Roles of Fas signaling pathway in vitamin E succinate-induced apoptosis in human gastric cancer SGC-7901 cells.
OBJECTIVE
To investigate the roles of Fas signaling pathway in vitamin E succinate-induced apoptosis in human gastric cancer SGC-7901 cells.


METHODS
Human gastric cancer SGC-7901 cells were treated with VES at 5, 10, 20 mg x L(-1), succinic acid and vitamin E as vehicle control and condition media only as untreated (UT) control. Apoptotic morphology was observed by DAPI staining. Western blot analysis was applied to measure the expression of Fas, FADD and caspase-8 proteins. After the cells were transiently transfected with Fas and FADD antisense oligonucleotides, respectively, caspase-8 activity was determined by flurometric method.


RESULTS
The morphologically apoptotic changes were observed after VES treatment by DAPI staining. 23.7 % and 89.6 % apoptosis occurred after 24 h and 48 h of 20 mg x L(-1) VES treatment, respectively. The protein levels of Fas, FADD and caspase-8 were evidently increased in a dose-dependent manner after 24 h of VES treatment. The blockage of Fas by transfection with Fas antisense oligonucleotides obviously inhibited the expression of FADD protein. After SGC-7901 cells were transfected with Fas and FADD antisense oligonucleotides, caspase-8 activity was obviously decreased (P<0.01), whereas Fas blocked more than FADD.


CONCLUSIONS
VES-induced apoptosis in human gastric cancer SGC-7901 cells involves Fas signaling pathway including the interaction of Fas, FADD and caspase-8.
Wu
Kun
K
Department of Nutrition and Food Hygiene, Public Health School, Harbin Medical University, Heilongjiang Province, China. wukun@public.hr.hl.cn
Li
Yao
Y
Zhao
Yan
Y
Shan
Yu-Juan
YJ
Xia
Wei
W
Yu
Wei-Ping
WP
Zhao
Lan
L
D048868:Adaptor Proteins, Signal Transducing; D017209:Apoptosis / Q000187:drug effects*; D002352:Carrier Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases / Q000378:metabolism; D053200:Fas-Associated Death Domain Protein; D006801:Humans; D016376:Oligonucleotides, Antisense / Q000235:genetics; D015398:Signal Transduction; D013274:Stomach Neoplasms / Q000188:drug therapy* / Q000378:metabolism* / Q000473:pathology; D024505:Tocopherols; D014162:Transfection; D014407:Tumor Cells, Cultured; D014810:Vitamin E / Q000031:analogs & derivatives* / Q000494:pharmacology*; D019014:fas Receptor / Q000235:genetics / Q000378:metabolism*
D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; C505533:FADD protein, human; D053200:Fas-Associated Death Domain Protein; D016376:Oligonucleotides, Antisense; D019014:fas Receptor; D014810:Vitamin E; C505530:CASP8 protein, human; C506433:CASP9 protein, human; D053181:Caspase 8; D053453:Caspase 9; D020169:Caspases; D024505:Tocopherols