Governing epidermal homeostasis by coupling cell-cell adhesion to integrin and growth factor signaling, proliferation, and apoptosis

Proc Natl Acad Sci U S A. 2012 Mar 27;109(13):4886-91. doi: 10.1073/pnas.1202120109. Epub 2012 Mar 12.

Abstract

Cadherin/catenin-based adhesions coordinate cellular growth, survival, migration, and differentiation within a tissue by mechanically anchoring cells to their neighbors. They also intersect with diverse signaling pathways in development and cancer. Although the adhesive functions of adherens junction proteins are well characterized, their contribution to other signaling pathways is less well understood. Here, we show that ablation of α-catenin in the epidermis selectively induces apoptosis in suprabasal differentiating keratinocytes while sparing basal cell progenitors. This protection from death is coupled to elevated focal adhesion signaling, faster migration, and an altered distribution of growth factor receptors. We show that simultaneous depletion of α-catenin and focal adhesion kinase or p21-activated kinase eliminates basal cell protection as well as the elevated migration and proliferation of cells. The increased dependency of cells upon matrix interactions for their survival when cell-cell adhesions are destabilized has important implications for cancer progression and metastasis.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adherens Junctions / metabolism
  • Animals
  • Apoptosis*
  • Cell Adhesion
  • Cell Movement
  • Cell Proliferation
  • Cytoskeleton / metabolism
  • Epidermal Cells*
  • Epidermis / enzymology
  • Extracellular Signal-Regulated MAP Kinases / metabolism
  • Focal Adhesion Protein-Tyrosine Kinases / metabolism
  • Focal Adhesions / metabolism
  • Homeostasis*
  • Integrins / metabolism*
  • Intercellular Signaling Peptides and Proteins / metabolism*
  • Keratinocytes / cytology
  • Keratinocytes / enzymology
  • Mice
  • Mice, Knockout
  • Morphogenesis
  • Phosphorylation
  • Receptors, Cell Surface / metabolism
  • Signal Transduction*
  • alpha Catenin / deficiency
  • alpha Catenin / metabolism
  • p21-Activated Kinases / metabolism

Substances

  • Integrins
  • Intercellular Signaling Peptides and Proteins
  • Receptors, Cell Surface
  • alpha Catenin
  • Focal Adhesion Protein-Tyrosine Kinases
  • p21-Activated Kinases
  • Extracellular Signal-Regulated MAP Kinases