Estrogen Receptor β Binds to and Regulates Three Distinct Classes of Target Genes

Abstract

Estrogen receptor ␤ (ER␤) has potent antiproliferative and anti-inflammatory properties, suggesting that ER␤-selective agonists might be a new class of therapeutic and chemopreventative agents. To understand how ER␤ regulates genes, we identified genes regulated by the unliganded and liganded forms of ER␣ and ER␤ in U2OS cells. Microarray data demonstrated that virtually no gene regulation occurred with unliganded ER␣, whereas many genes were regulated by estradiol (E 2 ). These results demonstrated that ER␣ requires a ligand to regulate a single class of genes. In contrast, ER␤ regulated three classes of genes. Class I genes were regulated primarily by unliganded ER␤. Class II genes were regulated only with E 2 , whereas class III genes were regulated by both unliganded ER␤ and E 2 . There were 453 class I genes, 258 class II genes, and 83 class III genes. To explore the mechanism whereby ER␤ regulates different classes of genes, chromatin immunoprecipitation-sequencing was performed to identify ER␤ binding sites and adjacent transcription factor motifs in regulated genes. AP1 binding sites were more enriched in class I genes, whereas ERE, NFB1, and SP1 sites were more enriched in class II genes. ER␤ bound to all three classes of genes, demonstrating that ER␤ binding is not responsible for differential regulation of genes by unliganded and liganded ER␤. The coactivator NCOA2 was differentially recruited to several target genes. Our findings indicate that the unliganded and liganded forms of ER␤ regulate three classes of genes by interacting with different transcription factors and coactivators.Estrogens are essential for the development of the reproductive system. They also exert important actions on nonreproductive tissues such as the bone (1) and cardiovascular system (2). Many biological effects of estrogens are mediated by two estrogen receptors (ERs), 4 estrogen receptor ␣ (ER␣; NR3A1 and ESR1) and estrogen receptor ␤ (ER␤; NR3A2 and ESR2) (3, 4).

Estrogen receptor β sustains epithelial differentiation by regulating prolyl hydroxylase 2 transcription

“…This enhancer is a unique variant of the consensus ERE sequence consistent with the reports that some variant EREs or half sites of the consensus ERE can function as cis-acting elements or enhancers for estrogen receptors (38,39). Our finding also agrees with ChIP-seq data, indicating that a small percentage of ER binding sites are located within the promoter of target genes and that most are located in intergenic sites or within intragenic regions (>1 kb from either end of transcripts) (38,39).…”

“…This enhancer is a unique variant of the consensus ERE sequence consistent with the reports that some variant EREs or half sites of the consensus ERE can function as cis-acting elements or enhancers for estrogen receptors (38,39). Our finding also agrees with ChIP-seq data, indicating that a small percentage of ER binding sites are located within the promoter of target genes and that most are located in intergenic sites or within intragenic regions (>1 kb from either end of transcripts) (38,39). Based on this information, it is possible that ERβ regulates PHD2 transcription by long-range chromatin interactions that involve interaction with other transcription factors such as Activator Protein1 (AP1) factors, Specific Protein1 (Sp1), Forkhead Box Protein A (FOXA), and cAMP response element binding protein 1 (CREB1) that exhibit ChIP enrichment within the PHD2 promoter region based on analysis of the EN-CODE database (http://genome.ucsc.edu/).…”

Effect of ligand-activated estrogen receptor β on lymphoma growth in vitro and in vivo

“…This may reflect the fact that a number of ERb target genes may be regulated by unliganded ERb. 38 Although previous studies have shown that cells of lymphoid origin express ERb at the protein level, very few have addressed the use of ERb-selective agonists on leukemias/lymphomas. A soy-derived isoflavone, genistein, with some selectivity for ERb, was recently shown to inhibit the growth of canine lymphoid cell lines.…”

Estrogen receptor β exon 3-deleted mouse: The importance of non-ERE pathways in ERβ signaling

“…It is now known that one-third of the categorized human 17β-estradiol-responsive genes are transcribed via indirect ER-DNA association through proteinprotein interactions with several transcription factors (13). Both ERα and ERβ can exert transcriptional regulation by tethering to other transcription factors such as c-Fos/c-Jun (activator protein-1, AP-1), Sp1, or NF-κB without themselves binding to EREs on DNA (13)(14)(15)(16)(17)(18). Genome landscaping has revealed that the non-ERE-dependent mode of transcription is the preferred pathway used by ERβ to regulate transcription of its target genes.…”