Direct inhibition of myosin II effectively blocks glioma invasion in the presence of multiple motogens

Mol Biol Cell. 2012 Feb;23(4):533-42. doi: 10.1091/mbc.E11-01-0039. Epub 2012 Jan 4.

Abstract

Anaplastic gliomas, the most common and malignant of primary brain tumors, frequently contain activating mutations and amplifications in promigratory signal transduction pathways. However, targeting these pathways with individual signal transduction inhibitors does not appreciably reduce tumor invasion, because these pathways are redundant; blockade of any one pathway can be overcome by stimulation of another. This implies that a more effective approach would be to target a component at which these pathways converge. In this study, we have investigated whether the molecular motor myosin II represents such a target by examining glioma invasion in a series of increasingly complex models that are sensitive to platelet-derived growth factor, epidermal growth factor, or both. Our results lead to two conclusions. First, malignant glioma cells are stimulated to invade brain through the activation of multiple signaling cascades not accounted for in simple in vitro assays. Second, even though there is a high degree of redundancy in promigratory signaling cascades in gliomas, blocking tumor invasion by directly targeting myosin II remains effective. Our results thus support our hypothesis that myosin II represents a point of convergence for signal transduction pathways that drive glioma invasion and that its inhibition cannot be overcome by other motility mechanisms.

Publication types

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

MeSH terms

  • Animals
  • Brain Neoplasms / metabolism
  • Brain Neoplasms / pathology*
  • Cell Line, Tumor
  • Cell Movement / drug effects
  • Cell Movement / physiology*
  • Epidermal Growth Factor / pharmacology
  • ErbB Receptors / agonists
  • ErbB Receptors / genetics
  • ErbB Receptors / metabolism
  • Glioma / metabolism
  • Glioma / pathology*
  • Humans
  • Neoplasm Invasiveness
  • Nonmuscle Myosin Type IIA / antagonists & inhibitors*
  • Nonmuscle Myosin Type IIA / metabolism
  • Phosphorylation
  • Platelet-Derived Growth Factor / pharmacology
  • Rats
  • Rats, Sprague-Dawley
  • Signal Transduction / drug effects

Substances

  • Platelet-Derived Growth Factor
  • Epidermal Growth Factor
  • ErbB Receptors
  • Nonmuscle Myosin Type IIA