The transfected cells or xenograft tumor tissue samples were rinsed with phosphate-buffered saline (PBS) and lysed in Pierce™ RIPA buffer (cat. no. 89900; Thermo Fisher Scientific, Inc.) with Halt™ phosphatase and protease inhibitor cocktail (cat. no. 1862495 and 1862209; Thermo Fisher Scientific, Inc.). The quantification of proteins in the cell lysate was performed using a BCA protein assay (cat. no. 23228; Thermo Fisher Scientific, Inc.). Equal amounts (20 µg/lane) of protein lysate were separated by electrophoresis on 8-12% polyacrylamide gels and transferred onto Immobilon®-P transfer membranes (cat. no. IPVH00010; MilliporeSigma). The blot membranes were incubated with 5% BSA solution at room temperature for 1 h and immunoblotted with specific antibodies (1:1,000 dilution) overnight at 4°C. Antibodies against ADAM12 (cat. no. ab28747), matrix metalloproteinase (MMP)2 (cat. no. ab37150) and MMP9 (cat. no. ab58803) were purchased from Abcam. Antibodies against E-cadherin (cat. no. #14472), Snail (cat. no. #3879), vimentin (cat. no. #5741), claudin-1 (cat. no. #4933), integrin α5 (cat. no. #4705), integrin β1 (cat. no. #9699), integrin β3 (cat. no. #13166), phosphorylated (p)-AKT (S473) (cat. no. #4060), p-phosphoinositide-dependent protein kinase 1 (PDK1) (S241) (cat. no. #3438), p-glycogen synthase kinase-3β (GSK-3β) (S9) (cat. no. #9323), total AKT (cat. no. #4691), total PDK1 (cat. no. #3062), total GSK-3β (cat. no. #9832) and Myc-tag (cat. no. #2278) were obtained from Cell Signaling Technology, Inc. Antibodies against β-tubulin (cat. no. sc-9104) and GAPDH (cat. no. sc-25778) were purchased from Santa Cruz Biotechnology, Inc. The blot membranes were washed four times with Tris-buffered saline-0.1% Tween-20 (TBS-T) and were then incubated with a horseradish peroxidase-conjugated secondary antibody (anti-rabbit, cat. no. #7074, anti-mouse, cat. no. #7076; Cell Signaling, Technology, Inc.) at 1:2,000 dilution for 1 h at room temperature. Amersham ECL Prime Western Blotting Detection Reagent (cat no. RPN2232SK; Cytiva) was used for blot development. Visualization of specific bands was obtained using the LAS-400 luminescent image analyzer (FUJIFILM Wako Pure Chemical Corporation). Semi-quantification of specific bands was performed using Multi-Gauge gel analysis software (version 3.0; FUJIFILM Wako Pure Chemical Corporation).