[Role of focal adhesion kinase in the hypoxia-induced invasion of SMMC-7721 cells].

ABSTRACT

OBJECTIVE: To study focal adhesion kinase (FAK) expression in hypoxia-stressed SMMC-7721 cells and the role of FAK expression in the hypoxia-induced invasion of SMMC-7721 cells. METHODS: SMMC-7721 cells were cultured in 21% O2 or 1% O2. FAK expression was determined by Western blot. The siRNA expression vector pshRNA-FAK targeting to FAK and the control vector pGensil-2 were transfected into SMMC-7721 cells. The hypoxia-induced migration and invasion ability of SMMC-7721 cells transfected with pshRNA-FAK were analyzed. In normoxia, invasion of SMMC-7721 cells transfected with pcDNA3-FAK was analyzed. RESULTS: The expression of FAK was increased significantly in SMMC-7721 cells 24 h after hypoxia stress (P<0.01). The level of FAK protein was decreased by 74.6%+/-5.1% after the pshRNA-FAK transfection in normoxia and hypoxia. The migration and invasion of SMMC-7721 cells was increased in 1% O2 (P<0.01). However, the migration and invasion of SMMC-7721 cells transfected with pshRNA-FAK was decreased in 1% O2 (P<0.05). Overexpression of FAK significantly stimulated the invasion of SMMC-7721 cells. CONCLUSION: Up-regulation of FAK may play an important role in the invasion of SMMC-7721 cells induced by hypoxia.