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

描述（申请人提供）：巴雷特食管（BE）是食管腺癌的重要危险因素。在一部分患者中，十二指肠胃反流导致慢性炎症和BE的发展1,2。慢性炎症可激活成纤维细胞，通过分泌生长因子促进胃肠道癌变4。已知肌成纤维细胞衍生的生长因子可促进上皮肿瘤的增殖5-7。虽然酸和胆汁促进Barrett上皮增殖，控制反流可减少增殖并促进分化8，而控制酸反流与BE发育不良风险降低有关9，但其确切机制、所需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导致间质成纤维细胞激活，通过生长因子的分泌促进肿瘤的发生。本提案的第一个目的是比较已知be无发育不良患者的间质激活，这些患者有控制和持续的酸反流。没有发育不良的BE患者将接受内镜活检和24小时pH值研究，以评估质子泵抑制剂（PPIs）的治疗效果。然后将患者分为A组（GER）：胃酸反流(内窥镜检查表现为食管炎（由洛杉矶分类确定）10，和/或标准标准定义的pH值阳性11；B组（NGER）：胃酸反流得到控制（内窥镜检查和pH值研究均为阴性）。我们将比较两组间肌成纤维细胞的存在和COX-2的表达，通过免疫组化评估。我们还将评估酸和胆汁对体外食管成纤维细胞增殖和凋亡的影响。本应用程序的第二个目的是利用免疫组织化学和定量PCR评估和比较持续和受控酸反流受试者的be活检中基质源性生长因子（EGF， HGF）及其受体（EGFR， EGF的HER2和HGF的c-Met）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，并尝试通过使用基质源性生长因子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巴雷特食管的新型化学预防药物。本研究旨在通过研究酸反流对Barrett食管基质-上皮相互作用的机制和影响，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确定酸反流控制在BE中调节基质激活和致癌作用。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中基质上皮相互作用的机制，并确定基于证据的化学预防BE中肿瘤的分子靶点，并开展化学预防药物的临床试验。本研究的目的是确定酸反流与Barrett食管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.