title: Green tea (-)-epigallocatechin-3-gallate down-regulates VASP expression and inhibits breast cancer cell migration and invasion by attenuating Rac1 activity.
abstract: (-)-Epigallocatechin-3-gallate (EGCG) is a polyphenolic compound from green tea that has been shown to have anti-tumor activities such as inhibiting adhesion, migration, and proliferation of tumor cells. However, the delicate mechanisms and signaling pathways underlying the potential anticancer effects of EGCG in breast cancer cells remain unclear. The goal of this study was to examine the effects of EGCG on the migration and invasion of MCF-7 cells and to identify the signaling pathway(s) underlying the cellular response to EGCG exposure. In a concentration-dependent manner, EGCG decreased the migratory and invasive potential of MCF-7 cells with a concomitant down-regulation of vasodilator-stimulated phosphoprotein (VASP) expression and Rac1 activity. Using specific siRNAs to block the expression of VASP and Rac1 in MCF-7 cells that were previously treated with epidermal growth factor (EGF), we demonstrated that the regulation of cell migration and invasion was associated with Rac1 activity and VASP expression. In addition, siRNA mediated knock-down of Rac1 decreased the amount of VASP expression at the mRNA level while VASP specific siRNA revealed no effect on the expression of Rac1 in MCF-7 cells. These findings suggest that the inhibitory effect of EGCG on MCF-7 cell migration and invasion may be produced by a down regulation of VASP expression via the Rac1 pathway.
authors.affiliation: Department of Pathology and Pathophysiology, Hubei Provincial Key Laboratory of Allergy and Immune-Related Diseases Centre for Medical Research, Wuhan University, Wuhan, China.
authors.forename: Yimin
authors.initials: Y
authors.lastname: Zhang
authors.forename: Guoge
authors.initials: G
authors.lastname: Han
authors.forename: Biao
authors.initials: B
authors.lastname: Fan
authors.forename: Yunfeng
authors.initials: Y
authors.lastname: Zhou
authors.forename: Xuan
authors.initials: X
authors.lastname: Zhou
authors.forename: Lei
authors.initials: L
authors.lastname: Wei
authors.forename: Jingwei
authors.initials: J
authors.lastname: Zhang
mesh_terms: D000818:Animals; D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D002392:Catechin / Q000031:analogs & derivatives* / Q000494:pharmacology; D015815:Cell Adhesion Molecules / Q000172:deficiency / Q000235:genetics*; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation / Q000187:drug effects*; D004789:Enzyme Activation / Q000187:drug effects; D004815:Epidermal Growth Factor / Q000494:pharmacology; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects*; D055785:Gene Knockdown Techniques; D006801:Humans; D051379:Mice; D008840:Microfilament Proteins / Q000172:deficiency / Q000235:genetics*; D009479:Neuropeptides / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D010750:Phosphoproteins / Q000172:deficiency / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics; D013662:Tea / Q000737:chemistry; D013997:Time Factors; D015854:Up-Regulation / Q000187:drug effects; D020744:rac GTP-Binding Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D020830:rac1 GTP-Binding Protein; D000098662:Vasodilator-Stimulated Phosphoprotein
chemical_list: D015815:Cell Adhesion Molecules; D008840:Microfilament Proteins; D009479:Neuropeptides; D010750:Phosphoproteins; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C484602:Rac1 protein, mouse; D013662:Tea; D000098662:Vasodilator-Stimulated Phosphoprotein; D004815:Epidermal Growth Factor; D002392:Catechin; C045651:epigallocatechin gallate; D020744:rac GTP-Binding Proteins; D020830:rac1 GTP-Binding Protein