Inhibitory effect of EGCG on proliferation and HIF-1α/VEGF expression in cell line HepG2

AIM:To study the molecular mechanism of EGCG on inhibiting the growth of hepatic carcinoma. METHODS: The proliferation of hepatic cell line HepG2 cultured with different doses of EGCG was studied by MTT and suspension/adherence methods. The effect of EGCG on the expression of HIF-1α/VEGF at mRNA and protein levels in vitro and in vivo was evaluated by RT-PCR and Western blotting,respectively. The inhibition of EGCG on the growth of tumor implanted into athymic nude mice was also observed. RESULTS: The proliferation of hepatic cell line HepG2 was inhibited by EGCG in a dose-dependent manner. The expression of HIF-1α/VEGF was suppressed markedly by EGCG at protein level. However,the inhibitory effect of EGCG on the mRNA expression was only observed on VEGF,not on HIF-1α. In the animal experiment,the implanted tumor growth was inhibited by 39.8%±5.1%. CONCLUSION: EGCG suppresses the hepatic carcinoma cell growth,and interrupts the HIF-1α/VEGF signaling pathway significantly,indicating a fundamental mechanism of EGCG for inhibiting tumor growth.