是确定并最终通过临床试验研究Barrett‘s食道的新型化学预防药物。这项翻译建议旨在通过研究酸反流对Barrett‘s食道间质-上皮相互作用的机制和影响来确定化学预防的新靶点。这项研究的成功完成将有助于进一步明确酸反流控制在调节BE间质激活和癌变中的作用。从这些实验中收集的初步数据将使我们能够进一步研究BE中间质上皮细胞相互作用的机制，并为BE中肿瘤的化学预防确定基于证据的分子靶点，并启动化学预防药物的临床试验。项目简介本研究的目的是确定胃酸反流与Barrett‘s食道细胞变化之间的关系。

DESCRIPTION (provided by applicant): Barrett's esophagus (BE) is an important risk factor for esophageal adenocarcinoma. Duodenogastric reflux leads to chronic inflammation and the development of BE in a subset of patients1, 2. Chronic inflammation may activate fibroblasts which can promote carcinogenesis in the gastrointestinal tract by secreting growth factors 4. Myofibroblast derived growth factors are known to promote proliferation of epithelial neoplasms 5-7. Although acid and bile promote proliferation of Barrett's epithelium, control of reflux decreases proliferation and promotes differentiation 8 and control of acid reflux is associated with lower risk of dysplasia in BE 9, the precise mechanisms, the degree of reflux control needed and the influence of acid reflux on BE stroma is unknown. Based on these concepts, it is our hypothesis that gastroduodenal reflux results in stromal fibroblast activation which promotes oncogenesis via growth factor secretion. The first aim of this proposal will be to compare stromal activation in patients with known BE without dysplasia, who have controlled and persistent acid reflux. Patients with BE without dysplasia will undergo endoscopy with biopsies and a 24 hour pH study on treatment with proton pump inhibitors (PPIs). Patients will then be divided into Group A (GER): with acid reflux (characterized by either presence of esophagitis (as determined by the Los Angeles classification) 10 on endoscopy, and/or a positive pH study defined by standard criteria 11 and Group B (NGER): with controlled acid reflux (negative endoscopy and pH study on treatment). We will compare the presence of myofibroblasts and expression of COX-2, assessed by immunohistochemistry between the 2 groups. We will also assess the influence of acid and bile on esophageal fibroblast proliferation and apoptosis in vitro. The second aim of this application will be to assess and compare the presence of stromal derived growth factors (EGF, HGF) and their receptors (EGFR, HER2 for EGF and c-Met for HGF) in BE biopsies of subjects with persistent and controlled acid reflux using immunohistochemistry and quantitative PCR. In addition we will also assess stromal epithelial interaction in BE using co-culture models and attempt to block this interaction by using inhibitors of stromal derived growth factors. The goal of our research program is to identify and ultimately study with clinical trials novel chemopreventive agents in Barrett's esophagus. This translational proposal aims to identify novel targets for chemoprevention by studying the mechanisms of and the influence of acid reflux on stromal-epithelial interaction in Barrett's esophagus. Successful completion of this study will help further define the role of acid reflux control in modulating stromal activation and carcinogenesis in BE. Preliminary data gathered from these experiments would allow us to further investigate mechanisms of stromal epithelial interaction in BE as well as identify evidence based molecular targets for the chemoprevention of neoplasia in BE and launch clinical trials for chemopreventive agents. Project Narrative The purpose of this study is to determine the association between acid reflux and cell changes in Barrett's esophagus.