The c-Rel subunit of NF-κB is a crucial regulator of phenotype and motility of HaCaT keratinocytes

Arch Dermatol Res. 2015 Aug;307(6):523-30. doi: 10.1007/s00403-015-1562-2. Epub 2015 Apr 5.

Abstract

The transcription factor NF-κB exerts key functions in epidermal homeostasis and carcinogenesis. Its c-Rel subunit is expressed in squamous cell carcinoma, and c-Rel down-regulation results in increased apoptosis, G2/M cell cycle delay with reduced proliferation and aberrant mitotic spindle formation. To further study the impact of c-Rel on essential keratinocyte features such as migration and epithelial morphology, c-Rel was down-regulated in HaCaT keratinocytes by a siRNA approach. This inhibition of c-Rel impaired the keratinocyte-typical clustered growth leading to a more scattered appearance of the cultures. The cells were more spindle-shaped and elongated, albeit without expression changes of markers characteristic for epithelial mesenchymal transition. In addition, wound healing-related migration and adhesion to type I collagen, fibronectin, laminin and vitronectin were significantly impaired. On the sub-cellular level, these functional features were not associated with quantitatively altered adhesion receptor or Rho-GTPase expression, but rather with a significantly reduced length of cell-matrix adhesion complexes and altered appearance of filamentous actin. Thus, our studies support a role for c-Rel in processes crucial for keratinocyte integrity and malignant transformation such as adhesion and migration.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blotting, Western
  • Cell Adhesion / physiology
  • Cell Movement / physiology*
  • Cells, Cultured
  • Collagen Type I / metabolism
  • Down-Regulation / physiology
  • Fibronectins / metabolism
  • Fluorescent Antibody Technique
  • Genes, rel / physiology*
  • Humans
  • Keratinocytes / metabolism*
  • Laminin / metabolism
  • NF-kappa B / metabolism*
  • Phenotype
  • RNA, Small Interfering / genetics
  • Transfection
  • Vitronectin / metabolism
  • rho GTP-Binding Proteins / metabolism

Substances

  • Collagen Type I
  • Fibronectins
  • Laminin
  • NF-kappa B
  • RNA, Small Interfering
  • Vitronectin
  • rho GTP-Binding Proteins