Suppressing effects of green tea extract and Epigallocatechin-3-gallate (EGCG) on TGF-β- induced Epithelial-to-mesenchymal transition via ROS/Smad signaling in human cervical cancer cells

Transforming growth factor-β (TGF-β)-induced Epithelial-to-mesenchymal transition (EMT) process is a fundamental target for preventing cervical cancer cells' progression and invasion. Green tea and its principal active substance, Epigallocatechin-3-gallate (EGCG), demonstrate anti-tumor activities in various tumor cells. The cell viability of two cervical cancer cell lines, Hela and SiHa, in the experimental groups was examined employing the MTT method, and ROS generation was probed applying 2′,7′-dichlorofluorescein diacetate-based assay. The Smad signaling and EMT process was evaluated utilizing western blot analysis and quantitative real-time polymerase chain reaction (qRT-PCR). Chromatin immunoprecipitation (ChIP) and Smad binding element (SBE)-luciferase assays were employed to measure Smad-DNA interaction and Smad transcriptional activity, respectively. EGCG (0–100 μmol/L) and green tea extract (0–250 μg/ml) suppressed the viability of cancer cells in a dose-dependent manner (p