REG Iα protein expression in Barrett's esophagus

Abstract

Accelerated cellular proliferation in Barrett's esophagus has been implicated in Barrett's elongation and malignant transformation. Therefore, growth factors may play important roles in the pathophysiology of Barrett's esophagus. Regenerating gene (REG), an epithelial growth factor, has been reported to link mucosal inflammation and subsequent carcinogenesis in the gastrointestinal tract. The aim of this study was to investigate whether REG is expressed in Barrett's esophagus and to elucidate the relationship between REG protein expression and clinicopathological factors of Barrett's esophagus. Between July 2003 and June 2004, 266 patients with endoscopically and histologically proven Barrett's esophagus were enrolled in this study. Before endoscopic examination, all participants were requested to answer structured questionnaires on gastroesophageal reflux symptoms and drugs usage. Mucin phenotype, cyclooxygenase-2 expression, cellular proliferation, apoptosis and REG Ialpha protein expression were investigated in the biopsy samples taken from Barrett's esophagus. Clinicopathological factors that correlated with REG Ialpha protein expression in patients with Barrett's esophagus were evaluated using multivariate logistic regression analysis. REG Ialpha protein expression was observed in 48 (18.0%) of 266 patients with Barrett's esophagus by immunohistochemistry. Newly developed squamous re-epithelialization of Barrett's esophagus at biopsy sites, presence of hiatal hernia and aging were shown to correlate with REG Ialpha protein expression. The present study is the first to show REG expression in Barrett's esophagus. Expression of REG Ialpha was more frequently observed in patients who showed squamous re-epithelialization of Barrett's esophagus at biopsy sites.