Epigallocatechin-3-gallate inhibits the invasion of human oral cancer cells and decreases the productions of matrix metalloproteinases and urokinase-plasminogen activator

Background: Green tea polyphenols are considered beneficial to human health, especially as cancer chemopreventive agents in recent years. Epigallocatechin- 3-gallate (EGCG), the most abundant polyphenol in green tea, has been proven to suppress colonic tumorigenesis in animal and epidemiological studies, whereas its role in the oral carcinogenesis remains to be elucidated. Methods: Cytotoxicity, invasion, and migration assays were used to investigate the effects of human oral cancer cell line OC2 cells exposed to EGCG. To look at the precise involvement of EGCG in cancer metastasis, gelatin zymography and casein zymography were performed to evaluate the impacts of EGCG on matrix metalloproteinase (MMP)-2, MMP-9, and urokinase plasminogen activator (uPA) secretion in OC2 cells. Results: EGCG exhibited a dose-dependent inhibitory effect on the invasion and migration of OC2 cells in the absence of cytotoxicity (P < 0.05). EGCG was also found to decrease the expressions of MMP-2, MMP-9, and uPA in a concentration-dependent manner (P < 0.05). Conclusion: Taken together, these results suggest that EGCG could inhibit the invasion and migration of human oral cancer cells and that the effects may partially because of the decreased productions of MMP-2, MMP-9, and uPA.