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PARP inhibition restores extrinsic apoptotic sensitivity in glioblastoma

Georg Karpel-Massler1, Fresia Pareja1, Pascaline Aimé1

  • 1Department of Pathology & Cell Biology, Columbia University Medical Center, New York, New York, United States of America.

Plos One
|December 23, 2014
PubMed
Abstract

Insights

Targeting poly (ADP-ribose) polymerase (PARP) with inhibitors like Olaparib sensitizes glioblastoma cells to TRAIL-induced apoptosis. This combination therapy reduces tumor growth and overcomes resistance, offering a promising treatment strategy for glioblastoma.

Area of Science:

  • Oncology
  • Molecular Biology
  • Cancer Therapeutics

Background:

  • Glioblastoma (GBM) exhibits resistance to apoptosis, a major challenge in treatment.
  • Targeting poly (ADP-ribose) polymerase (PARP) with small molecule inhibitors like Olaparib or PJ34 reduces GBM cell proliferation and sensitizes them to apoptosis.

Purpose of the Study:

  • To investigate the sensitizing effects of PARP inhibition on TRAIL-mediated apoptosis in glioblastoma.
  • To evaluate the efficacy and toxicity of combining PARP inhibitors with TRAIL in glioblastoma models.

Main Methods:

  • Viability assays, flow cytometry, western blots, and gene silencing were used in GBM cell lines, neurospheres, and astrocytes.
  • In vivo studies utilized a murine subcutaneous xenograft model to assess tumor growth inhibition.

Main Results:

  • Combination treatment of PARP inhibitors and TRAIL significantly increased glioblastoma cell death and inhibited neurosphere formation.
  • PARP inhibition induced a nuclear stress response, up-regulated DR5 protein levels, and enhanced TRAIL-mediated apoptosis.
  • Combination therapy showed no toxicity in human astrocytes and significantly reduced tumor growth in vivo.

Conclusions:

  • PARP inhibition is a promising strategy to overcome apoptotic resistance in glioblastoma.
  • Combining PARP inhibitors with TRAIL offers a potential therapeutic approach for glioblastoma treatment.

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