摘要
BACKGROUND:The death ligand,tumor necrosis factor(TNF)related apoptosis-inducing ligand(TRAIL),induces apoptosis and non-apoptotic signaling in some tumor cells.The purpose of this study was to investigate the roles of the pro-apoptotic TRAIL receptors,TRAIL-R1 and TRAIL-R2,as well as Bcl-xL and TRAF2 in TRAIL-induced expression of the pro-inflammatory cytokine IL-8 and the invasion-promoting protein urokinase(uPA) in pancreatic ductal adenocarcinoma(PDAC) cells.METHODS:Colo357wt,Colo357/TRAF2,Colo357/Bcl-xL,Panc89 and PancTuI cells were stimulated with TRAIL and uPA and IL-8 expression was detected using real-time PCR.Antagonistic,receptor-specific antibodies were used to investigate the effects of TRAIL-R1 or TRAIL-R2 inhibition.RESULTS:Dose-dependent increases in uPA and IL-8 expression were detected following TRAIL stimulation in PDAC cells.These effects were inhibited when TRAIL-R1 but not TRAIL-R2 was blocked.Overexpression of TRAF2 or Bcl-xL strongly increased TRAIL-mediated upregulation of uPA and IL-8.CONCLUSIONS:In PDAC cells,TRAIL strongly induced uPA and IL-8 via TRAIL-R1.This response was further enhanced in cells overexpressing TRAF2 and Bcl-xL.Therefore,inhibition of the non-apoptotic "side-effects" of TRAIL treatments by inactivation of TRAF2 and Bcl-xL might represent additional relevant strategies for the treatment of pancreatic cancer.
BACKGROUND:The death ligand,tumor necrosis factor(TNF)related apoptosis-inducing ligand(TRAIL),induces apoptosis and non-apoptotic signaling in some tumor cells.The purpose of this study was to investigate the roles of the pro-apoptotic TRAIL receptors,TRAIL-R1 and TRAIL-R2,as well as Bcl-xL and TRAF2 in TRAIL-induced expression of the pro-inflammatory cytokine IL-8 and the invasion-promoting protein urokinase(uPA) in pancreatic ductal adenocarcinoma(PDAC) cells.METHODS:Colo357wt,Colo357/TRAF2,Colo357/Bcl-xL,Panc89 and PancTuI cells were stimulated with TRAIL and uPA and IL-8 expression was detected using real-time PCR.Antagonistic,receptor-specific antibodies were used to investigate the effects of TRAIL-R1 or TRAIL-R2 inhibition.RESULTS:Dose-dependent increases in uPA and IL-8 expression were detected following TRAIL stimulation in PDAC cells.These effects were inhibited when TRAIL-R1 but not TRAIL-R2 was blocked.Overexpression of TRAF2 or Bcl-xL strongly increased TRAIL-mediated upregulation of uPA and IL-8.CONCLUSIONS:In PDAC cells,TRAIL strongly induced uPA and IL-8 via TRAIL-R1.This response was further enhanced in cells overexpressing TRAF2 and Bcl-xL.Therefore,inhibition of the non-apoptotic "side-effects" of TRAIL treatments by inactivation of TRAF2 and Bcl-xL might represent additional relevant strategies for the treatment of pancreatic cancer.
基金
supported by the grants from the Science and Technology Department of Zhejiang Province (2006C33062)
the Scientific Research Foundation for Returned Overseas Chinese Scholars,Personnel Affairs Bureau of Zhejiang Province(491010-G50557)
