Failure of Bcl-2 to block mitochondrial dysfunction during TRAIL-induced apoptosis. Tumor necrosis-related apoptosis-inducing ligand

Int J Oncol. 2001 Jan;18(1):187-94.


Tumor necrosis (TNF)-related apoptosis-inducing ligand (TRAIL) is a member of the TNF family of cytokines that promotes apoptosis. TRAIL induces apoptosis in a wide variety of tumor cells but not in normal cells. Oncogene Bcl-2 can protect cells from apoptosis induced by various stress stimuli. However, it is not clear whether Bcl-2 can regulate TRAIL-induced apoptosis. The objective of this study was to investigate whether Bcl-2 can regulate apoptosis induced by TRAIL. TRAIL initiates the activation of caspases, the loss of mitochondrial transmembrane potential (Delta psi(m)), and the redistribution of mitochondrial cytochrome c. TRAIL has no effect on Delta psi(m) and apoptosis in Jurkat cells deficient in either FADD or caspase-8, suggesting both FADD and caspase-8 are required for TRAIL signaling. Overexpression of Bcl-2 delays, but does not inhibit, TRAIL-induced Delta psi(m), cytochrome c release from mitochondria and apoptosis, whereas etoposide-induced apoptosis is blocked by Bcl-2. XIAP, cowpox virus CrmA and baculovirus p35 inhibits TRAIL-induced apoptosis. These data suggest that TRAIL can be used to kill Bcl-2 positive cells that can not be killed by other class of chemotherapeutic drugs.

MeSH terms

  • Apoptosis / physiology*
  • Apoptosis Regulatory Proteins
  • Caspase 3
  • Caspase Inhibitors
  • Caspases / metabolism
  • Cytochrome c Group / metabolism
  • Drug Interactions
  • Enzyme Activation
  • Enzyme Inhibitors / pharmacology
  • Humans
  • Inhibitor of Apoptosis Proteins
  • Membrane Glycoproteins / genetics
  • Membrane Glycoproteins / pharmacology*
  • Membrane Potentials
  • Mitochondria / physiology*
  • Proteins / pharmacology
  • Proto-Oncogene Proteins c-bcl-2 / physiology*
  • Recombinant Proteins / pharmacology
  • Serpins / pharmacology
  • TNF-Related Apoptosis-Inducing Ligand
  • Tumor Cells, Cultured
  • Tumor Necrosis Factor-alpha / genetics
  • Tumor Necrosis Factor-alpha / pharmacology*
  • U937 Cells
  • Viral Proteins / pharmacology
  • X-Linked Inhibitor of Apoptosis Protein


  • Apoptosis Regulatory Proteins
  • Caspase Inhibitors
  • Cytochrome c Group
  • Enzyme Inhibitors
  • Inhibitor of Apoptosis Proteins
  • Membrane Glycoproteins
  • Proteins
  • Proto-Oncogene Proteins c-bcl-2
  • Recombinant Proteins
  • Serpins
  • TNF-Related Apoptosis-Inducing Ligand
  • TNFSF10 protein, human
  • Tumor Necrosis Factor-alpha
  • Viral Proteins
  • X-Linked Inhibitor of Apoptosis Protein
  • XIAP protein, human
  • inhibitor of apoptosis, Nucleopolyhedrovirus
  • interleukin-1beta-converting enzyme inhibitor
  • CASP3 protein, human
  • Caspase 3
  • Caspases