TY - JOUR
T1 - Glycogen synthase kinase-3 inhibitors augment TRAIL-induced apoptotic death in human hepatoma cells
AU - Beurel, Eléonore
AU - Blivet-Van Eggelpoël, Marie José
AU - Kornprobst, Michel
AU - Moritz, Sylviane
AU - Delelo, Roland
AU - Paye, François
AU - Housset, Chantal
AU - Desbois-Mouthon, Christèle
PY - 2009/1/1
Y1 - 2009/1/1
N2 - Hepatocellular carcinoma (HCC) displays a striking resistance to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). Therefore, the characterization of pharmacological agents that overcome this resistance may provide new therapeutic modalities for HCC. Here, we examined whether glycogen synthase kinase-3 (GSK-3) inhibitors could restore TRAIL sensitivity in hepatoma cells. To this aim, the effects of two GSK-3 inhibitors, lithium and SB-415286, were analyzed on TRAIL apoptotic signaling in human hepatoma cell lines in comparison with normal hepatocytes. We observed that both inhibitors sensitized hepatoma cells, but not normal hepatocytes, to TRAIL-induced apoptosis by enhancing caspase-8 activity and the downstream recruitment of the mitochondrial machinery. GSK-3 inhibitors also stabilized p53 and the down-regulation of p53 by RNA interference abolished the sensitizing effect of lithium on caspase-3 activation. Concomitantly, GSK-3 inhibitors strongly activated c-Jun N-terminal kinases (JNKs). The pharmacological inhibition of JNKs with AS601245 or SP600125 resulted in an earlier and stronger induction of apoptosis indicating that activated JNKs transduced protective signals and provided an anti-apoptotic balance to the pro-apoptotic effects of GSK-3 inhibitors. These findings demonstrate that GSK-3 exerts a negative and complex constraint on TRAIL apoptotic signaling in hepatoma cells, which can be greatly alleviated by GSK-3 inhibitors. Therefore, GSK-3 inhibitors may open new perspectives to enhance the anti-tumor activity of TRAIL in HCC.
AB - Hepatocellular carcinoma (HCC) displays a striking resistance to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). Therefore, the characterization of pharmacological agents that overcome this resistance may provide new therapeutic modalities for HCC. Here, we examined whether glycogen synthase kinase-3 (GSK-3) inhibitors could restore TRAIL sensitivity in hepatoma cells. To this aim, the effects of two GSK-3 inhibitors, lithium and SB-415286, were analyzed on TRAIL apoptotic signaling in human hepatoma cell lines in comparison with normal hepatocytes. We observed that both inhibitors sensitized hepatoma cells, but not normal hepatocytes, to TRAIL-induced apoptosis by enhancing caspase-8 activity and the downstream recruitment of the mitochondrial machinery. GSK-3 inhibitors also stabilized p53 and the down-regulation of p53 by RNA interference abolished the sensitizing effect of lithium on caspase-3 activation. Concomitantly, GSK-3 inhibitors strongly activated c-Jun N-terminal kinases (JNKs). The pharmacological inhibition of JNKs with AS601245 or SP600125 resulted in an earlier and stronger induction of apoptosis indicating that activated JNKs transduced protective signals and provided an anti-apoptotic balance to the pro-apoptotic effects of GSK-3 inhibitors. These findings demonstrate that GSK-3 exerts a negative and complex constraint on TRAIL apoptotic signaling in hepatoma cells, which can be greatly alleviated by GSK-3 inhibitors. Therefore, GSK-3 inhibitors may open new perspectives to enhance the anti-tumor activity of TRAIL in HCC.
KW - Apoptosis
KW - c-Jun N-terminal kinase
KW - CD95
KW - Hepatocellular carcinoma
KW - Lithium
KW - SB-415286
UR - http://www.scopus.com/inward/record.url?scp=57049124808&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=57049124808&partnerID=8YFLogxK
U2 - 10.1016/j.bcp.2008.09.026
DO - 10.1016/j.bcp.2008.09.026
M3 - Article
C2 - 18938143
AN - SCOPUS:57049124808
VL - 77
SP - 54
EP - 65
JO - Biochemical Pharmacology
JF - Biochemical Pharmacology
SN - 0006-2952
IS - 1
ER -