scholarly journals Immunohistochemical assessment of PTEN expression and itsassociation with tamoxifen resistance in ER positive breast cancers

2021 ◽  
Vol 26 (3) ◽  
pp. 105
Author(s):  
T. W. Wijesiri ◽  
H. H. Peiris ◽  
L. K. B. Mudduwa
Keyword(s):  
Tamoxifen Resistance ◽  
Pten Expression ◽  
Breast Cancers ◽  
Er Positive ◽  
Immunohistochemical Assessment

miR10a Mediate Tamoxifen Resistance in ER-Positive Breast Cancer Cells Through Down-Regulation of RFPL-3/hTERT

2021 ◽  
Author(s):  
Wei Sun ◽  
Wenjie Han ◽  
Aiying Li ◽  
Youkui Shi
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Tamoxifen Resistance ◽  
Negative Regulator ◽  
Luciferase Reporter ◽  
Endocrine Treatment ◽  
Breast Cancers ◽  
Er Positive ◽  
Positive Breast Cancer

Abstract Tamoxifen (TAM) is used as a first-line endocrine treatment for estrogen receptor (ER)-positive breast cancers. However, some patients develop TAM resistance after treatment and the role of miRNAs in TAM resistance still unknown. qPCR assay was performed to assess the expression levels of miR10a and RFPL-3 /hTERT. Western blot analysis was used to determine RFPL-3 /hTERT levels. The direct correlation between miR10a and RFPL-3 was verified by dual-luciferase reporter assay. CCK-8 assay and PicoGreen dsDNA quantification assay were applied to determine cell proliferation ability. In this study, we found that miR10a is downregulated in breast cancer with TAM resistance and that low expression of miR10a is associated with poor prognosis. By studying the regulatory mechanism, we found that miR10a functions as a negative regulator of RFPL-3 mRNA by binding the 3’-UTR region and disrupting the interaction between RFPL-3 and hTERT, which inhibits the proliferation of ER-positive breast cancer cells with TAM resistance. Collectively, our study findings indicate that the downregulation of miR10a activates RFPL-3/hTERT and induces tamoxifen resistance in ER-positive breast cancer cells.

scholarly journals Relationship Between Plasma Estradiol Levels and Estrogen-Responsive Gene Expression in Estrogen Receptor–Positive Breast Cancer in Postmenopausal Women

2010 ◽  
Vol 28 (7) ◽  
pp. 1161-1167 ◽  
Author(s):  
Anita K. Dunbier ◽  
Helen Anderson ◽  
Zara Ghazoui ◽  
Elizabeth J. Folkerd ◽  
Roger A'Hern ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Gene Expression ◽  
Estrogen Receptor ◽  
Postmenopausal Women ◽  
Multivariable Analysis ◽  
Independent Set ◽  
Breast Cancers ◽  
Plasma Estradiol ◽  
Er Positive ◽  
Positive Breast Cancer

Purpose To determine whether plasma estradiol (E2) levels are related to gene expression in estrogen receptor (ER)–positive breast cancers in postmenopausal women. Materials and Methods Genome-wide RNA profiles were obtained from pretreatment core-cut tumor biopsies from 104 postmenopausal patients with primary ER-positive breast cancer treated with neoadjuvant anastrozole. Pretreatment plasma E2 levels were determined by highly sensitive radioimmunoassay. Genes were identified for which expression was correlated with pretreatment plasma E2 levels. Validation was performed in an independent set of 73 ER-positive breast cancers. Results The expression of many known estrogen-responsive genes and gene sets was highly significantly associated with plasma E2 levels (eg, TFF1/pS2, GREB1, PDZK1 and PGR; P < .005). Plasma E2 explained 27% of the average expression of these four average estrogen-responsive genes (ie, AvERG; r = 0.51; P < .0001), and a standardized mean of plasma E2 levels and ER transcript levels explained 37% (r, 0.61). These observations were validated in an independent set of 73 ER-positive tumors. Exploratory analysis suggested that addition of the nuclear coregulators in a multivariable analysis with ER and E2 levels might additionally improve the relationship with the AvERG. Plasma E2 and the standardized mean of E2 and ER were both significantly correlated with 2-week Ki67, a surrogate marker of clinical outcome (r = −0.179; P = .05; and r = −0.389; P = .0005, respectively). Conclusion Plasma E2 levels are significantly associated with gene expression of ER-positive breast cancers and should be considered in future genomic studies of ER-positive breast cancer. The AvERG is a new experimental tool for the study of putative estrogenic stimuli of breast cancer.

Short Preoperative Treatment With Erlotinib Inhibits Tumor Cell Proliferation in Hormone Receptor–Positive Breast Cancers

2008 ◽  
Vol 26 (6) ◽  
pp. 897-906 ◽  
Author(s):  
Marta Guix ◽  
Nara de Matos Granja ◽  
Ingrid Meszoely ◽  
Theresa B. Adkins ◽  
Bobbye M. Wieman ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Proliferation ◽  
Tumor Cell ◽  
Growth Factor Receptor ◽  
Preoperative Treatment ◽  
Breast Cancers ◽  
Tumor Cell Proliferation ◽  
Hormone Receptor Positive ◽  
Er Positive ◽  
Her 2

Purpose To administer the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor erlotinib to patients with operable untreated breast cancer during the immediate preoperative period and to measure an antiproliferative and/or a proapoptotic effect in the post-therapy specimen and determine a biomarker profile associated with evidence of erlotinib-mediated cellular activity. Patients and Methods Newly diagnosed patients with stages I to IIIA invasive breast cancer were treated with erlotinib 150 mg/d orally for 6 to 14 days until the day before surgery. Erlotinib plasma levels were measured by tandem mass spectrometry the day of surgery. Drug-induced changes in tumor cell proliferation and apoptosis were assessed by Ki67 immunohistochemistry and terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate-biotin nick-end labeling analysis, respectively, in biopsies from the pretherapy and surgical specimens. Biopsies were also evaluated for P-EGFR, P-HER-2, P-MAPK, P-Akt, P-S6, and S118 P-ERα. Results In drug-sensitive PC9 xenografts, 5 days of treatment with erlotinib were enough to induce a maximal inhibition of cell proliferation and induction of apoptosis. Forty-one patients completed preoperative treatment with erlotinib. Grade ≤ 2 rash and diarrhea were the main toxicities. Erlotinib inhibited tumor cell proliferation (Ki67), P-EGFR, and P-HER-2. The inhibition of proliferation occurred in estrogen receptor (ER) –positive but not in human epidermal growth factor receptor 2 (HER-2) –positive or triple-negative cancers. Treatment was associated with a significant reduction of P-MAPK, P-Akt, P-S6, and S118 P-ERα in hormone receptor–positive cancers. Conclusion A presurgical approach to evaluate cellular responses to new drugs is feasible in breast cancer. EGFR inhibitors are worthy of testing against ER-positive breast cancers but are unlikely to have clinical activity against HER-2–positive or triple-negative breast cancers.

scholarly journals Overexpression of BQ323636.1 Modulated AR/IL-8/CXCR1 Axis to Confer Tamoxifen Resistance in ER-Positive Breast Cancer

Life ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 93
Author(s):  
Ho Tsoi ◽  
Ling Shi ◽  
Man-Hong Leung ◽  
Ellen P. S. Man ◽  
Zi-Qing So ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Tamoxifen Resistance ◽  
In Silico Analysis ◽  
Luciferase Reporter ◽  
Androgen Response Element ◽  
Er Positive

NCOR2 is a co-repressor for estrogen receptor (ER) and androgen receptor (AR). Our group previously identified a novel splice variant of NCOR2, BQ323636.1 (BQ), that mediates tamoxifen resistance via interference of NCOR2 repression on ER. Luciferase reporter assay showed BQ overexpression could enhance the transcriptional activity of androgen response element (ARE). We proposed that BQ employs both AR and ER to confer tamoxifen resistance. Through in silico analysis, we identified interleukin-8 (IL-8) as the sole ERE and ARE containing gene responsiveness to ER and AR activation. We confirmed that BQ overexpression enhanced the expression of IL-8 in ER+ve breast cancer cells, and AR inhibition reduced IL-8 expression in the BQ overexpressing cell lines, suggesting that AR was involved in the modulation of IL-8 expression by BQ. Moreover, we demonstrated that IL-8 could activate both AKT and ERK1/2 via CXCR1 to confer tamoxifen resistance. Targeting CXCR1/2 by a small inhibitor repertaxin reversed tamoxifen resistance of BQ overexpressing breast cancer cells in vitro and in vivo. In conclusion, BQ overexpression in ER+ve breast cancer can enhance IL-8 mediated signaling to modulate tamoxifen resistance. Targeting IL-8 signaling is a promising approach to overcome tamoxifen resistance in ER+ve breast cancer.

scholarly journals Breast cancer chemoprevention

2011 ◽  
Vol 2 (4) ◽  
pp. 223
Author(s):  
Ivana Sestak ◽  
Jack Cuzick
Keyword(s):  
Breast Cancer ◽  
Cancer Chemoprevention ◽  
Similar Efficacy ◽  
Breast Cancers ◽  
New Agents ◽  
Breast Cancer Chemoprevention ◽  
Er Positive ◽  
Prevention Trials ◽  
Endometrial Cancers ◽  
Positive Breast Cancer

Trials with tamoxifen have clearly shown that the risk of developing oestrogen receptor positive breast cancer can be reduced by at least 50% with prophylactic agents. The current challenge is to find new agents which achieve this or better efficacy, but with fewer side effects. Recent results indicate that the SERM raloxifene has similar efficacy to tamoxifen, but leads to fewer endometrial cancers, gynecological symptoms, and thromboembolic events. Results for contralateral tumors in adjuvant trials suggest that aromatase inhibitors may be able to prevent up to 70%–80% of ER-positive breast cancers, and this is currently being investigated in two large prevention trials, one using anastrozole (IBIS-II) and the other exemestane (MAP.3). New agents are needed for receptor negative breast cancer and several possibilities are currently under investigation.

scholarly journals MACROD2overexpression mediates estrogen independent growth and tamoxifen resistance in breast cancers

2014 ◽  
Vol 111 (49) ◽  
pp. 17606-17611 ◽  
Author(s):  
Morassa Mohseni ◽  
Justin Cidado ◽  
Sarah Croessmann ◽  
Karen Cravero ◽  
Ashley Cimino-Mathews ◽  
...  
Keyword(s):  
Tamoxifen Resistance ◽  
Breast Cancers

Analysis of Low Estrogen Receptor (ER+) Breast Carcinomas in a Large Community Breast Cancer Center in Northern California

2021 ◽  
Vol 156 (Supplement_1) ◽  
pp. S26-S27
Author(s):  
G Bulusu ◽  
K Duncan ◽  
A Wheeler
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Histological Grade ◽  
Statistical Significance ◽  
Cancer Center ◽  
Pathology Report ◽  
Breast Cancers ◽  
Breast Carcinomas ◽  
Ki 67 ◽  
Er Positive

Abstract Introduction/Objective Estrogen Receptor (ER) expression in breast cancers is a crucial factor for endocrine therapy in patients with tumors expressing ER in ≥1% of tumor cells. The 2019 guidelines published by ASCO/CAP states that breast cancers that have a 1% to 10% of cells staining Estrogen Receptor (ER) positive should be reported as ER Low Positive cases. This study aims to address this subset of low-positive ER tumors and compare the clinical features to other known breast cancer subtypes. Methods/Case Report We conducted a retrospective review of a prospectively maintained breast cancer registry from 2013 to 2021 at Mills-Peninsula Medical Center, a Sutter Health Affiliate. The study reviewed patient charts with respect to the pathology report, operative report, chemotherapy regimen, and clinical outcomes. Statistical analyses were conducted using R Project for Statistical Coding, with The Student’s T-test used to compare continuous variables. Two-sided P values less than 0.05 indicate statistical significance. Results (if a Case Study enter NA) Our study identified 1316 cases of invasive breast carcinomas, of which 29 (2.16%) demonstrated ER Low-Positive expression. We aimed to evaluate the clinical and pathological features, such as histological grade, ER, PR, HER-2, Ki-67%, and patient age for these tumors. We found that ER Low-Positive tumors demonstrated higher mean histological grade morphology (2.5 out of 3, p&lt;0.001) that was similar to that of Triple Negative Breast Cancers (TNBC) (3 of 3, p&lt;0.001) than to High ER-Positive (1.6 of 3, p&lt;0.001) cancers. Further observations, through examining proliferation rates by utilizing the Ki-67 index, indicate comparative trends between the ER Low-Positive cohort and the TNBC cohort. Conclusion The results suggest that the ER Low-Positive carcinomas, despite reported as ER-positive cases, present with similar clinicopathological features to those of ER-negative tumors. Through this study and future research, we would like to emphasize a stricter set of guidelines that can be adopted to reduce variability for reporting biomarkers. This standardization will allow oncologists to provide more appropriate treatment options and improve the quality of patient care.

Detection of estrogen receptor in bone marrow from patients with metastatic breast cancer.

1987 ◽  
Vol 5 (11) ◽  
pp. 1779-1782 ◽  
Author(s):  
U Berger ◽  
J L Mansi ◽  
P Wilson ◽  
R C Coombes
Keyword(s):  
Breast Cancer ◽  
Bone Marrow ◽  
Endocrine Therapy ◽  
Tumor Cells ◽  
Epithelial Membrane Antigen ◽  
Metastatic Breast ◽  
Breast Cancers ◽  
Double Staining ◽  
Primary Tumors ◽  
Er Positive

We devised a method of detecting estrogen receptors (ER) in bone marrow metastases from patients with breast cancer. The method involves a sequential double-staining immunocytochemical technique, with a monoclonal antibody to ER and a polyclonal antibody recognizing epithelial membrane antigen to confirm the epithelial nature of suspected tumor cells. Twenty-seven patients were assessed: ten were found to have ER-positive tumor cells in the bone marrow; ten had ER-negative cells; and the remaining seven patients had no tumor cells in the bone marrow smears. Of the ten patients with ER-positive cells, eight (80%) either had a response to endocrine therapy, implying that they possess ER-positive breast cancers, or had ER-positive primary tumors as determined by the dextran-coated charcoal biochemical assay (DCC). Of the ten patients with ER-negative cells in the bone marrow, eight failed to respond to endocrine therapy. This technique therefore provides a means of predicting which patients will respond to endocrine therapy, and is particularly important in those patients whose ER status is unknown.

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