Low Expression of Transforming Growth Factor β in the Epithelium of Barrett's Esophagus

Background: The aim of this study was to investigate the expression of transforming growth factor beta (TGF-beta) in the different stages of Barrett's esophagus (BE). Methods: Paired endoscopic esophageal biopsy samples were obtained from patients with BE prospectively. Subjects were classified into three groups: BE, BE with dysplasia, and adenocarcinoma (AC) arising from BE. Biopsy specimens over normal esophageal epithelium and gastric cardiac epithelium of limited cases were done. Four cell lines, HETA1 (human esophageal epithelium), CA-A and CP-C (non-dysplastic metaplasia), and OE33 (AC) were analyzed for quantitative mRNA and Western blotting of TGF-beta. Results: All 30 subjects with BE were enrolled. Expression of TGF-beta mRNA in BE were significantly (P < 0.01) lower than that in the normal esophagus and cardiac epithelium. The BE tissue showed a lower positive ratio of TGF-beta immunohistochemical (IHC) stain than the cardiac epithelium. The expression of TGF-beta mRNA in the cell lines CA-A, CP-3, OE-33, was significantly (P < 0.05) lower than that in the cell line HETA-1. The Western blotting result showed lower TGF-beta protein expression of the cell lines CA-A, CP-3, and OE-33. Conclusions: The expression of TGF-beta was lower in the tissue of BE.