Identification of a novel pro-apoptotic role of NF-κB in the regulation of TRAIL- and CD95-mediated apoptosis of glioblastoma cells

Oncogene. 2012 Mar 15;31(11):1468-74. doi: 10.1038/onc.2011.333. Epub 2011 Aug 8.

Abstract

We recently reported that nuclear factor-kappa B (NF-κB) promotes DNA damage-triggered apoptosis in glioblastoma, the most common brain tumor. In the present study, we investigated the role of NF-κB in death receptor-mediated apoptosis. Here, we identify a novel pro-apopotic function of NF-κB in TRAIL- and CD95-induced apoptosis. Inhibition of NF-κB by overexpression of the dominant-negative IκBα-superrepressor (IκBα-SR) significantly decreases tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL)- or CD95-induced apoptosis. Vice versa, activation of NF-κB via overexpression of constitutively active IκB kinase complex (IKK)β (IKK-EE) significantly increases TRAIL-mediated apoptosis. Intriguingly, NF-κB inhibition reduces the recruitment of Fas-associated death domain and caspase-8 and formation of the death-inducing signaling complex (DISC) upon stimulation of TRAIL receptors or CD95. This results in reduced TRAIL-mediated activation of caspases, loss of mitochondrial potential and cytochrome c release in IκBα-SR-expressing cells. In comparison, NF-κB inhibition strongly enhances TNF-α-mediated apoptosis. Comparative studies revealed that TNF-α rapidly stimulates transcriptional activation and upregulation of anti-apoptotic proteins, whereas TRAIL causes apoptosis before transcriptional activation. Thus, this study demonstrates for the first time that NF-κB exerts a pro-apoptotic role in TRAIL- and CD95-induced apoptosis in glioblastoma cells by facilitating DISC formation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects*
  • Brain Neoplasms / metabolism*
  • Caspases
  • Cell Line, Tumor
  • Glioblastoma / metabolism*
  • Humans
  • Mice
  • NF-kappa B / antagonists & inhibitors
  • NF-kappa B / physiology*
  • TNF-Related Apoptosis-Inducing Ligand / metabolism*
  • Transcriptional Activation
  • fas Receptor / metabolism*

Substances

  • NF-kappa B
  • TNF-Related Apoptosis-Inducing Ligand
  • fas Receptor
  • Caspases