Exogenous expression of E-cadherin in gallbladder carcinoma cell line G-415 restores its cellular polarity and differentiation

Citation
W. Jiao et al., Exogenous expression of E-cadherin in gallbladder carcinoma cell line G-415 restores its cellular polarity and differentiation, INT J ONCOL, 19(6), 2001, pp. 1099-1107
Citations number
69
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Onconogenesis & Cancer Research
Journal title
INTERNATIONAL JOURNAL OF ONCOLOGY
ISSN journal
1019-6439 → ACNP
Volume
19
Issue
6
Year of publication
2001
Pages
1099 - 1107
Database
ISI
SICI code
1019-6439(200112)19:6<1099:EEOEIG>2.0.ZU;2-B
Abstract
E-cadherin (E-cad) is critical for the development and maintenance of polar ity and differentiation of epithelial cells. Our previous study revealed ga llbladder (GB) cancer cell lines expressing E-cadherin could form cystic or spheroid-like structures in a 3-D matrix. This differentiated phenotype wa s disrupted by addition of anti-E-cad antibody. By extrapolation, we postul ated that E-cad might directly regulate epithelial morphogenesis in GB carc inoma. In the present study, we introduced an expression plasmid harboring mouse E-cad cDNA (pBATEM2) into an undifferentiated GB cancer cell line (G- 415) which did not express E-cad. We systemically compared differences incl uding cell phenotype, morphogenesis, and ultrastructure between the parenta l G-415 cells (parental-cells) and E-cad transfected cells (E-cad-cells) un der various conditions such as monolayer culture, 3-D gel culture as well a s inoculation of nude mice. In contrast to parental-cells, E-cadcells prese nted a typical epithelial shape with tight intercellular connections in mon olayer culture. They developed round multicellular cystic structures in 3-D gel. The cysts secreted mucous substances via the apical surface into the cystic lumen, in which the substances were positively stained by alcian blu e (pH 2.5). Ultrastructural sections of gel/xenograft tumor revealed reesta blishment of adherens junctions and restoration of cell polarization. Immun ohistochemical and immunofluorescent staining showed exogenous E-cad primar ily accumulated at the extended cell-cell contact sites. Moreover, the memb ranous translocation of alpha-, and beta -catenin from cytoplasm was also f ound in 3-D matrix and xenograft tumor sections. Histopathologic examinatio n revealed papillary adenocarcinoma features in the central region of the x enograft tumors. Our results demonstrate that exogenous expression of E-cad in undifferentiated GB cancer G-415 cells reverses differentiated characte ristics in spatial growth conditions. Simultaneous translocation of alpha-, beta -catenin to membrane following functional E-cad expression may be a c ritical event for this process.