The antitumor effect of epigallocatechin-3-gallate on gastroenterological cancer.

335 Background: Green tea is one of the most popular beverages it contains many catechins such as epigallocatechin-3-gallate (EGCG) inhibits cancer growth. The aim of this study was to elucidate the anti-tumor effect and the effect for spheres of EGCG. Methods: Human hepatoma-derived cell line (HepG2) and human colorectal carcinoma cell line (HCT-116) were used. The anticancer effects of EGCG was studied by MTT assay. We made cancer sphere from HepG2 cells, and we added EGCG to cancer sphere. And we compared the gene expressions of RT-PCR between normal HepG2 and cancer sphere groups. Results: EGCG had the anti-tumor effect in dose-dependent. Furthermore, EGCG cancelled this spheroid formation, EGCG down-regulated the Nanog and CD133, related stemnesss genes. And then, EGCG down-regulated the ABCG1and Nek2, related ABC transporter genes, expression in sphere. Conclusions: EGCG had the anti-tumor effects on gastroenterological cancer, and EGCG had the effect to sphere, same as cancer stem cell thorough the down-regulation of ABC transporter related genes. Therefore, EGCG might be used as the safe and novel antitumor agents.