Antitumor Effects of Epigallocatechin-3-Gallate on Colorectal Cancer: An In Vitro and In Vivo Study

Background/Aim: Tea consumption is widely reported to have beneficial effects on cancer prevention. Epigallocatechin-3-gallate (EGCG), a major bioactive component of green tea, has demonstrated anti-proliferative effects against various cancer cell types. This study aimed to evaluate the antitumor effects of EGCG on human colon and colorectal cancer cells both in vitro and in vivo and to identify microRNAs (miRNAs) associated with its antitumor activity.

Materials and Methods: We investigated the ability of EGCG to inhibit cell proliferation by apoptosis and analyzed its effects on cell cycle-related molecules in multiple human colon cancer cell lines. Additionally, EGCG-induced alterations in activated receptor tyrosine kinases and angiogenesis-related proteins were assessed using protein arrays. miRNA array analysis was performed to identify EGCG-regulated miRNAs. An in vivo mouse xenograft model was used to assess the tumor-suppressive potential of EGCG.

Results: EGCG induced apoptosis and significantly suppressed the proliferation of colon cancer cells, both in vitro and in vivo. In the miRNA array analysis, EGCG-treated CW-2 cells exhibited up-regulation of seven miRNAs and down-regulation of eight miRNAs. Notably, the down-regulation of hsa-miR-187-5p was most significant.

Conclusion: EGCG suppresses the proliferation of human colon cancer cells through induction of apoptosis. Down-regulation of hsa-miR-187-5p may be a potential marker for the effect of EGCG in regulating colorectal cancer. These findings suggest that EGCG may serve as a promising therapeutic agent or adjunct in the treatment of colorectal cancer.