Podoplanin associates with CD44 to promote directional cell migration

Mol Biol Cell. 2010 Dec;21(24):4387-99. doi: 10.1091/mbc.E10-06-0489. Epub 2010 Oct 20.

Abstract

Podoplanin is a transmembrane glycoprotein up-regulated in different human tumors, especially those derived from squamous stratified epithelia (SCCs). Its expression in tumor cells is linked to increased cell migration and invasiveness; however, the mechanisms underlying this process remain poorly understood. Here we report that CD44, the major hyaluronan (HA) receptor, is a novel partner for podoplanin. Expression of the CD44 standard isoform (CD44s) is coordinately up-regulated together with that of podoplanin during progression to highly aggressive SCCs in a mouse skin model of carcinogenesis, and during epithelial-mesenchymal transition (EMT). In carcinoma cells, CD44 and podoplanin colocalize at cell surface protrusions. Moreover, CD44 recruitment promoted by HA-coated beads or cross-linking with a specific CD44 antibody induced corecruitment of podoplanin. Podoplanin-CD44s interaction was demonstrated both by coimmunoprecipitation experiments and, in vivo, by fluorescence resonance energy transfer/fluorescence lifetime imaging microscopy (FRET/FLIM), the later confirming its association on the plasma membrane of cells with a migratory phenotype. Importantly, we also show that podoplanin promotes directional persistence of motility in epithelial cells, a feature that requires CD44, and that both molecules cooperate to promote directional migration in SCC cells. Our results support a role for CD44-podoplanin interaction in driving tumor cell migration during malignancy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Carcinoma, Squamous Cell / pathology*
  • Cell Adhesion
  • Cell Movement*
  • Cells, Cultured
  • Epithelial-Mesenchymal Transition
  • Fluorescence Resonance Energy Transfer
  • Humans
  • Hyaluronan Receptors / genetics
  • Hyaluronan Receptors / metabolism*
  • Hyaluronic Acid / metabolism
  • Membrane Glycoproteins / genetics
  • Membrane Glycoproteins / metabolism*
  • Mice
  • Microscopy, Fluorescence
  • Neoplasm Invasiveness
  • Protein Isoforms / genetics
  • Protein Isoforms / metabolism
  • Skin Neoplasms / pathology*
  • Up-Regulation

Substances

  • Hyaluronan Receptors
  • Membrane Glycoproteins
  • PDPN protein, human
  • Protein Isoforms
  • Hyaluronic Acid