title: Evaluation of the coordinated actions of estrogen receptors with epidermal growth factor receptor and insulin-like growth factor receptor in the expression of cell surface heparan sulfate proteoglycans and cell motility in breast cancer cells.
abstract: Estradiol (E2)-estrogen receptor (ER) actions are implicated in initiation, growth and progression of hormone-dependent breast cancer. Crosstalk between ERs, epidermal growth factor receptor (EGFR) and/or insulin-like growth factor receptor (IGFR) is critical for the observed resistance to endocrine therapies. Cell surface heparan sulfate proteoglycans (HSPGs) are principal mediators of cancer cell properties and the E2-ER pathway as well as those activated by EGFR and IGFR have significant roles in regulating the expression of certain cell surface HSPGs, such as syndecan-2 (SDC-2), syndecan-4 (SDC-4) and glypican-1. In this study, we therefore evaluated the role of EGFR-IGFR signaling on the constitutive expression and E2-mediated expression of ERs and HSPGs as well as the effect of E2-ERs and IGFR/EGFR-mediated cell migration in ERα+ (MCF-7) and ERβ+ (MDA-MB-231) breast cancer cells using specific intracellular inhibitors of EGFR and IGFR. We report that the expression of ERα is mainly enhanced by IGFR, whereas ERβ expression is mainly coordinated by EGFR. Moreover, constitutive SDC-2 expression in ERα+ and ERβ+ cells is mainly mediated through the IGFR, whereas in ERα+ E2-treated cells EGFR is the active one. In contrast, SDC-4 expression is regulated by IGFR in the presence and absence of E2. E2 also seems to diminish the inhibitory effect of EGFR and IGFR inhibitors in breast cancer cell migration. These data suggest that the coordinated action of ERs with EGFR and/or IGFR is of crucial importance, providing potential targets for designing and developing novel multi-potent agents for endocrine therapies.
authors: Laboratory of Biochemistry, Department of Chemistry, University of Patras, Patras, Greece.
authors: Anastasios I
authors: AI
authors: Tsonis
authors: Nikolaos
authors: N
authors: Afratis
authors: Chrisostomi
authors: C
authors: Gialeli
authors: Maria-Ioanna
authors: MI
authors: Ellina
authors: Zoi
authors: Z
authors: Piperigkou
authors: Spyridon S
authors: SS
authors: Skandalis
authors: Achilleas D
authors: AD
authors: Theocharis
authors: George N
authors: GN
authors: Tzanakakis
authors: Nikos K
authors: NK
authors: Karamanos
mesh_terms: D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology; D002465:Cell Movement / Q000187:drug effects*; D066246:ErbB Receptors / Q000037:antagonists & inhibitors / Q000378:metabolism*; D004958:Estradiol / Q000378:metabolism* / Q000494:pharmacology; D047628:Estrogen Receptor alpha / Q000235:genetics / Q000378:metabolism*; D047629:Estrogen Receptor beta / Q000235:genetics / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation; D053673:Glypicans / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000037:antagonists & inhibitors / Q000378:metabolism*; D061986:MCF-7 Cells; D011799:Quinazolines / Q000494:pharmacology; D020239:Receptor Cross-Talk; D015398:Signal Transduction; D053669:Syndecan-2 / Q000235:genetics / Q000378:metabolism*; D053671:Syndecan-4 / Q000235:genetics / Q000378:metabolism; D020032:Tyrphostins / Q000494:pharmacology
chemical_list: C506487:ESR1 protein, human; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D053673:Glypicans; D011799:Quinazolines; C508245:SDC2 protein, human; C508304:SDC4 protein, human; D053671:Syndecan-4; D020032:Tyrphostins; C447031:tyrphostin AG 1024; D053669:Syndecan-2; C101044:RTKI cpd; D004958:Estradiol; D007334:Insulin-Like Growth Factor I; C512478:EGFR protein, human; D066246:ErbB Receptors