Nuclear Alternate Estrogen Receptor GPR30 Mediates 17β-Estradiol–Induced Gene Expression and Migration in Breast Cancer–Associated Fibroblasts

Abstract

Fibroblasts are the principal cellular component of connective tissue and are associated with cancer cells at all stages of tumor progression. Structural and functional contributions of fibroblasts to the growth, survival, and invasive capacity of cancer cells are beginning to emerge. In breast carcinoma, ∼80% of stromal fibroblasts termed cancer-associated fibroblasts (CAF) are thought to manifest an activated phenotype that promotes cancer cell proliferation tumor growth at metastatic sites similar to the primary tumor. In this report, we show that CAFs respond to physiologic concentrations of 17β-estradiol (E2) by rapidly inducing extracellular signal-regulated kinase phosphorylation and immediate early gene expression, including c-fos and connective tissue growth factor, and cyclin D1. Notably, the E2 response is mediated by the alternate estrogen receptor GPR30, which interfaces with the epidermal growth factor receptor (EGFR) signaling pathway. In particular, E2 stimulates a physical interaction between GPR30 and phosphorylated EGFR, recruiting them to the cyclin D1 gene promoter. Nuclear localization induced by E2 was confirmed by cellular immunofluorescence methods. GPR30 was required for CAF proliferation and migration induced by E2. Our results provide important new mechanistic insights into how CAFs are stimulated by estrogen through a GPR30-mediated nuclear signaling pathway. More generally, they define estrogenic GPR30 signaling as a functionally important component of the tumor microenvironment. Cancer Res; 70(14); 6036-46. ©2010 AACR.

GPER1 is regulated by insulin in cancer cells and cancer-associated fibroblasts

“…It has been well established that a cooperative crosstalk between insulin and estrogen signaling pathways triggers multiple biological events in breast carcinogenesis (Rose & Vona-Davis 2012, Catsburg et al 2014. Estrogens mainly act through the classical estrogen receptor a (ESR1) and b (ESR2) (Hall et al 2001), however many effects induced by these steroids are mediated by the G protein estrogen receptor 1 (GPER1, formerly known as GPR30) in several types of tumor cells and cancer-associated fibroblasts (CAFs), major players in the tumor microenvironment driving tumor progression (Madeo & Maggiolini 2010. In this respect, the recent identification of molecules acting as selective agonist or antagonist ligands of GPER1 has allowed the evaluation of the transduction mechanisms involved in the estrogenic GPER1 signaling in numerous pathophysiological conditions (Dennis et al 2011.…”

GPCRs and cancer

“…The signaling events upon GPER activation by both estrogens and notably ER antagonists can lead to gene transcription as well as to the growth and migration in diverse hormone-sensitive tumors like breast, endometrial and ovarian cancer [142][143][144][145][146][147][148][149] . Notably, GPER was also involved in the stimulatory effects elicited by estrogens and ER antagonists in cancer-associated fibroblasts [147,150] . …”

The DHEA metabolite 7β-hydroxy-epiandrosterone exerts anti-estrogenic effects on breast cancer cell lines

“…Des travaux récents décrivent un GPR30 nucléaire (Madeo et Maggiolini, 2010) identifié dans des fibroblastes associés aux tumeurs (Cancer Associated Fibroblasts, CAFs) et jouant un rôle dans la progression tumorale (Kalluri et Zeisberg, 2006 ;. Dans ce modèle, 1nM d'E2 entraîne une phosphorylation de ERK1/2 médiée par le GPR30.…”

“…Le blocage du GPR30 ou de l'EGFR, connu pour être activé par le GPR30, abolit la surexpression de ces gènes. Ces résultats suggèrent que ces gènes sont régulés par le GPR30 et nécessite l'EGFR (Madeo et Maggiolini, 2010) (Figure 12). Des immunoprécipitations montrent aussi que la localisation nucléaire du GPR30 est associée à une interaction avec l'EGFR (Tableau 4).…”

“…L'interaction entre le GPR30 et l'EGFR ne s'observe que dans le noyau (Madeo et Maggiolini, 2010). Cependant, cette étude reste la seule à montrer une localisation nucléaire du GPR30 ainsi qu'une interaction avec l'EGFR de ce récepteur.…”