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1.
J Plast Reconstr Aesthet Surg ; 78: 19-28, 2023 03.
Article in English | MEDLINE | ID: mdl-36764040

ABSTRACT

INTRODUCTION: The optimal combination of radiotherapy and breast reconstruction has not yet been defined. Post-mastectomy radiotherapy (PMRT) has deleterious effects on breast reconstruction, leading to caution amongst surgeons. Pre-operative radiotherapy (PRT) is a growing area of interest, is demonstrated to be safe, and spares autologous flaps from radiotherapy. This study evaluates the aesthetic outcome of PRT and deep inferior epigastric artery perforator (DIEP) flap reconstruction within the Pre-operative Radiotherapy And Deep Inferior Epigastric artery Perforator (DIEP) flAp (PRADA) cohort. METHODS: PRADA was an observational cohort study designed to evaluate the feasibility and safety of PRT for women undergoing neoadjuvant chemotherapy and DIEP reconstruction. Panel evaluation of 3D surface images (3D-SIs) and patient-reported outcome measures (BREAST-Q) for a subset of women in the study were compared with those of a DIEP-PMRT cohort who had undergone DIEP reconstruction and PMRT. RESULTS: Seventeen out of 33 women from the PRADA study participated in this planned substudy. Twenty-eight women formed the DIEP-PMRT cohort (median follow-up 23 months). The median (inter-quartile range [IQR]) 'satisfaction with breasts' score at 12 months for the PRADA cohort was significantly better than the DIEP-PMRT cohort (77 [72-87] versus 64 [54-71], respectively), p=0.01). Median [IQR] panel evaluation (5-point scale) was also significantly better for the PRADA cohort than for the DIEP-PMRT cohort (4.3 [3.9-4.6] versus 3.6 [2.8-4] p=0.003). CONCLUSIONS: Aesthetic outcome for the PRADA cohort was reported to be 'good' or 'excellent' in 93% of cases using a bespoke panel assessment with robust methodology. Patient satisfaction at one year is encouraging and superior to DIEP-PMRT at 23 months. Switching surgery-radiotherapy sequencing leads to similar breast aesthetic outcomes and warrants further large-scale, multi-centre evaluation in a randomised trial.


Subject(s)
Breast Neoplasms , Mammaplasty , Perforator Flap , Female , Humans , Patient Satisfaction , Mastectomy/methods , Epigastric Arteries/surgery , Breast Neoplasms/radiotherapy , Breast Neoplasms/surgery , Perforator Flap/blood supply , Mammaplasty/methods , Esthetics , Retrospective Studies
2.
BJS Open ; 6(3)2022 05 02.
Article in English | MEDLINE | ID: mdl-35674701

ABSTRACT

BACKGROUND: Following therapeutic mammoplasty (TM), the contralateral breast may require a later balancing procedure to optimize shape and symmetry. The alternative is to offer patients simultaneous TM with immediate contralateral symmetrization via a dual-surgeon approach, with the goal of reducing costs and minimizing the number of subsequent hospital appointments in an era of COVID-19 surges. The aim of this cost-consequence analysis is to characterize the cost-benefit of immediate bilateral symmetrization dual-operator mammoplasty versus staged unilateral single operator for breast cancer surgery. METHOD: A prospective single-centre observational study was conducted at an academic teaching centre for breast cancer surgery in the UK. Pseudonymized data for clinicopathological variables and procedural care information, including the type of initial breast-conserving surgery and subsequent reoperation(s), were extracted from the electronic patient record. Financial data were retrieved using the Patient-Level Information and Costing Systems. RESULTS: Between April 2014 and March 2020, 232 women received either immediate bilateral (n = 44), staged unilateral (n = 57) for breast cancer, or unilateral mammoplasty alone (n = 131). The median (interquartile range (i.q.r.)) additional cost of unilateral mammoplasty with staged versus immediate bilateral mammoplasty was €5500 (€4330 to €6570) per patient (P < 0.001), which represents a total supplementary financial burden of €313 462 to the study institution. There was no significant difference between groups in age, Charlson comorbidity index, operating minutes, time to adjuvant radiotherapy in months, or duration of hospital stay. CONCLUSION: Synchronous dual-surgeon immediate bilateral TM can deliver safe immediate symmetrization and is financially beneficial, without delay to receipt of adjuvant therapy, or additional postoperative morbidity.


Subject(s)
Breast Neoplasms , COVID-19 , Mammaplasty , Breast Neoplasms/pathology , Female , Humans , Mammaplasty/methods , Mastectomy, Segmental/methods , Prospective Studies , Treatment Outcome
3.
Sci Rep ; 12(1): 8607, 2022 05 21.
Article in English | MEDLINE | ID: mdl-35597783

ABSTRACT

Re-operation due to disease being inadvertently close to the resection margin is a major challenge in breast conserving surgery (BCS). Indocyanine green (ICG) fluorescence imaging could be used to visualize the tumor boundaries and help surgeons resect disease more efficiently. In this work, ICG fluorescence and color images were acquired with a custom-built camera system from 40 patients treated with BCS. Images were acquired from the tumor in-situ, surgical cavity post-excision, freshly excised tumor and histopathology tumour grossing. Fluorescence image intensity and texture were used as individual or combined predictors in both logistic regression (LR) and support vector machine models to predict the tumor extent. ICG fluorescence spectra in formalin-fixed histopathology grossing tumor were acquired and analyzed. Our results showed that ICG remains in the tissue after formalin fixation. Therefore, tissue imaging could be validated in freshly excised and in formalin-fixed grossing tumor. The trained LR model with combined fluorescence intensity (pixel values) and texture (slope of power spectral density curve) identified the tumor's extent in the grossing images with pixel-level resolution and sensitivity, specificity of 0.75 ± 0.3, 0.89 ± 0.2.This model was applied on tumor in-situ and surgical cavity (post-excision) images to predict tumor presence.


Subject(s)
Breast Neoplasms , Indocyanine Green , Breast Neoplasms/diagnostic imaging , Breast Neoplasms/surgery , Female , Fluorescence , Formaldehyde , Humans , Margins of Excision , Mastectomy, Segmental/methods , Optical Imaging/methods
4.
Lancet Oncol ; 23(5): 682-690, 2022 05.
Article in English | MEDLINE | ID: mdl-35397804

ABSTRACT

BACKGROUND: Radiotherapy before mastectomy and autologous free-flap breast reconstruction can avoid adverse radiation effects on healthy donor tissues and delays to adjuvant radiotherapy. However, evidence for this treatment sequence is sparse. We aimed to explore the feasibility of preoperative radiotherapy followed by skin-sparing mastectomy and deep inferior epigastric perforator (DIEP) flap reconstruction in patients with breast cancer requiring mastectomy. METHODS: We conducted a prospective, non-randomised, feasibility study at two National Health Service trusts in the UK. Eligible patients were women aged older than 18 years with a laboratory diagnosis of primary breast cancer requiring mastectomy and post-mastectomy radiotherapy, who were suitable for DIEP flap reconstruction. Preoperative radiotherapy started 3-4 weeks after neoadjuvant chemotherapy and was delivered to the breast, plus regional nodes as required, at 40 Gy in 15 fractions (over 3 weeks) or 42·72 Gy in 16 fractions (over 3·2 weeks). Adverse skin radiation toxicity was assessed preoperatively using the Radiation Therapy Oncology Group toxicity grading system. Skin-sparing mastectomy and DIEP flap reconstruction were planned for 2-6 weeks after completion of preoperative radiotherapy. The primary endpoint was the proportion of open breast wounds greater than 1 cm width requiring a dressing at 4 weeks after surgery, assessed in all participants. This study is registered with ClinicalTrials.gov, NCT02771938, and is closed to recruitment. FINDINGS: Between Jan 25, 2016, and Dec 11, 2017, 33 patients were enrolled. At 4 weeks after surgery, four (12·1%, 95% CI 3·4-28·2) of 33 patients had an open breast wound greater than 1 cm. One (3%) patient had confluent moist desquamation (grade 3). There were no serious treatment-related adverse events and no treatment-related deaths. INTERPRETATION: Preoperative radiotherapy followed by skin-sparing mastectomy and immediate DIEP flap reconstruction is feasible and technically safe, with rates of breast open wounds similar to those reported with post-mastectomy radiotherapy. A randomised trial comparing preoperative radiotherapy with post-mastectomy radiotherapy is required to precisely determine and compare surgical, oncological, and breast reconstruction outcomes, including quality of life. FUNDING: Cancer Research UK, National Institute for Health Research.


Subject(s)
Breast Neoplasms , Mammaplasty , Perforator Flap , Breast Neoplasms/radiotherapy , Breast Neoplasms/surgery , Feasibility Studies , Female , Humans , Male , Mammaplasty/adverse effects , Mastectomy/adverse effects , Perforator Flap/surgery , Prospective Studies , Quality of Life , State Medicine
5.
Ann Surg ; 275(3): e568-e574, 2022 03 01.
Article in English | MEDLINE | ID: mdl-32590540

ABSTRACT

OBJECTIVE: A simulator to enable safe practice and assessment of ALND has been designed, and face, content and construct validity has been investigated. SUMMARY AND BACKGROUND DATA: The reduction in the number of ALNDs conducted has led to decreased resident exposure and confidence. METHODS: A cross-sectional multicenter observational study was carried out between July 2017 and August 2018. Following model development, 30 surgeons of varying experience (n = "experts," n = 11 "senior residents," and n = 10 "junior residents") were asked to perform a simulated ALND. Face and content validity questionnaires were administered immediately after ALND. All ALND procedures were retrospectively assessed by 2 attending breast surgeons, blinded to operator identity, using a video-based assessment tool, and an end product assessment tool. RESULTS: Statistically significant differences between groups were observed across all operative subphases on the axillary clearance assessment tool (P < 0.001). Significant differences between groups were observed for overall procedure quality (P < 0.05) and total number of lymph nodes harvested (P < 0.001). However, operator grade could not be distinguished across other end product variables such as axillary vein damage (P = 0.864) and long thoracic nerve injury (P = 0.094). Overall, participants indicated that the simulator has good anatomical (median score >7) and procedural realism (median score >7). CONCLUSIONS: Video-based analysis demonstrates construct validity for ALND assessment. Given reduced ALND exposure, this simulation is a useful adjunct for both technical skills training and formative Deanery or Faculty administered assessments.


Subject(s)
Clinical Competence , Lymph Node Excision/standards , Axilla , Cross-Sectional Studies , Humans , Retrospective Studies
6.
Ann Surg Oncol ; 28(10): 5617-5625, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34347221

ABSTRACT

BACKGROUND: On average, 21% of women in the USA treated with Breast Conserving Surgery (BCS) undergo a second operation because of close positive margins. Tumor identification with fluorescence imaging could improve positive margin rates through demarcating location, size, and invasiveness of tumors. We investigated the technique's diagnostic accuracy in detecting tumors during BCS using intravenous indocyanine green (ICG) and a custom-built fluorescence camera system. METHODS: In this single-center prospective clinical study, 40 recruited BCS patients were sub-categorized into two cohorts. In the first 'enhanced permeability and retention' (EPR) cohort, 0.25 mg/kg ICG was injected ~ 25 min prior to tumor excision, and in the second 'angiography' cohort, ~ 5 min prior to tumor excision. Subsequently, an in-house imaging system was used to image the tumor in situ prior to resection, ex vivo following resection, the resection bed, and during grossing in the histopathology laboratory to compare the technique's diagnostic accuracy between the cohorts. RESULTS: The two cohorts were matched in patient and tumor characteristics. The majority of patients had invasive ductal carcinoma with concomitant ductal carcinoma in situ. Tumor-to-background ratio (TBR) in the angiography cohort was superior to the EPR cohort (TBR = 3.18 ± 1.74 vs 2.10 ± 0.92 respectively, p = 0.023). Tumor detection reached sensitivity and specificity scores of 0.82 and 0.93 for the angiography cohort and 0.66 and 0.90 for the EPR cohort, respectively (p = 0.1051 and p = 0.9099). DISCUSSION: ICG administration timing during the angiography phase compared with the EPR phase improved TBR and diagnostic accuracy. Future work will focus on image pattern analysis and adaptation of the camera system to targeting fluorophores specific to breast cancer.


Subject(s)
Breast Neoplasms , Indocyanine Green , Breast Neoplasms/diagnostic imaging , Breast Neoplasms/surgery , Female , Humans , Margins of Excision , Mastectomy, Segmental , Prospective Studies
7.
Ann Surg Oncol ; 28(10): 5742-5751, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34333706

ABSTRACT

BACKGROUND: In 2017, the American Society of Breast Surgeons (ASBrS) published expert panel recommendations for patients at risk for breast cancer-related lymphedema (BCRL) and those affected by BCRL. This study sought to determine BCRL practice patterns. METHODS: A survey was sent to 2975 ASBrS members. Questions evaluated members' clinical practice type, practice duration, and familiarity with BCRL recommendations. Descriptive statistics, the chi-square test, and Fisher's exact test were used. RESULTS: Of the ASBrS members surveyed, 390 (13.1%) responded. Most of the breast surgeons (58.5%, 228/390) indicated unfamiliarity with recommendations. Nearly all respondents (98.7%, 385/390) educate at-risk patients. Most (60.2%, 234/389) instruct patients to avoid venipuncture, injection or blood pressure measurements in the at-risk arm, and 35.6% (138/388) recommend prophylactic compression sleeve use during air travel. Nearly all (97.7%, 380/389) encourage those at-risk to exercise, including resistance exercise (86.2%, 331/384). Most do not perform axillary reverse mapping (ARM) (67.9%, 264/389) or a lymphatic preventive healing approach (LYMPHA) (84.9%, 331/390). Most (76.1%, 296/389) screen at-risk patients for BCRL. The most frequently used screening tools include self-reported symptoms (81%, 255/315), circumferential tape measure (54%, 170/315) and bioimpedance spectroscopy (27.3%, 86/315). After a BCRL diagnosis, most (90%, 351/390) refer management to a lymphedema-certified physical therapist. For affected patients, nearly all encourage exercise (98.7%, 384/389). Many (49%, 191/390) refer affected patients for consideration of lymphovenous bypass or lymph node transfer. CONCLUSION: Most respondents were unfamiliar with the ASBrS expert panel recommendations for patients at risk for BCRL and those affected by BCRL. Opportunities exist to increase awareness of best practices and to acquire ARM and LYMPHA technical expertise.


Subject(s)
Breast Cancer Lymphedema , Breast Neoplasms , Lymphedema , Surgeons , Breast Cancer Lymphedema/etiology , Breast Neoplasms/complications , Breast Neoplasms/surgery , Female , Humans , Lymph Nodes , Lymphedema/etiology , Lymphedema/prevention & control , United States
8.
Ann Surg Oncol ; 28(7): 3738-3748, 2021 Jul.
Article in English | MEDLINE | ID: mdl-33156466

ABSTRACT

INTRODUCTION: Conventional methods for axillary sentinel lymph node biopsy (SLNB) are fraught with complications such as allergic reactions, skin tattooing, radiation, and limitations on infrastructure. A novel technique has been developed for lymphatic mapping utilizing fluorescence imaging. This meta-analysis aims to compare the gold standard blue dye and radioisotope (BD-RI) technique with fluorescence-guided SLNB using indocyanine green (ICG). METHODS: This study was registered with PROSPERO (CRD42019129224). The MEDLINE, EMBASE, Scopus, and Web of Science databases were searched using the Medical Subject Heading (MESH) terms 'Surgery' AND 'Lymph node' AND 'Near infrared fluorescence' AND 'Indocyanine green'. Studies containing raw data on the sentinel node identification rate in breast cancer surgery were included. A heterogeneity test (using Cochran's Q) determined the use of fixed- or random-effects models for pooled odds ratios (OR). RESULTS: Overall, 1748 studies were screened, of which 10 met the inclusion criteria for meta-analysis. ICG was equivalent to radioisotope (RI) at sentinel node identification (OR 2.58, 95% confidence interval [CI] 0.35-19.08, p < 0.05) but superior to blue dye (BD) (OR 9.07, 95% CI 6.73-12.23, p < 0.05). Furthermore, ICG was superior to the gold standard BD-RI technique (OR 4.22, 95% CI 2.17-8.20, p < 0.001). CONCLUSION: Fluorescence imaging for axillary sentinel node identification with ICG is equivalent to the single technique using RI, and superior to the dual technique (RI-BD) and single technique with BD. Hospitals using RI and/or BD could consider changing their practice to ICG given the comparable efficacy and improved safety profile, as well as the lesser burden on hospital infrastructure.


Subject(s)
Breast Neoplasms , Sentinel Lymph Node , Breast Neoplasms/diagnostic imaging , Breast Neoplasms/surgery , Coloring Agents , Female , Fluorescence , Humans , Indocyanine Green , Optical Imaging , Radioisotopes , Sentinel Lymph Node/diagnostic imaging , Sentinel Lymph Node/surgery , Sentinel Lymph Node Biopsy
9.
J Plast Reconstr Aesthet Surg ; 73(11): 1917-1923, 2020 11.
Article in English | MEDLINE | ID: mdl-32948493

ABSTRACT

The coronavirus disease-2019 pandemic has had a significant impact on the delivery of surgical services, particularly reconstructive surgery. This article examines the current evidence to assess the feasibility of recommencing immediate breast reconstruction services during the pandemic and highlights considerations required to ensure patient safety.


Subject(s)
Coronavirus Infections/epidemiology , Mammaplasty , Pandemics , Pneumonia, Viral/epidemiology , Betacoronavirus , Breast Neoplasms/surgery , COVID-19 , Clinical Protocols , Coronavirus Infections/transmission , Cross Infection/prevention & control , Feasibility Studies , Female , Humans , Mammaplasty/adverse effects , Mammaplasty/methods , Mastectomy , Patient Selection , Pneumonia, Viral/transmission , Postoperative Complications , Risk Assessment , SARS-CoV-2 , Time Factors
10.
11.
J Surg Educ ; 75(5): 1281-1286, 2018.
Article in English | MEDLINE | ID: mdl-29605705

ABSTRACT

INTRODUCTION: Management of the axilla in invasive breast cancer (IBC) has shifted away from more radical surgery such as axillary lymph node dissection (ALND), towards less invasive procedures, such as sentinel lymph node biopsy. Because of this shift, we hypothesize that there has been a national downward trend in ALND procedures, subsequently impacting surgical trainee exposure to this procedure using the ACS-NSQIP database to evaluate this. METHODS: Women with IBC were identified in the ACS-NSQIP database from 2007 to 2014. Procedures including ALND were identified using CPT codes. This number was divided by total cases, given a varying number of participating institutions each year. Next, cases involving resident participation were identified and divided by training level: junior (post graduate year-[PGY] 1-2), senior (PGY 3-5) and fellow (PGY ≥ 6). Two tailed z tests were used to compare proportions, with significance determined when p < 0.05. RESULTS: A total of 128,372 women were identified with IBC with 36,844 ALND. ALND rates decreased by an average of 2.43% yearly from 2007 to 2014. Resident participation significantly drops in 2011, from 49.3% before to 29.4% after (p < 0.01). Junior residents experienced a significant decrease in participation rate (43.3%-32.2%, p < 0.05). Senior residents and fellows experienced an upward trend in their participation, although not significant (51.2%-56.3%, p = 0.35, and 5.6%-11.6%, p = 0.056, respectively). CONCLUSIONS: Using the ACS-NSQIP database, we demonstrate the downward trend in rate of ALND for IBC with subsequent decrease in resident participation. Junior residents experienced a significant decrease in their participation with no significant change for senior or fellow-level trainees. Awareness of this trend is important when creating future surgical curriculum changes for general surgery and fellowship training programs.


Subject(s)
Breast Neoplasms/epidemiology , Breast Neoplasms/pathology , Carcinoma, Ductal, Breast/pathology , Carcinoma, Ductal, Breast/surgery , Lymph Node Excision/statistics & numerical data , Adult , Age Distribution , Aged , Axilla/surgery , Breast Neoplasms/surgery , Carcinoma, Ductal, Breast/mortality , Databases, Factual , Disease-Free Survival , Fellowships and Scholarships , Female , Humans , Incidence , Internationality , Internship and Residency , Lymph Node Excision/methods , Lymph Nodes/pathology , Lymph Nodes/surgery , Middle Aged , Neoplasm Invasiveness/pathology , Neoplasm Staging , Prognosis , Retrospective Studies , Risk Assessment , Sex Distribution , Survival Analysis , Treatment Outcome , United States
12.
Gland Surg ; 6(4): 394-398, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28861381

ABSTRACT

Nipple reconstructions are prone to a variable and unpredictable degree of flattening, which in some cases lead to secondary reconstruction. The use of an acellular dermal matrix (ADM) augmentation may be appropriate in cases with very thin dermis that are particularly prone to flattening or in revision cases where the first procedure has already failed. The authors present a series of 13 nipple reconstructions in ten cases. Average projection at 12 months was 51% in primary cases and 46% in secondary revision cases. This represents a better than expected long term result in a difficult cohort of patients.

15.
Nucleic Acids Res ; 41(22): 10228-40, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24049078

ABSTRACT

Oestrogen receptor α (ERα) is a nuclear receptor that is the driving transcription factor expressed in the majority of breast cancers. Recent studies have demonstrated that the liver receptor homolog-1 (LRH-1), another nuclear receptor, regulates breast cancer cell proliferation and promotes motility and invasion. To determine the mechanisms of LRH-1 action in breast cancer, we performed gene expression microarray analysis following RNA interference for LRH-1. Interestingly, gene ontology (GO) category enrichment analysis of LRH-1-regulated genes identified oestrogen-responsive genes as the most highly enriched GO categories. Remarkably, chromatin immunoprecipitation coupled to massively parallel sequencing (ChIP-seq) to identify genomic targets of LRH-1 showed LRH-1 binding at many ERα binding sites. Analysis of select binding sites confirmed regulation of ERα-regulated genes by LRH-1 through binding to oestrogen response elements, as exemplified by the TFF1/pS2 gene. Finally, LRH-1 overexpression stimulated ERα recruitment, while LRH-1 knockdown reduced ERα recruitment to ERα binding sites. Taken together, our findings establish a key role for LRH-1 in the regulation of ERα target genes in breast cancer cells and identify a mechanism in which co-operative binding of LRH-1 and ERα at oestrogen response elements controls the expression of oestrogen-responsive genes.


Subject(s)
Breast Neoplasms/genetics , Estrogen Receptor alpha/metabolism , Gene Expression Regulation, Neoplastic , Receptors, Cytoplasmic and Nuclear/metabolism , Animals , Breast Neoplasms/metabolism , COS Cells , Chlorocebus aethiops , Female , MCF-7 Cells , Response Elements
17.
Breast Cancer Res Treat ; 128(2): 357-68, 2011 Jul.
Article in English | MEDLINE | ID: mdl-20730598

ABSTRACT

Estrogen receptor-α (ERα) positive breast cancer frequently responds to inhibitors of ERα activity, such as tamoxifen, and/or to aromatase inhibitors that block estrogen biosynthesis. However, many patients become resistant to these agents through mechanisms that remain unclear. Previous studies have shown that expression of ERα in ERα-negative breast cancer cell lines frequently inhibits their growth. In order to determine the consequence of ERα over-expression in ERα-positive breast cancer cells, we over-expressed ERα in the MCF-7 breast cancer cell line using adenovirus gene transduction. ERα over-expression led to ligand-independent expression of the estrogen-regulated genes pS2 and PR and growth in the absence of estrogen. Interestingly, prolonged culturing of these cells in estrogen-free conditions led to the outgrowth of cells capable of growth in cultures from ERα transduced, but not in control cultures. From these cultures a line, MLET5, was established which remained ERα-positive, but grew in an estrogen-independent manner. Moreover, MLET5 cells were inhibited by anti-estrogens showing that ERα remains important for their growth. Gene expression microarray analysis comparing MCF-7 cells with MLET5 highlighted apoptosis as a major functional grouping that is altered in MLET5 cells, such that cell survival would be favoured. This conclusion was further substantiated by the demonstration that MLET5 show resistance to etoposide-induced apoptosis. As the gene expression microarray analysis also shows that the apoptosis gene set differentially expressed in MLET5 is enriched for estrogen-regulated genes, our findings suggest that transient over-expression of ERα could lead to increased cell survival and the development of estrogen-independent growth, thereby contributing to resistance to endocrine therapies in breast cancer patients.


Subject(s)
Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Cell Proliferation , Drug Resistance, Neoplasm , Estrogen Receptor alpha/metabolism , Estrogens/pharmacology , Adenoviridae/genetics , Antineoplastic Agents, Hormonal/therapeutic use , Apoptosis , Biomarkers, Tumor/genetics , Biomarkers, Tumor/metabolism , Blotting, Western , Breast Neoplasms/genetics , Cell Cycle , Estrogen Receptor alpha/genetics , Female , Gene Expression Profiling , Gene Expression Regulation, Neoplastic , Humans , Oligonucleotide Array Sequence Analysis , RNA, Messenger/genetics , Reverse Transcriptase Polymerase Chain Reaction , Tamoxifen/therapeutic use , Tumor Cells, Cultured
18.
Breast Cancer Res Treat ; 127(2): 385-96, 2011 Jun.
Article in English | MEDLINE | ID: mdl-20607599

ABSTRACT

Estrogen receptor-α (ER) is expressed in the great majority of breast cancers, and the inhibition of ER action is a key part of breast cancer treatment. The inhibition of ER action is achieved using anti-estrogens, primarily tamoxifen, and with aromatase inhibitors that inhibit estrogen biosynthesis, thereby preventing ER activation. However, resistance to these therapies is common. With the aim of identifying new molecular targets for breast cancer therapy, we have identified the liver receptor homolog-1 (LRH-1) as an estrogen-regulated gene. RNA interference and over-expression studies were used to investigate the role of the LRH-1 in regulating breast cancer growth and to identify the targets of an LRH-1 action. Promoter recruitment was determined using reporter gene and chromatin immunoprecipitation (ChIP) assays. We show that LRH-1 regulates breast cancer cell growth by regulating the ER expression. Reporter gene and in vitro DNA-binding assays identified an LRH-1-binding site in the ER gene promoter, and ChIP assays have demonstrated in vivo binding at this site. We also provide evidence for new LRH-1 variants in breast cancer cells arising from the use of alternative promoters. Previous studies have shown that LRH-1 functions in estrogen biosynthesis by regulating aromatase expression. Our findings extend this by highlighting LRH-1 as a key regulator of the estrogen response in breast cancer cells through the regulation of ER expression. Hence, inhibition of LRH-1 could provide a powerful new approach for the treatment of endocrine-resistant breast cancer.


Subject(s)
Breast Neoplasms/physiopathology , Gene Expression Regulation, Neoplastic , Receptors, Cytoplasmic and Nuclear/metabolism , Receptors, Estrogen/metabolism , Amino Acid Sequence , Animals , Aromatase/metabolism , Base Sequence , Breast Neoplasms/genetics , Breast Neoplasms/metabolism , COS Cells , Cell Line, Tumor , Cell Proliferation , Chlorocebus aethiops , Female , Gene Order , Hep G2 Cells , Humans , Molecular Sequence Data , Promoter Regions, Genetic/genetics , Receptors, Cytoplasmic and Nuclear/genetics , Receptors, Estrogen/genetics , Sequence Alignment
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