title: Mucoepidermoid carcinoma of the thyroid: a tumour histotype characterised by P-cadherin neoexpression and marked abnormalities of E-cadherin/catenins complex.
abstract: The cadherin/catenins complex regulates cell-cell adhesion and motility and is believed to have an invasion suppressor role. Primary mucoepidermoid carcinoma of the thyroid (MECT) is a rare tumour characterised by a distinct morphological appearance and a questionable histogenesis. The coexistence of papillary thyroid carcinoma (PTC) foci in many patients with MECT suggests an association between the two tumour histotypes. In an attempt to clarify the putative relationship between MECT and PTC, we analysed tissue from 11 patients with MECT by immunohistochemistry (E-, P- and N-cadherins and alpha-, beta- and gamma-catenins). The E-cadherin gene was also analysed by polymerase chain reaction (PCR)/single-strand conformation polymorphism (SSCP). The results were compared with a control group of normal thyroid, classical PTC and the diffuse sclerosing variant of PTC. Compared with normal thyroid and PTC, MECT displays marked abnormalities of the cadherin/catenin complex. Such abnormalities include the consistent neoexpression of P-cadherin and major alterations in the expression of E-cadherin and the three catenins. Our results point to the close relationship between the de novo expression of P-cadherin and the disruption of the cadherin/catenins complex with the squamoid phenotype of MECT.
authors.affiliation: Institute of Molecular Pathology and Immunology, University of Porto, R. Roberto Frias s/n, 4200-465 Porto, Portugal.
authors.forename: Ana S
authors.initials: AS
authors.lastname: Rocha
authors.forename: Paula
authors.initials: P
authors.lastname: Soares
authors.forename: José Carlos
authors.initials: JC
authors.lastname: Machado
authors.forename: Valdemar
authors.initials: V
authors.lastname: Máximo
authors.forename: Elsa
authors.initials: E
authors.lastname: Fonseca
authors.forename: Kaarle
authors.initials: K
authors.lastname: Franssila
authors.forename: Manuel
authors.initials: M
authors.lastname: Sobrinho-Simões
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015820:Cadherins / Q000032:analysis* / Q000235:genetics; D018277:Carcinoma, Mucoepidermoid / Q000737:chemistry* / Q000473:pathology; D002648:Child; D003598:Cytoskeletal Proteins / Q000032:analysis; D051180:Desmoplakins; D005260:Female; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D018807:Polymorphism, Single-Stranded Conformational; D013964:Thyroid Neoplasms / Q000737:chemistry* / Q000473:pathology; D015534:Trans-Activators; D051178:alpha Catenin; D051176:beta Catenin
chemical_list: C495273:CTNNA1 protein, human; C495270:CTNNB1 protein, human; D015820:Cadherins; D003598:Cytoskeletal Proteins; D051180:Desmoplakins; D015534:Trans-Activators; D051178:alpha Catenin; D051176:beta Catenin