Curcumin induces FasL-related apoptosis through p38 activation in human hepatocellular carcinoma Huh7 cells.
OBJECTIVE
The aim of this study is to explore the underlying molecular mechanism of curcumin-induced apoptosis in human hepatocellular carcinoma (HCC) Huh7 cells.


METHODS
Fas and FasL mRNA expression was analyzed by reverse transcription PCR. Western blot was applied to detect the protein expression of Bcl-2 family members, MAPK family members, c-Jun, c-Fos, ATF-2, caspase-3, PARP, TNF receptor family members and the respective ligands. Apoptotic cells were assayed with annexin V/PI double staining and flow cytometry.


RESULTS
Curcumin treatment resulted in a fast and significant increase of Fas and Fas ligand (FasL) along with activation of caspase-3 and cleavage of PARP in Huh7 cells. Inhibition of caspase-3 activity by the specific inhibitor Z-DEVD-FMK rescued Huh7 cells from curcumin-induced apoptosis. Neutralization of FasL significantly protected the cells from curcumin-induced caspase-3 activation and apoptosis in a dose-dependent manner. Moreover, p38 was rapidly activated in response to curcumin, and inactivation of p38 by pharmacologic inhibitor SB203580 dramatically suppressed curcumin-induced FasL expression and apoptosis.


CONCLUSIONS
Our results demonstrated that curcumin induces apoptosis through p38-denpendent up-regulation of FasL in Huh7 cells.
Guangdong Province Key Laboratory of Pharmaceutical Bioactive Substances, Guangdong Pharmaceutical University, Guangzhou, PR China. wwzss@163.com
Wei-Zhang
WZ
Wang
Li
L
Li
Man-Yu
MY
Liu
Xiao-Bao
XB
Jin
Jian-Wen
JW
Mao
Qiao-Hong
QH
Pu
Min-Jie
MJ
Meng
Xiao-Guang
XG
Chen
Jia-Yong
JY
Zhu
D017209:Apoptosis / Q000187:drug effects*; D006528:Carcinoma, Hepatocellular / Q000473:pathology; D053148:Caspase 3 / Q000096:biosynthesis; D061945:Caspase Inhibitors / Q000494:pharmacology; D045744:Cell Line, Tumor; D003474:Curcumin / Q000494:pharmacology*; D053222:Fas Ligand Protein / Q000096:biosynthesis*; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D009842:Oligopeptides / Q000494:pharmacology; D010766:Phosphorylation / Q000187:drug effects; D011725:Pyridines / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects; D015854:Up-Regulation / Q000187:drug effects; D019014:fas Receptor / Q000096:biosynthesis*; D048051:p38 Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*
D061945:Caspase Inhibitors; C491901:FAS protein, human; C505661:FASLG protein, human; D053222:Fas Ligand Protein; D007093:Imidazoles; D009842:Oligopeptides; D011725:Pyridines; C110772:benzoylcarbonyl-aspartyl-glutamyl-valyl-aspartyl-fluoromethyl ketone; D019014:fas Receptor; D048051:p38 Mitogen-Activated Protein Kinases; D053148:Caspase 3; D003474:Curcumin; C093642:SB 203580