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Suba Z. Rosetta Stone for Cancer Cure: Comparison of the Anticancer Capacity of Endogenous Estrogens, Synthetic Estrogens and Antiestrogens. Oncol Rev 2023; 17:10708. [PMID: 37152665 PMCID: PMC10154579 DOI: 10.3389/or.2023.10708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 03/30/2023] [Indexed: 05/09/2023] Open
Abstract
This work presents the history of the recognition of principal regulatory capacities of estrogen hormones having been mistakenly regarded as breast cancer promoting agents for more than 120 years. Comprehensive analysis of the results of clinical, epidemiological, immunological and molecular studies justified that endogenous estrogens are the principal regulators of embryonic development, survival and reproduction via orchestrating appropriate expression and even edition of all genes in mammalians. Medical use of chemically modified synthetic estrogens caused toxic complications; thromboembolic events and increased cancer risk in female organs as they proved to be endocrine disruptors deregulating estrogen receptors (ERs) rather than their activators. Synthetic estrogen treatment exhibits ambiguous correlations with cancer risk at different sites, which may be attributed to an inhibition of the unliganded activation of estrogen receptors (ERs) coupled with compensatory liganded activation. The principle of estrogen induced breast cancer led to the introduction of antiestrogen therapies against this tumor; inhibition of the liganded activation of estrogen receptors and aromatase enzyme activity. The initial enthusiasm turned into disappointment as the majority of breast cancers proved to be primarily resistant to antiestrogens. In addition, nearly all patients showing earlier good tumor responses to endocrine therapy, later experienced secondary resistance leading to metastatic disease and fatal outcome. Studying the molecular events in tumors responsive and unresponsive to antiestrogen therapy, it was illuminated that a complete inhibition of liganded ER activation stimulates the growth of cancers, while a successful compensatory upregulation of estrogen signal may achieve DNA restoration, tumor regression and patient's survival. Recognition of the principal role of endogenous estrogens in gene expression, gene edition and DNA repair, estrogen treatment and stimulation of ER expression in patients may bring about a great turn in medical practice.
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Intrinsic and Extrinsic Factors Governing the Transcriptional Regulation of ESR1. Discov Oncol 2020; 11:129-147. [PMID: 32592004 DOI: 10.1007/s12672-020-00388-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Accepted: 06/02/2020] [Indexed: 02/06/2023] Open
Abstract
Transcriptional regulation of ESR1, the gene that encodes for estrogen receptor α (ER), is critical for regulating the downstream effects of the estrogen signaling pathway in breast cancer such as cell growth. ESR1 is a large and complex gene that is regulated by multiple regulatory elements, which has complicated our understanding of how ESR1 expression is controlled in the context of breast cancer. Early studies characterized the genomic structure of ESR1 with subsequent studies focused on identifying intrinsic (chromatin environment, transcription factors, signaling pathways) and extrinsic (tumor microenvironment, secreted factors) mechanisms that impact ESR1 gene expression. Currently, the introduction of genomic sequencing platforms and additional genome-wide technologies has provided additional insight on how chromatin structures may coordinate with these intrinsic and extrinsic mechanisms to regulate ESR1 expression. Understanding these interactions will allow us to have a clearer understanding of how ESR1 expression is regulated and eventually provide clues on how to influence its regulation with potential treatments. In this review, we highlight key studies concerning the genomic structure of ESR1, mechanisms that affect the dynamics of ESR1 expression, and considerations towards affecting ESR1 expression and hormone responsiveness in breast cancer.
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Ahmadpour S, Hosseinimehr SJ. Recent developments in peptide-based SPECT radiopharmaceuticals for breast tumor targeting. Life Sci 2019; 239:116870. [DOI: 10.1016/j.lfs.2019.116870] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2019] [Revised: 09/09/2019] [Accepted: 09/10/2019] [Indexed: 12/31/2022]
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Becnel LB, Darlington YF, Ochsner SA, Easton-Marks JR, Watkins CM, McOwiti A, Kankanamge WH, Wise MW, DeHart M, Margolis RN, McKenna NJ. Nuclear Receptor Signaling Atlas: Opening Access to the Biology of Nuclear Receptor Signaling Pathways. PLoS One 2015; 10:e0135615. [PMID: 26325041 PMCID: PMC4556694 DOI: 10.1371/journal.pone.0135615] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 07/24/2015] [Indexed: 12/13/2022] Open
Abstract
Signaling pathways involving nuclear receptors (NRs), their ligands and coregulators, regulate tissue-specific transcriptomes in diverse processes, including development, metabolism, reproduction, the immune response and neuronal function, as well as in their associated pathologies. The Nuclear Receptor Signaling Atlas (NURSA) is a Consortium focused around a Hub website (www.nursa.org) that annotates and integrates diverse ‘omics datasets originating from the published literature and NURSA-funded Data Source Projects (NDSPs). These datasets are then exposed to the scientific community on an Open Access basis through user-friendly data browsing and search interfaces. Here, we describe the redesign of the Hub, version 3.0, to deploy “Web 2.0” technologies and add richer, more diverse content. The Molecule Pages, which aggregate information relevant to NR signaling pathways from myriad external databases, have been enhanced to include resources for basic scientists, such as post-translational modification sites and targeting miRNAs, and for clinicians, such as clinical trials. A portal to NURSA’s Open Access, PubMed-indexed journal Nuclear Receptor Signaling has been added to facilitate manuscript submissions. Datasets and information on reagents generated by NDSPs are available, as is information concerning periodic new NDSP funding solicitations. Finally, the new website integrates the Transcriptomine analysis tool, which allows for mining of millions of richly annotated public transcriptomic data points in the field, providing an environment for dataset re-use and citation, bench data validation and hypothesis generation. We anticipate that this new release of the NURSA database will have tangible, long term benefits for both basic and clinical research in this field.
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Affiliation(s)
- Lauren B. Becnel
- Dan L. Duncan Comprehensive Cancer Center Biomedical Informatics Group, One Baylor Plaza, Houston, Texas, United States of America
- Nuclear Receptor Signaling Atlas (NURSA) Informatics Hub
| | - Yolanda F. Darlington
- Dan L. Duncan Comprehensive Cancer Center Biomedical Informatics Group, One Baylor Plaza, Houston, Texas, United States of America
- Nuclear Receptor Signaling Atlas (NURSA) Informatics Hub
| | - Scott A. Ochsner
- Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, Texas, United States of America
- Nuclear Receptor Signaling Atlas (NURSA) Informatics Hub
| | - Jeremy R. Easton-Marks
- Dan L. Duncan Comprehensive Cancer Center Biomedical Informatics Group, One Baylor Plaza, Houston, Texas, United States of America
- Nuclear Receptor Signaling Atlas (NURSA) Informatics Hub
| | - Christopher M. Watkins
- Dan L. Duncan Comprehensive Cancer Center Biomedical Informatics Group, One Baylor Plaza, Houston, Texas, United States of America
- Nuclear Receptor Signaling Atlas (NURSA) Informatics Hub
| | - Apollo McOwiti
- Dan L. Duncan Comprehensive Cancer Center Biomedical Informatics Group, One Baylor Plaza, Houston, Texas, United States of America
- Nuclear Receptor Signaling Atlas (NURSA) Informatics Hub
| | - Wasula H. Kankanamge
- Dan L. Duncan Comprehensive Cancer Center Biomedical Informatics Group, One Baylor Plaza, Houston, Texas, United States of America
- Nuclear Receptor Signaling Atlas (NURSA) Informatics Hub
| | - Michael W. Wise
- National Institute of Diabetes, Digestive and Kidney Diseases, Division of Diabetes and Metabolic Diseases, Bethesda, Maryland, United States of America
- Nuclear Receptor Signaling Atlas (NURSA) Informatics Hub
| | - Michael DeHart
- Dan L. Duncan Comprehensive Cancer Center Biomedical Informatics Group, One Baylor Plaza, Houston, Texas, United States of America
- Nuclear Receptor Signaling Atlas (NURSA) Informatics Hub
| | - Ronald N. Margolis
- National Institute of Diabetes, Digestive and Kidney Diseases, Division of Diabetes and Metabolic Diseases, Bethesda, Maryland, United States of America
| | - Neil J. McKenna
- Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, Texas, United States of America
- Nuclear Receptor Signaling Atlas (NURSA) Informatics Hub
- * E-mail:
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5
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Légaré S, Cavallone L, Mamo A, Chabot C, Sirois I, Magliocco A, Klimowicz A, Tonin PN, Buchanan M, Keilty D, Hassan S, Laperrière D, Mader S, Aleynikova O, Basik M. The Estrogen Receptor Cofactor SPEN Functions as a Tumor Suppressor and Candidate Biomarker of Drug Responsiveness in Hormone-Dependent Breast Cancers. Cancer Res 2015; 75:4351-63. [PMID: 26297734 DOI: 10.1158/0008-5472.can-14-3475] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Accepted: 07/10/2015] [Indexed: 11/16/2022]
Abstract
The treatment of breast cancer has benefitted tremendously from the generation of estrogen receptor-α (ERα)-targeted therapies, but disease relapse continues to pose a challenge due to intrinsic or acquired drug resistance. In an effort to delineate potential predictive biomarkers of therapy responsiveness, multiple groups have identified several uncharacterized cofactors and interacting partners of ERα, including Split Ends (SPEN), a transcriptional corepressor. Here, we demonstrate a role for SPEN in ERα-expressing breast cancers. SPEN nonsense mutations were detectable in the ERα-expressing breast cancer cell line T47D and corresponded to undetectable protein levels. Further analysis of 101 primary breast tumors revealed that 23% displayed loss of heterozygosity at the SPEN locus and that 3% to 4% harbored somatically acquired mutations. A combination of in vitro and in vivo functional assays with microarray-based pathway analyses showed that SPEN functions as a tumor suppressor to regulate cell proliferation, tumor growth, and survival. We also found that SPEN binds ERα in a ligand-independent manner and negatively regulates the transcription of ERα targets. Moreover, we demonstrate that SPEN overexpression sensitizes hormone receptor-positive breast cancer cells to the apoptotic effects of tamoxifen, but has no effect on responsiveness to fulvestrant. Consistent with these findings, two independent datasets revealed that high SPEN protein and RNA expression in ERα-positive breast tumors predicted favorable outcome in patients treated with tamoxifen alone. Together, our data suggest that SPEN is a novel tumor-suppressor gene that may be clinically useful as a predictive biomarker of tamoxifen response in ERα-positive breast cancers.
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Affiliation(s)
- Stéphanie Légaré
- Department of Surgery and Oncology, McGill University, Montréal, Québec, Canada. Department of Oncology and Surgery, Lady Davis Institute for Medical Research, Montréal, Québec, Canada
| | - Luca Cavallone
- Department of Oncology and Surgery, Lady Davis Institute for Medical Research, Montréal, Québec, Canada
| | - Aline Mamo
- Department of Oncology and Surgery, Lady Davis Institute for Medical Research, Montréal, Québec, Canada
| | - Catherine Chabot
- Department of Oncology and Surgery, Lady Davis Institute for Medical Research, Montréal, Québec, Canada
| | - Isabelle Sirois
- Department of Surgery and Oncology, McGill University, Montréal, Québec, Canada. Department of Oncology and Surgery, Lady Davis Institute for Medical Research, Montréal, Québec, Canada
| | - Anthony Magliocco
- Department of Pathology, University of Calgary, Calgary, Alberta, Canada
| | | | - Patricia N Tonin
- Department of Human Genetics, McGill University and The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada. Department of Medicine, McGill University and The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada
| | - Marguerite Buchanan
- Department of Oncology and Surgery, Lady Davis Institute for Medical Research, Montréal, Québec, Canada
| | - Dana Keilty
- Department of Surgery and Oncology, McGill University, Montréal, Québec, Canada. Department of Oncology and Surgery, Lady Davis Institute for Medical Research, Montréal, Québec, Canada
| | - Saima Hassan
- Department of Surgery and Oncology, McGill University, Montréal, Québec, Canada. Department of Oncology and Surgery, Lady Davis Institute for Medical Research, Montréal, Québec, Canada
| | - David Laperrière
- Institut de recherche en immunologie et cancérologie, IRIC, Montréal, Québec, Canada
| | - Sylvie Mader
- Institut de recherche en immunologie et cancérologie, IRIC, Montréal, Québec, Canada. Department de Biochimie, Université de Montréal, Montréal, Québec, Canada
| | - Olga Aleynikova
- Department of Pathology, Jewish General Hospital, Montréal, Quebec, Canada
| | - Mark Basik
- Department of Surgery and Oncology, McGill University, Montréal, Québec, Canada. Department of Oncology and Surgery, Lady Davis Institute for Medical Research, Montréal, Québec, Canada.
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Suba Z. The pitfall of the transient, inconsistent anticancer capacity of antiestrogens and the mechanism of apparent antiestrogen resistance. DRUG DESIGN DEVELOPMENT AND THERAPY 2015; 9:4341-53. [PMID: 26273195 PMCID: PMC4532170 DOI: 10.2147/dddt.s89536] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Although antiestrogens have been available for breast cancer therapy since the early 1970s, neither their inconsistent anticancer capacity nor the developing antiestrogen resistance of tumors can be fully understood. Although clinical and experimental investigations revealed many tiny details concerning the link between estrogen signaling and tumor development, they yielded fairly controversial findings. Estrogen receptor (ER) overexpression in tumor cells induced by estrogen treatment was erroneously regarded as a promoter of DNA damage, genomic instability, and tumor growth. Similarly, compensatory ER overexpression caused by antiestrogen treatment or estrogen withdrawal was mistakenly evaluated as a key for rapid tumor growth attributed to acquired antiestrogen resistance. Nevertheless, ER upregulation induced by estrogen treatment is a physiologic process even in tumor cells, whereas in the case of antiestrogen administration, it is a contraregulatory action to defend the endangered estrogen signaling. Upregulation of estrogen signaling displays a unique dichotomy, ensuring the survival and safe proliferative activity of healthy cells, while inducing apoptotic death of malignant tumor cells. Analysis of the fairly controversial results justifies that whatever type of available endocrine therapies may be used, including estrogen, antiestrogen treatment, or oophorectomy, an extreme upregulation of ER signaling seems to be the crucial mechanism of successful prevention and treatment for breast cancer. The inconsistent therapeutic effects of antiestrogen administration may be explained by the different genetic capacities of patients for the compensatory upregulation of ER and aromatase enzyme expressions. The weaker the defensive counteraction against the inhibition of estrogen signaling, the poorer is the prognosis of the disease. De novo or acquired antiestrogen resistance of tumors may be associated with the missing capacity of patients for the extreme upregulation of estrogen signaling or with the exhaustion of defensive counteractions in cases that previously showed good reactivity. High-dose estrogen treatment is capable of restoring ER signaling and anticancer capacity even after heavy exposure to antiestrogen therapy.
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Affiliation(s)
- Zsuzsanna Suba
- National Institute of Oncology, Surgical and Molecular Tumor Pathology Centre, Budapest, Hungary
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Adams C, Cazzanelli G, Rasul S, Hitchinson B, Hu Y, Coombes RC, Raguz S, Yagüe E. Apoptosis inhibitor TRIAP1 is a novel effector of drug resistance. Oncol Rep 2015; 34:415-22. [PMID: 25998939 DOI: 10.3892/or.2015.3988] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 03/23/2015] [Indexed: 11/06/2022] Open
Abstract
TP53-regulated inhibitor of apoptosis 1 (TRIAP1) is a novel apoptosis inhibitor that binds HSP70 in the cytoplasm and blocks the formation of the apoptosome and caspase-9 activation. TRIAP1 has been shown to be upregulated in many types of cancers; however, its role remains elusive. We determined the TRIAP1 mRNA levels in a panel of human tissues and found its expression to be ubiquitous. Normal breast, as well as non-tumorigenic breast cells, exhibited lower TRIAP1 mRNA levels than breast cancer cells or their drug-resistant derivatives. TRIAP1 is a small, evolutionarily conserved protein that is 76 amino acids long. We found that yeast cells, in which the TRIAP1 homologue was knocked out, had increased sensitivity to doxorubicin. Equally, RNA interference in breast cancer drug-resistant cells demonstrated that downregulation of TRIAP1 impaired cell growth in the presence of doxorubicin. As expected, caspase-9 activation was diminished after overexpression of TRIAP1 in drug-resistant cells. Importantly, stable transfections of a TRIAP1 expression plasmid in CAL51 cells led to a marked increase in the number of doxorubicin-resistant clones, that was abolished when cells expressed hairpins targeting TRIAP1. In addition, we showed that TRIAP1 expression was also triggered by estrogen deprivation in MCF-7 cells. Although both polyclonal and monoclonal antibodies generated for the present study failed to robustly detect TRIAP1, we demonstrated that TRIAP1 represents a novel marker for drug resistance in breast cancer cells and it may be used in the stratification of breast cancer patients once a suitable antibody has been developed. Equally, these studies open potential drug development strategies for blocking TRIAP1 activity and avoiding drug resistance.
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Affiliation(s)
- Caroline Adams
- Cancer Research Centre, Division of Cancer, Imperial College London, Hammersmith Hospital Campus, London W12 0NN, UK
| | - Giulia Cazzanelli
- Cancer Research Centre, Division of Cancer, Imperial College London, Hammersmith Hospital Campus, London W12 0NN, UK
| | - Sabeena Rasul
- Cancer Research Centre, Division of Cancer, Imperial College London, Hammersmith Hospital Campus, London W12 0NN, UK
| | - Ben Hitchinson
- Cancer Research Centre, Division of Cancer, Imperial College London, Hammersmith Hospital Campus, London W12 0NN, UK
| | - Yunhui Hu
- Cancer Research Centre, Division of Cancer, Imperial College London, Hammersmith Hospital Campus, London W12 0NN, UK
| | - R Charles Coombes
- Cancer Research Centre, Division of Cancer, Imperial College London, Hammersmith Hospital Campus, London W12 0NN, UK
| | - Selina Raguz
- Institute of Clinical Sciences, Imperial College London, Hammersmith Hospital Campus, London W12 0NN, UK
| | - Ernesto Yagüe
- Cancer Research Centre, Division of Cancer, Imperial College London, Hammersmith Hospital Campus, London W12 0NN, UK
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Groenendijk FH, Bernards R. Drug resistance to targeted therapies: déjà vu all over again. Mol Oncol 2014; 8:1067-83. [PMID: 24910388 DOI: 10.1016/j.molonc.2014.05.004] [Citation(s) in RCA: 152] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Revised: 04/12/2014] [Accepted: 05/06/2014] [Indexed: 02/07/2023] Open
Abstract
A major limitation of targeted anticancer therapies is intrinsic or acquired resistance. This review emphasizes similarities in the mechanisms of resistance to endocrine therapies in breast cancer and those seen with the new generation of targeted cancer therapeutics. Resistance to single-agent cancer therapeutics is frequently the result of reactivation of the signaling pathway, indicating that a major limitation of targeted agents lies in their inability to fully block the cancer-relevant signaling pathway. The development of mechanism-based combinations of targeted therapies together with non-invasive molecular disease monitoring is a logical way forward to delay and ultimately overcome drug resistance development.
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Affiliation(s)
- Floris H Groenendijk
- Division of Molecular Carcinogenesis, Cancer Genomics Center Netherlands, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
| | - René Bernards
- Division of Molecular Carcinogenesis, Cancer Genomics Center Netherlands, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands.
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Pan G, Wang W, Wang L, Zhang F, Yin X, Wang J, Liang R. Anti-breast cancer effects and mechanisms of Xihuang pill on human breast cancer cell lines. J TRADIT CHIN MED 2014; 33:770-8. [PMID: 24660610 DOI: 10.1016/s0254-6272(14)60011-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
OBJECTIVE To investigate the anti-breast cancer (BC) effects and mechanisms of action of Xihuang pill (XHP) by conducting in vitro experiments on human BC cell lines. METHODS Two human BC cell lines (MCF-7 and MDA- MB231) were cultured and treated with XHP. Cell viability was detected using the 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Flow cytometry was used to measure the cell cycle and apoptosis. The cell cycle was analyzed with propidium iodide staining. Apoptosis was evaluated using the Annexin V-fluorescein isothiocyanate/propidium iodide method. Western blotting was used to analyze the expression of estrogen receptor (ER)-alpha and ER-beta. RESULTS XHP had growth-inhibitory effects on MCF-7 and MDA-MB231 cells with a half-maximal inhibitory concentration (IC50) of 10.14 mg/mL (MCF-7) and 8.98 mg/mL (MDA-MB231). Apoptosis was induced to some extent. Certain changes in the ER were caused. Upregulation of ER-a protein was found in MCF-7 cells. ER-beta expression in MDA-MB231 cells was increased. Cell-cycle arrest was not observed in the two BC cell lines. ER-1 expression in MCF-7 cells was unchanged. No ER-a expression was shown in MDA-MB231 cells. CONCLUSION These data suggest that XHP can affect cell viability and cause apoptosis, but that the cell cycle is not blocked. XHP has a certain impact on ER expression, but its mechanisms of action of anti-BC effects may not be due to regulation of ER expression.
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Jonsson P, Katchy A, Williams C. Support of a bi-faceted role of estrogen receptor β (ERβ) in ERα-positive breast cancer cells. Endocr Relat Cancer 2014; 21:143-60. [PMID: 24192230 PMCID: PMC3946733 DOI: 10.1530/erc-13-0444] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The expression of estrogen receptor α (ERα) in breast cancer identifies patients most likely to respond to endocrine treatment. The second ER, ERβ, is also expressed in breast tumors, but its function and therapeutic potential need further study. Although in vitro studies have established that ERβ opposes transcriptional and proliferative functions of ERα, several clinical studies report its correlation with proliferative markers and poorer prognosis. The data demonstrate that ERβ opposes ERα are primarily based on transient expression of ERβ. Here, we explored the functions of constitutively expressed ERβ in ERα-positive breast cancer lines MCF7 and T47D. We found that ERβ, under these conditions heterodimerized with ERα in the presence and absence of 17β-estradiol, and induced genome-wide transcriptional changes. Widespread anti-ERα signaling was, however, not observed and ERβ was not antiproliferative. Tamoxifen antagonized proliferation and ER-mediated gene regulation both in the presence and absence of ERβ. In conclusion, ERβ's role in cells adapted to its expression appears to differ from its role in cells with transient expression. Our study is important because it provides a deeper understanding of ERβ's role in breast tumors that coexpress both receptors and supports an emerging bi-faceted role of ERβ.
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Affiliation(s)
| | | | - Cecilia Williams
- To whom correspondence should be addressed:, Postal address: Center for Nuclear Receptors and Cell Signaling, 3605 Cullen Blvd., SERC Bldg. 545, Houston, TX 77204-5056,
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11
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Rieber M, Strasberg-Rieber M. p53 inactivation decreases dependence on estrogen/ERK signalling for proliferation but promotes EMT and susceptility to 3-bromopyruvate in ERα+ breast cancer MCF-7 cells. Biochem Pharmacol 2014; 88:169-77. [PMID: 24486524 DOI: 10.1016/j.bcp.2014.01.025] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 01/08/2014] [Accepted: 01/17/2014] [Indexed: 01/18/2023]
Abstract
BACKGROUND Most breast cancers express the estrogen receptor alpha (ERα(+)), harbor wt TP53, depend on estrogen/ERK signalling for proliferation, and respond to anti-estrogens. However, concomittant activation of the epidermal growth factor receptor (EGFR)/MEK pathway promotes resistance by decreasing estrogen dependence. Previously, we showed that retroviral transduction of mutant p53 R175H into wt TP53 ERα(+) MCF-7 cells induces epidermal growth factor (EGF)-independent proliferation, activation of the EGF receptor (p-EGFR) and some characteristics of epithelial-mesenchymal transition (EMT). PURPOSE To investigate whether p53 inactivation augments ERα(+) cell proliferation in response to restrictive estradiol, chemical MEK inhibition or metabolic inhibitors. RESULTS Introduction of mutant p53 R175H lowered expression of p53-dependent PUMA and p21WAF1, decreased E-cadherin and cytokeratin 18 associated with EMT, but increased the % of proliferating ERα(+)/Ki67 cells, diminishing estrogen dependence. These cells also exhibited higher proliferation in the presence of MEK-inhibitor UO126, reciprocally correlating with preferential susceptibility to the pyruvate analog 3-bromopyruvate (3-BrPA) without a comparable response to 2-deoxyglucose. p53 siRNA silencing by electroporation in wt TP53 MCF-7 cells also decreased estrogen dependence and response to MEK inhibition, while also conferring susceptibility to 3-BrPA. CONCLUSIONS (a) ERα(+) breast cancer cells dysfunctional for TP53 which proliferate irrespective of low estrogen and chemical MEK inhibition are likely to increase metabolic consumption becoming increasingly susceptible to 3-BrPA; (b) targeting the pyruvate pathway may improve response to endocrine therapy in ERα(+) breast cancer with p53 dysfunction.
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Affiliation(s)
- Manuel Rieber
- IVIC, Tumor Cell Biology Laboratory, Center for Microbiology & Cell Biology Apartado 21827, Caracas 1020 A, Venezuela.
| | - Mary Strasberg-Rieber
- IVIC, Tumor Cell Biology Laboratory, Center for Microbiology & Cell Biology Apartado 21827, Caracas 1020 A, Venezuela.
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12
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Modeling the estrogen receptor to growth factor receptor signaling switch in human breast cancer cells. FEBS Lett 2013; 587:3327-34. [PMID: 23994522 DOI: 10.1016/j.febslet.2013.08.022] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 08/06/2013] [Accepted: 08/12/2013] [Indexed: 02/07/2023]
Abstract
Breast cancer cells develop resistance to endocrine therapies by shifting between estrogen receptor (ER)-regulated and growth factor receptor (GFR)-regulated survival signaling pathways. To study this switch, we propose a mathematical model of crosstalk between these pathways. The model explains why MCF7 sub-clones transfected with HER2 or EGFR show three GFR-distribution patterns, and why the bimodal distribution pattern can be reversibly modulated by estrogen. The model illustrates how transient overexpression of ER activates GFR signaling and promotes estrogen-independent growth. Understanding this survival-signaling switch can help in the design of future therapies to overcome resistance in breast cancer.
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13
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Droog M, Beelen K, Linn S, Zwart W. Tamoxifen resistance: from bench to bedside. Eur J Pharmacol 2013; 717:47-57. [PMID: 23545365 DOI: 10.1016/j.ejphar.2012.11.071] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2012] [Revised: 11/20/2012] [Accepted: 11/23/2012] [Indexed: 01/09/2023]
Abstract
Although tamoxifen is a classical example of a targeted drug, a substantial proportion of estrogen receptor alpha positive breast cancer patients does not benefit from the drug. Over the last few decades, many potential biomarkers have been discovered in cell biological studies that may aid in the prediction of tamoxifen sensitivity and guide in treatment selection. Nonetheless, the transition of such a biomarker from the scientific community towards a diagnostic test that can be used in daily clinical practice has been far from ideal, and such markers seldom face clinical introduction. From a large number of potential predictive biomarkers as described in cell biological literature, the clinical (translational) scientist has to make a decision which of these biomarkers should be tested in clinical material to determine their clinical validity. This problem is not trivial, since patient samples with clinical follow-up are a valuable asset that should therefore be cherished. In this review, we will describe a number of 'cell biological biomarkers' for tamoxifen resistance and their possible clinical implications. This may guide the clinical scientist in choosing what potential biomarkers to test on tumour samples, which may catalyse the translation of scientific discoveries into daily clinical practice of breast cancer medicine.
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Affiliation(s)
- Marjolein Droog
- Department of Molecular Pathology, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
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14
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Lao J, Madani J, Puértolas T, Álvarez M, Hernández A, Pazo-Cid R, Artal Á, Antón Torres A. Liposomal Doxorubicin in the treatment of breast cancer patients: a review. JOURNAL OF DRUG DELIVERY 2013; 2013:456409. [PMID: 23634302 PMCID: PMC3619536 DOI: 10.1155/2013/456409] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/01/2012] [Accepted: 02/10/2013] [Indexed: 01/03/2023]
Abstract
Drug delivery systems can provide enhanced efficacy and/or reduced toxicity for anticancer agents. Liposome drug delivery systems are able to modify the pharmacokinetics and biodistribution of cytostatic agents, increasing the concentration of the drug released to neoplastic tissue and reducing the exposure of normal tissue. Anthracyclines are a key drug in the treatment of both metastatic and early breast cancer, but one of their major limitations is cardiotoxicity. One of the strategies designed to minimize this side effect is liposome encapsulation. Liposomal anthracyclines have achieved highly efficient drug encapsulation and they have proven to be effective and with reduced cardiotoxicity, as a single agent or in combination with other drugs for the treatment of either anthracyclines-treated or naïve metastatic breast cancer patients. Of particular interest is the use of the combination of liposomal anthracyclines and trastuzumab in patients with HER2-overexpressing breast cancer. In this paper, we discuss the different studies on liposomal doxorubicin in metastatic and early breast cancer therapy.
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Affiliation(s)
- Juan Lao
- Medical Oncology Department, Miguel Servet University Hospital, Paseo Isabel la Católica, 1-3, 50009 Zaragoza, Spain
- Aragón Institute of Health Sciences, Avda. San Juan Bosco, 13, planta 1, 50009 Zaragoza, Spain
| | - Julia Madani
- Medical Oncology Department, Miguel Servet University Hospital, Paseo Isabel la Católica, 1-3, 50009 Zaragoza, Spain
- Aragón Institute of Health Sciences, Avda. San Juan Bosco, 13, planta 1, 50009 Zaragoza, Spain
| | - Teresa Puértolas
- Medical Oncology Department, Miguel Servet University Hospital, Paseo Isabel la Católica, 1-3, 50009 Zaragoza, Spain
- Aragón Institute of Health Sciences, Avda. San Juan Bosco, 13, planta 1, 50009 Zaragoza, Spain
| | - María Álvarez
- Medical Oncology Department, Miguel Servet University Hospital, Paseo Isabel la Católica, 1-3, 50009 Zaragoza, Spain
| | - Alba Hernández
- Medical Oncology Department, Miguel Servet University Hospital, Paseo Isabel la Católica, 1-3, 50009 Zaragoza, Spain
| | - Roberto Pazo-Cid
- Medical Oncology Department, Miguel Servet University Hospital, Paseo Isabel la Católica, 1-3, 50009 Zaragoza, Spain
- Aragón Institute of Health Sciences, Avda. San Juan Bosco, 13, planta 1, 50009 Zaragoza, Spain
| | - Ángel Artal
- Medical Oncology Department, Miguel Servet University Hospital, Paseo Isabel la Católica, 1-3, 50009 Zaragoza, Spain
- Aragón Institute of Health Sciences, Avda. San Juan Bosco, 13, planta 1, 50009 Zaragoza, Spain
| | - Antonio Antón Torres
- Medical Oncology Department, Miguel Servet University Hospital, Paseo Isabel la Católica, 1-3, 50009 Zaragoza, Spain
- Aragón Institute of Health Sciences, Avda. San Juan Bosco, 13, planta 1, 50009 Zaragoza, Spain
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Tu CC, Kumar VB, Day CH, Kuo WW, Yeh SP, Chen RJ, Liao CR, Chen HY, Tsai FJ, Wu WJ, Huang CY. Estrogen receptor α (ESR1) over-expression mediated apoptosis in Hep3B cells by binding with SP1 proteins. J Mol Endocrinol 2013; 51:203-12. [PMID: 23733894 DOI: 10.1530/jme-13-0085] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Previous studies have reported that estrogen receptors (ERs) are expressed in normal human liver, chronic hepatitis, and benign hepatic tumor tissues. However, decreased expression of ERs can be observed in hepatocellular carcinoma (HCC) and the role of ERs in HCC is not fully understood. Thus, the present study aimed to investigate the molecular mechanism induced by the overexpression of ERα (ERα (ESR1)) in Hep3B cells. We first detected the induction of apoptosis in ER-negative Hep3B cells using DNA fragmentation assay and flow cytometry. We found that ERα and ERα plus 17β-estradiol treatment increased apoptosis in Hep3B cells. Additionally, western blotting showed increased expression of active caspase 3 and tumor necrosis factor α (TNFα (TNF)) in ERα-transfected cells. To further understand the importance of SP1-binding sites in the TNFα promoter, ERα-negative Hep3B cells were co-transfected with ERα and a wild-type TNFα plasmid or TNFα with deleted SP1 regions. Deletion of both distant and primal SP1 sites abolished the activity of ERα, and similar results were observed by blocking the expression of SP1 protein using mithramycin (MA). This result indicates that SP1 protein is essential for ERα-activated TNFα promoter activity. Co-immunoprecipitation assay further confirmed the binding interaction between ERα and SP1 in a ligand-dependent manner. In general, we demonstrate that the overexpression of ERα mediates apoptosis in ERα-negative Hep3B cells by the binding of ERα to SP1 protein. Additionally, this ERα-SP1 complex binds to the proximal and distal sites of the TNFα gene promoter and further induces the expression of active caspase 3 in a ligand-dependent manner.
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Affiliation(s)
- Chuan-Chou Tu
- Institute of Medical and Molecular Toxicology and Institute of Medicine, Chung Shan University, Taichung, Taiwan Division of Chest Medicine, Department of Internal Medicine, Armed Force Taichung General Hospital, Taichung, Taiwan
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16
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Wong C, Chen S. The development, application and limitations of breast cancer cell lines to study tamoxifen and aromatase inhibitor resistance. J Steroid Biochem Mol Biol 2012; 131:83-92. [PMID: 22265958 PMCID: PMC3369003 DOI: 10.1016/j.jsbmb.2011.12.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2011] [Revised: 11/28/2011] [Accepted: 12/12/2011] [Indexed: 12/20/2022]
Abstract
Estrogen plays important roles in hormone receptor-positive breast cancer. Endocrine therapies, such as the antiestrogen tamoxifen, antagonize the binding of estrogen to estrogen receptor (ER), whereas aromatase inhibitors (AIs) directly inhibit the production of estrogen. Understanding the mechanisms of endocrine resistance and the ways in which we may better treat these types of resistance has been aided by the development of cellular models for resistant breast cancers. In this review, we will discuss what is known thus far regarding both de novo and acquired resistance to tamoxifen or AIs. Our laboratory has generated a collection of AI- and tamoxifen-resistant cell lines in order to comprehensively study the individual types of resistance mechanisms. Through the use of microarray analysis, we have determined that our cell lines resistant to a particular AI (anastrozole, letrozole, or exemestane) or tamoxifen are distinct from each other, indicating that these mechanisms can be quite complex. Furthermore, we will describe two novel de novo AI-resistant cell lines that were generated from our laboratory. Initial characterization of these cells reveals that they are distinct from our acquired AI-resistant cell models. In addition, we will review potential therapies which may be useful for overcoming resistant breast cancers through studies using endocrine resistant cell lines. Finally, we will discuss the benefits and shortcomings of cell models. Together, the information presented in this review will provide us a better understanding of acquired and de novo resistance to tamoxifen and AI therapies, the use of appropriate cell models to better study these types of breast cancer, which are valuable for identifying novel treatments and strategies for overcoming both tamoxifen and AI-resistant breast cancers.
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Affiliation(s)
- Cynthie Wong
- Division of Tumor Cell Biology, Beckman Research Institute of the City of Hope, Duarte, CA 91010, USA
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The treatment of breast cancer using liposome technology. JOURNAL OF DRUG DELIVERY 2012; 2012:212965. [PMID: 22506119 PMCID: PMC3312267 DOI: 10.1155/2012/212965] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Accepted: 12/01/2011] [Indexed: 12/13/2022]
Abstract
Liposome-based chemotherapeutics used in the treatment of breast cancer can in principle enhance the therapeutic index of otherwise unencapsulated anticancer drugs. This is partially attributed to the fact that encapsulation of cytotoxic agents within liposomes allows for increased concentrations of the drug to be delivered to the tumor site. In addition, the presence of the phospholipid bilayer prevents the encapsulated active form of the drug from being broken down in the body prior to reaching tumor tissue and also serves to minimize exposure of the drug to healthy sensitive tissue. While clinically approved liposome-based chemotherapeutics such as Doxil have proven to be quite effective in the treatment of breast cancer, significant challenges remain involving poor drug transfer between the liposome and cancerous cells. In this review, we discuss the recent advancements made in the development of liposome-based chemotherapeutics with respect to improved drug transfer for use in breast cancer therapy.
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18
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Zhang X, Mukerji R, Samadi AK, Cohen MS. Down-regulation of estrogen receptor-alpha and rearranged during transfection tyrosine kinase is associated with withaferin a-induced apoptosis in MCF-7 breast cancer cells. BMC COMPLEMENTARY AND ALTERNATIVE MEDICINE 2011; 11:84. [PMID: 21978374 PMCID: PMC3198756 DOI: 10.1186/1472-6882-11-84] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Accepted: 10/06/2011] [Indexed: 12/21/2022]
Abstract
BACKGROUND Withaferin A (WA), a naturally occurring withanolide, induces apoptosis in both estrogen-responsive MCF-7 and estrogen-independent MDA-MB-231 breast cancer cell lines with higher sensitivity in MCF-7 cells, but the underlying mechanisms are not well defined. The purpose of this study was to determine the anti-cancer effects of WA in MCF-7 breast cancer cells and explore alterations in estrogen receptor alpha (ERα) and its associated molecules in vitro as novel mechanisms of WA action. METHODS The effects of WA on MCF-7 viability and proliferation were evaluated by 3-(4, 5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay and trypan blue exclusion assays. Apoptosis was evaluated by Annexin V-fluorescein isothiocyanate (FITC)/propidium iodide (PI) flow cytometry and Western blot analysis of poly (ADP-ribose) polymerase (PARP) cleavage. Cell cycle effects were analyzed by PI flow cytometry. Western blotting was also conducted to examine alterations in the expression of ERα and pathways that are associated with ERα function. RESULTS WA resulted in growth inhibition and decreased viability in MCF-7 cells with an IC50 of 576 nM for 72 h. It also caused a dose- and time-dependent apoptosis and G2/M cell cycle arrest. WA-induced apoptosis was associated with down-regulation of ERα, REarranged during Transfection (RET) tyrosine kinase, and heat shock factor-1 (HSF1), as well as up-regulation of phosphorylated p38 mitogen-activated protein kinase (phospho-p38 MAPK), p53 and p21 protein expression. Co-treatment with protein synthesis inhibitor cycloheximide or proteasome inhibitor MG132 revealed that depletion of ERα by WA is post-translational, due to proteasome-dependent ERα degradation. CONCLUSIONS Taken together, down-regulation of ERα, RET, HSF1 and up-regulation of phospho-p38 MAPK, p53, p21 are involved in the pro-apoptotic and growth-inhibitory effects of WA in MCF-7 breast cancer cells in vitro. Down-regulation of ERα protein levels by WA is caused by proteasome-dependent ERα degradation.
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Giamas G, Filipović A, Jacob J, Messier W, Zhang H, Yang D, Zhang W, Shifa BA, Photiou A, Tralau-Stewart C, Castellano L, Green AR, Coombes RC, Ellis IO, Ali S, Lenz HJ, Stebbing J. Kinome screening for regulators of the estrogen receptor identifies LMTK3 as a new therapeutic target in breast cancer. Nat Med 2011; 17:715-9. [PMID: 21602804 DOI: 10.1038/nm.2351] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Accepted: 03/10/2011] [Indexed: 12/20/2022]
Abstract
Therapies targeting estrogen receptor α (ERα, encoded by ESR1) have transformed the treatment of breast cancer. However, large numbers of women relapse, highlighting the need for the discovery of new regulatory targets modulating ERα pathways. An siRNA screen identified kinases whose silencing alters the estrogen response including those previously implicated in regulating ERα activity (such as mitogen-activated protein kinase and AKT). Among the most potent regulators was lemur tyrosine kinase-3 (LMTK3), for which a role has not previously been assigned. In contrast to other modulators of ERα activity, LMTK3 seems to have been subject to Darwinian positive selection, a noteworthy result given the unique susceptibility of humans to ERα+ breast cancer. LMTK3 acts by decreasing the activity of protein kinase C (PKC) and the phosphorylation of AKT (Ser473), thereby increasing binding of forkhead box O3 (FOXO3) to the ESR1 promoter. LMTK3 phosphorylated ERα, protecting it from proteasomal degradation in vitro. Silencing of LMTK3 reduced tumor volume in an orthotopic mouse model and abrogated proliferation of ERα+ but not ERα- cells, indicative of its role in ERα activity. In human cancers, LMTK3 abundance and intronic polymorphisms were significantly associated with disease-free and overall survival and predicted response to endocrine therapies. These findings yield insights into the natural history of breast cancer in humans and reveal LMTK3 as a new therapeutic target.
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Affiliation(s)
- Georgios Giamas
- Department of Surgery and Cancer, Imperial College London, Hammersmith Hospital Campus, London, UK.
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