title: N-cadherin-mediated adhesion and aberrant catenin expression in anaplastic thyroid-carcinoma cell lines.
abstract: The role of cadherins and catenins in the progression of thyroid carcinoma is unclear. We have investigated alpha-, beta- and gamma-catenins and p120(ctn) in relation to the expression of cadherins in human anaplastic thyroid-carcinoma cell lines (HTh7, HTh74, C643 and SW1736) with Western blotting and immunofluorescence. E-cadherin was lacking except in SW1736, which consisted of E-cadherin-positive (approx. 5%) and -negative cells. The alpha- and beta-catenin levels were similar to those of primary cultured non-neoplastic (E-cadherin-positive) human thyrocytes. In contrast, the expression of gamma-catenin was low and variable, correlating with the different levels of cytokeratin in the same cells (HTh74 > SW1736 > C643 > HTh7). p120(ctn) resolved as a doublet in Western blots; the approximately 100-kDa band also found in non-neoplastic epithelial cells was reduced whereas the approximately 115-kDa band, corresponding to the fibroblast-type isoform of p120(ctn), was neo-expressed. A DNA-demethylating agent, 5-aza-2'-deoxycytidine, up-regulated E-cadherin in SW1736 and gamma-catenin in SW1736 and C643, whereas the other cell lines were unresponsive; other catenins were not affected. The catenins were generally distributed along the cell borders. Immunostaining, cell-surface biotinylation and co-immunoprecipitation revealed that all cell lines expressed N-cadherin in connection with beta-catenin at the plasma membrane. Incubation with an N-cadherin antibody disrupted cell-cell adhesion. We conclude that E-cadherin-negative anaplastic thyroid-carcinoma cell lines display functional N-cadherin/beta-catenin complexes, partial or complete loss of gamma-catenin, and isoform shift of p120(ctn). The unequal expression of E-cadherin and gamma-catenin and the variable response to DNA de-methylation suggest that anaplastic thyroid carcinoma is not a uniform entity.
authors.affiliation: Institute of Anatomy and Cell Biology, Göteborg University, Göteborg, Sweden. johanna.husmark@anatcell.gu.se
authors.forename: J
authors.initials: J
authors.lastname: Husmark
authors.forename: N E
authors.initials: NE
authors.lastname: Heldin
authors.forename: M
authors.initials: M
authors.lastname: Nilsson
mesh_terms: D015820:Cadherins / Q000187:drug effects / Q000502:physiology*; D002277:Carcinoma / Q000378:metabolism* / Q000473:pathology; D051177:Catenins; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules / Q000187:drug effects / Q000378:metabolism; D003598:Cytoskeletal Proteins / Q000187:drug effects / Q000378:metabolism*; D051180:Desmoplakins; D006801:Humans; D009363:Neoplasm Proteins / Q000187:drug effects / Q000378:metabolism*; D010750:Phosphoproteins / Q000187:drug effects / Q000378:metabolism; D013964:Thyroid Neoplasms / Q000378:metabolism* / Q000473:pathology; D015534:Trans-Activators; D014407:Tumor Cells, Cultured; D051178:alpha Catenin; D051176:beta Catenin; D051185:gamma Catenin; D000095002:Delta Catenin
chemical_list: C495273:CTNNA1 protein, human; C495270:CTNNB1 protein, human; D015820:Cadherins; D051177:Catenins; D015815:Cell Adhesion Molecules; D003598:Cytoskeletal Proteins; D051180:Desmoplakins; C495292:JUP protein, human; D009363:Neoplasm Proteins; D010750:Phosphoproteins; D015534:Trans-Activators; D051178:alpha Catenin; D051176:beta Catenin; D051185:gamma Catenin; D000095002:Delta Catenin; C000722347:CTNND1 protein, human