Dynamin 2 mediates PDGFRα-SHP-2-promoted glioblastoma growth and invasion

Oncogene. 2012 May 24;31(21):2691-702. doi: 10.1038/onc.2011.436. Epub 2011 Sep 26.

Abstract

Dynamin 2 (Dyn2), a large GTPase, is involved in receptor tyrosine kinase (RTK)-promoted cell migration. However, the molecular mechanisms by which Dyn2 regulates RTK-induced cell migration have not been established. Recently, we reported that tyrosine-protein phosphatase non-receptor type 11 (SHP-2) and phosphatidylinositol 3-kinase (PI3K) mediate platelet-derived growth factor receptor-α (PDGFRα)-promoted glioma tumor growth and invasion. Here, we show that Dyn2 is an effector downstream of the PDGFRα-PI3K/SHP-2 signaling in glioma cells. Depletion of endogenous Dyn2 by short hairpin RNAs (shRNAs) inhibited PDGFRα-stimulated phosphorylation of Akt, Erk1/2, Rac1 and Cdc42 activities, glioma cell migration and survival in vitro and tumor growth and invasion in the brains of mice. Dyn2 binds to SHP-2 and PI3K and colocalizes with PDGFRα at the invasive fronts in PDGF-A-stimulated glioma cells. Inhibition of SHP-2 by siRNA knockdown abrogated Dyn2 association with activated PDGFRα and PDGFRα activation of Rac1 and Cdc42, and glioma cell migration, thereby establishing a link between SHP-2 interaction with Dyn2 and the PDGFRα signaling. Furthermore, a dominant-negative SHP-2 C459S mutant inhibited PDGF-A-stimulated glioma cell migration, phosphorylation of Dyn2 and concomitantly blocked PDGFRα-induced Src activation. Inhibition of Src by Src inhibitors attenuated PDGF-A-stimulated phosphorylation of Akt and Dyn2 and glioma cell migration. Additionally, mutations of binding sites to PI3K, SHP-2 or Src of PDGFRα impaired PDGFRα-stimulated phosphorylation of Akt and Dyn2, and Dyn2 association with activated PDGFRα. Taken together, this study identifies Dyn2 as an effector that mediates PDGFRα-SHP-2-induced glioma tumor growth and invasion, suggesting that targeting the PDGFRα-SHP-2-Dyn2 pathway may be beneficial to patients with malignant glioblastomas.

Publication types

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

MeSH terms

  • Animals
  • Cell Line, Tumor
  • Disease Progression
  • Dynamin II / genetics
  • Dynamin II / metabolism*
  • Gene Expression Regulation, Neoplastic
  • Gene Knockdown Techniques
  • Genes, src
  • Glioblastoma / genetics*
  • Humans
  • Mice
  • Neoplasm Invasiveness
  • Neoplasm Transplantation
  • Phosphatidylinositol 3-Kinases
  • Protein Tyrosine Phosphatase, Non-Receptor Type 11 / genetics*
  • Protein Tyrosine Phosphatase, Non-Receptor Type 11 / metabolism
  • Receptor, Platelet-Derived Growth Factor alpha / genetics*
  • Signal Transduction

Substances

  • Phosphatidylinositol 3-Kinases
  • Receptor, Platelet-Derived Growth Factor alpha
  • PTPN11 protein, human
  • Protein Tyrosine Phosphatase, Non-Receptor Type 11
  • Dynamin II