The apoptosis-resistance in t-AUCB-treated glioblastoma cells depends on activation of Hsp27

J Neurooncol. 2012 Nov;110(2):187-94. doi: 10.1007/s11060-012-0963-8. Epub 2012 Aug 18.

Abstract

We previously reported that sEH inhibitor t-AUCB suppresses the growth of human glioblastoma U251 and U87 cell lines and induces cell-cycle G0/G1 phase arrest. In present study, we found even 96 h-treatment of 200 μM t-AUCB can not induce apoptosis in U251 and U87 cells. We also revealed that 200 μM t-AUCB significantly elevates the activation of p38 MAPK, MAPKAPK2 and Hsp27. The p38 MAPK inhibitor SB203580 and the inhibitor of Hsp27 phosphorylation, KRIBB3, were used to investigate the mechanism of the apoptosis-resistance. The results showed that, after blocking the activation of Hsp27 by SB203580 or KRIBB3, 200 μM t-AUCB significantly induces apoptosis and increases caspase-3 activities in U251 and U87 cells. Our data demonstrated that t-AUCB induces cell apoptosis after blocking itself-induced activation of Hsp27, and that the activation of Hsp27 may confer chemoresistance in GBM cells. The combination of t-AUCB and the inhibitor of Hsp27 phosphorylation may be a potential strategy for treatment of glioblastoma.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis / drug effects*
  • Benzoates / pharmacology*
  • Blotting, Western
  • Brain Neoplasms / drug therapy
  • Brain Neoplasms / metabolism
  • Brain Neoplasms / pathology*
  • Caspase 3 / metabolism
  • Cell Proliferation / drug effects
  • Enzyme Inhibitors / pharmacology
  • Epoxide Hydrolases / antagonists & inhibitors*
  • Epoxide Hydrolases / metabolism
  • Flow Cytometry
  • Glioblastoma / drug therapy
  • Glioblastoma / metabolism
  • Glioblastoma / pathology*
  • HSP27 Heat-Shock Proteins / metabolism*
  • Humans
  • Intracellular Signaling Peptides and Proteins / metabolism
  • Phosphorylation / drug effects
  • Protein Serine-Threonine Kinases / metabolism
  • RNA, Messenger / genetics
  • Tumor Cells, Cultured
  • Urea / analogs & derivatives*
  • Urea / pharmacology
  • p38 Mitogen-Activated Protein Kinases / antagonists & inhibitors
  • p38 Mitogen-Activated Protein Kinases / metabolism

Substances

  • 4-(4-(3-adamantan-1-ylureido)cyclohexyloxy)benzoic acid
  • Benzoates
  • Enzyme Inhibitors
  • HSP27 Heat-Shock Proteins
  • Intracellular Signaling Peptides and Proteins
  • RNA, Messenger
  • Urea
  • MAP-kinase-activated kinase 2
  • Protein Serine-Threonine Kinases
  • p38 Mitogen-Activated Protein Kinases
  • Epoxide Hydrolases
  • Caspase 3