To investigate the synergistic effects of combining erlotinib and RNA-interference downregulation of focal adhesion kinase (FAK) expression on the proliferation, apoptosis, invasion and migration of the human gastric adenocarcinoma cell line AGS.

Cells were divided into five experimental groups: Group A, nontransfected control; Group B, transfected with empty vector; Group C, transfected with FAK-shRNA; Group D, erlotinib treatment; Group E, combination erlotinib treatment and transfected with FAK-shRNA. FAK protein levels were confirmed via Western blotting. Cell proliferation (CCK-8 assay, apoptosis (flow cytometry), cell invasion (transwell assay) and migration (scratch assay) were evaluated.

RNA interference significantly decreased FAK protein levels. Cell proliferation, invasion and migration were significantly lower in Groups C, D and E compared with Group A, and significantly lower in Group E than in Groups C and D.

RNA interference effectively silences FAK expression and inhibits malignant cell proliferation and invasion in gastric cancer cells. The effect of FAK inhibition is increased by co-treatment with erlotinib.