Effect of STAT3 silencing on metastatic potential of gastric cancer cells. SNU-638 cells (A-C) and MKN1 cells (D and E) were transiently transfected with control siRNA (siCtrl) or STAT3 siRNA (siSTAT3). (A and D) Cell migration capacity was evaluated by wound-healing assay 48 h after scratching. (B and E) Cell invasion ability was measured 48 h after cell plating. Results were calculated as percentages relative to control siRNA-transfected cells. * P < 0.05 versus control cells (n = 4). (C) The protein expressions of E-cadherin, Snail, MMP9 and β-actin in SNU-638 cells were determined by immunoblotting after STAT3 silencing.