Overexpression Of ESR1 Research Articles

Expression and Prognostic Potential of ESR1 in Breast Cancer

This study aims to explore the potential of ESR1 as a biomarker in breast cancer (BRCA) using bioinformatics analysis tools. The up-regulation of ESR1 expression in BRCA was investigated using UALCAN and GEPIA2, illustrating its role in BRCA progression. Furthermore, analyses based on various variables such as gender, age, race, and pathological stages of BRCA patients revealed a consistent up-regulation of ESR1, emphasizing its role in the development and progression of BRCA. Additionally, an analysis of ESR1 promoter methylation levels across various parameters revealed hypomethylation, affirming the inverse correlation between methylation and ESR1 expression. Prognostic analysis further indicated that overexpression of ESR1 is associated with poor overall survival, highlighting its potential as a prognostic biomarker in BRCA. Moreover, genetic mutation analysis using cBioPortal disclosed a minor role of ESR1 genetic mutations in BRCA, with only 2.5% of genetic alterations observed. The STRING and DAVID tools were utilized to conduct pathway enrichment analysis, revealing diverse biological functions of ESR1 and its 10 interconnected genes. Altogether, these results underscore the significance of understanding ESR1 up-regulation in BRCA and demonstrate its potential as a therapeutic, diagnostic, and prognostic biomarker.

Cardamomin Inhibits the Proliferation and Tumorigenesis of Bladder Cancer by ESR1 in PI3K/AKT Pathway.

Cardamomin has been widely studied in cancer, but its role in cancer bladder cancer has not been mentioned. In this study, we validated the anti-cancer effect of cardamom and whether its potential mechanism is related to the PI3K/AKT pathway. After treating with different doses of cardamomin, the cytotoxicity was studied by CCK8. Secondly, we analyzed the effect of cardamomin on the proliferation, apoptosis and cell movement. Next, we analyzed the regulation of ESR1 by western blot and its impact on the PI3K/AKT pathway. We also transfected ESR1 overexpression and silencing vectors, and verified the transfection efficiency through RT-qPCR. Further, the specific mechanism of the drug's inhibitory effect on bladder cancer was also determined. We constructed the subcutaneous tumor model in vivo. After cardamomin administration, we mainly analyzed the positive expression of KI67 in tumor tissues by immunohistochemistry, and the apoptotic cells in tumor tissues by TUNEL, and related proteins in PI3K/AKT pathway by western blot. In this paper, cardamomin inhibited cell proliferation and invasion ability, blocked the transition of G0/G1 phase to S phase, and increased apoptotic rate of 5637 and HT1376 cells, as well as raised ESR1 expression. Cardamomin exerted anti-tumor effect through PI3K/AKT pathway. In vivo animal experiments indicated the inhibitory effect of cardamomin on subcutaneous implanted tumor. Cardamomin inhibited the positive expression of KI67 and promoted the TUNEL-positive cells in tumor tissues. Consistent with in vitro assay, cardamomin increased the expression of ESR1 and downregulated the PI3K/AKT pathway. Cardamomin has a significant inhibitory effect on bladder cancer, and upregulate the expression of ESR1 in bladder cancer through PI3K/AKT.

Sexual Dimorphism in Mitochondrial Metabolism and Insulin Sensitivity Is Controlled by HSP72-ERa Crosstalk

HSP72 is highly induced during exercise, and muscle expression is reduced in obese and diabetic men. Muscle-specific HSP72 overexpression protects male mice against diet-induced obesity and insulin resistance. The current study objective was to determine the mechanisms by which HSP72 controls metabolic function and to ascertain whether these mechanisms are impacted by biological sex. We interrogated the impact of biological sex and estradiol action in the context of HSP72 loss and gain of expression in mice. HSP72 is a binding partner of the mitochondrial quality control protein Parkin. HSP72-KO led to metabolic dysfunction via impaired Parkin action, by promoting the retention of enlarged, fission incompetent mitochondria with reduced respiratory capacity. In contrast, female KOs remained lean and insulin sensitive with small spherical muscle mitochondria. Muscle estrogen receptor alpha transcript and protein (Esr1/ERa) was induced in female HSP72-KO vs. wildtype (WT), and this enhanced Parkin-DRP1-induced fatty acid oxidation and underpinned improvements in exercise capacity. The phenotype of female HSP72-KO mice recapitulates that of muscle-specific ESR1 overexpression animals. Because muscle ERa expression was identical between male genotypes, KO vs. WT, we treated male KO mice with 17β-estradiol and the treatment restored mitochondrial form/function as well as insulin sensitivity. In summary, biological sex is critical for understanding the impact of HSP72 in governing metabolic health and insulin sensitivity. National Institutes of Health DK060484 and P30DK063491. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Abstract 6279: Estrogen signaling in low-grade serous ovarian carcinoma

Abstract High level of estrogen in the blood of women has been linked to the progression and possibly development of ovarian cancer. Almost all low-grade serous ovarian cancer (LGSOC) expresses estrogen receptor alpha (ERα protein encoded by the gene ESR1) and develops during reproductive age of women. However, recent studies suggested that a higher expression of ERα correlates with better survival. In a phase II clinical trial, hormonal therapies have been shown to be associated with a clinical benefit rate of 61% for recurrent ER-positive LGSOC patients. The study also indicated that women with recurrent LGSOC who received hormonal therapies had a significantly longer progression-free survival but not overall survival. Endocrine therapies have proven to be effective in treating breast cancer. Unfortunately, in ovarian cancer clinical trials (GOG0281 and PARAGON), these treatments have not achieved comparable results, with an objective response rate of only approximately 14%. To understand the ESR1 regulation in LGSOC, we have performed RNAseq and ChIPseq analyses of LGSOC tumor tissues. We also forced over-expression of ESR1 in LGSOC cell lines. Using RNAseq data, we aligned the sequencing reads to all the known ESR1 transcript variants. We found that ESR1 transcript variant 1, 2, 3 and X11 were the major transcripts expressed. Variants 1, 2 and 3 encode the regular 66 kDa ESR1 protein, while the X11 variant encodes a 52 kDa ESR1 protein. Both 66 kDa and 52 kDa ESR1 proteins were also detected in LGSOC tumor tissues by western blots. To further explore the function of ESR1 66kDa in LGSOC, we over-expressed ESR1 variant 1 in two LGSOC cell lines (HOC-7 and HCC5075) by transfecting with an expression plasmid. Total proteins were extracted from the mock control and transfected cells for functional proteomic analysis by reverse phase protein arrays (RPPA). From the RPPA data, overexpressing ESR1 in LGSOC cell lines suppressed DNA repair pathways but activated cell cycle and mitosis pathways. To further delineate the ESR1 DNA binding sites in LGSOC, we performed ChIPseq analysis of these tumor samples as well as two ovarian cancer cell lines that express ESR1 protein. Our results demonstrated that ESR1 regulated “cistromes” in ER positive ovarian carcinoma is very different from that in ER positive breast cancer as much less ESR1 binding sites were found in LGSOC. There are ESR1 binding sites common to both types of cancers, but we found quite a few unique ESR1 binding sites. We are trying to integrate the ChIPseq and RNAseq data and hopefully identify, for the first time, an ovarian cancer specific ERα cistrome. ER expression may not always correlate with activation of ESR1 signaling pathways, which may be one of the reasons underlying endocrine therapy resistance in ovarian cancer. The results of an integrated analyses will also give us insight on the management of ER positive LGSOC by identifying new genetic targets that may be used in combination with endocrine therapy. Citation Format: Yvonne TM Tsang, Chun Wai Oscar Ng, David Gershenson, K-Kwok wong. Estrogen signaling in low-grade serous ovarian carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6279.

An estrogen-regulated long non-coding RNA NCALD promotes luminal breast cancer proliferation by activating GRHL2

PurposeLuminal breast cancer (BC) is a prevalent subtype associated with an increased risk of late disease recurrence and mortality. Long noncoding RNAs (lncRNAs) likely play significant roles in regulating tissue-specific gene expression during tumorigenesis. However, the biological function and underlying mechanisms of specific dysregulated lncRNAs in luminal BC remain largely unknown, which has drawn our attention.MethodsThe expression pattern of lncRNA NCALD in luminal BC was predicted and validated in collected tissue samples. Following cell transfection with knockdown of lncRNA NCALD and ESR1 and overexpression of GRHL2 and ESR1, we investigated the interactions among lncRNA NCALD, ESR1, and GRHL2. Additionally, their regulatory functions in luminal BC cell biological processes were studied. Subsequently, a xenograft tumor model was prepared for validation.ResultsOur study identified a specific overexpression of the lncRNA NCALD in luminal BC, which correlated with an unfavorable prognosis. Suppression of lncRNA NCALD or ESR1 led to inhibition of GRHL2 expression, while concurrent overexpression of ESR1 and lncRNA NCALD potentially elevated GRHL2 expression. Mechanistically, ERα may drive the expression of lncRNA NCALD. Furthermore, the 1–151 nt fragment of lncRNA NCALD was found to recruit ERα and interact with its oest-Recep domain located in the promoter region of GRHL2, ultimately inducing GRHL2 transcription.ConclusionsThese findings reveal the involvement of lncRNA NCALD and its specific expression pattern in luminal BC. Targeting lncRNA NCALD could be a potential therapeutic strategy for delaying the progression of BC.

High risk oral contraceptive hormones do not directly enhance endothelial cell procoagulant activity in vitro.

Oral contraceptive (OC) use increases venous thromboembolism risk 2-5-fold. Procoagulant changes can be detected in plasma from OC users even without thrombosis, but cellular mechanisms that provoke thrombosis have not been identified. Endothelial cell (EC) dysfunction is thought to initiate venous thromboembolism. It is unknown whether OC hormones provoke aberrant procoagulant activity in ECs. Characterize the effect of high-risk OC hormones (ethinyl estradiol [EE] and drospirenone) on EC procoagulant activity and the potential interplay with nuclear estrogen receptors ERα and ERβ and inflammatory processes. Human umbilical vein and dermal microvascular ECs (HUVEC and HDMVEC, respectively) were treated with EE and/or drospirenone. Genes encoding the estrogen receptors ERα and ERβ (ESR1 and ESR2, respectively) were overexpressed in HUVEC and HDMVEC via lentiviral vectors. EC gene expression was assessed by RT-qPCR. The ability of ECs to support thrombin generation and fibrin formation was measured by calibrated automated thrombography and spectrophotometry, respectively. Neither EE nor drospirenone, alone or together, changed expression of genes encoding anti- or procoagulant proteins (TFPI, THBD, F3), integrins (ITGAV, ITGB3), or fibrinolytic mediators (SERPINE1, PLAT). EE and/or drospirenone did not increase EC-supported thrombin generation or fibrin formation, either. Our analyses indicated a subset of individuals express ESR1 and ESR2 transcripts in human aortic ECs. However, overexpression of ESR1 and/or ESR2 in HUVEC and HDMVEC did not facilitate the ability of OC-treated ECs to support procoagulant activity, even in the presence of a pro-inflammatory stimulus. The OC hormones EE and drospirenone do not directly enhance thrombin generation potential of primary ECs in vitro.

Esr1 but Not CYP19A1 Overexpression in Mammary Epithelial Cells during Reproductive Senescence Induces Pregnancy-Like Proliferative Mammary Disease Responsive to Anti-Hormonals

Molecular-level analyses of breast carcinogenesis benefit from vivo disease models. Estrogen receptor 1 (Esr1) and cytochrome P450 family 19 subfamily A member 1 (CYP19A1) overexpression targeted to mammary epithelial cells in genetically engineered mouse models induces largely similar rates of proliferative mammary disease in prereproductive senescent mice. Herein, with natural reproductive senescence, Esr1 overexpression compared with CYP19A1 overexpression resulted in significantly higher rates of preneoplasia and cancer. Before reproductive senescence, Esr1, but not CYP19A1, overexpressing mice are tamoxifen resistant. However, during reproductive senescence, Esr1 mice exhibited responsiveness. Both Esr1 and CYP19A1 are responsive to letrozole before and after reproductive senescence. Gene Set Enrichment Analyses of RNA-sequencing data sets showed that higher disease rates in Esr1 mice were accompanied by significantly higher expression of cell proliferation genes, including members of prognostic platforms for women with early-stage hormone receptor-positive disease. Tamoxifen and letrozole exposure induced down-regulation of these genes and resolved differences between the two models. Both Esr1 and CYP19A1 overexpression induced abnormal developmental patterns of pregnancy-like gene expression. This resolved with progression through reproductive senescence in CYP19A1 mice, but was more persistent in Esr1 mice, resolving only with tamoxifen and letrozole exposure. In summary, genetically engineered mouse models of Esr1 and CYP19A1 overexpression revealed a diversion of disease processes resulting from the two distinct molecular pathophysiological mammary gland-targeted intrusions into estrogen signaling during reproductive senescence.

Overexpression of Estrogen Receptor α in Mammary Glands of Aging Mice Is Associated with a Proliferative Risk Signature and Generation of Estrogen Receptor α–Positive Mammary Adenocarcinomas

Age is a risk factor for human estrogen receptor-positive breast cancer, with highest prevalence following menopause. While transcriptome risk profiling is available for human breast cancers, it is not yet developed for prognostication for primary or secondary breast cancer development utilizing at-risk breast tissue. Both estrogen receptor α (ER) and aromatase overexpression have been linked to human breast cancer. Herein, conditional genetically engineered mouse models of estrogen receptor 1 (Esr1) and cytochrome P450 family 19 subfamily A member 1 (CYP19A1) were used to show that induction of Esr1 overexpression just before or with reproductive senescence and maintained through age 30 months resulted in significantly higher prevalence of estrogen receptor-positive adenocarcinomas than CYP19A1 overexpression. All adenocarcinomas tested showed high percentages of ER+cells. Mammary cancer development was preceded by a persistent proliferative transcriptome risk signature initiated within 1 week of transgene induction that showed parallels to the Prosigna/Prediction Analysis of Microarray 50 human prognostic signature for early-stage human ER+breast cancer. CYP19A1 mice also developed ER+mammary cancers, but histology was more divided between adenocarcinoma and adenosquamous, with one ER- adenocarcinoma. Results demonstrate that, like humans, generation of ER+adenocarcinoma in mice was facilitated by aging mice past the age of reproductive senescence. Esr1 overexpression was associated with a proliferative estrogen pathway-linked signature that preceded appearance of ER+mammary adenocarcinomas.

Transcriptional regulation of CYP19A1 expression in chickens: ESR1, ESR2 and NR5A2 form a functional network

Aromatase, encoded by CYP19A1, is responsible for the conversion of androgen to estrogen, which plays a vital role in the development and function of the ovary and functions in many other physiological processes in both sexes. Instead of being expressed in ovarian granulosa cells, as in mammals, CYP19A1 is expressed in chickens in the theca cells of ovarian follicles, and the mechanism of CYP19A1 expression regulation remains unknown. Here, using immunofluorescence and western blotting assay, we first confirmed that CYP19A1 and FOXL2 (Forkheadbox L2) were coexpressed in pre-granulosa cells of female chicken embryonic gonads, while FOXL2 did not affect aromatase expression at embryonic stages. Second, our research showed that CYP19A1, ESR1 (estrogen receptor alpha), ESR2 (estrogen receptor beta) and NR5A2 (liver receptor homologue-1) were coexpressed in the theca cell layers of chicken small yellow follicles. There was cross-talk between CYP19A1 and candidate transcription factors (ESR1, ESR2 and NR5A2), which was identified by generating a reliable theca cell culture model. Using luciferase assays in theca cells and chicken embryonic fibroblast (DF-1) cells, the results suggested that ESR1 and NR5A2 had potential effects on CYP19A1 promoter activity in chickens. Overexpression of ESR1, ESR2 and NR5A2 in chicken embryonic fibroblast (DF-1) cells upregulated the protein expression of CYP19A1, mutually restricted each other and formed a potential regulatory network to coordinate the expression of CYP19A1. To conclude, our results indicated that FOXL2 cannot regulate the expression of CYP19A1 at chicken embryonic stages and after sexual maturity, ESR1, ESR2 and NR5A2 form a functional network to affect the expression of CYP19A1. These results laid a foundation for further research on the transcriptional regulation of chicken aromatase.

Aberrant Claudin-6-Adhesion Signaling Promotes Endometrial Cancer Progression via Estrogen Receptor α.

Cell adhesion proteins not only maintain tissue integrity, but also possess signaling abilities to organize diverse cellular events in a variety of physiologic and pathologic processes; however, the underlying mechanism remains obscure. Among cell adhesion molecules, the claudin (CLDN) family is often aberrantly expressed in various cancers, but the biological relevance and molecular basis for this observation have not yet been established. Here, we show that high CLDN6 expression accelerates cellular proliferation and migration in two distinct human endometrial cancer cell lines in vitro. Using a xenograft model, we also revealed that aberrant CLDN6 expression promotes tumor growth and invasion in endometrial cancer tissues. The second extracellular domain and Y196/200 of CLDN6 were required to recruit and activate Src-family kinases (SFK) and to stimulate malignant phenotypes. Knockout and overexpression of ESR1 in endometrial carcinoma cells showed that the CLDN6-adhesion signal links to estrogen receptor α (ERα) to advance tumor progression. In particular, aberrant CLDN6-ERα signaling contributed to collective cell behaviors in the leading front of endometrial cancer cells. Importantly, we demonstrate that CLDN6/SFK/PI3K-dependent AKT and SGK (serum- and glucocorticoid-regulated kinase) signaling in endometrial cancer cells targets Ser518 in the human ERα to activate ERα transcriptional activity in a ligand-independent manner, thereby promoting tumor progression. Furthermore, CLDN6, at least in part, also regulated gene expression in an ERα-independent manner. IMPLICATIONS: The identification of this machinery highlights regulation of the transcription factors by cell adhesion to advance tumor progression.

Outcomes with CDK4/6 inhibitors based on endocrine sensitivity in hormone receptor-positive metastatic breast cancer (HR+ MBC).

e12526 Background: PALOMA-3 results demonstrated that patients (pts) with sensitivity to previous endocrine therapy had a substantial benefit with Palbociclib compared to those with intrinsic endocrine resistance (Turner NC et al. NEJM 2018). ESR1 mutation has been associated with decreased response to endocrine therapy (Fribbens C et al. JCO 2016) and NSD3 amplification in breast cancer cells have been correlated with the overexpression of ESR1 (Irish JC et al. Mol Oncol 2016). Here we demonstrate a real-world response to CDK4/6i based on high-risk features and correlation to biomarkers of response. Methods: We retrospectively analyzed 115 HR+MBC pts at a single large community cancer center who received CDK4/6i + endocrine therapy and 40 matched controls treated with endocrine therapy and underwent NextGen Sequencing (NGS) profiling of 592 genes (Caris Life Sciences, Phoenix, AZ). The primary outcome was progression-free survival (PFS). Hazard ratios were calculated from Cox proportional hazards models built using the survival package[1] in R. Results: Among 115 pts in the CDK4/6i cohort, the median PFS for pts treated in the first-line (N=77) versus (vs.) second-line (N=38) was 9.7 and 4.6 months (mo) respectively (HR 2.04, p=0.001). Further, the median PFS in first-line cases who had a Disease-Free Survival (DFS) of >2 years (endocrine sensitive) (N=27) was 11.9 mo, and in pts with DFS < 2years (endocrine resistant) (N=24), it was 7.7 mo (HR 0.71, p= 0.397). Six pts with ESR1 mutations had worse PFS compared to ESR1 wild-type (N=40) when treated with CDK4/6i in 1st line, 6.4 vs. 18 mo (HR: 2.25, p=0.052) and 2nd line 2.5 (N=9) vs. 5.6 mo (N=17) HR: 2.09, p=0.1). NSD3 amplification was the only other genomic alteration showing significance as a negative predictor of PFS (first-line: 6.1 vs. 14.7 mo, HR: 2.40, p=0.04; second-line: 2.8 vs. 6.5 mo, HR: 3.61, p=0.06). NSD3 amplification appeared to have no significant effect in the control cohort 6.5 vs. 4.4 mo, (HR 1.29, p=0.63). Conclusions: In this real-world cohort, CDK 4/6 combination therapy benefits HR+ MBC patients in the first and second-line setting. ESR1 mutation is a predictor of worse outcome. NSD3 gene amplification is a potential biomarker of resistance to CDK4/6i combination therapy. (Therneau T (2015). A Package for Survival Analysis in S version 2.38, https://CRAN.R-project.org/package=survival).

Gene Expression Analyses of HER-2/neu and ESR1 in Patients with Breast Cancer

ABSTRACT Background: Her-2 and ESR1 genes, that interact in the cell signaling pathway, are the most important molecular markers of breast cancer, which have been amplified or overexpressed in 30% and 70%, respectively. This study was performed to evaluate the gene expression levels of Her-2 and ESR1 genes in tumor cells and its adjacent normal tissue of breast cancer patients and compared them whit clinical-pathological features. Methods: In total, 80 tissue specimens from 40 patients, with an average age of 48.47 years, were examined by Real-time PCR technique, and ultimately evaluated the expression level of Her-2 and ESR1genes. The data were analyzed by REST 2009 V2.0.13 statistical software. Results: HER2 and ESR1 overexpression was identified in 19 (48%) and 12 (30%) of 40 patients respectively, which was higher and lower than that recorded in international statistics, respectively. ESR1 overexpression was associated with Stage 3A and lymph node involvement 2 (N2) (P = 0.04 and P = 0.047, respectively). No significant correlation was observed between the expression of HER2 and ESR1 and other clinical-pathological features, however, the relative differences were identified in the expression levels of genes between main group and groups that were classified according to the clinical-pathological features and age. Conclusions: Overexpression of Her-2 and ESR1 genes in the patients of our study are higher and lower than international statistics, respectively, indicating the differences in genetic, environmental and ethnic factors that involved in the developing of breast cancer.

A Generalized Gene-Regulatory Network Model of Stem Cell Differentiation for Predicting Lineage Specifiers.

SummaryIdentification of cell-fate determinants for directing stem cell differentiation remains a challenge. Moreover, little is known about how cell-fate determinants are regulated in functionally important subnetworks in large gene-regulatory networks (i.e., GRN motifs). Here we propose a model of stem cell differentiation in which cell-fate determinants work synergistically to determine different cellular identities, and reside in a class of GRN motifs known as feedback loops. Based on this model, we develop a computational method that can systematically predict cell-fate determinants and their GRN motifs. The method was able to recapitulate experimentally validated cell-fate determinants, and validation of two predicted cell-fate determinants confirmed that overexpression of ESR1 and RUNX2 in mouse neural stem cells induces neuronal and astrocyte differentiation, respectively. Thus, the presented GRN-based model of stem cell differentiation and computational method can guide differentiation experiments in stem cell research and regenerative medicine.

Estrogen receptor alpha (ESR1)-signaling regulates the expression of the taxane-response biomarker PRP4K

The pre-mRNA splicing factor 4 kinase PRP4K (PRPF4B), is an essential kinase that is a component of the U5 snRNP and functions in spliceosome assembly. We demonstrated that PRP4K is a novel biological marker for taxane response in ovarian cancer patients and reduced levels of PRP4K correlate with intrinsic and acquired taxane resistance in both breast and ovarian cancer. Breast cancer treatments are chosen based on hormone and growth factor receptor status, with HER2 (ERBB2) positive breast cancer patients receiving anti-HER2 agents and taxanes and estrogen receptor alpha (ESR1) positive (ER+) breast cancer patients receiving anti-estrogen therapies such as tamoxifen. Here we demonstrate that PRP4K is expressed in the normal mammary duct epithelial cells of the mouse, and that estrogen induces PRP4K gene and protein expression in ER+ human MCF7 breast cancer cells. Estrogen acts through ESR1 to regulate PRP4K expression, as over-expression of ESR1 in the ER-negative MDA-MB-231 breast cancer cell line increased the expression of this kinase, and knock-down of ESR1 in ER+ T47D breast cancer cells reduced PRP4K levels. Furthermore, treatment with 4-hydroxytamoxifen (4-OHT) resulted in a dose-dependent decrease in PRP4K protein expression in MCF7 cells. Consistent with our previous studies identifying PRP4K as a taxane-response biomarker, reduced PRP4K expression in 4-OHT-treated cells correlated with reduced sensitivity to paclitaxel. Thus, PRP4K is novel estrogen regulated kinase, and its levels can be reduced by 4-OHT in ER+ breast cancer cells altering their response to taxanes.

Expression of Genomic Functional Estrogen Receptor 1 in Mouse Sertoli Cells

There is no consensus whether Sertoli cells express estrogen receptor 1 (Esr1). Reverse transcription-polymerase chain reaction, Western blot, and immunofluorescence demonstrated that mouse Sertoli cell lines, TM4, MSC-1, and 15P-1, and purified primary mouse Sertoli cells (PSCs) contained Esr1 messenger RNA and proteins. Incubation of Sertoli cells with 17β-estradiol (E2) or ESR1 agonist stimulated the expression of an estrogen responsive gene Greb1, which was prevented by ESR inhibitor or ESR1 antagonist. Overexpression of Esr1 in MSC-1 enhanced E2-induced Greb1 expression, while knockdown of Esr1 by small interfering RNA in TM4 attenuated the response. Furthermore, E2-induced Greb1 expression was abolished in the PSCs isolated from Amh-Cre/Esr1-floxed mice in which Esr1 in Sertoli cells were selectively deleted. Chromatin immunoprecipitation assays indicated that E2-induced Greb1 expression in Sertoli cells was mediated by binding of ESR1 to estrogen responsive elements. In summary, ligand-dependent nuclear ESR1 was present in mouse Sertoli cells and mediates a classical genomic action of estrogens.

Neonatal overexpression of estrogen receptor-α alters midbrain dopamine neuron development and reverses the effects of low maternal care in female offspring.

Maternal behavior is dependent on estrogen receptor-alpha (ERα; Esr1) and oxytocin receptor (OTR) signaling in the medial preoptic area (MPOA) of the hypothalamus, as well as dopamine signaling from the ventral tegmental area (VTA) to forebrain regions. Previous studies in rats indicate that low levels of maternal care, particularly licking/grooming (LG), lead to reduced levels of MPOA ERα and VTA dopamine neurons in female offspring and predict lower levels of postpartum maternal behavior by these offspring. The aim of this study was to determine the functional impact on maternal behavior of neonatal manipulation of ERα in females that had experienced low versus high levels of postnatal maternal LG. Adenovirus expressing ESR1 was targeted to the MPOA in female pups from low and high LG litters on postnatal day 2-3. Overexpression of ESR1 in low LG offspring elevated the level of ERα-immunoreactive cells in the MPOA and of tyrosine hydroxylase cells in the VTA to that observed in high LG females. Amongst juvenile female low LG offspring, ESR1 overexpression also decreased the latency to engage in maternal behavior toward donor pups. These results show that virally mediated expression of ESR1 in the neonatal rat hypothalamus results in lasting changes in ESR1 expression through the juvenile period, and can "rescue" hormone receptor levels and behavior of offspring reared by low LG dams, potentially mediated by downstream alterations within reward circuitry. Thus, the transmission of maternal behavior from one generation to the next can be augmented by neonatal ERα in the MPOA.

Abstract 1996: Identification of four subgroups of Triple Negative Breast Cancer (TNBC) by genomic profiling.

Abstract Poorly defined molecular heterogeneity and a lack of effective molecular targets hinder advancements in the treatment of ER-/PR-/HER2- breast cancer (TNBC). Meta-analyses of public datasets have revealed new subgroups, but these studies are plagued by samples collected from multiple protocols and poor reproducibility. We aimed to identify stable subsets that could be treated with targeted therapy by employing integrated genomic profiling of a large number of TNBC cases (confirmed by IHC) from a single protocol before applying those subgroups to publicly available TNBC sets. We employed non-negative matrix factorization on two independent gene expression datasets (Discovery n = 84 and Validation n = 118) using the top 1000 variant genes in each set. Cophenetic, dispersion, and silhouette metrics revealed 4 clusters, with significant enrichment of differentially expressed (DE) genes in each subgroup among both sets (all comparisons Fisher Exact p < 2.2E-16). A parsimonious gene centroid signature of 480 total genes was selected based on Goeman's Global Test BH-adjusted p-values and fold change of only the Discovery Set. Subgroups were assigned by Pearson Correlation in the Discovery (Rand Index = 0.97) and Validation Sets (RI = 0.84), as well as an External Set made up of 214 IHC-confirmed cases of TNBCs, and another 5 publicly available studies with clinical outcome data for TNBCs. Ingenuity Pathway Analysis was carried out separately on DE genes from each dataset (BH adjusted p < 0.01). There was overwhelming statistical agreement for all subgroups between the Discovery, Validation, and External Sets. Subgroup 1 was defined by Intermediate Grade LumB tumors and overexpression of ESR1, HER-2, and AR, with activated downstream signaling of ESR1 despite being ER- by IHC. In subgroup 2, CDKN2A and TP53 appeared activated while MYC was inhibited. Dozens of immune cell signaling pathways were downregulated in the third subgroup, a basal-like set of TNBCs, which was driven by inhibition of cytokine gamma-IFN. Disease-free and Overall Survival was the worst for subgroup 3 (log rank p = 0.041 and 0.039). The final subgroup (4) was found to be p53 inactivated, a known feature of TNBC but specific to this second basal-like subgroup. Analysis of 84 and 58 cases with corresponding copy number profiling data from the Discovery and Validation Sets revealed subgroup specific copy number changes in addition to known TNBC patterns. Most notably, loss of chr 6 was unique to subgroup 1, while all other tumors shared common loss of chr 5. We have described four molecular phenotypes of TNBC in two independent sets from the same protocol, and a third set composed of public data. These subgroups have strong agreement of DE genes, pathways, and regulators, and are additionally supported by DNA events and prognostic differences between subgroups. We suggest several promising druggable targets based on overexpressed genes in each subgroup. Citation Format: Matthew D. Burstein, Anna Tsimelzon, Kyle R. Covington, Suzanne AW Fuqua, Jenny C. Chang, Susan G. Hilsenbeck, C Kent Osborne, Gordon B. Mills, Ching C. Lau, Powel H. Brown. Identification of four subgroups of Triple Negative Breast Cancer (TNBC) by genomic profiling. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1996. doi:10.1158/1538-7445.AM2013-1996

Genetically Induced Estrogen Receptor α mRNA (Esr1) Overexpression Does Not Adversely Affect Fertility or Penile Development in Male Mice

Previously, we reported that estrogen receptor α mRNA (Esr1) or protein (ESR1) overexpression resulting from neonatal exposure to estrogens in rats was associated with infertility and maldeveloped penis characterized by reduced length and weight and abnormal accumulation of fat cells. The objective of this study was to determine if mutant male mice overexpressing Esr1 are naturally infertile or have reduced fertility and/or develop abnormal penis. The fertility parameters, including fertility and fecundity indices, numbers of days from the day of cohabitation to the day of delivery, and numbers of pups per female, were not altered from controls as a result of Esr1 overexpression. Likewise, penile morphology, including the length, weight, and diameter and os penis development, was not altered from controls. Conversely, weights of the seminal vesicles and bulbospongiosus and levator ani (BS/LA) muscles were significantly (P < .05) lower as compared with controls; however, the weight of the testis, the morphology of the testis and epididymis, and the plasma and testicular testosterone concentration were not different from controls. Hence, genetically induced Esr1 overexpression alone, without an exogenous estrogen exposure during the neonatal period, is unable to adversely affect the development of the penis as well as other male reproductive organs, except for limited, but significant, reductions in weights of the seminal vesicles and BS/LA muscles.

Abstract 319: Comparison of fluorescence in situ hybridization of estrogen receptor genetic locus with protein expression in invasive breast carcinoma

Abstract INTRODUCTION: Evaluation of estrogen receptor (ESR1) status is recommended in all breast cancer patients and is generally performed using immunohistochemistry (IHC). However, the analytical sensitivity of IHC in detecting low levels of ESR1 amplification is often poor and likely due to methodological variation. Though FISH (fluorescent in-situ hybridization) has been proposed as an alternative approach for detection of ESR1 gain, results have been controversial with few studies evaluating concordance between FISH and IHC. In this study, we describe the performance of FISH using an ESR1 probe and correlation of the results with IHC for ESR protein expression. METHODS: FISH and IHC for ESR1 was performed on adjacent sections of formalin fixed paraffin embedded tumor sections from 32 patients with invasive breast cancer enrolled for treatment at MD Anderson Cancer Center. For FISH, pretreatment of the slides with the paraffin pretreatment kit III (Abbott Laboratories) was performed followed by incubation using the ESR1/Cen6 probe set (Zytovision). The number of fluorescent signals for each the ESR1 and centromere 6 were counted in a minimum of 200 non-overlapping, intact nuclei. Nuclei were characterized as normal (two signals for each locus), monosomy (one signal for ER and two signals for the centromere) or trisomy (three signals for ER and two signals for the centromere). IHC on primary tumor tissue sections was carried out in a Bond-maX machine (Leica Microsystems) with primary ER antibody (clone 6F11, Novocastra) at dilution of 1:35 and antigen retrieval using citrate buffer. Nuclear positivity in the tumor cells was expressed as percentage and categorized as negative, low positive or positive based on nuclear staining of 0%, 1-10% and &amp;gt;10% respectively. RESULTS: Of the 32 samples that were successful for both FISH and IHC, a comparison was made to determine concordance of FISH signals to ER IHC results. We calculated the percentage of cells having ≫3 ESR1 signals and those that contained &amp;lt;2 ESR1 signals in all 32 cases. Based on a FISH percentage cutoff of 2.0, cases could be classified into three groups: negative (n=7), equivocal (n=8) and amplified (n=10) with seven cases being discordant when compared to IHC results. The p-value for the ratio of ER negative to ER positive cohort was found to be statistically significant (p=0.026). Based on these criteria we observe a concordance of 75% between the two technologies. CONCLUSION: 1. There is a significant heterogeneity between the gene amplification status and protein overexpression of ESR1. 2. The gene status of ESR1 ranges from negative, equivocal and amplified in both ER negative and ER immunopositive cases. 3. The significance of heterogeneity at the ESR1 gene locus in ascertaining the prognosis and predictive response to antiestrogen therapy needs further evaluation in larger prospective clinical trials. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 319. doi:10.1158/1538-7445.AM2011-319

Genetically-Induced Estrogen Receptor Alpha (ESR1) Overexpression Does Not Adversely Affect Fertility or Penile Development in Male Mice.

Previously, we reported that ESR1 overexpression resulting from neonatal exposure to estrogens in rats and wild-type mice was associated with infertility and mal-developed penis characterized by reduced length and weight and abnormal accumulation of fat cells. The objective of this study was to determine if mutant male mice overexpressing ESR1 are naturally infertile or have reduced fertility and/or develop abnormal penis. The fertility parameters, including fertility and fecundity indices, numbers of days from the day of cohabitation to the day of delivery, and numbers of pups per female, were not altered from controls, as a result of ESR1 overexpression. Likewise, penile morphology, including the length, weight, and diameter and os penis development, was not altered from controls. Conversely, weights of the seminal vesicles and bulbospongiosus and levator ani (BS/LA) muscles were significantly (P < 0.05) lower as compared to controls; however, the weight of the testis, the morphology of the testis and epididymis, and the plasma and testicular testosterone concentration were not different from controls. Hence, this study concludes that the genetically-induced ESR1 overexpression in male mice does not adversely affect fertility, penis, testis or epididymis, but significantly reduces weights of the seminal vesicles and BS/LA muscles. (poster)