Anticancer activities of epigallocatechin-3-gallate against cholangiocarcinoma cells

PURPOSE: Epigallocatechin-3-gallate (EGCG) is an antioxidant agent derived from green tea. Because it has chemopreventive and anti-invasive effect against various cancer cells, EGCG can be used to inhibit proliferation and invasion of cholangiocarcinoma (CCA) cells. METHODS: The anticancer effects of EGCG were studied using human CCA cells (HuCC-T1). Apoptosis was analyzed by Western blotting. Invasion and migration of cancer cells were assessed with Matrigel(®) and wound healing assays. An animal tumor xenograft model of HuCC-T1 was used to study the in vivo antitumor activities of EGCG. RESULTS: EGCG effectively inhibited the growth of HuCC-T1 cells with no adverse effects on the viability of 293T cells. EGCG induced apoptotic cell death at 5 µg/mL concentration. It inhibited the expression of mutant p53 and induced apoptotic molecular signals such as Bax/Bcl-2, Caspase, and cytochrome C. Furthermore, EGCG dose-dependently inhibited the activity of matrix metalloproteinase (MMP)-2/9, invasion, and migration. In the animal tumor xenograft model of HuCC-T1 cells, EGCG was subcutaneously administered beside the tumor for local treatment. EGCG efficiently inhibited growth of the tumor and suppressed carcinogenic molecular signals such as Notch1, MMP-2/9, and proliferating cell nuclear antigen. CONCLUSION: EGCG induced apoptosis of cancer cells without adverse effects on normal cells. EGCG inhibited growth, invasion, and migration of HuCC-T1 cells. We suggest EGCG as a promising candidate for local treatment of CCA.