Abstract
Purpose and experimental design:
The purpose of this study was to examine the effect of combined treatment with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and cisplatin in human head and neck squamous cell carcinoma. HNSCC-6 cells were treated with 0.1-1 micro g/ml TRAIL and/or 1-10 micro g/ml cisplatin for 24 h.
Results:
TRAIL alone or cisplatin alone caused minimal cytotoxicity. The combination of TRAIL and cisplatin synergistically enhanced apoptotic death, caspase-8 and caspase-3 activation, as well as poly(ADP-ribose) polymerase cleavage. However, the total cellular levels and the surface expression of TRAIL receptor proteins, such as death receptors 4 and 5 and decoy receptors 2 and 1, were not significantly changed by treatment with TRAIL and cisplatin. Interestingly, the level of the short form of Fas-associated death domain-like interleukin-1beta-converting enzyme-inhibitory protein (FLIP(S)) but not the long form of Fas-associated death domain-like interleukin-1beta-converting enzyme-inhibitory protein was reduced through cleavage. Benzyloxycarbonyl-Asp-Glu-Val-Asp-fluoromethylketone a caspase-3 inhibitor, blocked the cleavage of FLIP(S) and caspase-3 activation. Overexpression of FLIP(S) protected cells from apoptotic death and FLIP(S) cleavage during treatment with TRAIL in combination with cisplatin.
Conclusions:
These results suggest that caspase-3 is responsible for FLIP(S) cleavage, and the cleavage of FLIP(S) is one of facilitating factors for TRAIL-induced apoptotic death.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Adenoviridae / genetics
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Apoptosis
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Apoptosis Regulatory Proteins
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CASP8 and FADD-Like Apoptosis Regulating Protein
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Carcinoma, Squamous Cell / drug therapy*
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Carcinoma, Squamous Cell / metabolism
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Carrier Proteins / metabolism
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Caspase 3
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Caspase 8
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Caspases / metabolism
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Cell Line, Tumor
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Cisplatin / therapeutic use*
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Dose-Response Relationship, Drug
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Electrophoresis, Polyacrylamide Gel
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Enzyme Inhibitors / pharmacology
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Flow Cytometry
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GPI-Linked Proteins
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Genetic Vectors
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Head and Neck Neoplasms / drug therapy*
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Head and Neck Neoplasms / metabolism
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Humans
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Immunoblotting
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Intracellular Signaling Peptides and Proteins*
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Membrane Glycoproteins / therapeutic use*
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Membrane Proteins / metabolism
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Poly(ADP-ribose) Polymerases / metabolism
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RNA, Messenger / metabolism
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Receptors, TNF-Related Apoptosis-Inducing Ligand
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Receptors, Tumor Necrosis Factor / metabolism
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Receptors, Tumor Necrosis Factor, Member 10c
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Recombinant Proteins / metabolism
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Recombinant Proteins / therapeutic use
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TNF-Related Apoptosis-Inducing Ligand
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Time Factors
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Tumor Cells, Cultured
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Tumor Necrosis Factor Decoy Receptors
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Tumor Necrosis Factor-alpha / therapeutic use*
Substances
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Apoptosis Regulatory Proteins
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CASP8 and FADD-Like Apoptosis Regulating Protein
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CFLAR protein, human
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Carrier Proteins
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Enzyme Inhibitors
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GPI-Linked Proteins
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Intracellular Signaling Peptides and Proteins
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Membrane Glycoproteins
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Membrane Proteins
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RNA, Messenger
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Receptors, TNF-Related Apoptosis-Inducing Ligand
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Receptors, Tumor Necrosis Factor
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Receptors, Tumor Necrosis Factor, Member 10c
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Recombinant Proteins
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TNF-Related Apoptosis-Inducing Ligand
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TNFRSF10A protein, human
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TNFRSF10B protein, human
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TNFRSF10C protein, human
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TNFRSF10D protein, human
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TNFSF10 protein, human
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Tumor Necrosis Factor Decoy Receptors
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Tumor Necrosis Factor-alpha
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Poly(ADP-ribose) Polymerases
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CASP3 protein, human
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CASP8 protein, human
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Caspase 3
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Caspase 8
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Caspases
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Cisplatin