Black Tea Polyphenols Reverse Epithelial-to-Mesenchymal Transition and Suppress Cancer Invasion and Proteases in Human Oral Cancer Cells

Epithelial-to-mesenchymal transition (EMT) in. cancer cells is considered to be a prerequisite for acquiring invasive/migratory :phenotype and subsequent metastasis. This study provides molecular evidence associated with the antimetastatic effect of black tea polyphenol extracts (BTE), which contain polyphenols including,gallic.: acid, gallocatechin catechin, epigallocatechin-3-gallate, epicatechin-3-gallate, and theaflavin 3,3'-digallate, in an an oral. squamous cell culture system by showing a nearly complete inhibition on the invasion (p < 0.001). of SCC-4 cells via reduced activities of MMP-2 (p < 0.001) and u-PA (p < 0.001). Immunoblot was performed to find that BTE could induce up-regulation Of epithelial markers such as E,cadherin and inhibit mesenchymall markers such as snail-1 and vimentin. BTE inhibited p-FAK and p-paxillin, indicating the anti-EMT effect of BTE in oral squamous cell carcinoma: BTE was evidenced by its inhibition: of the tumor growth of SCC-4 cells via calker cell xenografted nude mice mode. These results suggested that BTE could reduce invasion by reversing EMT in human oral cancer cells.