Cortactin involvement in the keratinocyte growth factor and fibroblast growth factor 10 promotion of migration and cortical actin assembly in human keratinocytes

Exp Cell Res. 2007 May 15;313(9):1758-77. doi: 10.1016/j.yexcr.2007.03.013. Epub 2007 Mar 24.

Abstract

Keratinocyte growth factor (KGF/FGF7) and fibroblast growth factor 10 (FGF10/KGF2) regulate keratinocyte proliferation and differentiation by binding to the tyrosine kinase KGF receptor (KGFR). KGF induces keratinocyte motility and cytoskeletal rearrangement, whereas a direct role of FGF10 on keratinocyte migration is not clearly established. Here we analyzed the motogenic activity of FGF10 and KGF on human keratinocytes. Migration assays and immunofluorescence of actin cytoskeleton revealed that FGF10 is less efficient than KGF in promoting migration and exerts a delayed effect in inducing lamellipodia and ruffles formation. Both growth factors promoted phosphorylation and subsequent membrane translocation of cortactin, an F-actin binding protein involved in cell migration; however, FGF10-induced cortactin phosphorylation was reduced, more transient and delayed with respect to that promoted by KGF. Cortactin phosphorylation induced by both growth factors was Src-dependent, while its membrane translocation and cell migration were blocked by either Src and PI3K inhibitors, suggesting that both pathways are involved in KGF- and FGF10-dependent motility. Furthermore, siRNA-mediated downregulation of cortactin inhibited KGF- and FGF10-induced migration. These results indicate that cortactin is involved in keratinocyte migration promoted by both KGF and FGF10.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actin Cytoskeleton / drug effects
  • Actin Cytoskeleton / metabolism
  • Actins / metabolism*
  • Cell Differentiation / drug effects
  • Cell Differentiation / physiology
  • Cell Line
  • Cell Membrane / metabolism
  • Cell Movement / drug effects
  • Cell Movement / physiology*
  • Cortactin / metabolism*
  • Cytoplasm / drug effects
  • Cytoplasm / metabolism
  • Cytoskeleton / drug effects
  • Cytoskeleton / metabolism
  • Down-Regulation / genetics
  • Enzyme Inhibitors / pharmacology
  • Fibroblast Growth Factor 10 / metabolism*
  • Fibroblast Growth Factor 10 / pharmacology
  • Fibroblast Growth Factor 7 / metabolism*
  • Fibroblast Growth Factor 7 / pharmacology
  • Fluorescent Antibody Technique
  • Humans
  • Keratinocytes / drug effects
  • Keratinocytes / metabolism*
  • Paxillin / metabolism
  • Phosphorylation / drug effects
  • Protein Transport / physiology
  • Pseudopodia / drug effects
  • Pseudopodia / metabolism
  • RNA, Small Interfering / genetics
  • Time Factors
  • Wound Healing / physiology
  • src-Family Kinases / metabolism

Substances

  • Actins
  • Cortactin
  • Enzyme Inhibitors
  • FGF10 protein, human
  • Fibroblast Growth Factor 10
  • Paxillin
  • RNA, Small Interfering
  • Fibroblast Growth Factor 7
  • src-Family Kinases