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TNF-related apoptosis-inducing ligand-induced apoptosis of melanoma is associated with changes in mitochondrial membrane potential and perinuclear clustering of mitochondria.
- Source :
-
Journal of immunology (Baltimore, Md. : 1950) [J Immunol] 2000 Nov 15; Vol. 165 (10), pp. 5612-20. - Publication Year :
- 2000
-
Abstract
- Past studies have shown that TNF-related apoptosis-inducing ligand (TRAIL) induced apoptosis in a high proportion of cultured melanoma by caspase-dependent mechanisms. In the present studies we have examined whether TRAIL-induced apoptosis of melanoma was mediated by direct activation of effector caspases or whether apoptosis was dependent on changes in mitochondrial membrane potential (MMP) and mitochondrial-dependent pathways of apoptosis. Changes in MMP were measured by fluorescent emission from rhodamine 123 in mitochondria. TRAIL, but not TNF-alpha or Fas ligand, was shown to induce marked changes in MMP in melanoma, which showed a high correlation with TRAIL-induced apoptosis. This was associated with activation of proapoptotic protein Bid and release of cytochrome c into the cytosol. Overexpression of B cell lymphoma gene 2 (Bcl-2) inhibited TRAIL-induced release of cytochrome c, changes in MMP, and apoptosis. The pan caspase inhibitor z-Val-Ala-Asp-fluoromethylketone (zVAD-fmk) and the inhibitor of caspase-8 (z-Ile-Glu-Thr-Asp-fluoromethylketone; zIETD-fmk) blocked changes in MMP and apoptosis, suggesting that the changes in MMP were dependent on activation of caspase-8. Activation of caspase-9 also appeared necessary for TRAIL-induced apoptosis of melanoma. In addition, TRAIL, but not TNF-alpha or Fas ligand, was shown to induce clustering of mitochondria around the nucleus. This process was not essential for apoptosis but appeared to increase the rate of apoptosis. Taken together, these results suggest that TRAIL induces apoptosis of melanoma cells by recruitment of mitochondrial pathways to apoptosis that are dependent on activation of caspase-8. Therefore, factors that regulate the mitochondrial pathway may be important determinants of TRAIL-induced apoptosis of melanoma.
- Subjects :
- Amino Acid Chloromethyl Ketones pharmacology
Apoptosis drug effects
Apoptosis Regulatory Proteins
BH3 Interacting Domain Death Agonist Protein
Carrier Proteins metabolism
Caspase 8
Caspase 9
Caspase Inhibitors
Caspases metabolism
Cytochrome c Group metabolism
Cytosol enzymology
Enzyme Activation drug effects
Enzyme Inhibitors pharmacology
Humans
Immunity, Innate
Intracellular Membranes drug effects
Intracellular Membranes metabolism
Ligands
Melanoma enzymology
Melanoma immunology
Membrane Glycoproteins antagonists & inhibitors
Membrane Potentials drug effects
Membrane Potentials immunology
Mitochondria drug effects
Mitochondria enzymology
Mitochondria metabolism
Proto-Oncogene Proteins c-bcl-2 biosynthesis
Proto-Oncogene Proteins c-bcl-2 genetics
TNF-Related Apoptosis-Inducing Ligand
Transfection
Tumor Cells, Cultured
Tumor Necrosis Factor-alpha antagonists & inhibitors
Apoptosis immunology
Cell Nucleus metabolism
Intracellular Membranes physiology
Melanoma metabolism
Melanoma pathology
Membrane Glycoproteins physiology
Mitochondria physiology
Tumor Necrosis Factor-alpha physiology
Subjects
Details
- Language :
- English
- ISSN :
- 0022-1767
- Volume :
- 165
- Issue :
- 10
- Database :
- MEDLINE
- Journal :
- Journal of immunology (Baltimore, Md. : 1950)
- Publication Type :
- Academic Journal
- Accession number :
- 11067917
- Full Text :
- https://doi.org/10.4049/jimmunol.165.10.5612