title: Effect of disrupting cell contact on the nuclear accumulation of beta-catenin and subsequent apoptosis of rat ovarian surface epithelial cells in vitro.
abstract: The present studies were designed to determine how disrupting cell contact induces rat ovarian surface epithelial cells (i.e., ROSE-179 cells) to undergo apoptosis. In the first series of studies, the effect of depleting serum and calcium on the levels of the adhesion proteins N-cadherin and beta-catenin was examined. These studies revealed that the depletion of serum and calcium results in the degradation of N-cadherin but not beta-catenin. However, the localization of beta-catenin changed from principally the plasma membrane to the nucleus. The nuclear localization of beta-catenin was demonstrated by Western blot and confocal microscopy. A second series of studies demonstrated that cells that lost contact in response to the depletion of serum and calcium showed enhanced beta-catenin-dependent transcription. Finally, forced expression of a stable form of beta-catenin resulted in an increase in beta-catenin within the cytoplasm of transfected ROSE-179 cells. When these beta-catenin transfected ROSE-179 cells were deprived of serum and calcium, beta-catenin accumulated within the nucleus and accelerated the rate at which these cells became apoptotic. These data indicate that in viable cells, beta-catenin is part of the adhesion complex that maintains cell contact. If calcium-dependent cell contacts are broken, beta-catenin accumulates within the nucleus, where it promotes transcription and ultimately the apoptotic death of ROSE-179 cells.
authors.affiliation: Department of Physiology, University of Connecticut Health Center, Farmington, CT 06030, USA. peluso@nso2.uchc.edu
authors.forename: J J
authors.initials: JJ
authors.lastname: Peluso
authors.forename: A
authors.initials: A
authors.lastname: Pappalardo
authors.forename: S A
authors.initials: SA
authors.lastname: Hess
mesh_terms: D000818:Animals; D017209:Apoptosis; D001769:Blood; D015153:Blotting, Western; D015820:Cadherins / Q000378:metabolism; D002118:Calcium / Q000008:administration & dosage; D002448:Cell Adhesion; D002450:Cell Communication; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism*; D003470:Culture Media; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism / Q000648:ultrastructure; D005260:Female; D010053:Ovary / Q000378:metabolism* / Q000648:ultrastructure*; D051381:Rats; D015534:Trans-Activators; D014158:Transcription, Genetic; D014162:Transfection; D051176:beta Catenin
chemical_list: D015820:Cadherins; C495268:Ctnnb1 protein, rat; D003470:Culture Media; D003598:Cytoskeletal Proteins; D015534:Trans-Activators; D051176:beta Catenin; D002118:Calcium