Linking of N-Myc to death receptor machinery in neuroblastoma cells

J Biol Chem. 2005 Mar 11;280(10):9474-81. doi: 10.1074/jbc.M410450200. Epub 2005 Jan 4.

Abstract

The oncogene MYCN is amplified in aggressive neuroblastomas in which caspase-8, an essential component of death receptor pathways, is frequently inactivated, suggesting a critical role of death receptor-mediated apoptosis in suppression of N-Myc oncogenic activity. Elevated levels of N-Myc sensitize neuroblastoma cells to apoptosis induced by various death ligands. Using tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis as a model, we define the mechanism underlying the sensitization effect. In neuroblastoma cells with increased expression of N-Myc, TRAIL triggers high levels of caspase-8 activation and Bid cleavage, leading to release of cytochrome c and Smac/DIABLO from mitochondria. However, the apoptotic process requires Smac/DIABLO, but not cytochrome c-mediated caspase-9 activation. N-Myc sensitizes neuroblastoma cells to TRAIL by up-regulating TRAIL receptor-2/DR5/KILLER and Bid. Moreover, DR5 mRNA is increased after N-Myc overexpression, and the human DR5 promoter contains two noncanonical E-boxes critical for the transcriptional activation by N-Myc. These findings establish a mechanistic link between N-Myc and death receptor machinery, which may serve as a checkpoint to guard the cell from N-Myc-initiated tumorigenesis.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Apoptosis / physiology
  • Apoptosis Regulatory Proteins
  • Carrier Proteins / genetics
  • Carrier Proteins / physiology
  • Caspase 3
  • Caspases / metabolism
  • Cell Line, Tumor
  • Enzyme Activation
  • Genes, myc
  • Humans
  • Intracellular Signaling Peptides and Proteins
  • Ligands
  • Membrane Glycoproteins / genetics
  • Membrane Glycoproteins / physiology
  • Mitochondrial Proteins / genetics
  • Mitochondrial Proteins / physiology
  • Neuroblastoma / genetics*
  • Plasmids
  • Proto-Oncogene Proteins c-myc / physiology*
  • TNF-Related Apoptosis-Inducing Ligand
  • Tumor Necrosis Factor-alpha / genetics
  • Tumor Necrosis Factor-alpha / physiology

Substances

  • Apoptosis Regulatory Proteins
  • Carrier Proteins
  • DIABLO protein, human
  • Intracellular Signaling Peptides and Proteins
  • Ligands
  • Membrane Glycoproteins
  • Mitochondrial Proteins
  • Proto-Oncogene Proteins c-myc
  • TNF-Related Apoptosis-Inducing Ligand
  • TNFSF10 protein, human
  • Tumor Necrosis Factor-alpha
  • CASP3 protein, human
  • Caspase 3
  • Caspases