title: Alterations of the Wnt signaling pathway during the neoplastic progression of Barrett's esophagus.
abstract: Aberrant activation of the Wnt signaling pathway has been reported during neoplastic progression in Barrett's esophagus (BE). However, mutations in APC and CTNNB1 genes were rarely observed. In this study, expression pattern of Wnt ligands, Frizzled receptors and APC, as well as the methylation status of the APC, SFRP1 and SFRP2 promoter genes were investigated in normal esophageal mucosa and in preneoplastic and neoplastic lesions of BE patients. Promoter methylation of APC was found in all BE samples and in 95% of esophageal adenocarcinomas (EAC). Full methylation of APC correlated with lack of expression. In EAC, nuclear translocation of beta-catenin was observed regardless of the expression of APC. WNT2 expression was higher in dysplasia and EAC than in BE, with 20/26 (77%) of the EAC showing high expression of WNT2. SFRP1 methylation occurred in all BE samples and in 96% of EAC, while SFRP2 was methylated in 73% of the normal squamous esophageal mucosa samples. In conclusion, (1) alterations of key regulators of the Wnt signaling are frequent in the pathogenesis of BE; (2) the APC and SFRP1 genes are inactivated by promoter methylation in BE; (3) the WNT2 gene is upregulated along the progression from low-grade dysplasia to EAC.
authors.affiliation: Institut de Pathologie, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland.
authors.forename: G
authors.initials: G
authors.lastname: Clément
authors.forename: R
authors.initials: R
authors.lastname: Braunschweig
authors.forename: N
authors.initials: N
authors.lastname: Pasquier
authors.forename: F T
authors.initials: FT
authors.lastname: Bosman
authors.forename: J
authors.initials: J
authors.lastname: Benhattar
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D001374:Azacitidine / Q000031:analogs & derivatives / Q000494:pharmacology; D001471:Barrett Esophagus / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D002455:Cell Division / Q000187:drug effects; D045744:Cell Line, Tumor / Q000187:drug effects / Q000378:metabolism; D018899:CpG Islands; D019175:DNA Methylation / Q000187:drug effects; D004273:DNA, Neoplasm / Q000235:genetics / Q000378:metabolism; D000077209:Decitabine; D018450:Disease Progression; D004938:Esophageal Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D005786:Gene Expression Regulation / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D020868:Gene Silencing / Q000187:drug effects; D017491:Genes, APC / Q000187:drug effects; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics; D008565:Membrane Proteins / Q000235:genetics; D009092:Mucous Membrane / Q000378:metabolism; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology; D011230:Precancerous Conditions / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D011401:Promoter Regions, Genetic / Q000187:drug effects / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis; D012334:RNA, Neoplasm / Q000096:biosynthesis; D034741:RNA, Small Interfering / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects; D014162:Transfection; D051153:Wnt Proteins / Q000502:physiology*; D051154:Wnt2 Protein / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology; D051176:beta Catenin / Q000096:biosynthesis / Q000235:genetics; D000094742:Secreted Frizzled-Related Proteins
chemical_list: D001374:Azacitidine; D004273:DNA, Neoplasm; D000077209:Decitabine; D036341:Intercellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D034741:RNA, Small Interfering; D051153:Wnt Proteins; D051154:Wnt2 Protein; D051176:beta Catenin; C495270:CTNNB1 protein, human; C117636:SFRP1 protein, human; D000094742:Secreted Frizzled-Related Proteins; C109618:SFRP2 protein, human; C495244:WNT2 protein, human