Novel Estrogen Receptor-α Binding Sites and Estradiol Target Genes Identified by Chromatin Immunoprecipitation Cloning in Breast Cancer

2007 ◽  
Vol 67 (10) ◽  
pp. 5017-5024 ◽  
Author(s):  
Zhihong Lin ◽  
Scott Reierstad ◽  
Chiang-Ching Huang ◽  
Serdar E. Bulun
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Chromatin Immunoprecipitation ◽  
Binding Sites ◽  
Target Genes ◽  
Estrogen Receptor Α

scholarly journals PARP7 and Mono-ADP-Ribosylation Negatively Regulate Estrogen Receptor α Signaling in Human Breast Cancer Cells

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 623
Author(s):  
Marit Rasmussen ◽  
Susanna Tan ◽  
Venkata S. Somisetty ◽  
David Hutin ◽  
Ninni Elise Olafsen ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Protein Modification ◽  
Target Genes ◽  
Estrogen Receptor Α ◽  
Transactivation Domain ◽  
Adp Ribosylation ◽  
Protein Levels ◽  
17Β Estradiol ◽  
Mcf 7

ADP-ribosylation is a post-translational protein modification catalyzed by a family of proteins known as poly-ADP-ribose polymerases. PARP7 (TIPARP; ARTD14) is a mono-ADP-ribosyltransferase involved in several cellular processes, including responses to hypoxia, innate immunity and regulation of nuclear receptors. Since previous studies suggested that PARP7 was regulated by 17β-estradiol, we investigated whether PARP7 regulates estrogen receptor α signaling. We confirmed the 17β-estradiol-dependent increases of PARP7 mRNA and protein levels in MCF-7 cells, and observed recruitment of estrogen receptor α to the promoter of PARP7. Overexpression of PARP7 decreased ligand-dependent estrogen receptor α signaling, while treatment of PARP7 knockout MCF-7 cells with 17β-estradiol resulted in increased expression of and recruitment to estrogen receptor α target genes, in addition to increased proliferation. Co-immunoprecipitation assays revealed that PARP7 mono-ADP-ribosylated estrogen receptor α, and mass spectrometry mapped the modified peptides to the receptor’s ligand-independent transactivation domain. Co-immunoprecipitation with truncated estrogen receptor α variants identified that the hinge region of the receptor is required for PARP7-dependent mono-ADP-ribosylation. These results imply that PARP7-mediated mono-ADP-ribosylation may play an important role in estrogen receptor positive breast cancer.

scholarly journals AKT Alters Genome-Wide Estrogen Receptor α Binding and Impacts Estrogen Signaling in Breast Cancer

2008 ◽  
Vol 28 (24) ◽  
pp. 7487-7503 ◽  
Author(s):  
Poornima Bhat-Nakshatri ◽  
Guohua Wang ◽  
Hitesh Appaiah ◽  
Nikhil Luktuke ◽  
Jason S. Carroll ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Binding Sites ◽  
Transforming Growth Factor ◽  
Cell Types ◽  
Estrogen Receptor Α ◽  
Estrogen Signaling ◽  
Primary Tumors ◽  
Genome Wide ◽  
Extracellular Signal

ABSTRACT Estrogen regulates several biological processes through estrogen receptor α (ERα) and ERβ. ERα-estrogen signaling is additionally controlled by extracellular signal activated kinases such as AKT. In this study, we analyzed the effect of AKT on genome-wide ERα binding in MCF-7 breast cancer cells. Parental and AKT-overexpressing cells displayed 4,349 and 4,359 ERα binding sites, respectively, with ∼60% overlap. In both cell types, ∼40% of estrogen-regulated genes associate with ERα binding sites; a similar percentage of estrogen-regulated genes are differentially expressed in two cell types. Based on pathway analysis, these differentially estrogen-regulated genes are linked to transforming growth factor β (TGF-β), NF-κB, and E2F pathways. Consistent with this, the two cell types responded differently to TGF-β treatment: parental cells, but not AKT-overexpressing cells, required estrogen to overcome growth inhibition. Combining the ERα DNA-binding pattern with gene expression data from primary tumors revealed specific effects of AKT on ERα binding and estrogen-regulated expression of genes that define prognostic subgroups and tamoxifen sensitivity of ERα-positive breast cancer. These results suggest a unique role of AKT in modulating estrogen signaling in ERα-positive breast cancers and highlights how extracellular signal activated kinases can change the landscape of transcription factor binding to the genome.

Calcineurin regulates the stability and activity of estrogen receptor α

2021 ◽  
Vol 118 (44) ◽  
pp. e2114258118
Author(s):  
Takahiro Masaki ◽  
Makoto Habara ◽  
Yuki Sato ◽  
Takahiro Goshima ◽  
Keisuke Maeda ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Cancer Cells ◽  
Cancer Progression ◽  
Breast Cancer Cells ◽  
Molecular Mechanisms ◽  
Target Genes ◽  
Estrogen Receptor Α ◽  
The Stability ◽  
Positive Breast Cancer

Estrogen receptor α (ER-α) mediates estrogen-dependent cancer progression and is expressed in most breast cancer cells. However, the molecular mechanisms underlying the regulation of the cellular abundance and activity of ER-α remain unclear. We here show that the protein phosphatase calcineurin regulates both ER-α stability and activity in human breast cancer cells. Calcineurin depletion or inhibition down-regulated the abundance of ER-α by promoting its polyubiquitination and degradation. Calcineurin inhibition also promoted the binding of ER-α to the E3 ubiquitin ligase E6AP, and calcineurin mediated the dephosphorylation of ER-α at Ser294 in vitro. Moreover, the ER-α (S294A) mutant was more stable and activated the expression of ER-α target genes to a greater extent compared with the wild-type protein, whereas the extents of its interaction with E6AP and polyubiquitination were attenuated. These results suggest that the phosphorylation of ER-α at Ser294 promotes its binding to E6AP and consequent degradation. Calcineurin was also found to be required for the phosphorylation of ER-α at Ser118 by mechanistic target of rapamycin complex 1 and the consequent activation of ER-α in response to β-estradiol treatment. Our study thus indicates that calcineurin controls both the stability and activity of ER-α by regulating its phosphorylation at Ser294 and Ser118. Finally, the expression of the calcineurin A–α gene (PPP3CA) was associated with poor prognosis in ER-α–positive breast cancer patients treated with tamoxifen or other endocrine therapeutic agents. Calcineurin is thus a promising target for the development of therapies for ER-α–positive breast cancer.

scholarly journals miR-1290 and its potential targets are associated with characteristics of estrogen receptor α-positive breast cancer

2012 ◽  
Vol 20 (1) ◽  
pp. 91-102 ◽  
Author(s):  
Yumi Endo ◽  
Tatsuya Toyama ◽  
Satoru Takahashi ◽  
Nobuyasu Yoshimoto ◽  
Mai Iwasa ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Target Genes ◽  
Expression Profiles ◽  
Expression Patterns ◽  
Estrogen Receptor Α ◽  
Breast Cancer Tissue ◽  
Cancer Tissue ◽  
Er Positive ◽  
Positive Breast Cancer

Recent analyses have identified heterogeneity in estrogen receptor α (ERα)-positive breast cancer. Subtypes called luminal A and luminal B have been identified, and the tumor characteristics, such as response to endocrine therapy and prognosis, are different in these subtypes. However, little is known about how the biological characteristics of ER-positive breast cancer are determined. In this study, expression profiles of microRNAs (miRNAs) and mRNAs in ER-positive breast cancer tissue were compared between ERhighKi67lowtumors and ERlowKi67hightumors by miRNA and mRNA microarrays. Unsupervised hierarchical clustering analyses revealed distinct expression patterns of miRNAs and mRNAs in these groups. We identified a downregulation of miR-1290 in ERhighKi67lowtumors. Among 11 miRNAs that were upregulated in ERhighKi67lowtumors, quantitative RT-PCR detection analysis using 64 samples of frozen breast cancer tissue identified six miRNAs (let-7a, miR-15a, miR-26a, miR-34a, miR-193b, and miR-342-3p). We picked up 11 genes that were potential target genes of the selected miRNAs and that were differentially expressed in ERhighKi67lowtumors and ERlowKi67hightumors. Protein expression patterns of the selected target genes were analyzed in 256 ER-positive breast cancer samples by immunohistochemistry: miR-1290 and its putative targets,BCL2, FOXA1, MAPT, andNAT1, were identified. Transfection experiments revealed that introduction of miR-1290 into ER-positive breast cancer cells decreased expression of NAT1 and FOXA1. Our results suggest that miR-1290 and its potential targets might be associated with characteristics of ER-positive breast cancer.

scholarly journals Cell Cycle Progression Stimulated by Tamoxifen-Bound Estrogen Receptor-α and Promoter-Specific Effects in Breast Cancer Cells Deficient in N-CoR and SMRT

2005 ◽  
Vol 19 (6) ◽  
pp. 1543-1554 ◽  
Author(s):  
Erika Krasnickas Keeton ◽  
Myles Brown
Keyword(s):  
Breast Cancer ◽  
Cell Cycle ◽  
Estrogen Receptor ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Cell Cycle Progression ◽  
Hormone Receptors ◽  
Target Genes ◽  
Estrogen Receptor Α ◽  
Cycle Progression

Abstract Estrogen receptor α (ERα) mediates the effects of estrogens in breast cancer development and growth via transcriptional regulation of target genes. Tamoxifen can antagonize ERα activity and has been used in breast cancer therapy. Tamoxifen-bound ERα associates with nuclear receptor corepressor (N-CoR) and silencing mediator for retinoid and thyroid hormone receptors (SMRT) at certain target genes. Here we show the effects of reducing N-CoR and SMRT levels on the actions of estrogen and tamoxifen in breast cancer cells. Silencing both corepressors led to tamoxifen-stimulated cell cycle progression without activation of the ERα target genes c-myc, cyclin D1, or stromal cell-derived factor 1, which play a role in estrogen-induced proliferation. By contrast, expression of X-box binding protein 1 was markedly elevated in tamoxifen-treated cells in which N-CoR and SMRT had been silenced. The gain in cell cycle entry seen with tamoxifen when N-CoR and SMRT were silenced was dependent on ERα and not observed upon treatment with estradiol or epidermal growth factor. These results suggest that N-CoR and SMRT play an active role in preventing tamoxifen from stimulating proliferation in breast cancer cells through repression of a subset of target genes involved in ERα function and cell proliferation.

scholarly journals Stable Inhibition of Specific Estrogen Receptor α (ERα) Phosphorylation Confers Increased Growth, Migration/Invasion, and Disruption of Estradiol Signaling in MCF-7 Breast Cancer Cells

Endocrinology ◽  
2012 ◽  
Vol 153 (9) ◽  
pp. 4144-4159 ◽  
Author(s):  
B. P. Huderson ◽  
T. T. Duplessis ◽  
C. C. Williams ◽  
H. C. Seger ◽  
C. G. Marsden ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Estrogen Receptor ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Target Genes ◽  
Expression Patterns ◽  
Estrogen Receptor Α ◽  
Regulated Gene Expression ◽  
Mcf 7

Elevated phosphorylation of estrogen receptor α (ERα) at serines 118 (S118) and 167 (S167) is associated with favorable outcome for tamoxifen adjuvant therapy and may serve as surrogate markers for a functional ERα signaling pathway in breast cancer. It is possible that loss of phosphorylation at S118 and/or S167 could disrupt ERα signaling, resulting in aggressive ERα-independent breast cancer cells. To this end, MCF-7 breast cancer cells were stably transfected with an ERα-specific short hairpin RNA that reduced endogenous ERα. The resulting cell line was stably transfected with wild-type ERα (ER-AB cells), or ERα containing serine to alanine mutation at S118 or S167 (S118A cells and S167A cells, respectively). These stable cell lines expressed approximately equivalent ERα compared with parental MCF-7 cells and were evaluated for growth, morphology, migration/invasion, and ERα-regulated gene expression. S118A cells and S167A cells exhibited increased growth and migration/invasion in vitro. Forward- and side-scatter flow cytometry revealed that S167A cells were smaller in size, and both S118A and S167A cells exhibited less cellular complexity. S118A and S167A cells expressed pancytokeratin and membrane localization of β-catenin and did not express vimentin, indicating retention of epithelial lineage markers. Expression of ERα-target genes and other genes regulated by ERα signaling or involved in breast cancer were markedly altered in both S118A and S167A cells. In summary, attenuated phosphorylation of ERα at S118 and S167 significantly affected cellular physiology and behavior in MCF-7 breast cancer cells, resulting in increased growth, migration/invasion, compromised expression of ERα target genes, and markedly altered gene expression patterns.

scholarly journals Estrogen receptor-α, RBCK1, and protein kinase C β 1 cooperate to regulate estrogen receptor-α gene expression

2012 ◽  
Vol 49 (3) ◽  
pp. 277-287 ◽  
Author(s):  
Nina Gustafsson Sheppard ◽  
Nina Heldring ◽  
Karin Dahlman-Wright
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Cancer Cells ◽  
Molecular Mechanism ◽  
Breast Cancer Cells ◽  
Target Genes ◽  
Estrogen Receptor Α ◽  
Kinase C

Estrogen receptor α (ERα) is initially overexpressed in two-thirds of all breast cancers and is involved in its development and proliferation. We previously reported that the RanBP-type and C3HC4-type zinc finger containing 1 (RBCK1) interacts with the ERα promoter and that RBCK1 expression positively correlates with ERα levels, expression of ERα downstream target genes, and proliferation of breast cancer cells. Based on this, and that RBCK1 positively correlates with ERα expression in breast cancer samples, we propose RBCK1 as a potential therapeutic target in breast cancer acting as a modulator of ERα expression. To further explore this, the molecular mechanism by which RBCK1 regulates ERα expression has to be defined. Here, we show that ERα, RBCK1, and the RBCK1-interacting protein protein kinase C β 1 (PKCβI) co-occupy a previously identified ERα binding region in the proximal ERα promoter. We describe a number of mechanistic details of this complex including that RBCK1 recruitment to the ERα promoter B is facilitated by ERα, which in turn facilitates PKCβI recruitment and PKCβI-dependent histone modifications. Furthermore, ERα regulation of its own mRNA expression is facilitated by RBCK1 recruitment, suggesting an ERα coactivator function of RBCK1. The interaction between RBCK1 and ERα was dependent on the E3 ubiquitin ligase domain of RBCK1 and the activating function-1 domain of ERα. The ligand-binding function of ERα does not influence the interaction with RBCK1. In summary, our data provide insight into the molecular mechanism by which ERα expression is modulated in breast cancer cells.

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