Reconstitution of caspase-8 sensitizes JB6 cells to TRAIL.
TRAIL induces apoptosis in various tumor cells. We report here that caspase-8 is required in TRAIL-induced cell death. Western blot analyses and enzyme assays showed that exposing Jurkat cells to TRAIL resulted in activation of caspases-8 followed by caspase-3 and -9. Acetyl-IETD-fluoromethylketone, a caspase-8 inhibitor, potently suppressed TRAIL-induced cell death compared to acetyl-DEVD-fluoromethylketone and acetyl-LEHD-fluoromethylketone, inhibitors of caspase-3 and caspase-9, respectively. JB6 cells, a caspase-8-deficient Jurkat variant, were completely resistant to TRAIL. However, reconstitution with a caspase-8, but not with caspase-2 or -3, sensitized JB6 cells to subsequent exposure to TRAIL. These results are indicative of the crucial function of caspase-8 in TRAIL-induced apoptosis in Jurkat cells.
Kim
I K
IK
Department of Life Science, Kwangju Institute of Science and Technology, 1 Oryong Puk-Gu, Kwangju, 500-712, Korea.
Chung
C W
CW
Woo
H N
HN
Hong
G S
GS
Nagata
S
S
Jung
Y K
YK
D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins; D015153:Blotting, Western; D053148:Caspase 3; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D005799:Genes, Dominant; D006801:Humans; D019169:Jurkat Cells; D008562:Membrane Glycoproteins / Q000378:metabolism*; D009154:Mutation; D009842:Oligopeptides / Q000494:pharmacology; D010455:Peptides / Q000494:pharmacology; D010957:Plasmids / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D053221:TNF-Related Apoptosis-Inducing Ligand; D013997:Time Factors; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
D051017:Apoptosis Regulatory Proteins; D015853:Cysteine Proteinase Inhibitors; D008562:Membrane Glycoproteins; D009842:Oligopeptides; D010455:Peptides; D011993:Recombinant Fusion Proteins; D053221:TNF-Related Apoptosis-Inducing Ligand; C505653:TNFSF10 protein, human; D014409:Tumor Necrosis Factor-alpha; C110772:benzoylcarbonyl-aspartyl-glutamyl-valyl-aspartyl-fluoromethyl ketone; C403753:benzyloxycarbonyl-isoleucyl-glutamyl-threonyl-aspartic acid fluoromethyl ketone; C403754:benzyloxycarbonyl-leucyl-glutamyl-histidyl-aspartic acid fluoromethyl ketone; C505407:CASP3 protein, human; C505530:CASP8 protein, human; C506433:CASP9 protein, human; D053148:Caspase 3; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases