(-)-Epigallocatechin-3-gallate (EGCG) post-transcriptionally and post-translationally suppresses the cell proliferative protein TROP2 in human colorectal cancer cells.

Abstract

TROP-2 is a tumor-promoting molecule that has been found to be overexpressed in many cancer cells, making it a plausible biomarker of carcinogenesis. The main aim of this study was to examine the effect of green tea catechins (namely, (-)-epigallocatechin-3-gallate; EGCG) on TROP-2 expression. Western blot and RT-PCR were applied to assess TROP2 expression in colorectal cancer cells and tissues. Two different mechanisms were found to operate in diverse cell lines. In SW480 cells, EGCG affected the post-transcriptional processing of the TROP-2 mRNA, as this was quickly and specifically degraded in the presence of EGCG. In HCT-116 cells, EGCG affected TROP-2 expression at the post-translational level. TROP-2 was found to be highly expressed in colorectal tumors compared to adjacent normal tissues. This study provided a novel beneficial activity of green tea as an anti-tumorigenagent causing the suppression of TROP-2 in colorectal cancer.