OSU-03012 in the treatment of glioblastoma

Mol Pharmacol. 2006 Aug;70(2):437-9. doi: 10.1124/mol.106.026252. Epub 2006 May 4.

Abstract

In an article presented in this issue of Molecular Pharmacology, Yacoub et al. (p. 589) examine the actions of 2-amino-N{4-5-(2-phenanthrenyl)-3-(trifluoromethyl)-1H-pyrazol-1-yl]phenyl}-acetamide (OSU-03012) on both primary and glioblastoma cell lines. The authors found that OSU-03012 could induce tumor cell death by itself but also acted as a strong sensitizing agent to radiotherapy-induced cell death. Glioblastoma cells were also more sensitive to this compound than nontransformed astrocytes. Radiation-induced cell death was refractory to small interfering RNA-directed inhibition of PDK1 but not OSU-03012. These results indicate that OSU-03012, which has been thought to primarily mediate antitumor effects via the inhibition of PDK1, has actions independent of PDK1. Furthermore, the authors demonstrated that the effects of OSU-03012 were independent of ERB-B1-vIII and PTEN expression. These are important findings because they start to identify a new mechanism to sensitize glioblastoma cells and also suggest that OSU-03012 could be combined with existing inhibitors to further sensitize tumor cells. In glioblastoma cells, OSU-03012 seemed to induce apoptosis via endoplasmic reticulum stress-induced PERK-dependent signaling. OSU-03012-induced death of the glioblastoma was only weakly suppressed by the pan-caspase inhibitor, N-benzyloxycarbonyl-Val-Ala-Asp, suggesting that OSU-03012-induced cell death was largely caspase-independent. Overall, these are exciting results and suggest that new more effective treatment options may be obtainable for people suffering from these deadly tumors.

Publication types

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

MeSH terms

  • 3-Phosphoinositide-Dependent Protein Kinases
  • Brain Neoplasms / drug therapy*
  • Extracellular Signal-Regulated MAP Kinases / antagonists & inhibitors
  • Glioblastoma / drug therapy*
  • Humans
  • Phosphoinositide-3 Kinase Inhibitors
  • Protein Kinase Inhibitors / therapeutic use*
  • Protein-Serine-Threonine Kinases / antagonists & inhibitors*
  • Pyrazoles / therapeutic use*
  • Sulfonamides / therapeutic use*
  • eIF-2 Kinase / physiology

Substances

  • OSU 03012
  • Phosphoinositide-3 Kinase Inhibitors
  • Protein Kinase Inhibitors
  • Pyrazoles
  • Sulfonamides
  • 3-Phosphoinositide-Dependent Protein Kinases
  • PDPK1 protein, human
  • PERK kinase
  • Protein-Serine-Threonine Kinases
  • eIF-2 Kinase
  • Extracellular Signal-Regulated MAP Kinases