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Habara M, Shimada M. Estrogen receptor α revised: Expression, structure, function, and stability. Bioessays 2022; 44:e2200148. [PMID: 36192154 DOI: 10.1002/bies.202200148] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 09/09/2022] [Accepted: 09/09/2022] [Indexed: 11/11/2022]
Abstract
Estrogen receptor α (ERα) is a ligand-dependent transcription factor that regulates the expression of estrogen-responsive genes. Approximately 70% of patients with breast cancer are ERα positive. Estrogen stimulates cancer cell proliferation and contributes to tumor progression. Endocrine therapies, which suppress the ERα signaling pathway, significantly improve the prognosis of patients with breast cancer. However, the development of de novo or acquired endocrine therapy resistance remains a barrier to breast cancer treatment. Therefore, understanding the regulatory mechanisms of ERα is essential to overcome the resistance to treatment. This review focuses on the regulation of ERα expression, including copy number variation, epigenetic regulation, transcriptional regulation, and stability, as well as functions from the point of view post-translational modifications.
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Affiliation(s)
- Makoto Habara
- Department of Veterinary Biochemistry, Yamaguchi University, Yamaguchi, Yamaguchi, Japan
| | - Midori Shimada
- Department of Veterinary Biochemistry, Yamaguchi University, Yamaguchi, Yamaguchi, Japan
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2
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Tecalco-Cruz AC, Macías-Silva M, Ramírez-Jarquín JO, Ramírez-Jarquín UN. Decoding the Therapeutic Implications of the ERα Stability and Subcellular Distribution in Breast Cancer. Front Endocrinol (Lausanne) 2022; 13:867448. [PMID: 35498431 PMCID: PMC9044904 DOI: 10.3389/fendo.2022.867448] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 03/03/2022] [Indexed: 01/22/2023] Open
Abstract
Approximately 70% of all breast cancer cases are estrogen receptor-alpha positive (ERα+) and any ERα signaling pathways deregulation is critical for the progression of malignant mammary neoplasia. ERα acts as a transcription factor that promotes the expression of estrogen target genes associated with pro-tumor activity in breast cancer cells. Furthermore, ERα is also part of extranuclear signaling pathways related to endocrine resistance. The regulation of ERα subcellular distribution and protein stability is critical to regulate its functions and, consequently, influence the response to endocrine therapies and progression of this pathology. This minireview highlights studies that have deciphered the molecular mechanisms implicated in controlling ERα stability and nucleo-cytoplasmic transport. These mechanisms offer information about novel biomarkers, therapeutic targets, and promising strategies for breast cancer treatment.
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Affiliation(s)
- Angeles C. Tecalco-Cruz
- Posgrado en Ciencias Genómicas, Universidad Autónoma de la Ciudad de México (UACM), Mexico City, Mexico
| | - Marina Macías-Silva
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico
| | | | - Uri Nimrod Ramírez-Jarquín
- Neural Signal Transduction, Max Planck Florida Institute for Neuroscience, Jupiter, FL, United States
- Instituto Nacional de Cardiología “Ignacio Chávez”, Mexico City, Mexico
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3
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Chen Y, Britton D, Wood ER, Brantley S, Fournier M, Wloch M, Williams VL, Johnson J, Magliocco A, Pike I, Koomen JM. Quantification of Breast Cancer Protein Biomarkers at Different Expression Levels in Human Tumors. Methods Mol Biol 2018; 1788:251-268. [PMID: 29243084 PMCID: PMC7771335 DOI: 10.1007/7651_2017_113] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Liquid chromatography-selected reaction monitoring (LC-SRM) mass spectrometry has developed into a versatile tool for quantification of proteins with a wide range of applications in basic science, translational research, and clinical patient assessment. This strategy uniquely complements traditional pathology approaches, like hematoxylin and eosin (H&E) staining and immunohistochemistry (IHC). The multiplexing capabilities offered by mass spectrometry are currently unmatched by other techniques. However, quantification of biomarkers in tissue specimens without the other data obtained from H&E-stained slides or IHC, including tumor cellularity or percentage of positively stained cells inter alia, may not provide as much information that is needed to fully understand tumor biology or properly assess the patient. Therefore, additional characterization of the tissue proteome is needed, which in turn requires the ability to assess protein markers across a wide range of expression levels from a single sample. This protocol provides an example of multiplexed analysis in breast tumor tissue quantifying specific biomarkers, specifically estrogen receptor, progesterone receptor, and the HER2 receptor tyrosine kinase, in combination with other proteins that can report on tissue content and other aspects of tumor biology.
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Affiliation(s)
- Yi Chen
- Molecular Oncology/Proteomics SRB3, Moffitt Cancer Center, Tampa, FL, USA
| | | | - Elizabeth R Wood
- Molecular Oncology/Proteomics SRB3, Moffitt Cancer Center, Tampa, FL, USA
| | | | - Michelle Fournier
- Molecular Oncology/Proteomics SRB3, Moffitt Cancer Center, Tampa, FL, USA
| | - Marek Wloch
- Molecular Oncology/Proteomics SRB3, Moffitt Cancer Center, Tampa, FL, USA
| | - Vonetta L Williams
- Molecular Oncology/Proteomics SRB3, Moffitt Cancer Center, Tampa, FL, USA
| | - Joseph Johnson
- Molecular Oncology/Proteomics SRB3, Moffitt Cancer Center, Tampa, FL, USA
| | - Anthony Magliocco
- Molecular Oncology/Proteomics SRB3, Moffitt Cancer Center, Tampa, FL, USA
| | - Ian Pike
- Proteome Sciences, plc, Cobham, UK
| | - John M Koomen
- Molecular Oncology/Proteomics SRB3, Moffitt Cancer Center, Tampa, FL, USA.
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4
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Chen Y, Britton D, Wood ER, Brantley S, Magliocco A, Pike I, Koomen JM. Quantitative proteomics of breast tumors: Tissue quality assessment to clinical biomarkers. Proteomics 2017; 17. [PMID: 28127872 DOI: 10.1002/pmic.201600335] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2016] [Revised: 11/11/2016] [Accepted: 01/23/2017] [Indexed: 01/07/2023]
Abstract
Liquid chromatography-selected reaction monitoring mass spectrometry (LC-SRM) is not only a proven tool for clinical chemistry, but also a versatile method to enhance the capability to quantify biomarkers for tumor biology research. As the treatment of cancer continues to evolve, the ability to assess multiple biomarkers to assign cancer phenotypes based on the genetic background and the signaling of the individual tumor becomes paramount to our ability to treat the patient. In breast cancer, the American Society of Clinical Oncology has defined biomarkers for patient assessment to guide selection of therapy: estrogen receptor, progesterone receptor, and the HER2/Neu receptor tyrosine kinase; therefore, these proteins were selected for LC-SRM assay development. Detailed molecular characterization of these proteins is necessary for patient treatment, so expression and phosphorylation assays have been developed and applied. In addition, other LC-SRM assays were developed to further evaluate tumor biology (e.g. Ki-67 for proliferation and vimentin for tumor aggressiveness related to the epithelial-to-mesenchymal transition). These measurements combined with biomarkers for tissue quality and histological content are implemented in a three-tier multiplexed assay platform, which is translated from cell line models into frozen tumor tissues banked from breast cancer patients.
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Affiliation(s)
- Yi Chen
- Molecular Oncology, Moffitt Cancer Center, Tampa, FL, USA
| | | | | | | | | | - Ian Pike
- Proteome Sciences plc., Cobham, UK
| | - John M Koomen
- Molecular Oncology, Moffitt Cancer Center, Tampa, FL, USA.,Chemical Biology and Molecular Medicine, Moffitt Cancer Center, Tampa, FL, USA
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Nucleo-cytoplasmic transport of estrogen receptor alpha in breast cancer cells. Cell Signal 2017; 34:121-132. [PMID: 28341599 DOI: 10.1016/j.cellsig.2017.03.011] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2016] [Revised: 03/19/2017] [Accepted: 03/21/2017] [Indexed: 02/07/2023]
Abstract
Approximately 70% cases of breast cancers exhibit high expression and activity levels of estrogen receptor alpha (ERα), a transcription regulator that induces the expression of genes associated with cellular proliferation and survival. These nuclear functions of the receptor are associated with the development of breast cancer. However, ERα localization is not static, but rather, dynamic with continuous shuttling between the nucleus and the cytoplasm. Interestingly, both the nuclear import and export of ERα are modulated by several stimuli that include estradiol, antiestrogens, and growth factors. As ERα nuclear accumulation is critical to the regulation of gene expression, nuclear export of this receptor modulates the intensity and duration of its transcriptional activity. Thus, the subcellular spatial distribution of ERα ensures tight modulation of its concentration in cellular compartments, as well as of its nuclear and extranuclear functions. In this review, we will discuss current findings regarding the biological importance of molecular mechanisms of, and proteins responsible for, the nuclear import and export of ERα in breast cancer cells.
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Guerin M, Gonçalves A, Toiron Y, Baudelet E, Audebert S, Boyer JB, Borg JP, Camoin L. How may targeted proteomics complement genomic data in breast cancer? Expert Rev Proteomics 2016; 14:43-54. [PMID: 27813428 DOI: 10.1080/14789450.2017.1256776] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
INTRODUCTION Breast cancer (BC) is the most common female cancer in the world and was recently deconstructed in different molecular entities. Although most of the recent assays to characterize tumors at the molecular level are genomic-based, proteins are the actual executors of cellular functions and represent the vast majority of targets for anticancer drugs. Accumulated data has demonstrated an important level of quantitative and qualitative discrepancies between genomic/transcriptomic alterations and their protein counterparts, mostly related to the large number of post-translational modifications. Areas covered: This review will present novel proteomics technologies such as Reverse Phase Protein Array (RPPA) or mass-spectrometry (MS) based approaches that have emerged and that could progressively replace old-fashioned methods (e.g. immunohistochemistry, ELISA, etc.) to validate proteins as diagnostic, prognostic or predictive biomarkers, and eventually monitor them in the routine practice. Expert commentary: These different targeted proteomic approaches, able to complement genomic data in BC and characterize tumors more precisely, will permit to go through a more personalized treatment for each patient and tumor.
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Affiliation(s)
- Mathilde Guerin
- a Aix Marseille Univ, CNRS, INSERM, Institut Paoli-Calmettes, CRCM, Marseille Protéomique , Marseille , France.,b Department of Medical Oncology , Institut Paoli-Calmettes , Marseille , France
| | - Anthony Gonçalves
- a Aix Marseille Univ, CNRS, INSERM, Institut Paoli-Calmettes, CRCM, Marseille Protéomique , Marseille , France.,b Department of Medical Oncology , Institut Paoli-Calmettes , Marseille , France
| | - Yves Toiron
- b Department of Medical Oncology , Institut Paoli-Calmettes , Marseille , France
| | - Emilie Baudelet
- a Aix Marseille Univ, CNRS, INSERM, Institut Paoli-Calmettes, CRCM, Marseille Protéomique , Marseille , France
| | - Stéphane Audebert
- a Aix Marseille Univ, CNRS, INSERM, Institut Paoli-Calmettes, CRCM, Marseille Protéomique , Marseille , France
| | - Jean-Baptiste Boyer
- a Aix Marseille Univ, CNRS, INSERM, Institut Paoli-Calmettes, CRCM, Marseille Protéomique , Marseille , France
| | - Jean-Paul Borg
- a Aix Marseille Univ, CNRS, INSERM, Institut Paoli-Calmettes, CRCM, Marseille Protéomique , Marseille , France
| | - Luc Camoin
- a Aix Marseille Univ, CNRS, INSERM, Institut Paoli-Calmettes, CRCM, Marseille Protéomique , Marseille , France
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Anbalagan M, Rowan BG. Estrogen receptor alpha phosphorylation and its functional impact in human breast cancer. Mol Cell Endocrinol 2015; 418 Pt 3:264-72. [PMID: 25597633 DOI: 10.1016/j.mce.2015.01.016] [Citation(s) in RCA: 98] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 01/08/2015] [Accepted: 01/12/2015] [Indexed: 02/08/2023]
Abstract
Estrogen receptor α (ERα) is a member of the nuclear receptor superfamily of transcription factors that regulates cell proliferation, differentiation and homeostasis in various tissues. Sustained exposure to estrogen/estradiol (E2) increases the risk of breast, endometrial and ovarian cancers. ERα function is also regulated by phosphorylation through various kinase signaling pathways that will impact various ERα functions including chromatin interaction, coregulator recruitment and gene expression, as well impact breast tumor growth/morphology and breast cancer patient response to endocrine therapy. However, many of the previously characterized ERα phosphorylation sites do not fully explain the impact of receptor phosphorylation on ERα function. This review discusses work from our laboratory toward understanding a role of ERα site-specific phosphorylation in ERα function and breast cancer. The key findings discussed in this review are: (1) the effect of site specific ERα phosphorylation on temporal recruitment of ERα and unique coactivator complexes to specific genes; (2) the impact of stable disruption of ERα S118 and S167 phosphorylation in breast cancer cells on eliciting unique gene expression profiles that culminate in significant effects on breast cancer growth/morphology/migration/invasion; (3) the Src kinase signaling pathway that impacts ERα phosphorylation to alter ERα function; and (4) circadian disruption by light exposure at night leading to elevated ERK1/2 and Src kinase and phosphorylation of ERα, concomitant with tamoxifen resistance in breast tumor models. Results from these studies demonstrate that even changes to single ERα phosphorylation sites can have a profound impact on ERα function in breast cancer. Future work will extend beyond single site phosphorylation analysis toward identification of specific patterns/profiles of ERα phosphorylation under different physiological/pharmacological conditions to understand how common phosphorylation profiles in breast cancer program specific physiological endpoints such as growth, apoptosis, migration/invasion, and endocrine therapy response.
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Affiliation(s)
- Muralidharan Anbalagan
- Department of Structural and Cellular Biology, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Brian G Rowan
- Department of Structural and Cellular Biology, Tulane University School of Medicine, New Orleans, LA 70112, USA.
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9
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Elevated expression of TANK-binding kinase 1 enhances tamoxifen resistance in breast cancer. Proc Natl Acad Sci U S A 2014; 111:E601-10. [PMID: 24449872 DOI: 10.1073/pnas.1316255111] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Resistance to antiestrogens is one of the major challenges in breast cancer treatment. Although phosphorylation of estrogen receptor α (ERα) is an important factor in endocrine resistance, the contributions of specific kinases in endocrine resistance are still not fully understood. Here, we report that an important innate immune response kinase, the IκB kinase-related TANK-binding kinase 1 (TBK1), is a crucial determinant of resistance to tamoxifen therapies. We show that TBK1 increases ERα transcriptional activity through phosphorylation modification of ERα at the Ser-305 site. Ectopic TBK1 expression impairs the responsiveness of breast cancer cells to tamoxifen. By studying the specimens from patients with breast cancer, we find a strong positive correlation of TBK1 with ERα, ERα Ser-305, and cyclin D1. Notably, patients with tumors highly expressing TBK1 respond poorly to tamoxifen treatment and show high potential for relapse. Therefore, our findings suggest that TBK1 contributes to tamoxifen resistance in breast cancer via phosphorylation modification of ERα.
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Martín-Millán M, Castañeda S. Estrogens, osteoarthritis and inflammation. Joint Bone Spine 2013; 80:368-73. [PMID: 23352515 DOI: 10.1016/j.jbspin.2012.11.008] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Accepted: 11/30/2012] [Indexed: 10/27/2022]
Abstract
Estrogens participate in several biological processes through different molecular mechanisms. Their final actions consist of a combination of both direct and indirect effects on different organ and tissues. Estrogen may have pro- and anti-inflammatory properties depending on the situation and the involved tissue. In general, acute loss of estrogens increases the levels of reactive oxygen species and activates nuclear factor-κB and pro-inflammatory cytokine production, indicating their predominant anti-inflammatory properties. Furthermore, pro-inflammatory cytokine expression has been shown to be attenuated by estrogen replacement. Osteoarthritis and cardiovascular disease are two of the more prevalent diseases once menopause is established, which has suggested the link between estrogens and both processes. In addition, deletion of estrogen receptors in female mice results in cartilage damage, osteophytosis and changes in the subchondral bone of the joints suggesting that estrogens have a protective role on the maintenance of joint homeostasis. Furthermore, in spite of the negative effect of estrogen replacement reported in 2002 by the Women's Health Initiative study, several works published afterwards have explored the potential protective effect of estrogen supplementation in animal models and have postulated that these actions may justify a beneficial role of estrogens in different diseases where inflammation is the major feature. In this review, we will analyze the effects of estrogens on certain pathological situations such as osteoarthritis, some autoimmune diseases and coronary heart disease, especially in postmenopausal women.
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Affiliation(s)
- Marta Martín-Millán
- Department of Internal Medicine, IFIMAV, Hospital Universitario Marqués de Valdecilla, Avenida de Valdecilla s/n, 39008 Santander, Cantabria, Spain.
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Held JM, Britton DJ, Scott GK, Lee EL, Schilling B, Baldwin MA, Gibson BW, Benz CC. Ligand binding promotes CDK-dependent phosphorylation of ER-alpha on hinge serine 294 but inhibits ligand-independent phosphorylation of serine 305. Mol Cancer Res 2012; 10:1120-32. [PMID: 22669764 DOI: 10.1158/1541-7786.mcr-12-0099] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Phosphorylation of estrogen receptor-α (ERα) is critical for its transcription factor activity and may determine its predictive and therapeutic value as a biomarker for ERα-positive breast cancers. Recent attention has turned to the poorly understood ERα hinge domain, as phosphorylation at serine 305 (Ser305) associates with poor clinical outcome and endocrine resistance. We show that phosphorylation of a neighboring hinge domain site, Ser294, analyzed by multiple reaction monitoring mass spectrometry of ERα immunoprecipitates from human breast cancer cells is robustly phosphorylated exclusively by ligand (estradiol and tamoxifen) activation of ERα and not by growth factor stimulation (EGF, insulin, heregulin-β). In a reciprocal fashion, Ser305 phosphorylation is induced by growth factors but not ligand activation of ERα. Phosphorylation at Ser294 and Ser305 is suppressed upon co-stimulation by EGF and ligand, respectively, unlike the N-terminal (AF-1) domain Ser118 and Ser167 sites of ERα where phosphorylation is enhanced by ligand and growth factor co-stimulation. Inhibition of cyclin-dependent kinases (CDK) by roscovitine or SNS-032 suppresses ligand-activated Ser294 phosphorylation without affecting Ser118 or Ser104/Ser106 phosphorylation. Likewise, cell-free studies using recombinant ERα and specific cyclin-CDK complexes suggest that Ser294 phosphorylation is primarily induced by the transcription-regulating and cell-cycle-independent kinase CDK7. Thus, CDK-dependent phosphorylation at Ser294 differentiates ligand-dependent from ligand-independent activation of Ser305 phosphorylation, showing that hinge domain phosphorylation patterns uniquely inform on the various ERα activation mechanisms thought to underlie the biologic and clinical diversity of hormone-dependent breast cancers.
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Affiliation(s)
- Jason M Held
- Buck Institute for Research on Aging, Novato, CA 94945, USA
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Stebbing J, Filipovic A, Ellis IO, Green AR, D'Silva TR, Lenz HJ, Coombes RC, Wang T, Lee SC, Giamas G. LMTK3 expression in breast cancer: association with tumor phenotype and clinical outcome. Breast Cancer Res Treat 2012; 132:537-44. [PMID: 21671015 DOI: 10.1007/s10549-011-1622-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Accepted: 05/30/2011] [Indexed: 12/31/2022]
Abstract
Interactions between kinases and the estrogen receptor α (ERα) are thought to be a critical signaling pathway in the majority of human breast cancers. We have recently identified a previously uncharacterized molecule, lemur tyrosine kinase-3 (LMTK3) as a prognostic and predictive oncogenic ERα regulator with a central role in endocrine resistance. Unusually this protein has undergone Darwinian positive selection between Chimpanzees and humans suggesting it may contribute to human susceptibility to ERα-positive tumors. Using over 600 European primary breast cancer cases, we wished to establish tumor characteristics associated with both cytoplasmic and nuclear LMTK3 expression, and then externally validate our observed European clinical outcomes with samples from Asian individuals receiving chemotherapy. Both nuclear and cytoplasmic expression correlated with tumor grade (P < 0.001) and in the Asian cohort, independent blinded analyses demonstrated that high basal LMTK3 expression was associated with advanced stage of primary breast cancers as well as decreased overall (P = 0.03) and disease-free survival (P = 0.006). In summary, higher LMTK3 expression is associated with more aggressive cancers. These data support our previous findings and suggest LMTK3 expression may be a reliable new biomarker in breast cancer.
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Affiliation(s)
- Justin Stebbing
- Department of Surgery and Cancer, Division of Cancer, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 ONN, UK.
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Anbalagan M, Huderson B, Murphy L, Rowan BG. Post-translational modifications of nuclear receptors and human disease. NUCLEAR RECEPTOR SIGNALING 2012; 10:e001. [PMID: 22438791 PMCID: PMC3309075 DOI: 10.1621/nrs.10001] [Citation(s) in RCA: 159] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Accepted: 08/19/2011] [Indexed: 12/12/2022]
Abstract
Nuclear receptors (NR) impact a myriad of physiological processes including homeostasis, reproduction, development, and metabolism. NRs are regulated by post-translational modifications (PTM) that markedly impact receptor function. Recent studies have identified NR PTMs that are involved in the onset and progression of human diseases, including cancer. The majority of evidence linking NR PTMs with disease has been demonstrated for phosphorylation, acetylation and sumoylation of androgen receptor (AR), estrogen receptor α (ERα), glucocorticoid receptor (GR) and peroxisome proliferator activated receptor γ (PPARγ). Phosphorylation of AR has been associated with hormone refractory prostate cancer and decreased disease-specific survival. AR acetylation and sumoylation increased growth of prostate cancer tumor models. AR phosphorylation reduced the toxicity of the expanded polyglutamine AR in Kennedy's Disease as a consequence of reduced ligand binding. A comprehensive evaluation of ERα phosphorylation in breast cancer revealed several sites associated with better clinical outcome to tamoxifen therapy, whereas other phosphorylation sites were associated with poorer clinical outcome. ERα acetylation and sumoylation may also have predictive value for breast cancer. GR phosphorylation and acetylation impact GR responsiveness to glucocorticoids that are used as anti-inflammatory drugs. PPARγ phosphorylation can regulate the balance between growth and differentiation in adipose tissue that is linked to obesity and insulin resistance. Sumoylation of PPARγ is linked to repression of inflammatory genes important in patients with inflammatory diseases. NR PTMs provide an additional measure of NR function that can be used as both biomarkers of disease progression, and predictive markers for patient response to NR-directed treatments.
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Affiliation(s)
- Muralidharan Anbalagan
- Department of Structural and Cellular Biology, Tulane University School of Medicine, New Orleans, Louisiana, USA
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Le Romancer M, Poulard C, Cohen P, Sentis S, Renoir JM, Corbo L. Cracking the estrogen receptor's posttranslational code in breast tumors. Endocr Rev 2011; 32:597-622. [PMID: 21680538 DOI: 10.1210/er.2010-0016] [Citation(s) in RCA: 211] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Estrogen signaling pathways, because of their central role in regulating the growth and survival of breast tumor cells, have been identified as suitable and efficient targets for cancer therapies. Agents blocking estrogen activity are already widely used clinically, and many new molecules have entered clinical trials, but intrinsic or acquired resistance to treatment limits their efficacy. The basic molecular studies underlying estrogen signaling have defined the critical role of estrogen receptors (ER) in many aspects of breast tumorigenesis. However, important knowledge gaps remain about the role of posttranslational modifications (PTM) of ER in initiation and progression of breast carcinogenesis. Whereas major attention has been focused on the phosphorylation of ER, many other PTM (such as acetylation, ubiquitination, sumoylation, methylation, and palmitoylation) have been identified as events modifying ER expression and stability, subcellular localization, and sensitivity to hormonal response. This article will provide an overview of the current and emerging knowledge on ER PTM, with a particular focus on their deregulation in breast cancer. We also discuss their clinical relevance and the functional relationship between PTM. A thorough understanding of the complete picture of these modifications in ER carcinogenesis might not only open new avenues for identifying new markers for prognosis or prediction of response to endocrine therapy but also could promote the development of novel therapeutic strategies.
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Affiliation(s)
- Muriel Le Romancer
- Université de Lyon, Centre de Recherche en Cancérologie de Lyon, Centre Léon Bérard, Bâtiment Cheney D, 28 rue Laennec, 69373 Lyon Cedex 08, France.
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Chen HH, Sung WC, Liang SS, Chen SH. Functional Fluorinated Modifications on a Polyelectrolyte Coated Polydimethylsiloxane Substrate for Fabricating Antibody Microarrays. Anal Chem 2010; 82:7804-13. [DOI: 10.1021/ac101799f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Huang-Han Chen
- Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan
| | - Wang-Chou Sung
- Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan
| | - Shih-Shin Liang
- Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan
| | - Shu-Hui Chen
- Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan
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Domanski D, Murphy LC, Borchers CH. Assay development for the determination of phosphorylation stoichiometry using multiple reaction monitoring methods with and without phosphatase treatment: application to breast cancer signaling pathways. Anal Chem 2010; 82:5610-20. [PMID: 20524616 PMCID: PMC2909760 DOI: 10.1021/ac1005553] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
We have developed a phosphatase-based phosphopeptide quantitation (PPQ) method for determining phosphorylation stoichiometry in complex biological samples. This PPQ method is based on enzymatic dephosphorylation, combined with specific and accurate peptide identification and quantification by multiple reaction monitoring (MRM) with stable-isotope-labeled standard peptides. In contrast with classical MRM methods for the quantitation of phosphorylation stoichiometry, the PPQ-MRM method needs only one nonphosphorylated SIS (stable isotope-coded standard) and two analyses (one for the untreated sample and one for the phosphatase-treated sample), from which the expression and modification levels can accurately be determined. From these analyses, the percent phosphorylation can be determined. In this manuscript, we compare the PPQ-MRM method with an MRM method without phosphatase and demonstrate the application of these methods to the detection and quantitation of phosphorylation of the classic phosphorylated breast cancer biomarkers (ERalpha and HER2), and for phosphorylated RAF and ERK1, which also contain phosphorylation sites of biological importance. Using synthetic peptides spiked into a complex protein digest, we were able to use our PPQ-MRM method to accurately determine the total phosphorylation stoichiometry on specific peptides as well as the absolute amount of the peptide and phosphopeptide present. Analyses of samples containing ERalpha protein revealed that the PPQ-MRM method is capable of determining phosphorylation stoichiometry in proteins from cell lines, and is in good agreement with determinations obtained using the direct MRM approach in terms of phosphorylation and total protein amount.
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Affiliation(s)
- Dominik Domanski
- University of Victoria – Genome BC Proteomics Centre, #3101-4464 Markham St., Victoria, BC, Canada, V8Z-7X8
| | - Leigh C. Murphy
- Manitoba Institute of Cell Biology, University of Manitoba, 675 McDermot Ave. Rm. ON5008B, Winnipeg, MB R3E 0V9
| | - Christoph H. Borchers
- University of Victoria – Genome BC Proteomics Centre, #3101-4464 Markham St., Victoria, BC, Canada, V8Z-7X8
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Abstract
Most transcription factors including nuclear receptors (NRs) act as sensors of the extracellular and intracellular compartments. As such, NRs serve as integrating platforms for a variety of stimuli and are targets for Post-translational modifications such as phosphorylations. During the last decade, knowledge of NRs phosphorylation advanced considerably because of the emergence of new technologies. Indeed, the development of a wide range of phosphorylation site databases, high accuracy mass spectrometry, and phospho-specific antibodies allowed the identification of multiple novel phosphorylation sites in NRs. New and improved methods also emerge to connect these data with the downstream consequences of phosphorylation on NRs structure (computational prediction, NMR), intracellular localization (FRAP), interaction with coregulators (proteomics, FRET, FLIM), and affinity for DNA (ChIP, ChIP-seq, FRAP). In the future, such integrated strategies should provide data with a treasure-trove of information about the integration of numerous signaling events by NRs.
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Williams CC, Basu A, El-Gharbawy A, Carrier LM, Smith CL, Rowan BG. Identification of four novel phosphorylation sites in estrogen receptor alpha: impact on receptor-dependent gene expression and phosphorylation by protein kinase CK2. BMC BIOCHEMISTRY 2009; 10:36. [PMID: 20043841 PMCID: PMC2811108 DOI: 10.1186/1471-2091-10-36] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/22/2009] [Accepted: 12/31/2009] [Indexed: 12/13/2022]
Abstract
Background Estrogen receptor α (ERα) phosphorylation is important for estrogen-dependent transcription of ER-dependent genes, ligand-independent receptor activation and endocrine therapy response in breast cancer. However ERα phosphorylation at the previously identified sites does not fully account for these receptor functions. To determine if additional ERα phosphorylation sites exist, COS-1 cells expressing human ERα were labeled with [32P]H3PO4 in vivo and ERα tryptic phosphopeptides were isolated to identify phosphorylation sites. Results Previously uncharacterized phosphorylation sites at serines 46/47, 282, 294, and 559 were identified by manual Edman degradation and phosphoamino acid analysis and confirmed by mutagenesis and phospho-specific antibodies. Antibodies detected phosphorylation of endogenous ERα in MCF-7, MCF-7-LCC2, and Ishikawa cancer cell lines by immunoblot. Mutation of Ser-282 and Ser-559 to alanine (S282A, S559A) resulted in ligand independent activation of ERα as determined by both ERE-driven reporter gene assays and endogenous pS2 gene expression in transiently transfected HeLa cells. Mutation of Ser-46/47 or Ser-294 to alanine markedly reduced estradiol dependent reporter activation. Additionally protein kinase CK2 was identified as a kinase that phosphorylated ERα at S282 and S559 using motif analysis, in vitro kinase assays, and incubation of cells with CK2 kinase inhibitor. Conclusion These novel ERα phosphorylation sites represent new means for modulation of ERα activity. S559 represents the first phosphorylation site identified in the extreme C-terminus (F domain) of a steroid receptor.
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Affiliation(s)
- Christopher C Williams
- 1Division of Basic Pharmaceutical Sciences, College of Pharmacy, Xavier University of Louisiana, New Orleans, LA, USA.
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Grisouard J, Mayer D. Specific involvement of glycogen synthase kinase-3 in the function and activity of sex steroid hormone receptors reveals the complexity of their regulation. J Steroid Biochem Mol Biol 2009; 117:87-92. [PMID: 19703560 DOI: 10.1016/j.jsbmb.2009.08.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2009] [Revised: 08/12/2009] [Accepted: 08/13/2009] [Indexed: 12/15/2022]
Abstract
Protein kinases represent key nodes for the integration of multiple intracellular signalling pathways, resulting in modulation of both ligand-dependent and ligand-independent mechanisms of sex steroid receptor (sSR) signalling cascades. The proline-directed Ser/Thr kinases including mitogen-activated protein kinases and cyclin dependent kinases were especially reported to contribute to the function and activity of sSRs. The relevant effects of these kinases are well-documented but the impact of glycogen synthase kinase-3 (GSK-3), another member of this kinase family, has been underestimated. Indeed, the specific role of GSK-3 regarding the different sSRs will help to understand further the complexity of sSR signalling. So far, AR and ERalpha were identified as GSK-3 substrates. Additionally, the docking properties of GSK-3 were demonstrated to play a crucial role in sSR signal transduction. Reciprocally, GSK-3 was described as a potential target of non-genomic effects of sSRs. Therefore, GSK-3 regulates and is regulated by sSRs. This review focuses on the emerging and promising involvements of GSK-3 regarding the signalling cascade of the respective sSRs. This review represents a necessary complement of information to highlight the importance of GSK-3 regarding sSR function and activity.
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Affiliation(s)
- Jean Grisouard
- Hormones and Signal Transduction Group, German Cancer Research Center, DKFZ-ZMBH Alliance, Heidelberg, Germany
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Rao PS, Satelli A, Zhang S, Srivastava SK, Srivenugopal KS, Rao US. RNF2 is the target for phosphorylation by the p38 MAPK and ERK signaling pathways. Proteomics 2009; 9:2776-87. [PMID: 19405034 DOI: 10.1002/pmic.200800847] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
RNF2, a member of polycomb group (PcG) proteins, is involved in chromatin remodeling. However, mechanisms that regulate RNF2 function are unknown. To identify such mechanisms, RNF2 was expressed in HEK-293 cells and analyzed by 2-D electrophoresis. RNF2 was resolved into at least seven protein spots, migrating toward the lower pI from its expected pI of 6.38, suggesting that RNF2 undergoes post-translational modifications. Western blotting indicated that majority of these RNF2 spots contained phosphoserine(s), which were completely dephosphorylated upon treatment with a phosphatase. SB203580, a specific inhibitor of p38 MAPK, inhibited RNF2 phosphorylation at one site. On the other hand, PD98059, an inhibitor of MEK1/2, inhibited majority of the phosphorylation events in RNF2. Mass spectrometry analysis identified that RNF2 expressed in Sf9 insect cells undergoes co-translational excision of (1)Met coupled to N-acetylation of (2)Ser, and phosphorylation of (41)Ser. Interestingly, (41)Ser is a predicted p38/MAPK phosphorylation site, consistent with the loss of phosphorylation induced by SB203580. Further analysis indicated that RNF2 phosphorylation differentially modulates the expression of transcription factors and histone 2B acetylation. These results provide first evidence for phosphorylation of RNF2, and suggest that the mitogen activated protein kinases including p38 MAPK and ERK1/2 regulate growth, stress response, differentiation and other cellular processes, through phosphorylation of RNF2.
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Affiliation(s)
- Prema S Rao
- Department of Pharmaceutical Sciences, School of Pharmacy, Texas Tech University Health Sciences Center, 1300 Coulter Rd., Amarillo, TX 79106, USA
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Guillard M, Gloerich J, Wessels HJCT, Morava E, Wevers RA, Lefeber DJ. Automated measurement of permethylated serum N-glycans by MALDI-linear ion trap mass spectrometry. Carbohydr Res 2009; 344:1550-7. [PMID: 19577739 DOI: 10.1016/j.carres.2009.06.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2009] [Revised: 06/04/2009] [Accepted: 06/12/2009] [Indexed: 11/19/2022]
Abstract
The use of N-glycan mass spectrometry for clinical diagnostics requires the development of robust high-throughput profiling methods. Still, structural assignment of glycans requires additional information such as MS(2) fragmentation or exoglycosidase digestions. We present a setting which combines a MALDI ionization source with a linear ion trap analyzer. This instrumentation allows automated measurement of samples thanks to the crystal positioning system, combined with MS(n) sequencing options. 2,5-Dihydroxybenzoic acid, commonly used for the analysis of glycans, failed to produce the required reproducibility due to its non-homogeneous crystallization properties. In contrast, alpha-cyano-4-hydroxycinnamic acid provided a homogeneous crystallization pattern and reproducibility of the measurements. Using serum N-glycans as a test sample, we focused on the automation of data collection by optimizing the instrument settings. Glycan structures were confirmed by MS(2) analysis. Although sample processing still needs optimization, this method provides a reproducible and high-throughput approach for measurement of N-glycans using a MALDI-linear ion trap instrument.
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Affiliation(s)
- Maïlys Guillard
- Laboratory of Pediatrics and Neurology, Radboud University Nijmegen Medical Centre, PO Box 9101, 6500 HB, Nijmegen, The Netherlands
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Atsriku C, Britton DJ, Held JM, Schilling B, Scott GK, Gibson BW, Benz CC, Baldwin MA. Systematic mapping of posttranslational modifications in human estrogen receptor-alpha with emphasis on novel phosphorylation sites. Mol Cell Proteomics 2008; 8:467-80. [PMID: 18984578 DOI: 10.1074/mcp.m800282-mcp200] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A systematic study of posttranslational modifications of the estrogen receptor isolated from the MCF-7 human breast cancer cell line is reported. Proteolysis with multiple enzymes, mass spectrometry, and tandem mass spectrometry achieved very high sequence coverage for the full-length 66-kDa endogenous protein from estradiol-treated cell cultures. Nine phosphorylated serine residues were identified, three of which were previously unreported and none of which were previously observed by mass spectrometry by any other laboratory. Two additional modified serine residues were identified in recombinant protein, one previously reported but not observed here in endogenous protein and the other previously unknown. Although major emphasis was placed on identifying new phosphorylation sites, N-terminal loss of methionine accompanied by amino acetylation and a lysine side chain acetylation (or possibly trimethylation) were also detected. The use of both HPLC-ESI and MALDI interfaced to different mass analyzers gave higher sequence coverage and identified more sites than could be achieved by either method alone. The estrogen receptor is critical in the development and progression of breast cancer. One previously unreported phosphorylation site identified here was shown to be strongly dependent on estradiol, confirming its potential significance to breast cancer. Greater knowledge of this array of posttranslational modifications of estrogen receptor, particularly phosphorylation, will increase our understanding of the processes that lead to estradiol-induced activation of this protein and may aid the development of therapeutic strategies for management of hormone-dependent breast cancer.
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