Phosphorylation of AKT induced by phosphorylated Hsp27 confers the apoptosis-resistance in t-AUCB-treated glioblastoma cells in vitro

J Neurooncol. 2015 Jan;121(1):83-9. doi: 10.1007/s11060-014-1610-3. Epub 2014 Sep 9.

Abstract

The aim of this study is to determine whether phosphorylation of AKT could be effected by t-AUCB-induced p-Hsp27 and whether p-AKT inhibition sensitizes glioblastoma cells to t-AUCB, and to evaluate the effects of simultaneous inhibition of p-Hsp27 and p-AKT on t-AUCB treated glioblastoma cells. Cell growth was detected using CCK-8 assay; Caspase-3 activity assay kits and flow cytometry were used in apoptosis analysis; Western blot analysis was used to detect p-Hsp27 and p-AKT levels; RNA interference using the siRNA oligos of Hsp27 was performed to knockdown gene expression of Hsp27. All data were analyzed by the Student-Newman-Keul's test. We demonstrated that t-AUCB treatment induces AKT phosphorylation by activating Hsp27 in U251 and LN443 cell lines. Inhibition of AKT phosphorylation by AKT inhibitor IV sensitizes glioblastoma cells to t-AUCB, strengthens t-AUCB suppressing cell growth and inducing cell apoptosis. We also found inhibiting both p-Hsp27 and p-AKT synergistically strengthen t-AUCB suppressing cell growth. Thus, p-AKT induced by p-Hsp27 confers the apoptosis-resistance in t-AUCB-treated glioblastoma cells. Targeting p-Hsp27 and/or p-AKT may be a potential effective strategy for the treatment of glioblastoma.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antineoplastic Agents / pharmacology*
  • Apoptosis / drug effects*
  • Apoptosis / physiology
  • Benzoates / pharmacology*
  • Blotting, Western
  • Caspase 3 / metabolism
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Cell Proliferation / physiology
  • Flow Cytometry
  • Glioblastoma / drug therapy*
  • Glioblastoma / physiopathology
  • HSP27 Heat-Shock Proteins / genetics
  • HSP27 Heat-Shock Proteins / metabolism*
  • Heat-Shock Proteins
  • Humans
  • Molecular Chaperones
  • Phosphorylation / drug effects
  • Proto-Oncogene Proteins c-akt / antagonists & inhibitors
  • Proto-Oncogene Proteins c-akt / metabolism*
  • RNA Interference
  • Urea / analogs & derivatives*
  • Urea / pharmacology

Substances

  • 4-(4-(3-adamantan-1-ylureido)cyclohexyloxy)benzoic acid
  • Antineoplastic Agents
  • Benzoates
  • HSP27 Heat-Shock Proteins
  • HSPB1 protein, human
  • Heat-Shock Proteins
  • Molecular Chaperones
  • Urea
  • Proto-Oncogene Proteins c-akt
  • CASP3 protein, human
  • Caspase 3