scholarly journals Genome-Wide Estrogen Receptor Activity in Breast Cancer

Endocrinology ◽  
2020 ◽  
Vol 162 (2) ◽  
Author(s):  
Anca M Farcas ◽  
Sankari Nagarajan ◽  
Sabina Cosulich ◽  
Jason S Carroll
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Estrogen Receptor Alpha ◽  
Regulatory Elements ◽  
Estrogen Signaling ◽  
Endocrine Treatment ◽  
Transcriptional Program ◽  
Genome Wide ◽  
Estrogen Receptor Activity ◽  
Dynamic Interplay

Abstract The largest subtype of breast cancer is characterized by the expression and activity of the estrogen receptor alpha (ERalpha/ER). Although several effective therapies have significantly improved survival, the adaptability of cancer cells means that patients frequently stop responding or develop resistance to endocrine treatment. ER does not function in isolation and multiple associating factors have been reported to play a role in regulating the estrogen-driven transcriptional program. This review focuses on the dynamic interplay between some of these factors which co-occupy ER-bound regulatory elements, their contribution to estrogen signaling, and their possible therapeutic applications. Furthermore, the review illustrates how some ER association partners can influence and reprogram the genomic distribution of the estrogen receptor. As this dynamic ER activity enables cancer cell adaptability and impacts the clinical outcome, defining how this plasticity is determined is fundamental to our understanding of the mechanisms of disease progression.

scholarly journals Regulatory Interplay between miR-181a-5p and Estrogen Receptor Signaling Cascade in Breast Cancer

Cancers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 543
Author(s):  
Rosaria Benedetti ◽  
Chiara Papulino ◽  
Giulia Sgueglia ◽  
Ugo Chianese ◽  
Tommaso De Marchi ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Endocrine Therapy ◽  
Mirna Expression ◽  
Estrogen Receptor Alpha ◽  
Estrogen Signaling ◽  
Integrated Analysis ◽  
Tumor Resistance ◽  
Estrogen Receptor Signaling

The efficacy and side effects of endocrine therapy in breast cancer (BC) depend largely on estrogen receptor alpha (ERα) expression, the specific drug administered, and treatment scheduling. Although the benefits of endocrine therapy outweigh any adverse effects in the initial stages of BC, later- or advanced-stage tumors acquire resistance to treatments. The mechanisms underlying tumor resistance to therapy are still not well understood, posing a major challenge for BC patient care. Epigenetic regulation and miRNA expression may be involved in the switch from a treatment-sensitive to a treatment-resistant state and could provide a valid therapeutic strategy for ERα negative BC. Here, a hybrid lysine-specific histone demethylase inhibitor, MC3324, displaying selective estrogen receptor down-regulator-like activities in BC, was used to highlight the interplay between epigenetic and ERα signaling. MC3324 anticancer action is mediated by microRNA (miRNA) expression regulation, indicating an innovative function for this molecule. Integrated analysis suggests a crosstalk between estrogen signaling, ERα interactors, miRNAs, and their putative targets. Specifically, miR-181a-5p expression is regulated by MC3324 and has an impact on cellular levels of ERα. A comparison of breast tumor versus healthy mammary tissues confirmed the important role of miR-181a-5p in ERα regulation and points to its putative predictive function in BC therapy.

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.

scholarly journals Obesity-Altered Adipose Stem Cells Promote ER+ Breast Cancer Metastasis through Estrogen Independent Pathways

2019 ◽  
Vol 20 (6) ◽  
pp. 1419 ◽  
Author(s):  
Rachel A. Sabol ◽  
Adam Beighley ◽  
Paulina Giacomelli ◽  
Rachel M. Wise ◽  
Mark A. A. Harrison ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Stem Cells ◽  
Estrogen Receptor ◽  
Tumor Growth ◽  
Estrogen Receptor Alpha ◽  
Cancer Metastasis ◽  
Breast Cancer Metastasis ◽  
Adipose Stem Cells ◽  
Estrogen Signaling ◽  
Promote Tumor Growth

Adipose stem cells (ASCs) play an essential role in tumor microenvironments. These cells are altered by obesity (obASCs) and previous studies have shown that obASCs secrete higher levels of leptin. Increased leptin, which upregulates estrogen receptor alpha (ERα) and aromatase, enhances estrogen bioavailability and signaling in estrogen receptor positive (ER+) breast cancer (BC) tumor growth and metastasis. In this study, we evaluate the effect of obASCs on ER+BC outside of the ERα signaling axis using breast cancer models with constitutively active ERα resulting from clinically relevant mutations (Y537S and D538G). We found that while obASCs promote tumor growth and proliferation, it occurs mostly through abrogated estrogen signaling when BC has constitutive ER activity. However, obASCs have a similar promotion of metastasis irrespective of ER status, demonstrating that obASC promotion of metastasis may not be completely estrogen dependent. We found that obASCs upregulate two genes in both ER wild type (WT) and ER mutant (MUT) BC: SERPINE1 and ABCB1. This study demonstrates that obASCs promote metastasis in ER WT and MUT xenografts and an ER MUT patient derived xenograft (PDX) model. However, obASCs promote tumor growth only in ER WT xenografts.

scholarly journals An H2A histone isotype regulates estrogen receptor target genes by mediating enhancer-promoter-3′-UTR interactions in breast cancer cells

2013 ◽  
Vol 42 (5) ◽  
pp. 3073-3088 ◽  
Author(s):  
Chia-Hsin Su ◽  
Tsai-Yu Tzeng ◽  
Ching Cheng ◽  
Ming-Ta Hsu
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Cancer Cells ◽  
Estrogen Receptor Alpha ◽  
Target Genes ◽  
Regulation Of Gene Expression ◽  
Estrogen Signaling ◽  
Cancer Drug ◽  
Histone H2a ◽  
Cancer Drug Discovery

Abstract A replication-dependent histone H2A isotype, H2ac, is upregulated in MCF-7 cells and in estrogen receptor-positive clinical breast cancer tissues. Cellular depletion of this H2A isotype leads to defective estrogen signaling, loss of cell proliferation and cell cycle arrest at G0/G1 phase. H2ac mediates regulation of estrogen receptor target genes, particularly BCL2 and c-MYC, by recruiting estrogen receptor alpha through its HAR domain and facilitating the formation of a chromatin loop between the promoter, enhancer and 3′-untranslated region of the respective genes. These findings reveal a new role for histone isotypes in the regulation of gene expression in cancer cells, and suggest that these molecules may be targeted for anti-cancer drug discovery.

scholarly journals The RNA-mediated estrogen receptor α interactome of hormone-dependent human breast cancer cell nuclei

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Giovanni Nassa ◽  
Giorgio Giurato ◽  
Annamaria Salvati ◽  
Valerio Gigantino ◽  
Giovanni Pecoraro ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Estrogen Receptor Alpha ◽  
Molecular Mechanisms ◽  
Affinity Purification ◽  
Regulatory Protein ◽  
Estrogen Signaling ◽  
Target Cells ◽  
Cell Nuclei

Abstract Estrogen Receptor alpha (ERα) is a ligand-inducible transcription factor that mediates estrogen signaling in hormone-responsive cells, where it controls key cellular functions by assembling in gene-regulatory multiprotein complexes. For this reason, interaction proteomics has been shown to represent a useful tool to investigate the molecular mechanisms underlying ERα action in target cells. RNAs have emerged as bridging molecules, involved in both assembly and activity of transcription regulatory protein complexes. By applying Tandem Affinity Purification (TAP) coupled to mass spectrometry (MS) before and after RNase digestion in vitro, we generated a dataset of nuclear ERα molecular partners whose association with the receptor involves RNAs. These data provide a useful resource to elucidate the combined role of nuclear RNAs and the proteins identified here in ERα signaling to the genome in breast cancer and other cell types.

scholarly journals Genome-wide mapping of FOXM1 binding reveals co-binding with estrogen receptor alpha in breast cancer cells

2013 ◽  
Vol 14 (1) ◽  
pp. R6 ◽  
Author(s):  
Deborah A Sanders ◽  
Caryn S Ross-Innes ◽  
Dario Beraldi ◽  
Jason S Carroll ◽  
Shankar Balasubramanian
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Estrogen Receptor Alpha ◽  
Receptor Alpha ◽  
Genome Wide

Endocrine Treatment of Breast Cancer: Current Perspectives, Future Directions

2017 ◽  
Vol 8 (03) ◽  
Author(s):  
Tazia Irfan ◽  
Mainul Haque ◽  
Sayeeda Rahman ◽  
Russell Kabir ◽  
Nuzhat Rahman ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Endocrine Therapy ◽  
Ovarian Function ◽  
Premenopausal Women ◽  
New Drugs ◽  
Effective Control ◽  
Endocrine Treatment ◽  
Estrogen Production ◽  
Hormone Sensitive

Breast cancer remains one of the major causes of death in women, and endocrine treatment is currently one of the mainstay of treatment in patients with estrogen receptor positive breast cancer. Endocrine therapy either slows down or stops the growth of hormone-sensitive tumors by blocking the body’s capability to yield hormones or by interfering with hormone action. In this paper, we intended to review various approaches of endocrine treatments for breast cancer highlighting successes and limitations. There are three settings where endocrine treatment of breast cancer can be used: neoadjuvant, adjuvant, or metastatic. Several strategies have also been developed to treat hormone-sensitive breast cancer which include ovarian ablation, blocking estrogen production, and stopping estrogen effects. Selective estrogen-receptor modulators (SERMs) (e.g. tamoxifen and raloxifene), aromatase inhibitors (AIs) (e.g. anastrozole, letrozole and exemestane), gonadotropin-releasing hormone agonists (GnRH) (e.g. goserelin), and selective estrogen receptor downregulators (SERDs) (e.g. fulvestrant) are currently used drugs to treat breast cancer. Tamoxifen is probably the first targeted therapy widely used in breast cancer treatment which is considered to be very effective as first line endocrine treatment in previously untreated patients and also can be used after other endocrine therapy and chemotherapy. AIs inhibit the action of enzyme aromatase which ultimately decrease the production of estrogen to stimulate the growth of ER+ breast cancer cells. GnRH agonists suppress ovarian function, inducing artificial menopause in premenopausal women. Endocrine treatments are cheap, well-tolerated and have a fixed single daily dose for all ages, heights and weights of patients. Endocrine treatments are not nearly as toxic as chemotherapy and frequent hospitalization can be avoided. New drugs in preliminary trials demonstrated the potential for improvement of the efficacy of endocrine therapy including overcoming resistance. However, the overall goals for breast cancer including endocrine therapy should focus on effective control of cancer, design personalized medical therapeutic approach, increase survival time and quality of life, and improve supportive and palliative care for end-stage disease.

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