Role of FAK in TNF-alpha/Cycloheximide-induced Apoptosis of SMMC-7721 Cells.
To explore the role of FAK in TNF-alpha/cycloheximide-induced apoptos is of human hepatocellular carcinoma cell line SMMC-7721, the FAK antisense plasmid was constructed and transfected into SMMC-7721 cells. Western blot assay was adopted to examine PKB level. Flow cytometry assay was used to detect apoptosis. It was shown that the SMMC-7721 cells were insensitive to TNF-alpha cytotoxicity, but they entered apoptosis quickly in the presence of cycloheximide and TNF-alpha. PKB was decreased during TNF-alpha/cycloheximide-induced apoptosis. No significant change of PKB level was found in the presence of TNF-alpha or cycloheximide, respectively, seeming that PKB level was closely correlated with apoptosis. When FAK was 60% reduced as a result of the transfection of SMMC-7721 cells with FAK antisense construct, the percentage of TNF-alpha/cycloheximide-induced apoptosis was enhanced at lower dose of TNF-alpha but decreased at higher dose of TNF-alpha, compared with the control. Correspondingly, the PKB level in FAK-down-regulated transfectants was lower at lower dose of TNF-alpha, but higher at higher dose of it. Therefore, FAK regulated TNF-alpha/cycloheximide-induced apoptosis in a biphase manner. This function might be related with PKB level.
Fang
Yi
Y
Key Laboratory of Glycoconjugate Research, Ministry of Health, Department of Biochemistry, School of Medicine, Fudan University, Shanghai 200032, China. xlzha@shmu.edu.cn
Jin
Jia-Wei
JW
Zha
Xi-Liang
XL