Kurarinone promotes TRAIL-induced apoptosis by inhibiting NF-kappaB-dependent cFLIP expression in HeLa cells
Experimental & Molecular Medicine
;
: 653-664, 2012.
Article
in English
| WPRIM
| ID: wpr-149763
ABSTRACT
This study was designed to investigate the effects of the prenylated flavonoid kurarinone on TNF-related apoptosis inducing ligand (TRAIL)-induced apoptosis and its underlying mechanism. A low dose of kurarinone had no significant effect on apoptosis, but this compound markedly promoted tumor cell death through elevation of Bid cleavage, cytochrome c release and caspase activation in HeLa cells treated with TRAIL. Caspase inhibitors inhibited kurarinone-mediated cell death, which indicates that the cytotoxic effect of this compound is mediated by caspase-dependent apoptosis. The cytotoxic effect of kurarinone was not associated with expression levels of Bcl-2 and IAP family proteins, such as Bcl-2, Bcl-xL, Bid, Bad, Bax, XIAP, cIAP-1 and cIAP-2. In addition, this compound did not regulate the death-inducing receptors DR4 and DR5. On the other hand, kurarinone significantly inhibited TRAIL-induced IKK activation, IkappaB degradation and nuclear translocation of NF-kappaB, as well as effectively suppressed cellular FLICE-inhibitory protein long form (cFLIPL) expression. The synergistic effects of kurarinone on TRAIL-induced apoptosis were mimicked when kurarinone was replaced by the NF-kappaB inhibitor withaferin A or following siRNA-mediated knockdown of cFLIPL. Moreover, cFLIP overexpression effectively antagonized kurarinone-mediated TRAIL sensitization. These data suggest that kurarinone sensitizes TRAIL-induced tumor cell apoptosis via suppression of NF-kappaB-dependent cFLIP expression, indicating that this compound can be used as an anti-tumor agent in combination with TRAIL.
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Flavonoids
/
HeLa Cells
/
Signal Transduction
/
Gene Expression
/
Up-Regulation
/
NF-kappa B
/
Apoptosis
/
Protein Transport
/
RNA, Small Interfering
/
Drug Synergism
Limits:
Humans
Language:
English
Journal:
Experimental & Molecular Medicine
Year:
2012
Type:
Article
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