Genistein suppresses adhesion-induced protein tyrosine phosphorylation and invasion of B16-BL6 melanoma cells

Protein tyrosine phosphorylation occurs as one of the earlier events in cancer cell–extracellular matrix (ECM) interaction. With immunoblot analysis and immunofluorescence microscopy, genistein was found to suppress the tyrosine phosphorylation of proteins located at the cell periphery, including a 125 kDa protein, when B16-BL6 melanoma cells attached to and interacted with ECM. When accompanied by the suppression of adhesion-induced protein tyrosine phosphorylation, the invasive potential of B16-BL6 cells through reconstituted basement membrane was decreased significantly. However, neither adhesive capability nor cell growth was significantly affected by genistein. Therefore, the interruption of cancer cell–ECM interaction by suppression of protein tyrosine phosphorylation may contribute to invasion prevention of genistein.