Effect of tumor gangliosides on tyrosine phosphorylation of p125FAK in platelet adhesion to collagen

Oncol Rep. 2013 Jan;29(1):343-8. doi: 10.3892/or.2012.2092. Epub 2012 Oct 19.

Abstract

The exact mechanisms as to how platelets influence blood-borne metastasis remain poorly understood. Gangliosides, sialic acid-containing glycosphingolipids, are associated with tumor progression and metastasis in humans. Gangliosides isolated from tumor cells promote collagen-stimulated platelet aggregation and ATP secretion and enhance platelet adhesion to immobilized collagen. Gangliosides interact with a number of cell surface receptors including integrin receptors. In this study, we examined the effects of α2β1 integrin-mediated platelet adhesion to collagen and phosphotyrosine signaling of focal adhesion kinase, p125FAK (FAK). platelets pre-incubated with neuroblastoma tumor gangliosides (NBTGs) or their major component GD2 (disialoganglioside) were more adherent to immobilized collagen (OD570 0.43±0.12, 0.39±0.13) compared to platelets pre-incubated with MTB (0.14±0.06, p<0.001); the effect of NBTGs was blocked by F-17 anti-α2 antibody. Pre-incubation of platelets with NBTGs resulted in a marked increase in the phosphotyrosine content of p125FAK in the adherent platelets compared to the MTB-pre-incubated adherent platelets. F-17 anti-α2 antibody decreased protein tyrosine phosphorylation of NBTG-incubated platelets adherent to collagen. These results indicate that the tumor gangliosides enhance platelet adhesion to extracellular matrix collagen by upregulating integrin α2β1-mediated tyrosine phosphorylation of p125FAK, thereby providing insight into how this interaction may be involved in neuroblastoma metastasis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Monoclonal / pharmacology
  • Blotting, Western
  • Cell Adhesion / drug effects
  • Cell Proliferation / drug effects
  • Collagen / metabolism*
  • Focal Adhesion Kinase 1 / antagonists & inhibitors
  • Focal Adhesion Kinase 1 / immunology
  • Focal Adhesion Kinase 1 / metabolism*
  • Gangliosides / isolation & purification
  • Gangliosides / pharmacology*
  • Humans
  • Immunoprecipitation
  • Integrin alpha2beta1 / metabolism*
  • Mice
  • Neuroblastoma / drug therapy
  • Neuroblastoma / metabolism*
  • Neuroblastoma / pathology
  • Phosphorylation / drug effects
  • Phosphotyrosine / metabolism*
  • Platelet Adhesiveness / drug effects*
  • Platelet Aggregation
  • Tumor Cells, Cultured

Substances

  • Antibodies, Monoclonal
  • Gangliosides
  • Integrin alpha2beta1
  • Phosphotyrosine
  • Collagen
  • Focal Adhesion Kinase 1