An inducible pathway for degradation of FLIP protein sensitizes tumor cells to TRAIL-induced apoptosis

被引:280
作者
Kim, Y
Suh, N
Sporn, M
Reed, JC
机构
[1] Burnham Inst, La Jolla, CA 92037 USA
[2] Dartmouth Coll, Sch Med, Dept Pharmacol, Hanover, NH 03755 USA
关键词
D O I
10.1074/jbc.M202458200
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
TRAIL (Apo2 ligand) is a member of the tumor necrosis factor (TNF) family of cytokines that induces apoptosis. Because TRAIL preferentially kills tumor cells, sparing normal tissues, interest has emerged in applying this biological factor for cancer therapy in humans. However, not all tumors respond to TRAIL, raising questions about resistance mechanisms. We demonstrate here that a variety of natural and synthetic ligands of peroxisome proliferator-activated receptor-gamma (PPARgamma) sensitize tumor but not normal cells to apoptosis induction by TRAIL. PPARgamma ligands selectively reduce levels of FLIP, an apoptosis-suppressing protein that blocks early events in TRAIL/TNF family death receptor signaling. Both PPARgamma agonists and antagonists displayed these effects, regardless of the levels of PPARgamma expression and even in the presence of a PPARgamma dominant-negative mutant, indicating a PPARgamma-independent mechanism. Reductions in FLIP and sensitization to TRAIL-induced apoptosis were also not correlated with TNF-kappaB, further suggesting a novel mechanism. PPARgamma modulators induced ubiquitination and proteasome-dependent degradation of FLIP, without concomitant reductions in FLIP mRNA. The findings suggest the existence of a pharmacologically regulated novel target of this class of drugs that controls FLIP protein turnover, and raise the possibility of combining PPARgamma modulators with TRAIL for more efficacious elimination of tumor cells through apoptosis.
引用
收藏
页码:22320 / 22329
页数:10
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共 54 条
  • [51] Surfing the p53 network
    Vogelstein, B
    Lane, D
    Levine, AJ
    [J]. NATURE, 2000, 408 (6810) : 307 - 310
  • [52] NF-κB antiapoptosis:: Induction of TRAF1 and TRAF2 and c-IAP1 and c-IAP2 to suppress caspase-8 activation
    Wang, CY
    Mayo, MW
    Korneluk, RG
    Goeddel, DV
    Baldwin, AS
    [J]. SCIENCE, 1998, 281 (5383) : 1680 - 1683
  • [53] A synthetic triterpenoid, 2-cyano-3,12-dioxooleana-1,9-dien-28-oic acid (CDDO), is a ligand for the peroxisome proliferator-activated receptor γ
    Wang, YP
    Porter, WW
    Suh, NJ
    Honda, T
    Gribble, GW
    Leesnitzer, LM
    Plunket, KD
    Mangelsdorf, DJ
    Blanchard, SG
    Willson, TM
    Sporn, MB
    [J]. MOLECULAR ENDOCRINOLOGY, 2000, 14 (10) : 1550 - 1556
  • [54] The PPARs: From orphan receptors to drug discovery
    Willson, TM
    Brown, PJ
    Sternbach, DD
    Henke, BR
    [J]. JOURNAL OF MEDICINAL CHEMISTRY, 2000, 43 (04) : 527 - 550