Tumor cell invasion is vital for cancer progression and metastasis. Adhesion, 
migration, and degradation of the extracellular matrix are important events 
involved in the establishment of cancer cells at a new site, and therefore 
molecular targets are sought to inhibit such processes. The effect of a plant 
proteinase inhibitor, Enterolobium contortisiliquum trypsin inhibitor (EcTI), on 
the adhesion, migration, and invasion of gastric cancer cells was the focus of 
this study. EcTI showed no effect on the proliferation of gastric cancer cells 
or fibroblasts but inhibited the adhesion, migration, and cell invasion of 
gastric cancer cells; however, EcTI had no effect upon the adhesion of 
fibroblasts. EcTI was shown to decrease the expression and disrupt the cellular 
organization of molecules involved in the formation and maturation of 
invadopodia, such as integrin β1, cortactin, neuronal Wiskott-Aldrich syndrome 
protein, membrane type 1 metalloprotease, and metalloproteinase-2. Moreover, 
gastric cancer cells treated with EcTI presented a significant decrease in 
intracellular phosphorylated Src and focal adhesion kinase, integrin-dependent 
cell signaling components. Together, these results indicate that EcTI inhibits 
the invasion of gastric cancer cells through alterations in integrin-dependent 
cell signaling pathways.