Estrogen Receptor In Breast Cancer Research Articles

Co-delivery of epirubicin and paclitaxel using an estrone-targeted PEGylated liposomal nanoparticle for breast cancer.

Breast cancer is one of the most frequent malignancies in the female population. Recently, the development of medical products has been advanced for this disease; however, patients still suffer from the failure of current treatments and new therapeutic strategies are urgently required. In this study, due to the overexpression of the estrogen receptor (ER) in breast cancer and the ability of ER to specifically bind to its ligand estrone (ES), an ES-targeted PEGylated epirubicin (EPI) and paclitaxel (PTX) co-loaded liposomal nanoparticle (NP) (termed as ES-SSL-EPI/PTX) was developed. Physicochemical studies demonstrated that the ES-SSL-EPI/PTX had a nanoscaled particle size (~120 nm) and a neutral zeta potential (~-5 mV) and presented favorable stability in physiological media. In vitro, the ES-SSL-EPI/PTX showed a significantly higher cellular uptake in human breast cancer MCF-7 cells mainly via the receptor-ligand mediated pathway resulting in effective cytotoxic activity. In vivo targeting study, the accumulation of targeted liposomes in tumor was significantly improved. The systemic circulation time and biodistribution in main organs of EPI and PTX delivered by ES-SSL-Liposomes were increased. Consequently, the ES-SSL-EPI/PTX significantly suppressed tumor growth in the MCF-7-derived tumor-bearing mouse model without inducing toxicity. These results suggested that the ES-SSL-EPI/PTX was a promising formulation for co-delivery of chemotherapeutics in the treatment of breast cancer.

Androgen Receptor Is a Non-canonical Inhibitor of Wild-Type and Mutant Estrogen Receptors in Hormone Receptor-Positive Breast Cancers.

SummarySustained treatment of estrogen receptor (ER)-positive breast cancer with ER-targeting drugs results in ER mutations and refractory unresponsive cancers. Androgen receptor (AR), which is expressed in 80%–95% of ER-positive breast cancers, could serve as an alternate therapeutic target. Although AR agonists were used in the past to treat breast cancer, their use is currently infrequent due to virilizing side effects. Discovery of tissue-selective AR modulators (SARMs) has renewed interest in using AR agonists to treat breast cancer. Using translational models, we show that AR agonist and SARM, but not antagonist, inhibit the proliferation and growth of ER-positive breast cancer cells, patient-derived tissues, and patient-derived xenografts (PDX). Ligand-activated AR inhibits wild-type and mutant ER activity by reprogramming the ER and FOXA1 cistrome and rendering tumor growth inhibition. These findings suggest that ligand-activated AR may function as a non-canonical inhibitor of ER and that AR agonists may offer a safe and effective treatment for ER-positive breast cancer.

External quality assessment (EQA) program for the immunohistochemical detection of ER, PR and Ki-67 in breast cancer: results of an interlaboratory reproducibility ring study in China

BackgroundAn External Quality Assessment (EQA) program was developed to investigate the status of estrogen receptor (ER), progesterone receptor (PR), and Ki-67 immunohistochemical (IHC) detection in breast cancer and to evaluate the reproducibility of staining and interpretation in 44 pathology laboratories in China.MethodsThis program was implemented through three specific steps. In study I, three revising centres defined the reference value for 11 sections. In study II, 41 participating centres (PC) stained and interpreted 11 sections by their own daily practice IHC protocols. In study III, all cases received second interpretation opinions.ResultsThe stained slides of 44 laboratories were up to the interpretation standard. The overall interpretation concordance rate of this study was over 90%. A perfect agreement was reached among the PCs for the cases with ER+ and PR+ > 50% and Ki-67 > 30%, whereas a moderate agreement was observed for intermediate categories. After second interpretations, the misclassification rates for ER were reduced by 12.20%, for PR were reduced by 17.07%, and for Ki-67 were reduced by 4.88%. Up to 31 PCs observed a benefit from the second opinion strategy.ConclusionsThis project is the first EQA study performed on a national scale for assessment of ER, PR and Ki-67 status by IHC in China. In the whole IHC evaluation process, the intermediate categories were less reproducible than those with high expression rates. Second opinions can significantly improve the diagnostic agreement of pathologists’ interpretations.

Analyses of an epigenetic switch involved in the activation of pioneer factor FOXA1 leading to the prognostic value of estrogen receptor and FOXA1 co-expression in breast cancer

Forkhead box protein A1 (FOXA1) is a pioneer factor of estrogen receptor α (ER)–chromatin binding and function, yet the role of FOXA1 in breast cancer and the underlying molecular mechanisms have not yet been elucidated. To evaluate gene expression alterations during breast carcinogenesis, FOXA1 expression was analyzed using the Serial Analysis of Gene Expression Genie suite, a gene expression profiling interactive analysis, and Oncomine analyses. The correlation between methylation and expression was analyzed using the MEXPRESS tool and UCSC Xena browser. Then, the expression and prognostic value of FOXA1 was validated by our own breast cancer samples using RT-PCR. We obtained the following important results. (1) The expression level of FOXA1 was significantly higher in breast cancer than normal tissues. (2) ER, PR, HEGR-2, and nodal status were positively correlated with FOXA1 expression. (3) Among patients with ER+ tumors, those with higher FOXA1 expression levels had better survival probabilities. (4) The major mutation type in FOXA1 in breast cancer samples was missense mutations. (5) FOXA1 expression was significantly higher in ER+ breast tumors than in ER− tumors or normal tissues. Our findings suggest that the aberrant DNA hypomethylation of promoter regions is one mechanism underlying the aberrant expression of FOXA1 in ER+ breast cancer, which might be a potential indicator of favorable prognosis.

Expression discordances and clinical values of ER, PR, HER-2 and Ki-67 in primary and metastatic breast cancer

Objective: To investigate the expression discordances of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor2 (HER-2) and Ki-67 in primary and metastatic breast cancer specimens and explore the clinical significances. Methods: Biopsies of metastatic lesions were performed in 203 patients with breast cancer recurrence and metastasis indicated by physical examination and/or imaging examination. We confirmed pathological properties and assessed the expressions of ER, PR, HER-2 and Ki-67 in primary and metastatic lesions, their relationships with prognosis were also analyzed. Results: Biopsy failed in 3 patients, the pathology and immunohistochemitry results of metastatic lesions were not obtained. One person was diagnosed as tuberculosis and another was primary lung cancer. Among the 198 cases of primary and metastatic lesions, the discordance rates of ER, PR, HER-2 and Ki-67 were 27.3%, 34.3%, 11.8% and 15.1%, respectively.The expressions of ER, HER-2 and Ki-67 were not significantly different between the primary and metastatic lesions, however, the expressions of PR were more likely to turn negative in the metastases (P<0.001). The disease-free survival (DFS) of patients with ER, PR positive, HER-2 negative and low expression of Ki-67 in metastatic lesion was much longer (P<0.05). Conclusions: The expressions of ER, PR, HER-2 and Ki-67 in metastatic lesions are associated with the prognosis of breast cancer patients.Their expression discordances between primary and metastatic lesions can guide the treatment and evaluate the risks of recurrence and prognosis.

Chromatin regulation at the intersection of estrogen receptor and PI3K pathways in breast cancer

ABSTRACTEstrogen Receptor (ER) and the phosphoinositide 3-kinase (PI3K) pathways participate in regulatory crosstalk in breast cancer. We identified that chromatin regulation is at the intersection of oncogenic PI3K and ER. The PI3K effectors AKT, also known as protein kinase B (PKB), and SGK (serum/glucocorticoid-regulated kinase) play a redundant role by phosphorylating the chromatin regulator KMT2D and modulating ER activity and therapy resistance.

The Histone Demethylase Enzymes KDM3A and KDM4B Co-Operatively Regulate Chromatin Transactions of the Estrogen Receptor in Breast Cancer.

Many estrogen receptor (ER)-positive breast cancers develop resistance to endocrine therapy but retain canonical receptor signalling in the presence of selective ER antagonists. Numerous co-regulatory proteins, including enzymes that modulate the chromatin environment, control the transcriptional activity of the ER. Targeting ER co-regulators has therefore been proposed as a novel therapeutic approach. By assessing DNA-binding dynamics in ER-positive breast cancer cells, we have identified that the histone H3 lysine 9 demethylase enzymes, KDM3A and KDM4B, co-operate to regulate ER activity via an auto-regulatory loop that facilitates the recruitment of each co-activating enzyme to chromatin. We also provide evidence that suggests that KDM3A primes chromatin for deposition of the ER pioneer factor FOXA1 and recruitment of the ER-transcriptional complex, all prior to ER recruitment, therefore establishing an important mechanism of chromatin regulation involving histone demethylases and pioneer factors, which controls ER functionality. Importantly, we show via global gene-expression analysis that a KDM3A/KDM4B/FOXA1 co-regulated gene signature is enriched for pro-proliferative and ER-target gene sets, suggesting that abrogation of this network could be an efficacious therapeutic strategy. Finally, we show that depletion of both KDM3A and KDM4B has a greater inhibitory effect on ER activity and cell growth than knockdown of each individual enzyme, suggesting that targeting both enzymes represents a potentially efficacious therapeutic option for ER-driven breast cancer.

Absence of estrogen receptor is associated with worse oncologic outcome in patients who were received neoadjuvant chemotherapy for breast cancer

Neoadjuvant chemotherapy (NAC) is a standard treatment for locally advanced breast cancer, especially for HER2-positive or triple negative breast cancer which shows good response to chemotherapy. However, because a result of biomarkers is, occasionally, changed after NAC, the treatment strategy should be differently applied for patients with locally advanced breast cancer. We compared the results of biomarkers before and after NAC to evaluate the association with disease prognosis and oncologic results. Fifty-seven patients with locally advanced breast cancer underwent NAC and the immunohistochemical (IHC) staining results were compared between before and after NAC. And the association between oncologic outcomes and biomarkers was analyzed. Negative status of estrogen receptor (ER) was associated with locoregional recurrence and distant metastasis both before and after NAC (p=0.021, 0.019; p=0.018, 0.036). And the negative status of progesterone receptor (PR) and triple negative status before neoadjuvant chemotherapy were also associated with death and distant metastasis, respectively. However, the changes of biomarkers after NAC in breast cancer were not directly associated with any oncologic outcomes. The absence of ER in breast cancer before and after NAC would be a significant prognostic factor for local recurrence and distant metastasis. Therefore, the absence of ER should be considered as important factor in determining the treatment strategy.

Estrogen receptor α regulates the expression of syndecan-1 in human breast carcinoma cells.

Breast cancer (BC) is the primary cause of cancer-related mortality among women. Patients who express the estrogen receptor (ER), which mediates the tumorigenic effects of estrogens, respond to antihormonal therapy. Loss of ER expression or acquired resistance to E2 is associated with aggressive malignant phenotypes, which lead to relapse. These BC subtypes overexpress syndecan-1 (SDC1), a transmembrane heparan sulfate proteoglycan that mediates angiogenesis as well as the proliferation and invasiveness of cancer cells. We showed here that the activation of ER-alpha (ERα) by estrogens induces downregulation of SDC1 expression in ER(+) MCF7 cells but not in T47D cells. Loss of ERα expression, induced by RNA interference or a selective ER downregulator, led to subsequent SDC1 overexpression. E2-dependent downregulation of SDC1 expression required de novo protein synthesis and was antagonized by treatment with BAY 11-7085, an irreversible inhibitor of IκBα phosphorylation, which inhibits the activation of NFκB. Downregulation of SDC1 expression required ERα and activation of IKK, but was independent to downstream transcriptional regulators of NFκB. BAY 11-7085 prevented E2-mediated phosphorylation of ERα on Ser118, increasing its proteasomal degradation, suggesting that IKK stabilized E2-activated ERα, leading to subsequent downregulation of SDC1 expression. Our results showed that sustained ER signaling inhibits SDC1 expression. Such antagonism elucidates the inverse correlation between SDC1 and ER expression in ER(+) BC as well as the overexpression of SDC1 in hormone receptor-negative BC subtypes with the most aggressive phenotypes. These results identify SDC1 as an attractive therapeutic target for BC as well as for other endocrine-associated cancers.

Estrogen receptor signaling is reprogrammed during breast tumorigenesis

Limited knowledge of the changes in estrogen receptor (ER) signaling during the transformation of the normal mammary gland to breast cancer hinders the development of effective prevention and treatment strategies. Differences in estrogen signaling between normal human primary breast epithelial cells and primary breast tumors obtained immediately following surgical excision were explored. Transcriptional profiling of normal ER+ mature luminal mammary epithelial cells and ER+ breast tumors revealed significant difference in the response to estrogen stimulation. Consistent with these differences in gene expression, the normal and tumor ER cistromes were distinct and sufficient to segregate normal breast tissues from breast tumors. The selective enrichment of the DNA binding motif GRHL2 in the breast cancer-specific ER cistrome suggests that it may play a role in the differential function of ER in breast cancer. Depletion of GRHL2 resulted in altered ER binding and differential transcriptional responses to estrogen stimulation. Furthermore, GRHL2 was demonstrated to be essential for estrogen-stimulated proliferation of ER+ breast cancer cells. DLC1 was also identified as an estrogen-induced tumor suppressor in the normal mammary gland with decreased expression in breast cancer. In clinical cohorts, loss of DLC1 and gain of GRHL2 expression are associated with ER+ breast cancer and are independently predictive for worse survival. This study suggests that normal ER signaling is lost and tumor-specific ER signaling is gained during breast tumorigenesis. Unraveling these changes in ER signaling during breast cancer progression should aid the development of more effective prevention strategies and targeted therapeutics.

The effect of metformin on sex hormones in non-diabetic breast cancer patients in CCTG MA.32: A Phase III randomized adjuvant trial of metformin versus placebo in addition to standard therapy.

529 Background: The effect of metformin on sex hormones (SHs) levels that may impact breast cancer (BC) outcome, is unclear. We evaluated the effect of metformin on SHs in a subgroup of women enrolled in the placebo-controlled MA.32 trial, a phase III randomized study of nondiabetic subjects with T1-3, N0-3 BC randomized to receive metformin 850 mg po bid or placebo for 5 years. Methods: Our substudy was conducted on the group of post-menopausal women with estrogen receptor (ER) and progesterone receptor (PR) negative BC and not receiving endocrine treatment enrolled in the trial. Post-menopausal was defined as prior bilateral oophorectomy or &gt; 12 months since last menses without prior hysterectomy. Fasting blood and adherence to study drug at baseline and 6 months was required. Sex hormone binding globulin (SHBG), free testosterone and estradiol serum levels were evaluated using Roche Modular competitive ECLIA (electrochemiluminescense immunoassay). We compared change from baseline to 6 months in estradiol, SHBG and free testosterone between study arms using Wilcoxon sum rank tests and regression models to adjust for baseline BMI and weight change. Results: 304 women were eligible, 135 metformin vs 169 placebo; tumor stage and prior (neo)adjuvant chemotherapy (98% in both arms) and HER2 targeted treatment were well balanced between arms. At baseline mean age was 58.2±6.9 vs 57.6±7.9 years, mean BMI 26.9±4.9 vs 28.6±6.2 Kg/m2, median estradiol 29.82 vs 31.01 pmol/L, SHBG 80.6 vs 73.7 nmol/L and free testosterone 0.02 vs 0.03 nmol/L in metformin vs placebo patients, respectively. In univariable analysis, median estradiol decreased significantly between baseline and 6 months on the metformin vs placebo arm (-4.81 vs 0 pmol/L, p = &lt; 0.0001); this difference remained significant after controlling for baseline BMI (p = 0.0001) and weight change (mean weight change -1.8±3.5 vs 0.4±3.5 Kg, p = &lt; 0.0001 for metformin vs placebo respectively) between baseline and 6 months (p = 0.0007). In contrast, there was no significant change in SHBG or free testosterone (median change SHBG -5.5 vs -5.9 nmol/L, p = 0.33; median change free testosterone 0 vs 0 nmol/L, p = 0.33 for metformin vs placebo respectively). Conclusions: Metformin lowered estradiol levels, independent of weight change in non-diabetic post-menopausal women with ER and PR negative BC enrolled onto MA.32 trial. This observation suggests a new metformin action that has potential relevance to BC management.

Changes of estrogen receptor, progesterone receptor and HER2 expression in breast cancer with/without neoadjuvant chemotherapy or endocrine therapy.

e14699 Background: Concordance in hormone receptor and Human Epidermal Growth Factor Type 2 (HER2) status in breast cancer was observed between initial biopsy and surgical specimens. This study aimed to analyze the correlation in Estrogen receptor (ER), Progesterone receptor (PR) and HER2 status of the initial biopsy and surgical specimen in non-neoadjuvant therapy (CON), neoadjuvant chemotherapy (NAC) and neoadjuvant endocrine therapy (NAE). Secondary aim is to know the changed expression of ER, PR and HER2 as predictive marker for overall survival. Methods: We retrospectively analyzed 1265 surgical specimens from April 2007 to January 2018 in National Nagasaki Medical Center. Out of 1265 patients, 752 CON, 144 NAC and 28 NAE pairs of samples from initial core biopsy and surgical specimen were compared to the expression of the ER, PR and HER2 by immunohistochemically. Spearman’s rank correlation coefficient is calculated. Results: See table. Conclusions: ER and PR expression percentage is highly correlated between core needle biopsy and surgical specimen. After neoadjuvant chemotherapy, PR lost 8.2% after NAC and 40.8% after NAE. PR loss may become predictive marker after systemic therapy.[Table: see text][Table: see text]

The Association between Dietary Patterns and Breast Cancer Pathobiological Factors Progesterone Receptor (PR) and Estrogen Receptors (ER): New Findings from Iranian Case-Control Study

Background: Breast cancer (BrCa) is the most frequently diagnosed cancer among females and second cancer after lung cancer in many societies. Ignoring the phenotypes of the BrCa can affect the interpretation of the association between diet and BrCa. The aim of this study was to determine the association between dietary patterns and estrogen receptor (ER), and progesterone receptor (PR) status in women with BrCa.Methods: This study includes 150 cases of BrCa. Controls were 150 healthy adults, frequency matching based on age. The individual information, food frequency questionnaire, and physical activity were completed while interviews. Information about the pathologic factors obtained from patients' files. Factor analysis method used to determine the dietary patterns; logistic regression used to measure the odds ratios.Results: Getting upper median intake of unhealthy diet had a strong association with BrCa-positive ER and positive PR (OR: 4.98, 95% CI: 2.65–9.34 and OR: 4.99, 95% CI: 2.56–9.75, respectively) compared to under median intake of unhealthy diet. In addition, the protective effect of the healthy diet was stronger on BrCa-negative ER, negative PR (OR: 0.11, 95% CI: 0.04–0.34 and OR: 0.10, 95% CI: 0.03–0.25, respectively).Conclusion: The protective effect of a healthy dietary pattern was stronger on BrCa negative ER and negative PR. The unhealthy dietary pattern had a strong association with BrCa positive ER and positive PR.

Abstract P2-08-06: Standardized nCounter-based determination of estrogen receptor (ER), progesterone receptor (PR) and HER2 receptor status in breast cancer

Abstract Background: The expression of ER, PR and HER2 in breast cancer is determined by routine pathology assessment to indicate systemic treatment. Here, we investigated the ability of a standardized mRNA-based assay to predict ER, PR and HER2 status and treatment response. Methods: ESR1, PGR and ERBB2 expression was analyzed from the standardized nCounter-based PAM50 assay in 1,544 FFPE breast tumors obtained from 13 independent studies (NeoEribulin, GEICAM 2012-09, TBCRC023/006, LPT109096, EGF117165, PAMELA, PerELISA, GEICAM 2003-11, VENTANA, IBIMA and HCB). All immunohistochemical and in situ hybridization analyses followed ASCO/CAP criteria and were performed in central labs except for Neoeribulin and VENTANA studies. To explore the best cutoff for each gene, we used Monte Carlo cross validation (repeated 1000 times, 2/3 training, 1/3 testing) to achieve the highest kappa values when gene expression was compared to pathology assessment. Receiver operating characteristic analysis and area under the ROC curve (AUC) was used to evaluate the performance of each gene to predict ER, PR and HER2 status. Finally, the association of each gene (using the pre-established cutoffs) with pathological complete response (pCR) was evaluated using univariate logistic regression analyses in 2 neoadjuvant cohorts: 1) A combined HER2+ cohort using 191 tumor samples from PAMELA/PerELISA phase II trials, where patients received neoadjuvant dual HER2 blockade without chemotherapy for 15-18 weeks and 2) a combined cohort of hormone receptor-positive/HER2-negative using 205 tumor samples from IBIMA/HCB consecutive series, where patients received anthracycline/taxane-based chemotherapy. Results: Concordance between ESR1 and ER was 95.3% (95% confidence interval [95CI] 94.0-96.4%; AUC=0.98). ER+ and ER- cases were classified as ESR1- and ESR1+ in 5.5% and 4.8% of the cases, respectively. Concordance between PR and PGR was 85.2% (95CI 83.1-87.1%; AUC=0.95), and between ERBB2 and HER2 was 92.8% (95CI 91.4-94.1%; AUC=0.95). HER2+ and HER2- cases were classified ERBB2- and ERBB2+ in 16.7% and 2.9% of the cases, respectively. In the neoadjuvant HER2+ cohort, the pCR rates were 44.6% in ESR1- and 18.8% in ESR1+ (odds ratio [OR] 3.9; 95CI 1.9-8.4; p&amp;lt;0.001), 38.5 in PGR- and 15.8% in PGR+ (OR 3.2; 95CI 1.6-6.7; p=0.001), 2.6% in ERBB2- and 35.3% in ERBB2+ (OR 19.7; 95CI 2.6-149.1; p&amp;lt;0.001). In the neoadjuvant HR+/HER2- cohort, the pCR rates were 40% in ESR1- and 5.12% in ESR1+ (OR 11.5; 95IC 2.7-48.5; p&amp;lt;0.001), 15.5% in PGR- and 4.3% in PGR+ (OR 3.8; 95IC 1.3-11.7; p=0.019), 7.36% in ERBB2- and 0% in ERBB2+ (OR NA). Finally, ESR1, PGR and ERBB2 expression as continuous variables were found significantly associated with pCR in both cohorts. Conclusion: ESR1, PGR and ERBB2 standardized mRNA levels show high concordance with ER, PR and HER2, and might provide a more objective and quantitative prediction of response to chemotherapy and anti-HER2 therapy. The level of concordance between GE and pathology-based assessments is similar to 2 FDA 510(k) cleared pathology-based ER assays (e.g. SP1 versus 6F11 antibody clones), local versus central HER2 testing, and ER or PR status when determined by the ligand-binding assay versus immunohistochemistry. Citation Format: Pascual T, Tsai YS, Martín M, Lluch A, Cortes J, Llombart A, Conte P, Guarneri V, Rimawi MF, Alba E, Ruiz-Borrego M, Rojo F, de la Haba J, Schiff R, Adamo B, Vidal M, Paré L, Chic N, Muñoz M, Galvan P, Gonzalez-Farre B, Brauer HA, Sullivan A, Nuciforo P, Parker JS, Prat A. Standardized nCounter-based determination of estrogen receptor (ER), progesterone receptor (PR) and HER2 receptor status in breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-08-06.

Synthesis and In vitro/In vivo Characterization of Raloxifene Grafted Poly(Styrene Maleic Acid)-Poly(Amide-Ether-Ester-Imide) Micelles for Targeted Delivery of Docetaxel in G Protein-Coupled Estrogen Receptor Breast Cancer.

To reduce the nonspecifically distribution of chemotherapeutic agents throughout the whole body, which causes severe toxicity in normal tissues, targeting them towards a receptor overexpressed on tumor tissue, is a promising method for cancer therapy. The aim of the present study was development of novel copolymeric micelles of raloxifene targeted Styrene Maleic Acid-Poly Amide Ether Ester Imide-Poly Ethylene Glycol (SMA-PAEEI-PEG-RA) and loading them with Docetaxel (DTX). Successful synthesis of the targeted copolymer was confirmed by FTIR and C-NMR spectroscopy. The micelles physicochemical properties like morphology, particle size, poly dispersity index, zeta potential, drug loading, release, stability, in vitro cytotoxicity and cellular uptake were analyzed. The in vivo antitumor activity of DTX-loaded micelles were assessed and compared with free DTX and non-targeted micelles in breast cancer bearing Balb-c mice. Particle sizes, zeta potentials and the encapsulation efficiency of the drug in targeted micelles were 115.9- 142.8 nm, -4.9 to -12.9 mV, and 54.1-67.8%, respectively. Cell toxicity tests showed that IC50 of DTX-loaded SMAPAEEI- PEG-RA micelles increased five-fold as compared with free DTX. Survival rate of the mice improved more effectively than free DTX so that, the percentage of increase in lifespan (ILS%) and the tumor inhibition ratio (TIR) changed from 41.66% and 51.19% in free drug to 83.33% and 78.57% in the targeted micelles, respectively. Therefore, the raloxifene conjugated PEG-derived micelles may provide a novel and effective delivery system for DTX in breast cancer.

G-Protein Coupled Estrogen Receptor in Breast Cancer.

The G-protein coupled estrogen receptor (GPER), an alternate estrogen receptor (ER) with a structure distinct from the two canonical ERs, being ERα, and ERβ, is expressed in 50% to 60% of breast cancer tissues and has been presumed to be associated with the development of tamoxifen resistance in ERα positive breast cancer. On the other hand, triple-negative breast cancer (TNBC) constitutes 15% to 20% of breast cancers and frequently displays a more aggressive behavior. GPER is prevalent and involved in TNBC and can be a therapeutic target. However, contradictory results exist regarding the function of GPER in breast cancer, proliferative or pro-apoptotic. A better understanding of the GPER, its role in breast cancer, and the interactions with the ER and epidermal growth factor receptor will be beneficial for the disease management and prevention in the future.

Immunohistochemical analysis of estrogen receptor in breast cancer with ESR1 mutations detected by hybrid capture-based next-generation sequencing

Estrogen receptor-α (ER-α), encoded by ESR1, is detected by immunohistochemistry in approximately 70% of invasive breast cancers and serves as a strong predictive biomarker. ESR1-activating mutations in the ligand-binding domain have been reported in up to 35–40% of ER-positive metastatic breast cancers and are associated with endocrine therapy resistance and disease progression. At present, it is unclear whether ESR1 mutations alter the immunohistochemical detection of ER performed in routine clinical practice. In this study, ESR1 mutations in breast cancer were identified utilizing Memorial Sloan Kettering-Integrated Mutation Profiling of Actionable Cancer Targets (MSK-IMPACT), a Food and Drug Administration-approved hybridization capture-based next-generation sequencing assay. Five hundred and eighty-six breast cancers from patients with locally advanced or metastatic disease were analyzed using MSK-IMPACT in the study period. ESR1 somatic alterations were identified in 67 breast cancer samples from 66 patients. Immunohistochemical analysis of ER, progesterone receptor, and human epidermal growth factor receptor 2 was performed on the primary and treated breast cancers from these patients at the time of diagnosis. Twenty unique ESR1 mutations were identified involving the ligand-binding domain, all in breast cancer samples from patients previously treated with endocrine therapy. The most frequent mutations were D538G (n = 22), Y537S (n = 7), and E380Q (n = 7). All breast cancer samples with an ESR1 mutation were ER-positive by immunohistochemistry. Review of the ER immunohistochemistry in the paired untreated primary tumor and treated tumor from 34 patients showed no detectable change in the ER-positive immunohistochemical status (median percentage of invasive tumor cells with nuclear staining: untreated primary tumor 90%, treated tumor 95%). We conclude that ESR1 mutations do not appreciably diminish ER-positive staining by immunohistochemistry. In addition to standard biomarker testing by immunohistochemistry, the assessment of ESR1 mutations by molecular testing can help guide the clinical management of patients with ER-positive breast cancer in the setting of endocrine resistance and progression of disease.

The potential influence of breast cancer estrogen receptors' distribution on active DNA demethylation.

Alterations in DNA methylation may cause disturbances in regulation of gene expression, including drug metabolism and distribution. Moreover, many cancers, including breast cancer, are characterized by DNA hypomethylation and a decreased 5-hydroxymethylcytosine level. The abnormal cell growth found in breast carcinoma might be the result of impaired up-regulation of breast cancer receptors. Receptors’ expression in breast cancer determines clinical outcome, and it is possible that they lead to different DNA methylation patterns. Excessive steroid exposure can affect DNA methylation by promoting demethylation of CpG islands in promoter regions of genes, and hence may have an impact on promotion and progression of breast cancer cells. Tamoxifen, as a leading drug in breast cancer hormone therapy, has an ability to act like estrogen or antiestrogen depending on the type and localization of the breast cancer receptor. Further studies are needed to determine whether tamoxifen, similarly to steroids, may evoke changes in methylation pattern.

Estrogen Receptor, Progesterone Receptor, and Human Epidermal Growth Factor Receptor-2 Testing in Breast Cancer: Assessing the Value of Repeated Centralized Testing in Excision Specimens.

At some tertiary breast care centers, where many patients are referred from other institutions, it is routine to repeat testing for estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor-2 (HER2/neu) in excision specimens if these tests were performed on the preceding biopsy at the referring facility. The goal of this study is to assess the value of this practice. We documented results from ER, PR, and HER2 testing in 541 consecutive invasive breast cancers excised over a 2.5-year period and analyzed the subset (n=153) for which testing was performed on the excision specimen solely due to the fact that testing on the preceding biopsy was performed at an outside institution. The rates and directions of biopsy-to-excision change were as follows: ER [1.3% (2/153), 100% from (+) to (-)]; PR [4% (6/153), 83% from (+) to (-)]; HER2/neu assessed by immunohistochemistry [21% (29/137)]; HER2/neu assessed by fluorescence in situ hybridization [3.3% (2/61); 50% from amplified to nonamplified and 50% vice versa]. There were no ER(-) and PR(-) biopsy cases that became ER and/or PR(+) in the excision. By coordinate analysis for the hormone receptors [ie, ER and/or PR(+) being indicative of "hormone receptor" (HR) positivity], there were no cases that changed from HR(+) in the biopsy to HR(-) in the excision (or vice versa), which suggests that repeat testing for ER and PR in this setting is of limited value. In an analysis that incorporated both immunohistochemistry and in situ fluorescence hybridization results, there were 2 cases with a clinically significant biopsy-to-excision change in HER2/neu status in which that change was detected primarily because the excision was retested. These findings provide baseline data for formulating policies on whether repeat testing should routinely be performed in the described scenario.

Increased PD-1 MRNA Expression in Peripheral Blood Cells of ER+ and PR+ Breast Cancer Patients and Its Unfavorable Prognostic Value

Background: The clinical significance of programmed cell death 1 (PD-1) and cytotoxic T lymphocyte-associated protein 4 (CTLA-4) expression on tumor infiltrating lymphocytes in breast cancer patients has been confirmed, while that of peripheral blood cells derived immune molecules remain unclear. Aim: We aimed to investigate the clinical importance of immune molecules, including PD-1 and CTLA-4, expression in peripheral blood cells of breast cancer patients, especially in terms of the relationship between immune molecules and estrogen receptor (ER)/progesterone receptor (PR) status, as well as their prognostic values. Methods: We enrolled 109 breast cancer patients, including 52 cases before surgery and neoadjuvant treatment (PreS group), 18 cases postsurgery and adjuvant chemoradiotherapy (PostS group), 39 metastatic cases presalvage treatment (Met group), and 21 age- and sex-matched healthy volunteers). The mRNA abundance of PD-1, CTLA-4, IL-2 receptor alpha (IL-2Rα), and cluster of differentiation 28 (CD28), forkhead box P3 (FOXP3), transforming growth factor beta (TGF-β), and interleukin-10 (IL-10) in pretreatment peripheral blood were analyzed by quantitative real-time PCR. Results: ER+ breast cancer patients showed significant higher mRNA levels of PD-1, CTLA-4, IL-2Rα, and CD28 with fold changes of 10.8, 2.4, 5.0, and 3.8, respectively ( P &lt; 0.05) than that of ER− cases. Similarly, PR+ patients showed increased levels of PD-1, CTLA-4, and CD28 with fold changes of 6.7, 2.0, and 2.5, respectively ( P &lt; 0.05) comparing to that of PR− cases. Patients in PreS group and Met group showed higher mRNA levels of PD-1, CTLA-4, IL-2Rα, CD28, FOXP3, TGF-β, and IL-10 than PostS group and healthy volunteers. Univariable analysis revealed that high PD-1 expression was associated with poorer progression-free survival (PFS) in metastatic breast cancer patients (5.9 vs 14.6 months, HR: 2.47, 95% CI: 1.22-5.02, P = 0.046). Meanwhile, the prognostic value of PD-1 was remained in multivariate analyses (HR: 2.22, 95% CI: 1.04-4.73, P = 0.039). Conclusion: Increased PD-1, CTLA-4, and CD28 mRNA abundance were showed in breast cancer patients and ER+/PR+ cases, which may provide the rationale for combining checkpoint inhibitors with endocrine therapy for breast cancer treatment. Furthermore, PD-1 is a promising prognostic biomarker for metastatic breast cancer.