title: GPER activates Notch signaling in breast cancer cells and cancer-associated fibroblasts (CAFs).
abstract: The G protein-coupled receptor GPR30/GPER has been shown to mediate rapid effects of 17β-estradiol (E2) in diverse types of cancer cells. Here, we provide evidence for a novel crosstalk between GPER and the Notch signaling pathway in breast cancer cells and cancer-associated fibroblasts (CAFs). We show that E2 and the GPER selective ligand G-1 induce both the γ-secretase-dependent activation of Notch-1 and the expression of the Notch target gene Hes-1. These inductions are prevented by knocking down GPER or by using a dominant-negative mutant of the Notch transcriptional co-activator Master-mind like-1 (DN-MAML-1), hence suggesting the involvement of GPER in the Notch-dependent transcription. By performing chromatin-immunoprecipitation experiments and luciferase assays, we also demonstrate that E2 and G-1 induce the recruitment of the intracellular domain of Notch-1 (N1ICD) to the Hes-1 promoter and the transactivation of a Hes-1-reporter gene, respectively. Functionally, the E2 and G-1-induced migration of breast cancer cells and CAFs is abolished in presence of the γ-secretase inhibitor GSI or DN-MAML-1, which both inhibit the Notch signaling pathway. In addition, we demonstrate that E2 and G-1 prevent the expression of VE-Cadherin, while both compounds induce the expression of Snail, a Notch target gene acting as a repressor of cadherins expression. Notably, both GSI and DN-MAML-1 abolish the up-regulation of Snail-1 by E2 and G-1, whereas the use of GSI rescues VE-Cadherin expression. Taken together, our results prove the involvement of the Notch signaling pathway in mediating the effects of estrogenic GPER signaling in breast cancer cells and CAFs.
authors.affiliation: Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Rende, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Pupo
authors.affiliation: Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Rende, Italy.
authors.forename: Assunta
authors.initials: A
authors.lastname: Pisano
authors.affiliation: Regional Hospital, Cosenza, Italy.
authors.forename: Sergio
authors.initials: S
authors.lastname: Abonante
authors.affiliation: Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Rende, Italy. Electronic address: marcellomaggiolini@yahoo.it.
authors.forename: Marcello
authors.initials: M
authors.lastname: Maggiolini
authors.affiliation: Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Rende, Italy; Institute for Clinical Neurobiology, University of Würzburg, Würzburg, Germany. Electronic address: E_Musti_A@klinik.uni-wuerzburg.de.
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Musti
mesh_terms: D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D045744:Cell Line, Tumor; D003517:Cyclopentanes / Q000494:pharmacology; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D061986:MCF-7 Cells; D011804:Quinolines / Q000494:pharmacology; D020239:Receptor Cross-Talk; D011960:Receptors, Estrogen / Q000378:metabolism*; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism*; D051880:Receptors, Notch / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D015854:Up-Regulation / Q000187:drug effects
chemical_list: C517943:1-(4-(6-bromobenzo(1,3)dioxol-5-yl)-3a,4,5,9b-tetrahydro-3H-cyclopenta(c)quinolin-8-yl)ethanone; D003517:Cyclopentanes; C109584:GPER1 protein, human; D011804:Quinolines; D011960:Receptors, Estrogen; D043562:Receptors, G-Protein-Coupled; D051880:Receptors, Notch; D004958:Estradiol
keywords: Breast cancer; Cancer-associated fibroblasts; Estrogens signaling; GPER; Notch signaling