Carcinogens, such as arecoline, play a crucial role in cancer progression and continuous gene mutations by generating reactive oxygen species (ROS). Antioxidants can reduce ROS levels and potentially prevent cancer progression but may paradoxically enhance the survival of cancer cells. This study investigated whether epigallocatechin-3-gallate (EGCG), an antioxidant from green tea, could resolve this paradox. Prostate cancer cells (PC-3 cell line) were cultured and treated with arecoline combined with NAC (N-acetylcysteine) or EGCG; the combined effects on intracellular ROS levels and cell viability were examined using the MTT and DCFDA assays, respectively. In addition, apoptosis, cell cycle, and protein expression were investigated using flow cytometry and western blot analysis. Our results showed that EGCG, similar to NAC (N-acetylcysteine), reduced the intracellular ROS levels, which were elevated by arecoline. Moreover, EGCG not only caused cell cycle arrest but also facilitated cell apoptosis in arecoline-treated cells in a synergistic manner. These were evidenced by elevated levels of cyclin B1 and p27, and increased fragmentation of procaspase-3, PARP, and DNA. Our findings highlight the potential use of EGCG for cancer prevention and therapy.

Trophoblast migration and invasion play crucial roles in placental development. However, the effects of (-)-epigallocatechin-3-gallate (EGCG) on trophoblast cell functions remain largely unexplored. In this study, we investigated the impact of EGCG on the survival of trophoblast cells and employed a proteomics analysis to evaluate its influence on trophoblast cell migration and invasion. Be-Wo trophoblast cells were treated with EGCG, and a zone closure assay was conducted to assess the cell migration and invasion. Subsequently, a proteomics analysis was performed on the treated and control groups, followed by a bioinformatics analysis to evaluate the affected biological pathways and protein networks. A quantitative real-time PCR and Western blot analysis were carried out to validate the proteomics findings. Our results showed that EGCG significantly suppressed the trophoblast migration and invasion at a concentration not affecting cell survival. The proteomics analysis revealed notable differences in the protein expression between the EGCG-treated and control groups. Specifically, EGCG downregulated the signaling pathways related to EIF2, mTOR, and estrogen response, as well as the processes associated with the cytoskeleton, extracellular matrix, and protein translation. Conversely, EGCG upregulated the pathways linked to lipid degradation and oxidative metabolism. The quantitative PCR showed that EGCG modulated protein expression by regulating gene transcription, and the Western blot analysis confirmed its impact on cytoskeleton and extracellular matrix reorganization. These findings suggest EGCG may inhibit trophoblast migration and invasion through multiple signaling pathways, highlighting the potential risks associated with consuming EGCG-containing products during pregnancy. Future research should investigate the impact of EGCG intake on maternal and fetal proteoforms.

Breast cancer and lung adenocarcinoma share common features, including female predominance and the expression of estrogen receptor (ER) and epidermal growth factor receptor (EGFR) during carcinogenesis. Patients with breast cancer have a significantly higher risk of developing second primary lung cancer than those without breast cancer. ER beta expression is associated with resistance to EGFR tyrosine kinase inhibitors (TKIs) in EGFR-mutant lung adenocarcinoma, indicating a potentially important interaction between ER and EGFR. However, the mechanisms underlying this crosstalk remain poorly understood. Our clinical data showed a significant correlation between antiestrogen treatment for breast cancer and mutant EGFR expression (p = 0.021) in lung adenocarcinoma patients. In vitro, tamoxifen upregulated phosphorylated EGFR (p-EGFR) in EGFR-mutant lung adenocarcinoma cell lines. Heparin-binding EGF-like growth factor was identified as a key mediator from the ER pathway that stimulates p-EGFR. Tamoxifen counteracts estrogen’s effect and restores p-EGFR upregulation. Furthermore, coadministration of tamoxifen and the EGFR TKI gefitinib potentially inhibited p-EGFR expression in EGFR-mutant lung adenocarcinoma. Regular follow-up with chest computed tomography is recommended for patients with breast cancer. For those diagnosed with both ER-positive breast cancer and EGFR-mutant lung adenocarcinoma, combined tamoxifen and EGFR TKI therapy may offer an effective targeted treatment strategy.