Β-elemene inhibits Hsp90/Raf-1 molecular complex inducing apoptosis of glioblastoma cells

J Neurooncol. 2012 Apr;107(2):307-14. doi: 10.1007/s11060-011-0770-7. Epub 2011 Dec 11.

Abstract

β-Elemene, an active component of herb medicine Curcuma wenyujin, has been shown to antagonize glioblastoma cells by inducing apoptosis. However, how β-elemene induces apoptosis of these cells remains unclear. In this study, we report that β-elemene disrupted the formation of the Hsp90/Raf-1 complex, a key step in maintaining the conformation stability of Raf-1, and caused deactivation of Raf-1 and inhibition of the ERK pathway, thereby leading to apoptosis of glioblastoma cells. Specifically, treatment of glioblastoma cell lines with β-elemene attenuated phosphorylation of multiple members of the kinase families in the Ras/Raf/MEK/ERK cascade, including Raf-1 and ERK as well as downstream signaling targets such as Bcl-2. These results suggest that the Hsp90/Raf-1 complex could be a promising molecular target for new drug development for the treatment of glioblastoma.

MeSH terms

  • Animals
  • Apoptosis / drug effects*
  • Brain Neoplasms / diet therapy
  • Cell Line, Tumor
  • Disease Models, Animal
  • Dose-Response Relationship, Drug
  • Flow Cytometry
  • Gene Expression Regulation, Neoplastic / drug effects*
  • Glioblastoma / drug therapy
  • Glioblastoma / pathology
  • HSP90 Heat-Shock Proteins / metabolism*
  • Humans
  • Immunoprecipitation
  • Mice
  • Mice, Nude
  • Proto-Oncogene Proteins c-bcl-2 / metabolism
  • Proto-Oncogene Proteins c-raf / metabolism*
  • Sesquiterpenes / pharmacology*
  • Signal Transduction / drug effects*
  • Time Factors
  • Xenograft Model Antitumor Assays
  • bcl-2-Associated X Protein / metabolism

Substances

  • HSP90 Heat-Shock Proteins
  • Proto-Oncogene Proteins c-bcl-2
  • Sesquiterpenes
  • bcl-2-Associated X Protein
  • beta-elemene
  • Proto-Oncogene Proteins c-raf