Role of FAK in
TNF-α/Cycloheximide-induced Apoptosis of SMMC-7721 Cells
FANG Yi, JIN Jia-Wei, ZHA Xi-Liang*
( Key Laboratory of Glycoconjugate Research, Ministry of Health, Department
of Biochemistry, School of Medicine, Fudan University, Shanghai 200032,
China )
Abstract To explore
the role of FAK in TNF-α/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-α
cytotoxicity,but they entered apoptosis quickly in the presence of
cycloheximide and TNF-α. PKB was decreased during TNF-α/cycloheximide-induced
apoptosis. No significant change of PKB level was found in the presence of
TNF-α 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-α/cycloheximide-induced apoptosis was enhanced at lower dose of TNF-α but
decreased at higher dose of TNF-α, compared with the control. Correspondingly,
the PKB level in FAK-down-regulated transfectants was lower at lower dose of
TNF-α, but higher at higher dose of it. Therefore,FAK regulated
TNF-α/cycloheximide induced apoptosis in a biphase manner. This function might
be related with PKB level.
Key words FAK；PKB；apoptosis；TNF-α；SMMC-7721 cells
*Corresponding author：Tel,86-21-64041900-2696；e-mail,[email protected]