Death receptor-4 (DR4) expression is regulated by transcription factor NF-kappaB in response to etoposide treatment

Apoptosis. 2008 Jun;13(6):756-70. doi: 10.1007/s10495-008-0210-0.

Abstract

Tumour necrosis factor related apoptosis inducing ligand (TRAIL) binds to death receptor 4 (DR4) activating the apoptotic signalling pathway. DNA damaging agents (genotoxins) such as etoposide increase DR4 expression and when combined with TRAIL induce a synergistic apoptotic response. The mechanism for up-regulation of DR4 expression following genotoxin treatment is not well understood. Herein, we determined that transcription factor NF-kappaB plays a role in genotoxin induced DR4 expression. Increased expression of DR4 following etoposide treatment is blocked by inhibition of the NF-kappaB pathway. Moreover, expression of the p65 subunit of NF-kappaB is sufficient to increase DR4 protein levels. Indeed, knockdown of p65 by RNA interference blocked etoposide up-regulation of DR4. We further identified a functional NF-kappaB binding site located in the DR4 promoter. Mutation of this site abrogates the induction of luciferase activity after p65 over-expression. Furthermore, electromobility shift assays and chromatin immunoprecipitaton suggest that NF-kappaB binds to this site upon etoposide treatment. MEK kinase 1 (MEKK1) is a serine threonine kinase that is activated following etoposide treatment and activates NF-kappaB. Expression of the kinase inactive MEKK1 (MEKK1-KM) abrogates the up-regulation of DR4 after etoposide treatment. Taken together, NF-kappaB plays a role in up-regulation of DR4 following etoposide treatment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Monoclonal / pharmacology
  • Antibodies, Monoclonal, Humanized
  • Apoptosis / drug effects
  • Binding Sites
  • Cell Line
  • DNA Fragmentation / drug effects
  • Etoposide / pharmacology*
  • HT29 Cells
  • Humans
  • MAP Kinase Kinase Kinase 1 / physiology
  • NF-kappa B / physiology*
  • Nitriles / pharmacology
  • Promoter Regions, Genetic / drug effects
  • Receptors, TNF-Related Apoptosis-Inducing Ligand
  • Receptors, Tumor Necrosis Factor / biosynthesis*
  • Sulfones / pharmacology
  • TNF-Related Apoptosis-Inducing Ligand / pharmacology
  • Transcription Factor RelA / physiology
  • Up-Regulation

Substances

  • 3-(4-methylphenylsulfonyl)-2-propenenitrile
  • Antibodies, Monoclonal
  • Antibodies, Monoclonal, Humanized
  • NF-kappa B
  • Nitriles
  • Receptors, TNF-Related Apoptosis-Inducing Ligand
  • Receptors, Tumor Necrosis Factor
  • Sulfones
  • TNF-Related Apoptosis-Inducing Ligand
  • TNFRSF10A protein, human
  • TNFSF10 protein, human
  • Transcription Factor RelA
  • Etoposide
  • MAP Kinase Kinase Kinase 1
  • mapatumumab