Caveolin-1-enhanced motility and focal adhesion turnover require tyrosine-14 but not accumulation to the rear in metastatic cancer cells

PLoS One. 2012;7(4):e33085. doi: 10.1371/journal.pone.0033085. Epub 2012 Apr 10.

Abstract

Caveolin-1 is known to promote cell migration, and increased caveolin-1 expression is associated with tumor progression and metastasis. In fibroblasts, caveolin-1 polarization and phosphorylation of tyrosine-14 are essential to promote migration. However, the role of caveolin-1 in migration of metastatic cells remains poorly defined. Here, caveolin-1 participation in metastatic cell migration was evaluated by shRNA targeting of endogenous caveolin-1 in MDA-MB-231 human breast cancer cells and ectopic expression in B16-F10 mouse melanoma cells. Depletion of caveolin-1 in MDA-MB-231 cells reduced, while expression in B16-F10 cells promoted migration, polarization and focal adhesion turnover in a sequence of events that involved phosphorylation of tyrosine-14 and Rac-1 activation. In B16-F10 cells, expression of a non-phosphorylatable tyrosine-14 to phenylalanine mutant failed to recapitulate the effects observed with wild-type caveolin-1. Alternatively, treatment of MDA-MB-231 cells with the Src family kinase inhibitor PP2 reduced caveolin-1 phosphorylation on tyrosine-14 and cell migration. Surprisingly, unlike for fibroblasts, caveolin-1 polarization and re-localization to the trailing edge were not observed in migrating metastatic cells. Thus, expression and phosphorylation, but not polarization of caveolin-1 favor the highly mobile phenotype of metastatic cells.

Publication types

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

MeSH terms

  • Animals
  • Breast Neoplasms / genetics
  • Breast Neoplasms / metabolism*
  • Breast Neoplasms / pathology*
  • Caveolin 1 / genetics
  • Caveolin 1 / metabolism*
  • Cell Line, Tumor
  • Cell Movement / physiology*
  • Cells, Cultured
  • Female
  • Fibroblasts / metabolism
  • Focal Adhesions / genetics
  • Focal Adhesions / metabolism*
  • GTP Phosphohydrolases / metabolism
  • HEK293 Cells
  • Humans
  • Mice
  • Phosphorylation
  • Rats
  • Tyrosine / metabolism*
  • rho-Associated Kinases / metabolism
  • src-Family Kinases / antagonists & inhibitors
  • src-Family Kinases / metabolism

Substances

  • Caveolin 1
  • Tyrosine
  • src-Family Kinases
  • rho-Associated Kinases
  • GTP Phosphohydrolases