title: Hepatocyte Antigen Expression in Barrett Esophagus and Associated Neoplasia.
abstract: Hepatocyte antigen or hepatocyte paraffin 1 (Hep Par 1) is widely used as a diagnostic immunomarker for hepatocellular carcinoma. It has also been identified as a rate-limiting enzyme of the urea cycle, carbamoyl phosphate synthetase 1. Hep Par 1 has been detected in non-neoplastic small intestinal epithelium, but its expression in Barrett esophagus and its related neoplasia has not been well investigated. We immunohistochemically evaluated expression of Hep Par 1 on 75 cases of Barrett esophagus (25 cases without dysplasia, 16 cases with low-grade dysplasia, 25 cases with high-grade dysplasia, and 9 cases with intramucosal adenocarcinoma) on endoscopic biopsies and endoscopic mucosal resections. All 25 cases without dysplasia (100%) showed granular cytoplasmic Hep Par 1 staining (24 diffuse and 1 focal). Of the 16 cases with low-grade dysplasia, 12 (75%) were positive (5 diffuse and 7 focal), whereas 4 (25%) were negative (P=0.018). Of the 25 cases with high-grade dysplasia, 9 (36%) showed focal positivity, whereas 16 (64%) were negative (P=0.0001). Similarly of the 9 cases of intramucosal adenocarcinomas 3 (33%) were focally positive, whereas 6 (67%) were negative (P=0.0001). Hep Par 1 is diffusely expressed in non-neoplastic Barrett esophagus while it is frequently lost in related dysplasia and adenocarcinoma, suggesting decreased level of HepPar1 may represent an early event in Barrett-related tumor genesis. This warrants additional investigation to look for the possible role of carbamoyl phosphate synthetase 1 in the pathogenesis of Barrett-related neoplasia.
authors.affiliation: Department of Anatomic Pathology, Mayo Clinic, Rochester, MN.
authors.forename: Sejal S
authors.initials: SS
authors.lastname: Shah
authors.forename: Vishal S
authors.initials: VS
authors.lastname: Chandan
mesh_terms: D000230:Adenocarcinoma / Q000201:enzymology* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000951:Antigens, Neoplasm / Q000096:biosynthesis*; D001471:Barrett Esophagus / Q000201:enzymology* / Q000473:pathology; D002222:Carbamoyl-Phosphate Synthase (Ammonia) / Q000096:biosynthesis*; D004938:Esophageal Neoplasms / Q000201:enzymology* / Q000473:pathology; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000096:biosynthesis*
chemical_list: D000951:Antigens, Neoplasm; D009363:Neoplasm Proteins; D002222:Carbamoyl-Phosphate Synthase (Ammonia)