Trans-resveratrol, a grapevine-derived polyphenol, blocks hepatocyte growth factor-induced invasion of hepatocellular carcinoma cells

Abstract

We have shown that liver myofibroblasts stimulate in vitro invasion of hepatocellular carcinoma cell lines through a hepatocyte growth factor/urokinase-dependent mechanism. Resveratrol, a grapevine-derived polyphenol, has been shown to inhibit cellular events associated with tumor initiation, promotion and progression. The aim of this study was to evaluate the effects of trans-resveratrol on invasion of the human hepatoma cell line HepG2. Cell invasion was assessed using a Boyden chamber assay. Activation of the HGF signal transduction pathways was evaluated by Western blot with phospho-specific antibodies. Urokinase expression was measured by RT-PCR and zymography. Trans-resveratrol decreased hepatocyte growth factor-induced cell scattering and invasion. It also decreased cell proliferation without evidence for cytotoxicity or apoptosis. Trans-resveratrol did not decrease the level of the hepatocyte growth factor receptor c-met and did not impede the hepatocyte growth factor-induced increase in c-met precursor synthesis. Moreover, trans-resveratrol did not decrease hepatocyte growth factor-induced c-met autophosphorylation, or Akt-1 or extracellular-regulated kinases-1 and -2 activation. Finally, it did not decrease urokinase expression and did not block the catalytic activity of urokinase. In conclusion, our results demonstrate that trans-resveratrol decreases hepatocyte growth factor-induced HepG2 cell invasion by an as yet unidentified post-receptor mechanism.