Simultaneous expression of caveolin-1 and E-cadherin in ovarian carcinoma cells stabilizes adherens junctions through inhibition of src-related kinases

Am J Pathol. 2005 Nov;167(5):1411-27. doi: 10.1016/S0002-9440(10)61228-X.

Abstract

Cadherin-mediated adhesion plays an important role in maintaining cell-cell contacts and reducing tumor metastasis. However, neo-expression of E-cadherin in ovarian carcinoma does not prevent the release and spread of cells from the primary tumor. Because caveolin-1 is down-regulated concomitantly with E-cad expression, we investigated whether the stability of adherens junctions in ovarian carcinoma was affected by caveolin-1 expression. We used IGROV1 cells transfected with caveolin-1 (IGtC3), mock-transfected control cells (IGtM87), and SKOV3 cells that endogenously express caveolin-1. Simultaneous expression of caveolin-1 and E-cadherin favored membrane distribution of E-cadherin and its associated catenin (p120ctn), even when caveolin-1 was only focally associated with adherens junctions. Silencing of caveolin-1 induced intracellular E-cadherin redistribution in IGtC3 and SKOV3 cells. Treatment with the specific src kinase inhibitor PP1 increased E-cadherin expression in IGtM87 and SKOV3 cells and enhanced membrane localization of both E-cadherin and p120ctn. However, PP1 could not completely reverse the detrimental effects on cell-cell adhesion induced by Ca2+ depletion in IGtM87 cells. Together, our data suggest that caveolin-1 expression indirectly promotes cell-cell adhesion in ovarian carcinoma cells by a mechanism involving inhibition of src-related kinases. Thus, down-regulation or loss of caveolin-1 might contribute significantly to the spread of tumor cells from the primary tumor.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adherens Junctions / genetics
  • Adherens Junctions / physiology*
  • Animals
  • Blotting, Western
  • Cadherins / biosynthesis*
  • Cadherins / genetics
  • Calcium / metabolism
  • Catenins
  • Caveolin 1 / biosynthesis*
  • Caveolin 1 / genetics
  • Cell Adhesion
  • Cell Adhesion Molecules / analysis
  • Cell Line, Tumor
  • Cell Membrane / chemistry
  • Delta Catenin
  • Electrophoresis, Polyacrylamide Gel
  • Enzyme Inhibitors / pharmacology
  • Female
  • Gene Silencing
  • Humans
  • Immunohistochemistry
  • Immunoprecipitation
  • Membrane Microdomains / chemistry
  • Microscopy, Confocal
  • Microscopy, Fluorescence
  • Ovarian Neoplasms / metabolism*
  • Ovarian Neoplasms / ultrastructure*
  • Phosphoproteins / analysis
  • Pyrazoles / pharmacology
  • Pyrimidines / pharmacology
  • Transfection
  • src-Family Kinases / antagonists & inhibitors

Substances

  • 4-amino-5-(4-methylphenyl)-7-(tert-butyl)pyrazolo(3,4-d)pyrimidine
  • Cadherins
  • Catenins
  • Caveolin 1
  • Cell Adhesion Molecules
  • Enzyme Inhibitors
  • Phosphoproteins
  • Pyrazoles
  • Pyrimidines
  • src-Family Kinases
  • Calcium
  • Delta Catenin
  • CTNND1 protein, human