Abstract
Catechins found in green tea, in particular (−)-epigallocatechin-3-gallate (EGCG), have antitumor activity. The primary antitumor actions of catechins are anti-oxidative, anti-angiogenic, and anti-metastatic effects. Cell migration and invasion contribute to the metastatic potential of tumors. Real-time cell analysis (RTCA) measures cell migration and invasion in vitro. In the present study, using RTCA, we investigated whether the cell migration and invasion of oral squamous cell carcinomas (OSCCs) of the tongue and floor of the mouth were inhibited by EGCG. Studies were performed using the human SCC-4 and SAS cell lines, which are poorly differentiated OSCCs of the tongue, and the HO-1-u-1 cell line, an OSCC of the floor of the mouth. SCC-4 cells exhibited high cell migration and invasion compared with the SAS and HO-1-u-1 cells. EGCG was most effective in inhibiting the migration and invasion of SCC-4 cells, and inhibited OSCC cell invasion more strongly than it inhibited cell migration. EGCG inhibited the expression of matrix metalloproteinase (MMP)-2, MMP-9, and integrin α1 and β1 mRNA in the OSCC cell lines, particularly SCC-4 cells. The findings of the present study suggest that EGCG inhibits OSCC cell migration and invasion by inhibiting MMP-2, MMP-9, and integrin α1 and β1 expression. Thus, EGCG may be a suitable agent or lead compound for the inhibition of OSCC metastasis.
