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Xie Y, Shan M, Yu J, Du Y, Wu C, Liu S, Li J, Xiao Y, Yan Y, Li N, Qin J, Lan L, Wang Y. LINC00173 silence and estrone supply suppress ER + breast cancer by estrogen receptor α degradation and LITAF activation. Cancer Sci 2024; 115:2318-2332. [PMID: 38705575 PMCID: PMC11247560 DOI: 10.1111/cas.16201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 04/03/2024] [Accepted: 04/17/2024] [Indexed: 05/07/2024] Open
Abstract
Persistent activation of estrogen receptor alpha (ERα)-mediated estrogen signaling plays a pivotal role in driving the progression of estrogen receptor positive (ER+) breast cancer (BC). In the current study, LINC00173, a long non-coding RNA, was found to bind both ERα and lipopolysaccharide (LPS)-induced tumor necrosis factor alpha (TNFα) factor (LITAF), then cooperatively to inhibit ERα protein degradation by impeding the nuclear export of ERα. Concurrently, LITAF was found to attenuate TNFα transcription after binding to LINC00173, and this attenuating transcriptional effect was quite significant under lipopolysaccharide stimulation. Distinct functional disparities between estrogen subtypes emerge, with estradiol synergistically promoting ER+ BC cell growth with LINC00173, while estrone (E1) facilitated LITAF-transcriptional activation. In terms of therapeutic significance, silencing LINC00173 alongside moderate addition of E1 heightened TNFα and induced apoptosis, effectively inhibiting ER+ BC progression.
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Affiliation(s)
- Yu Xie
- School of Medicine, Nankai University, Tianjin, China
| | - Meihua Shan
- Department of Clinical Biochemistry, Army Medical University (Third Military Medical University), Chongqing, China
| | - Jing Yu
- School of Medicine, Nankai University, Tianjin, China
| | - Yongjun Du
- School of Medicine, Nankai University, Tianjin, China
| | - Chengkun Wu
- School of Medicine, Nankai University, Tianjin, China
| | - Shujing Liu
- School of Medicine, Nankai University, Tianjin, China
| | - Jiayin Li
- School of Medicine, Nankai University, Tianjin, China
| | - Yupeng Xiao
- School of Medicine, Nankai University, Tianjin, China
| | - Yan Yan
- Tianjin Key Laboratory of Oral and Maxillofacial Function Reconstruction, Hospital of Stomatology, Nankai University, Tianjin, China
| | - Ning Li
- Institute of Disaster and Emergency Medicine, Tianjin University, Tianjin, China
| | - Junfang Qin
- School of Medicine, Nankai University, Tianjin, China
| | - Lan Lan
- Department of Integrated Traditional & Western Medicine, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China
| | - Yue Wang
- School of Medicine, Nankai University, Tianjin, China
- Tianjin Key Laboratory of Oral and Maxillofacial Function Reconstruction, Hospital of Stomatology, Nankai University, Tianjin, China
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2
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Eerlings R, Gupta P, Lee XY, Nguyen T, El Kharraz S, Handle F, Smeets E, Moris L, Devlies W, Vandewinkel B, Thiry I, Ta DT, Gorkovskiy A, Voordeckers K, Henckaerts E, Pinheiro VB, Claessens F, Verstrepen KJ, Voet A, Helsen C. Rational evolution for altering the ligand preference of estrogen receptor alpha. Protein Sci 2024; 33:e4940. [PMID: 38511482 PMCID: PMC10955623 DOI: 10.1002/pro.4940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 02/07/2024] [Accepted: 02/09/2024] [Indexed: 03/22/2024]
Abstract
Estrogen receptor α is commonly used in synthetic biology to control the activity of genome editing tools. The activating ligands, estrogens, however, interfere with various cellular processes, thereby limiting the applicability of this receptor. Altering its ligand preference to chemicals of choice solves this hurdle but requires adaptation of unspecified ligand-interacting residues. Here, we provide a solution by combining rational protein design with multi-site-directed mutagenesis and directed evolution of stably integrated variants in Saccharomyces cerevisiae. This method yielded an estrogen receptor variant, named TERRA, that lost its estrogen responsiveness and became activated by tamoxifen, an anti-estrogenic drug used for breast cancer treatment. This tamoxifen preference of TERRA was maintained in mammalian cells and mice, even when fused to Cre recombinase, expanding the mammalian synthetic biology toolbox. Not only is our platform transferable to engineer ligand preference of any steroid receptor, it can also profile drug-resistance landscapes for steroid receptor-targeted therapies.
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Affiliation(s)
- Roy Eerlings
- Molecular Endocrinology Laboratory, Department of Cellular and Molecular MedicineKU LeuvenLeuvenBelgium
- Laboratory of Systems BiologyVIB‐KU Leuven Center for MicrobiologyLeuvenBelgium
- Laboratory for Genetics and Genomics, Center of Microbial and Plant Genetics, Department M2SKU LeuvenHeverleeBelgium
| | - Purvi Gupta
- Laboratory of Biomolecular Modelling and Design, Department of ChemistryKU LeuvenHeverleeBelgium
| | - Xiao Yin Lee
- Molecular Endocrinology Laboratory, Department of Cellular and Molecular MedicineKU LeuvenLeuvenBelgium
| | - Tien Nguyen
- Laboratory of Biomolecular Modelling and Design, Department of ChemistryKU LeuvenHeverleeBelgium
| | - Sarah El Kharraz
- Molecular Endocrinology Laboratory, Department of Cellular and Molecular MedicineKU LeuvenLeuvenBelgium
| | - Florian Handle
- Molecular Endocrinology Laboratory, Department of Cellular and Molecular MedicineKU LeuvenLeuvenBelgium
| | - Elien Smeets
- Molecular Endocrinology Laboratory, Department of Cellular and Molecular MedicineKU LeuvenLeuvenBelgium
| | - Lisa Moris
- Molecular Endocrinology Laboratory, Department of Cellular and Molecular MedicineKU LeuvenLeuvenBelgium
- Department of UrologyUniversity Hospitals LeuvenLeuvenBelgium
| | - Wout Devlies
- Molecular Endocrinology Laboratory, Department of Cellular and Molecular MedicineKU LeuvenLeuvenBelgium
- Department of UrologyUniversity Hospitals LeuvenLeuvenBelgium
| | - Bram Vandewinkel
- Laboratory of Viral Cell Biology and Therapeutics, Department of Cellular and Molecular Medicine, Department of Microbiology, Immunology and TransplantationKU LeuvenLeuvenBelgium
| | - Irina Thiry
- Laboratory of Viral Cell Biology and Therapeutics, Department of Cellular and Molecular Medicine, Department of Microbiology, Immunology and TransplantationKU LeuvenLeuvenBelgium
| | - Duy Tien Ta
- Laboratory of Viral Cell Biology and Therapeutics, Department of Cellular and Molecular Medicine, Department of Microbiology, Immunology and TransplantationKU LeuvenLeuvenBelgium
| | - Anton Gorkovskiy
- Laboratory of Systems BiologyVIB‐KU Leuven Center for MicrobiologyLeuvenBelgium
- Laboratory for Genetics and Genomics, Center of Microbial and Plant Genetics, Department M2SKU LeuvenHeverleeBelgium
| | - Karin Voordeckers
- Laboratory of Systems BiologyVIB‐KU Leuven Center for MicrobiologyLeuvenBelgium
- Laboratory for Genetics and Genomics, Center of Microbial and Plant Genetics, Department M2SKU LeuvenHeverleeBelgium
| | - Els Henckaerts
- Laboratory of Viral Cell Biology and Therapeutics, Department of Cellular and Molecular Medicine, Department of Microbiology, Immunology and TransplantationKU LeuvenLeuvenBelgium
| | - Vitor B. Pinheiro
- KU Leuven, Department of Pharmaceutical and Pharmacological SciencesRega Institute for Medical ResearchLeuvenBelgium
| | - Frank Claessens
- Molecular Endocrinology Laboratory, Department of Cellular and Molecular MedicineKU LeuvenLeuvenBelgium
| | - Kevin J. Verstrepen
- Laboratory of Systems BiologyVIB‐KU Leuven Center for MicrobiologyLeuvenBelgium
- Laboratory for Genetics and Genomics, Center of Microbial and Plant Genetics, Department M2SKU LeuvenHeverleeBelgium
| | - Arnout Voet
- Laboratory of Biomolecular Modelling and Design, Department of ChemistryKU LeuvenHeverleeBelgium
| | - Christine Helsen
- Molecular Endocrinology Laboratory, Department of Cellular and Molecular MedicineKU LeuvenLeuvenBelgium
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3
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Gao S, Wang Y, Xu Y, Liu L, Liu S. USP46 enhances tamoxifen resistance in breast cancer cells by stabilizing PTBP1 to facilitate glycolysis. Biochim Biophys Acta Mol Basis Dis 2024; 1870:167011. [PMID: 38176460 DOI: 10.1016/j.bbadis.2023.167011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Revised: 12/10/2023] [Accepted: 12/27/2023] [Indexed: 01/06/2024]
Abstract
Tamoxifen (TAM) is the primary drug for treating estrogen receptor alpha-positive (ER+) breast cancer (BC). However, resistance to TAM can develop in some patients, limiting its therapeutic efficacy. The ubiquitin-specific protease (USP) family has been associated with the development, progression, and drug resistance of various cancers. To explore the role of USPs in TAM resistance in BC, we used qRT-PCR to compare USP expression between TAM-sensitive (MCF-7 and T47D) and TAM-resistant cells (MCF-7R and T47DR). We then modulated USP46 expression and examined its impact on cell proliferation, drug resistance (via CCK-8 and EdU experiments), glycolysis levels (using a glycolysis detection assay), protein interactions (confirmed by co-IP), and protein changes (analyzed through Western blotting). Our findings revealed that USP46 was significantly overexpressed in TAM-resistant BC cells, leading to the inhibition of the ubiquitin degradation of polypyrimidine tract-binding protein 1 (PTBP1). Overexpression of PTBP1 increased the PKM2/PKM1 ratio, promoted glycolysis, and intensified TAM resistance in BC cells. Knockdown of USP46 induced downregulation of PTBP1 protein by promoting its K48-linked ubiquitination, resulting in a decreased PKM2/PKM1 ratio, reduced glycolysis, and heightened TAM sensitivity in BC cells. In conclusion, this study highlights the critical role of the USP46/PTBP1/PKM2 axis in TAM resistance in BC. Targeted therapy against USP46 may represent a promising strategy to improve the prognosis of TAM-resistant patients.
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Affiliation(s)
- Shun Gao
- Department of Breast and Thyroid Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Yuan Wang
- Department of Breast and Thyroid Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Yingkun Xu
- Department of Breast and Thyroid Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Li Liu
- Department of Breast and Thyroid Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Shengchun Liu
- Department of Breast and Thyroid Surgery, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China.
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Singh A, Mishra R, Mazumder A. Breast cancer and its therapeutic targets: A comprehensive review. Chem Biol Drug Des 2024; 103:e14384. [PMID: 37919259 DOI: 10.1111/cbdd.14384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2023] [Revised: 09/14/2023] [Accepted: 10/17/2023] [Indexed: 11/04/2023]
Abstract
Breast cancer is a common and deadly disease, so there is a constant need for research to find efficient targets and therapeutic approaches. Breast cancer can be classified on a molecular and histological base. Breast cancer can be divided into ER (estrogen receptor)-positive and ER-negative, HER2 (human epidermal growth factor receptor2)-positive and HER2-negative subtypes based on the presence of specific biomarkers. Targeting hormone receptors, such as the HER2, progesterone receptor (PR), and ER, is very significant and plays a vital role in the onset and progression of breast cancer. Endocrine treatments and HER2-targeted drugs are examples of targeted therapies now being used against these receptors. Emerging immune-based medicines with promising outcomes in the treatment of breast cancer include immune checkpoint inhibitors, cancer vaccines, and adoptive T-cell therapy. It is also explored how immune cells and the tumor microenvironment affect breast cancer development and treatment response. The major biochemical pathways, signaling cascades, and DNA repair mechanisms that are involved in the development and progression of breast cancer, include the PI3K/AKT/mTOR system, the MAPK pathway, and others. These pathways are intended to be inhibited by a variety of targeted drugs, which are then delivered with the goal of restoring normal cellular function. This review aims to shed light on types of breast cancer with the summarization of different therapeutic approaches which can target different pathways for tailored medicines and better patient outcomes.
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Affiliation(s)
- Ayushi Singh
- Noida Institute of Engineering and Technology (Pharmacy Institute), Greater Noida, Uttar Pradesh, India
| | - Rakhi Mishra
- Noida Institute of Engineering and Technology (Pharmacy Institute), Greater Noida, Uttar Pradesh, India
| | - Avijit Mazumder
- Noida Institute of Engineering and Technology (Pharmacy Institute), Greater Noida, Uttar Pradesh, India
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5
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Xie Y, Han X, Yu J, Yuan M, Yan Y, Qin J, Lan L, Wang Y. EGR3 and estrone are involved in the tamoxifen resistance and progression of breast cancer. J Cancer Res Clin Oncol 2023; 149:18103-18117. [PMID: 37999751 DOI: 10.1007/s00432-023-05503-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2023] [Accepted: 10/31/2023] [Indexed: 11/25/2023]
Abstract
BACKGROUND Tamoxifen (Tam) is an effective treatment for estrogen receptor (ER) positive breast cancer. However, a significant proportion of patients develop resistance under treatment, presenting a therapeutic challenge. The study aims to determine the role of early growth response protein (EGR) 3 in tamoxifen resistance (TamR) and elucidate its molecular mechanism. METHODS TamR cell models were established and NGS was used to screening signaling alternation. Western blot and qRT-PCR were used to analysis the expression of ERα, EGR3, MCL1 and factors associated with apoptosis. CCK8, colony formation and apoptosis assay were used to analysis resistance to Tam. Immunofluorescence, chromatin immunoprecipitation, and dual luciferase assays were used to investigate mechanism of regulation. RESULTS We observed that EGR3, a deeply rooted ERα response factor, showed increased upregulation in response to both estrone (E1) and Tam in TamR cells with elevated level of E1 and ERα expression, indicating a potential connection between EGR3 and TamR. Mechanically, manipulating EGR3 expression revealed that it imparted resistance to Tam through increased expression of the downstream molecule MCL1 (apoptosis suppressor gene) that it regulated. Mechanismly, EGR3 directly binds to the promoter of the anti-apoptotic factor MCL1 gene, facilitating its transcription. Furthermore, apoptosis assays revealed that E1 reduces Tam induced apoptosis by upregulating EGR3 expression. Importantly, clinical public database confirmed the high expression of EGR3 in breast cancer tissue and in Tam-treated patients. CONCLUSIONS These findings shed light on the novel estrogen/EGR3/MCL1 axis and its role in inducing TamR in ER positive breast cancer. EGR3 emerges as a promising target to overcome TamR. The elucidation of this mechanism holds potential for the development of new therapeutic modalities to overcome endocrine therapy resistance in clinical settings.
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Affiliation(s)
- Yu Xie
- School of Medicine, Nankai University, Tianjin, 300071, China
| | - Xiao Han
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Nankai University, Tianjin, 300350, China
| | - Jing Yu
- School of Medicine, Nankai University, Tianjin, 300071, China
| | - Mengci Yuan
- School of Medicine, Nankai University, Tianjin, 300071, China
| | - Yan Yan
- Tianjin Key Laboratory of Oral and Maxillofacial Function Reconstruction, Hospital of Stomatology, Nankai University, Tianjin, 300041, China
| | - Junfang Qin
- School of Medicine, Nankai University, Tianjin, 300071, China
| | - Lan Lan
- Department of Integrated Traditional and Western Medicine, Tianjin Medical University Cancer Institute and Hospital, Tianjin, 300060, China
| | - Yue Wang
- School of Medicine, Nankai University, Tianjin, 300071, China.
- Tianjin Key Laboratory of Oral and Maxillofacial Function Reconstruction, Hospital of Stomatology, Nankai University, Tianjin, 300041, China.
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6
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Chandarlapaty S, Dickler MN, Perez Fidalgo JA, Villanueva-Vázquez R, Giltnane J, Gates M, Chang CW, Cheeti S, Fredrickson J, Wang X, Collier A, Moore HM, Metcalfe C, Lauchle J, Humke EW, Bardia A. An Open-label Phase I Study of GDC-0927 in Postmenopausal Women with Locally Advanced or Metastatic Estrogen Receptor-Positive Breast Cancer. Clin Cancer Res 2023; 29:2781-2790. [PMID: 37261814 PMCID: PMC10390885 DOI: 10.1158/1078-0432.ccr-23-0011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 03/01/2023] [Accepted: 05/30/2023] [Indexed: 06/02/2023]
Abstract
PURPOSE GDC-0927 is a novel, potent, nonsteroidal, orally bioavailable, selective estrogen receptor (ER) degrader that induces tumor regression in ER+ breast cancer xenograft models. PATIENTS AND METHODS This phase I dose-escalation multicenter study enrolled postmenopausal women with ER+/HER2- metastatic breast cancer to determine the safety, pharmacokinetics, and recommended phase II dose of GDC-0927. Pharmacodynamics was assessed with [18F]-fluoroestradiol (FES) PET scans. RESULTS Forty-two patients received GDC-0927 once daily. The MTD was not reached. The most common adverse events (AE) regardless of causality were nausea, constipation, diarrhea, arthralgia, fatigue, hot flush, back pain, and vomiting. There were no deaths, grade 4/5 AEs, or treatment-related serious AEs. Two patients experienced grade 2 AEs of special interest of deep vein thrombosis and jugular vein thrombosis, both considered unrelated to GDC-0927. Following dosing, approximately 1.6-fold accumulation was observed, consistent with the observed half-life and dosing frequency. There were no complete or partial responses. Pharmacodynamics was supported by >90% reduction in FES uptake and an approximately 40% reduction in ER expression, suggesting ER degradation is not the mechanistic driver of ER antagonism. Twelve patients (29%) achieved clinical benefit; 17 patients (41%) showed a confirmed best overall response of stable disease. Baseline levels of ER and progesterone receptor protein and mutant ESR1 circulating tumor DNA did not correlate with clinical benefit. CONCLUSIONS GDC-0927 appeared to be well tolerated with pharmacokinetics supporting once-daily dosing. There was evidence of target engagement and preliminary evidence of antitumor activity in heavily pretreated patients with advanced/metastatic ER+/HER2- breast cancer with and without ESR1 mutations.
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Affiliation(s)
| | | | | | | | | | - Mary Gates
- Genentech, Inc., South San Francisco, California
| | | | | | | | | | - Ann Collier
- Genentech, Inc., South San Francisco, California
| | | | | | | | | | - Aditya Bardia
- Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, Massachusetts
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7
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Treeck O, Haerteis S, Ortmann O. Non-Coding RNAs Modulating Estrogen Signaling and Response to Endocrine Therapy in Breast Cancer. Cancers (Basel) 2023; 15:cancers15061632. [PMID: 36980520 PMCID: PMC10046587 DOI: 10.3390/cancers15061632] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 02/28/2023] [Accepted: 03/02/2023] [Indexed: 03/09/2023] Open
Abstract
The largest part of human DNA is transcribed into RNA that does not code for proteins. These non-coding RNAs (ncRNAs) are key regulators of protein-coding gene expression and have been shown to play important roles in health, disease and therapy response. Today, endocrine therapy of ERα-positive breast cancer (BC) is a successful treatment approach, but resistance to this therapy is a major clinical problem. Therefore, a deeper understanding of resistance mechanisms is important to overcome this resistance. An increasing amount of evidence demonstrate that ncRNAs affect the response to endocrine therapy. Thus, ncRNAs are considered versatile biomarkers to predict or monitor therapy response. In this review article, we intend to give a summary and update on the effects of microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) on estrogen signaling in BC cells, this pathway being the target of endocrine therapy, and their role in therapy resistance. For this purpose, we reviewed articles on these topics listed in the PubMed database. Finally, we provide an assessment regarding the clinical use of these ncRNA types, particularly their circulating forms, as predictive BC biomarkers and their potential role as therapy targets to overcome endocrine resistance.
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Affiliation(s)
- Oliver Treeck
- Department of Gynecology and Obstetrics, University Medical Center Regensburg, 93053 Regensburg, Germany
- Correspondence:
| | - Silke Haerteis
- Institute for Molecular and Cellular Anatomy, University of Regensburg, 93053 Regensburg, Germany
| | - Olaf Ortmann
- Department of Gynecology and Obstetrics, University Medical Center Regensburg, 93053 Regensburg, Germany
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8
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Iwata H, Nakamura R, Masuda N, Yamashita T, Yamamoto Y, Kobayashi K, Tsurutani J, Iwasa T, Yonemori K, Tamura K, Aruga T, Tokunaga E, Kaneko K, Lee MJ, Yuno A, Kawabata A, Seike T, Kaneda A, Nishimura Y, Trepel JB, Saji S. Efficacy and exploratory biomarker analysis of entinostat plus exemestane in advanced or recurrent breast cancer: phase II randomized controlled trial. Jpn J Clin Oncol 2023; 53:4-15. [PMID: 36398439 PMCID: PMC9825728 DOI: 10.1093/jjco/hyac166] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 10/07/2022] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND We aimed to confirm the efficacy and safety of the oral histone deacetylase inhibitor entinostat in Japanese patients with hormone receptor-positive advanced/recurrent breast cancer and to explore potential biomarkers. METHODS This phase II, double-blind, randomized, placebo-controlled trial (ClinicalTrials.gov; NCT03291886) was conducted at 28 Japanese sites (September 2017-July 2020; interim analysis cutoff: April 2019). Patients with progression/relapse following non-steroidal aromatase inhibitors were randomized 1:1 to entinostat (5 mg/week) or placebo, plus exemestane (25 mg/day). Primary endpoint was progression-free survival; secondary endpoints included overall survival and safety. Exploratory biomarker outcomes included lysine acetylation, immune cell profiles, estrogen receptor 1 mutations and plasma chemokines. RESULTS Of 133 randomized patients, 131 (65 entinostat, 66 placebo) who received study drug were analyzed. Median (95% confidence interval) progression-free survival was 5.8 (3.2-7.8) months for entinostat and 3.3 (3.1-5.8) months for placebo (hazard ratio [95% confidence interval]: 0.75 [0.50 - 1.14]; P = 0.189). Median overall survival was not reached in either group. Entinostat tended to prolong progression-free survival in patients aged ≥65 years, not endocrine resistant, or with estrogen receptor 1 Y537S mutation. Candidate biomarkers of efficacy (progression-free survival) included lysine acetylation in CD3+ cells, plasma interferon gamma-induced protein 10, dendritic cell CD86 expression, and CD4+ cell expression of human leukocyte antigen-DR and inducible T-cell co-stimulator. Safety was similar to non-Japanese populations; however, seven entinostat-treated patients (10.8%) had reversible lung injury. CONCLUSIONS In Japanese patients, the safety of entinostat plus exemestane was acceptable and progression-free survival was prolonged, although not significantly. Exploratory analyses identified potential biomarkers, including lysine acetylation, of efficacy.
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Affiliation(s)
- Hiroji Iwata
- Department of Breast Oncology, Aichi Cancer Center Hospital, Aichi, Japan
| | - Rikiya Nakamura
- Division of Breast Surgery, Chiba Cancer Center, Chiba, Japan
| | - Norikazu Masuda
- Department of Surgery, Breast Oncology, National Hospital Organization, Osaka National Hospital, Osaka, Japan
| | - Toshinari Yamashita
- Department of Breast and Endocrine Surgery, Kanagawa Cancer Center, Yokohama, Japan
| | - Yutaka Yamamoto
- Department of Breast and Endocrine Surgery, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Kokoro Kobayashi
- Department of Breast Medical Oncology, Cancer Institute Hospital of Japanese Foundation for Cancer Research, Tokyo, Japan
| | - Junji Tsurutani
- Advanced Cancer Translational Research Institute, Showa University, Tokyo, Japan
| | - Tsutomu Iwasa
- Advanced Cancer Translational Research Institute, Showa University, Tokyo, Japan
| | - Kan Yonemori
- Department of Medical Oncology, National Cancer Center Hospital, Tokyo, Japan
| | - Kenji Tamura
- Department of Medical Oncology, National Cancer Center Hospital, Tokyo, Japan
| | - Tomoyuki Aruga
- Department of Breast Surgery, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, Tokyo, Japan
| | - Eriko Tokunaga
- Department of Breast Oncology, National Hospital Organization Kyushu Cancer Center, Fukuoka, Japan
| | - Koji Kaneko
- Department of Surgery, Niigata Cancer Center Hospital, Niigata, Japan
| | - Min-Jung Lee
- Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Akira Yuno
- Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | | | | | - Ayumi Kaneda
- R&D Division, Kyowa Kirin Co., Ltd, Tokyo, Japan
| | | | - Jane B Trepel
- Developmental Therapeutics Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Shigehira Saji
- Department of Medical Oncology, Fukushima Medical University, Fukushima, Japan
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Ubiquitin-Specific Peptidase 8 Modulates Cell Proliferation and Induces Cell Cycle Arrest and Apoptosis in Breast Cancer by Stabilizing Estrogen Receptor Alpha. JOURNAL OF ONCOLOGY 2023; 2023:8483325. [PMID: 36644233 PMCID: PMC9839415 DOI: 10.1155/2023/8483325] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 12/05/2022] [Accepted: 12/14/2022] [Indexed: 01/09/2023]
Abstract
Breast cancer (BC) is the most common neoplastic and lethal malignancy in women. Although antiendocrine therapy is the main treatment for estrogen receptor alpha (ERα)-positive BC, the development of resistance is a major clinical complication. In this study, we aimed to explore the role of ubiquitin-specific peptidase 8 (USP8) in ERα signaling and identify potential targets for endocrine resistance. Public databases were used to analyze USP8 expression, prognosis, clinical characteristics, and immune cell infiltration. Immunohistochemistry and western blot assays were used to detect protein levels and ERα signaling. Quantitative reverse transcription-PCR was used to measure ERα target gene expression. The cell counting kit-8, wound-healing, clone formation, and Transwell assays were used to investigate the effects of USP8 depletion or inhibition on cell proliferation, migration, and invasion. An immunofluorescence assay was used for localizing USP8 and ERα, and a protein stability assay was performed for detecting the degradation of ERα protein. The cell cycle and apoptosis were assessed using flow cytometry. USP8 was highly expressed in the luminal subtype of BC and was associated with poor prognosis. The infiltration levels of many immune cells were positively correlated with USP8 expression. Depletion of USP8 dramatically decreased the ERα signaling activity and weakened the proliferation, migration, and invasion capabilities of BC cells. USP8 knockdown markedly induced apoptosis and cell cycle arrest (G0/G1). Colocalization analysis and protein stability assays indicated a probable mechanism by which USP8 regulates ERα. Our study demonstrates that USP8 might be crucial in BC development and may be considered a potential target for treating ER-positive BC malignancies in vitro.
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10
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Zhang X, Yang Y, Li D, Wu Z, Liu H, Zhao Z, Zhu H, Xie F, Li X. MOF negatively regulates estrogen receptor α signaling via CUL4B-mediated protein degradation in breast cancer. Front Oncol 2022; 12:868866. [PMID: 36212422 PMCID: PMC9539768 DOI: 10.3389/fonc.2022.868866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Accepted: 09/05/2022] [Indexed: 11/29/2022] Open
Abstract
Estrogen receptor α (ERα) is the dominant tumorigenesis driver in breast cancer (BC), and ERα-positive BC (ERα+ BC) accounts for more than two-thirds of BC cases. MOF (males absent on the first) is a highly conserved histone acetyltransferase that acetylates lysine 16 of histone H4 (H4K16) and several non-histone proteins. Unbalanced expression of MOF has been identified, and high MOF expression predicted a favorable prognosis in BC. However, the association of MOF with ERα and the regulatory mechanisms of MOF in ERα signaling remain elusive. Our study revealed that the expression of MOF is negatively correlated with that of ERα in BC. In ERα+ BC cells, MOF overexpression downregulated the protein abundance of ERα in both cytoplasm and nucleus, thus attenuating ERα-mediated transactivation as well as cellular proliferation and in vivo tumorigenicity of BC cells. MOF promoted ERα protein degradation through CUL4B-mediated ubiquitin–proteasome pathway and induced HSP90 hyperacetylation that led to the loss of chaperone protection of HSP90 to ERα. We also revealed that suppression of MOF restored ERα expression and increased the sensitivity of ERα-negative BC cells to tamoxifen treatment. These results provide a new insight into the tumor-suppressive role of MOF in BC via negatively regulating ERα action, suggesting that MOF might be a potential therapeutic target for BC.
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Affiliation(s)
- Xu Zhang
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China
| | - Yang Yang
- School of Pharmacy, Binzhou Medical University, Yantai, China
| | - Danyang Li
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China
- Rehabilitation Center, Qilu Hospital, Cheelo College of Medicine, Shandong University, Jinan, China
| | - Zhen Wu
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China
| | - Haoyu Liu
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China
| | - Ziyan Zhao
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China
| | - Hongying Zhu
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China
| | - Fei Xie
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China
| | - Xiangzhi Li
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, School of Life Sciences, Shandong University, Qingdao, China
- *Correspondence: Xiangzhi Li,
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11
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Musheyev D, Alayev A. Endocrine therapy resistance: what we know and future directions. EXPLORATION OF TARGETED ANTI-TUMOR THERAPY 2022; 3:480-496. [PMID: 36071983 PMCID: PMC9446423 DOI: 10.37349/etat.2022.00096] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 05/24/2022] [Indexed: 11/19/2022] Open
Abstract
Endocrine resistance is a major hurdle in the treatment of estrogen receptor (ER)-positive breast cancer. When abnormally regulated, molecular signals responsible for cellular proliferation, as well as ER itself, allow for cellular evasion of ER-dependent treatments. Therefore, pharmacological treatments that target these evasion mechanisms are beneficial for the treatment of endocrine-resistant breast cancers. This review summarizes currently understood molecular signals that contribute to endocrine resistance and their crosstalk that stem from mitogen-activated protein kinase (MAPK), phosphoinositol-3 kinase/protein kinase B (PI3K/AKT), mechanistic target of rapamycin (mTOR), cyclin-dependent kinases 4 and 6 (CDK4/6) and aberrant ER function. Recent clinical trials that target these molecular signals as a treatment strategy for endocrine-resistant breast cancer are also highlighted.
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Affiliation(s)
- David Musheyev
- Alayev Lab, Stern College for Women, Biology Department, Yeshiva University, New York, NY 10174, USA
| | - Anya Alayev
- Alayev Lab, Stern College for Women, Biology Department, Yeshiva University, New York, NY 10174, USA
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12
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Development of Potent ERα Inhibitors: Effectively Inhibit the Growth of Breast Cancer Cells. ChemistrySelect 2022. [DOI: 10.1002/slct.202201451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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13
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Jeffreys SA, Becker TM, Khan S, Soon P, Neubauer H, de Souza P, Powter B. Prognostic and Predictive Value of CCND1/Cyclin D1 Amplification in Breast Cancer With a Focus on Postmenopausal Patients: A Systematic Review and Meta-Analysis. Front Endocrinol (Lausanne) 2022; 13:895729. [PMID: 35784572 PMCID: PMC9249016 DOI: 10.3389/fendo.2022.895729] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 05/10/2022] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Up to 80% of breast cancers (BCa) are estrogen receptor positive and current treatments target the estrogen receptor (endocrine therapies) and/or CDK4/6 (CDK4/6 inhibitors). CCND1 encodes the protein cyclin D1, responsible for regulation of G1 to S phase transition in the cell cycle. CCND1 amplification is common in BCa and contributes to increased cyclin D1 expression. As there are signalling interactions between cyclin D1 and the estrogen receptor, understanding the impact of CCND1 amplification on estrogen receptor positive patients' disease outcomes, is vital. This review aims to evaluate CCND1 amplification as a prognostic and predictive biomarker in BCa. MATERIALS AND METHODS Publications were retrieved from the databases: PubMed, MEDLINE, Embase and Cochrane library. Exclusion criteria were duplication, publication type, non-English language, in vitro and animal studies, not BCa, male BCa, premenopausal BCa, cohort size <35, CCND1 amplification not reported. Publications with cohort duplication, and inadequate recurrence free survival (RFS) and overall survival (OS) data, were also excluded. Included publications were assessed for Risk of Bias (RoB) using the Quality In Prognosis Studies tool. Statistical analyses (Inverse Variance and Mantel-Haenszel) were performed in Review Manager. The PROSPERO registration number is [CRD42020208179]. RESULTS CCND1 amplification was significantly associated with positive estrogen receptor status (OR:1.70, 95% CI:1.19-2.43, p = 0.004) and cyclin D1 overexpression (OR: 5.64, 95% CI: 2.32-13.74, p=0.0001). CCND1 amplification was significantly associated with shorter RFS (OR: 1.64, 95% CI: 1.13-2.38, p = 0.009), and OS (OR: 1.51, 95% CI: 1.19-1.92, p = 0.0008) after removal of studies with a high RoB. In endocrine therapy treated patients specifically, CCND1 amplification predicted shorter RFS (HR: 2.59, 95% CI: 1.96-3.41, p < 0.00001) and OS (HR: 1.59, 95% CI: 1.00-2.49, p = 0.05) also after removal of studies with a high RoB. CONCLUSION While a lack of standardised approach for the detection of CCND1 amplification is to be considered as a limitation, CCND1 amplification was found to be prognostic of shorter RFS and OS in BCa. CCND1 amplification is also predictive of reduced RFS and OS in endocrine therapy treated patients specifically. With standardised methods and cut offs for the detection of CCND1 amplification, CCND1 amplification would have potential as a predictive biomarker in breast cancer patients. SYSTEMATIC REVIEW REGISTRATION https://www.crd.york.ac.uk/prospero/, identifier CRD42020208179.
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Affiliation(s)
- Sarah A. Jeffreys
- Centre of Circulating Tumour Cell Diagnostics and Research, Ingham Institute of Applied Medical Research, Liverpool, NSW, Australia
- School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
- *Correspondence: Sarah A. Jeffreys,
| | - Therese M. Becker
- Centre of Circulating Tumour Cell Diagnostics and Research, Ingham Institute of Applied Medical Research, Liverpool, NSW, Australia
- South Western Sydney Clinical School, University of New South Wales, Liverpool Hospital, Liverpool, NSW, Australia
| | - Sarah Khan
- Department of Medical Oncology, Bankstown Cancer Centre, Bankstown, NSW, Australia
| | - Patsy Soon
- Centre of Circulating Tumour Cell Diagnostics and Research, Ingham Institute of Applied Medical Research, Liverpool, NSW, Australia
- South Western Sydney Clinical School, University of New South Wales, Liverpool Hospital, Liverpool, NSW, Australia
- Department of Surgery, Bankstown Hospital, Bankstown, NSW, Australia
| | - Hans Neubauer
- Department of Obstetrics and Gynaecology, University Hospital and Medical Faculty of the Heinrich-Heine University Düsseldorf, Düsseldorf, Germany
| | - Paul de Souza
- Centre of Circulating Tumour Cell Diagnostics and Research, Ingham Institute of Applied Medical Research, Liverpool, NSW, Australia
- School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
- South Western Sydney Clinical School, University of New South Wales, Liverpool Hospital, Liverpool, NSW, Australia
| | - Branka Powter
- Centre of Circulating Tumour Cell Diagnostics and Research, Ingham Institute of Applied Medical Research, Liverpool, NSW, Australia
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14
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Wright RHG, Vastolo V, Oliete JQ, Carbonell-Caballero J, Beato M. Global signalling network analysis of luminal T47D breast cancer cells in response to progesterone. Front Endocrinol (Lausanne) 2022; 13:888802. [PMID: 36034422 PMCID: PMC9403329 DOI: 10.3389/fendo.2022.888802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 07/11/2022] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Breast cancer cells enter into the cell cycle following progestin exposure by the activation of signalling cascades involving a plethora of enzymes, transcription factors and co-factors that transmit the external signal from the cell membrane to chromatin, ultimately leading to a change of the gene expression program. Although many of the events within the signalling network have been described in isolation, how they globally team up to generate the final cell response is unclear. METHODS In this study we used antibody microarrays and phosphoproteomics to reveal a dynamic global signalling map that reveals new key regulated proteins and phosphor-sites and links between previously known and novel pathways. T47D breast cancer cells were used, and phospho-sites and pathways highlighted were validated using specific antibodies and phenotypic assays. Bioinformatic analysis revealed an enrichment in novel signalling pathways, a coordinated response between cellular compartments and protein complexes. RESULTS Detailed analysis of the data revealed intriguing changes in protein complexes involved in nuclear structure, epithelial to mesenchyme transition (EMT), cell adhesion, as well as transcription factors previously not associated with breast cancer cell proliferation. Pathway analysis confirmed the key role of the MAPK signalling cascade following progesterone and additional hormone regulated phospho-sites were identified. Full network analysis shows the activation of new signalling pathways previously not associated with progesterone signalling in T47D breast cancer cells such as ERBB and TRK. As different post-translational modifications can mediate complex crosstalk mechanisms and massive PARylation is also rapidly induced by progestins, we provide details of important chromatin regulatory complexes containing both phosphorylated and PARylated proteins. CONCLUSIONS This study contributes an important resource for the scientific community, as it identifies novel players and connections meaningful for breast cancer cell biology and potentially relevant for cancer management.
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Affiliation(s)
- Roni H. G. Wright
- Center for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
- Basic Sciences Department, Faculty of Medicine and Health Sciences, Universitat Internacional de Catalunya, Barcelona, Spain
- *Correspondence: Roni H. G. Wright, ; Miguel Beato,
| | - Viviana Vastolo
- Center for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
| | - Javier Quilez Oliete
- Center for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
| | - José Carbonell-Caballero
- Center for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
| | - Miguel Beato
- Center for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
- *Correspondence: Roni H. G. Wright, ; Miguel Beato,
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15
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Porras L, Ismail H, Mader S. Positive Regulation of Estrogen Receptor Alpha in Breast Tumorigenesis. Cells 2021; 10:cells10112966. [PMID: 34831189 PMCID: PMC8616513 DOI: 10.3390/cells10112966] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 10/23/2021] [Accepted: 10/24/2021] [Indexed: 12/31/2022] Open
Abstract
Estrogen receptor alpha (ERα, NR3A1) contributes through its expression in different tissues to a spectrum of physiological processes, including reproductive system development and physiology, bone mass maintenance, as well as cardiovascular and central nervous system functions. It is also one of the main drivers of tumorigenesis in breast and uterine cancer and can be targeted by several types of hormonal therapies. ERα is expressed in a subset of luminal cells corresponding to less than 10% of normal mammary epithelial cells and in over 70% of breast tumors (ER+ tumors), but the basis for its selective expression in normal or cancer tissues remains incompletely understood. The mapping of alternative promoters and regulatory elements has delineated the complex genomic structure of the ESR1 gene and shed light on the mechanistic basis for the tissue-specific regulation of ESR1 expression. However, much remains to be uncovered to better understand how ESR1 expression is regulated in breast cancer. This review recapitulates the current body of knowledge on the structure of the ESR1 gene and the complex mechanisms controlling its expression in breast tumors. In particular, we discuss the impact of genetic alterations, chromatin modifications, and enhanced expression of other luminal transcription regulators on ESR1 expression in tumor cells.
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16
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Jerusalem G, Farah S, Courtois A, Chirgwin J, Aebi S, Karlsson P, Neven P, Hitre E, Graas MP, Simoncini E, Abdi E, Kamby C, Thompson A, Loibl S, Gavilá J, Kuroi K, Marth C, Müller B, O'Reilly S, Gombos A, Ruhstaller T, Burstein HJ, Rabaglio M, Ruepp B, Ribi K, Viale G, Gelber RD, Coates AS, Loi S, Goldhirsch A, Regan MM, Colleoni M. Continuous versus intermittent extended adjuvant letrozole for breast cancer: final results of randomized phase III SOLE (Study of Letrozole Extension) and SOLE Estrogen Substudy. Ann Oncol 2021; 32:1256-1266. [PMID: 34384882 DOI: 10.1016/j.annonc.2021.07.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 07/28/2021] [Accepted: 07/29/2021] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Late recurrences in postmenopausal women with hormone receptor-positive breast cancers remain an important challenge. Avoidance or delayed development of resistance represents the main objective in extended endocrine therapy (ET). In animal models, resistance was reversed with restoration of circulating estrogen levels during interruption of letrozole treatment. This phase III, randomized, open-label Study of Letrozole Extension (SOLE) studied the effect of extended intermittent letrozole treatment in comparison with continuous letrozole. In parallel, the SOLE estrogen substudy (SOLE-EST) analyzed the levels of estrogen during the interruption of treatment. PATIENTS AND METHODS SOLE enrolled 4884 postmenopausal women with hormone receptor-positive, lymph node-positive, operable breast cancer between December 2007 and October 2012 and among them, 104 patients were enrolled in SOLE-EST. They must have undergone local treatment and have completed 4-6 years of adjuvant ET. Patients were randomized between continuous letrozole (2.5 mg/day orally for 5 years) and intermittent letrozole treatment (2.5 mg/day for 9 months followed by a 3-month interruption in years 1-4 and then 2.5 mg/day during all of year 5). RESULTS Intention-to-treat population included 4851 women in SOLE (n = 2425 in the intermittent and n = 2426 in the continuous letrozole groups) and 103 women in SOLE-EST (n = 78 in the intermittent and n = 25 in the continuous letrozole groups). After a median follow-up of 84 months, 7-year disease-free survival (DFS) was 81.4% in the intermittent group and 81.5% in the continuous group (hazard ratio: 1.03, 95% confidence interval: 0.91-1.17). Reported adverse events were similar in both groups. Circulating estrogen recovery was demonstrated within 6 weeks after the stop of letrozole treatment. CONCLUSIONS Extended adjuvant ET by intermittent administration of letrozole did not improve DFS compared with continuous use, despite the recovery of circulating estrogen levels. The similar DFS coupled with previously reported quality-of-life advantages suggest intermittent extended treatment is a valid option for patients who require or prefer a treatment interruption.
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Affiliation(s)
- G Jerusalem
- International Breast Cancer Study Group, Bern, Switzerland; Medical Oncology Department, CHU Liège, Liège University, Liège, Belgium.
| | - S Farah
- International Breast Cancer Study Group Statistical Center, Division of Biostatistics, Dana-Farber Cancer Institute, Boston, USA
| | - A Courtois
- Medical Oncology Department, CHU Liège, Liège University, Liège, Belgium
| | - J Chirgwin
- Breast Cancer Trials-Australia and New Zealand, University of Newcastle, Callaghan, Australia; Box Hill and Maroondah Hospitals, Monash University, Clayton, Australia
| | - S Aebi
- Division of Medical Oncology, Cancer Center, Lucerne Cantonal Hospital, Lucerne, Switzerland; Faculty of Medicine, University of Bern, Bern, Switzerland
| | - P Karlsson
- Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
| | - P Neven
- Gynecologic Oncology and Multidisciplinary Breast Center, University Hospitals UZ-Leuven, KU Leuven, Leuven, Belgium
| | - E Hitre
- Department of Medical Oncology and Clinical Pharmacology "B", National Institute of Oncology, Budapest, Hungary
| | | | - E Simoncini
- ASST Spedali Civili di Brescia, Brescia, Italy
| | - E Abdi
- The Tweed Hospital, Griffith University Gold Coast, Tweed Heads, Australia
| | - C Kamby
- Danish Breast Cancer Group and Rigshospitalet, Copenhagen, Denmark
| | - A Thompson
- Scottish Cancer Trials Breast Group and Division of Surgical Oncology, Baylor College of Medicine, Houston, USA
| | - S Loibl
- German Breast Group Forschungs GmbH, Neu-Isenburg, Germany
| | - J Gavilá
- SOLTI Group and Fundación Instituto Valenciano de Oncologia, Valencia, Spain
| | - K Kuroi
- Japan Breast Cancer Research Group and Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, Tokyo, Japan
| | - C Marth
- Austrian Breast & Colorectal Cancer Study Group and Department of Obstetrics and Gynecology, Medical University Innsbruck, Innsbruck, Austria
| | - B Müller
- Chilean Cooperative Group for Oncologic Research (GOCCHI), Providencia, Santiago, Chile
| | - S O'Reilly
- Cancer Trials Ireland, Dublin, Ireland; University College Cork, Cork University Hospital, Cork, Ireland
| | - A Gombos
- Université Libre de Bruxelles, Institut Jules Bordet, Brussels, Belgium
| | - T Ruhstaller
- International Breast Cancer Study Group, Bern, Switzerland; Swiss Group for Clinical Cancer Research SAKK, Bern, Switzerland; Breast Center St. Gallen, St. Gallen, Switzerland; Faculty of Medicine, University of Basel, Basel, Switzerland
| | - H J Burstein
- Medical Oncology Department, CHU Liège, Liège University, Liège, Belgium; Harvard Medical School, Boston, USA; Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, USA
| | - M Rabaglio
- International Breast Cancer Study Group, Bern, Switzerland; Swiss Group for Clinical Cancer Research SAKK, Bern, Switzerland; Department of Medical Oncology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - B Ruepp
- International Breast Cancer Study Group, Bern, Switzerland
| | - K Ribi
- International Breast Cancer Study Group, Bern, Switzerland
| | - G Viale
- Department of Pathology, University of Milan, Milan, Italy; IEO European Institute of Oncology IRCCS, Milan, Italy
| | - R D Gelber
- International Breast Cancer Study Group Statistical Center, Division of Biostatistics, Dana-Farber Cancer Institute, Boston, USA; Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, USA; Harvard TH Chan School of Public Health, Boston, USA; Frontier Science Foundation, Boston, USA
| | - A S Coates
- International Breast Cancer Study Group, Bern, Switzerland; NHMRC Clinical Trials Centre, University of Sydney, Sydney, Australia
| | - S Loi
- International Breast Cancer Study Group, Bern, Switzerland; Peter MacCallum Cancer Center, University of Melbourne, Melbourne, Australia
| | - A Goldhirsch
- International Breast Cancer Study Group, Bern, Switzerland; IEO European Institute of Oncology, IRCCS, Milan, Italy
| | - M M Regan
- International Breast Cancer Study Group Statistical Center, Division of Biostatistics, Dana-Farber Cancer Institute, Boston, USA; Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, USA
| | - M Colleoni
- International Breast Cancer Study Group, Bern, Switzerland; Division of Medical Senology, IEO, European Institute of Oncology, IRCCS, Milan, Italy
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