Department of Medicine and Surgery, University of Parma, Via Gramsci 14, 43126 Parma, Italy.
National Institute of Biostructure and Biosystems (INBB), Viale Medaglie d'Oro 305, 00136 Rome, Italy.
Nutrients. 2018 Dec 6;10(12):1936. doi: 10.3390/nu10121936.
Green tea is a beverage that is widely consumed worldwide and is believed to exert effects on different diseases, including cancer. The major components of green tea are catechins, a family of polyphenols. Among them, epigallocatechin-gallate (EGCG) is the most abundant and biologically active. EGCG is widely studied for its anti-cancer properties. However, the cellular and molecular mechanisms explaining its action have not been completely understood, yet. EGCG is effective in vivo at micromolar concentrations, suggesting that its action is mediated by interaction with specific targets that are involved in the regulation of crucial steps of cell proliferation, survival, and metastatic spread. Recently, several proteins have been identified as EGCG direct interactors. Among them, the trans-membrane receptor 67LR has been identified as a high affinity EGCG receptor. 67LR is a master regulator of many pathways affecting cell proliferation or apoptosis, also regulating cancer stem cells (CSCs) activity. EGCG was also found to be interacting directly with Pin1, TGFR-II, and metalloproteinases (MMPs) (mainly MMP2 and MMP9), which respectively regulate EGCG-dependent inhibition of NF-kB, epithelial-mesenchimal transaction (EMT) and cellular invasion. EGCG interacts with DNA methyltransferases (DNMTs) and histone deacetylases (HDACs), which modulates epigenetic changes. The bulk of this novel knowledge provides information about the mechanisms of action of EGCG and may explain its onco-suppressive function. The identification of crucial signalling pathways that are related to cancer onset and progression whose master regulators interacts with EGCG may disclose intriguing pharmacological targets, and eventually lead to novel combined treatments in which EGCG acts synergistically with known drugs.
绿茶是一种在全球范围内广泛消费的饮料,被认为对包括癌症在内的多种疾病有影响。绿茶的主要成分是儿茶素,这是一类多酚。其中,表没食子儿茶素没食子酸酯(EGCG)含量最丰富,生物活性也最强。EGCG 因其抗癌特性而被广泛研究。然而,其作用的细胞和分子机制尚未完全阐明。EGCG 在体内以微摩尔浓度有效,表明其作用是通过与特定靶标相互作用介导的,这些靶标参与细胞增殖、存活和转移扩散的关键步骤的调节。最近,已经鉴定出几种蛋白质是 EGCG 的直接相互作用蛋白。其中,跨膜受体 67LR 已被鉴定为 EGCG 的高亲和力受体。67LR 是影响细胞增殖或凋亡的许多途径的主要调节剂,也调节癌症干细胞(CSC)的活性。还发现 EGCG 与 Pin1、TGF-β 受体 II 和金属蛋白酶(MMPs)(主要是 MMP2 和 MMP9)直接相互作用,分别调节 EGCG 依赖性 NF-κB 抑制、上皮-间质转化(EMT)和细胞侵袭。EGCG 与 DNA 甲基转移酶(DNMTs)和组蛋白去乙酰化酶(HDACs)相互作用,调节表观遗传变化。这些新的知识为 EGCG 的作用机制提供了信息,并可能解释其抑癌功能。确定与癌症发生和进展相关的关键信号通路,这些通路的主调节因子与 EGCG 相互作用,可能揭示出有趣的药理靶点,并最终导致新的联合治疗,其中 EGCG 与已知药物协同作用。