ESR1 (Ab-106) Antibody
Description
Biological Functions of ESR1
Understanding the antibody's target is essential for appreciating its research applications. ESR1, upon activation by estradiol, engages in numerous protein-protein interactions that collectively regulate gene expression patterns across diverse cellular and viral genes . These interactions are critical for normal physiological functions but also play significant roles in disease processes.
Transcriptional Regulation Mechanisms
ESR1 interacts with the nuclear transcription factor Sp1 in the presence of estradiol to regulate expression of diverse cellular and viral genes . Additionally, ESR1 activated by estradiol interacts with transcription factor Sp3 to downregulate vascular endothelial growth factor (VEGF) in endometrial cancer cells, suggesting a crucial role in cancer development and progression .
The receptor can tether to DNA through protein-protein interactions with other transcription factors, including activator protein 1 (AP1) family members such as c-Jun, c-Fos, and activating transcription factor (ATF) . These interactions expand the regulatory capacity of ESR1 beyond direct DNA binding to influence broader gene expression networks.
Role in Cancer Progression
ESR1 and NF-κB cooperatively upregulate anti-apoptotic Baculoviral IAP (inhibitor of apoptosis protein) Repeat Containing 3 (BIRC3), promoting breast cancer cell survival and tumor progression . Research has also shown that Deleted in bladder cancer protein 1 (DBC1) modulates the expression of ESR1 and may promote the proliferation of breast cancer tissues .
Immune and Bone Regulation
Beyond cancer, ESR1 has important functions in other physiological systems. Interleukin-6 expression is suppressed by ligand-activated ESR1 through interaction with NF-κB, thereby inhibiting osteoporosis . Additionally, ESR1 is potent in maintaining human immunodeficiency virus (HIV) latency, with evidence suggesting that latency maintenance and HIV RNA levels may be gender-specific due to differential estrogen sensitivity .
ESR1 Phosphorylation at Serine 104 and 106
The ESR1 (Ab-106) Antibody targets a region containing critical phosphorylation sites at serines 104 and 106. These phosphorylation events play crucial roles in regulating receptor activity and function.
Comparative analysis reveals that these phosphorylation sites are conserved across species, with homologous sites at Ser108 and Ser110 in mouse and Ser109 and Ser111 in rat . This evolutionary conservation underscores the functional importance of these phosphorylation sites in ESR1 activity.
Research on phosphorylation-specific antibodies targeting ESR1 at S104 and S106 has shown that these sites are particularly important for:
-
Modulating the transcriptional activity of ESR1
-
Regulating protein-protein interactions
-
Influencing receptor localization and turnover
-
Mediating responses to estrogen and anti-estrogen therapies
The availability of antibodies specifically recognizing these phosphorylation states, such as the Anti-Estrogen Receptor alpha (phospho S104 + S106) antibody, allows researchers to investigate the functional consequences of these post-translational modifications in various experimental contexts .
Applications of ESR1 (Ab-106) Antibody in Research
The ESR1 (Ab-106) Antibody has demonstrated utility across multiple experimental applications, making it a versatile tool for researchers investigating estrogen receptor biology.
Western Blotting
For western blotting applications, the antibody is recommended at dilutions between 1:500 and 1:1000 . This application allows researchers to detect and quantify ESR1 protein levels in various cell and tissue lysates, providing insights into expression patterns under different experimental conditions.
Immunohistochemistry
In immunohistochemistry on paraffin-embedded tissues (IHC-P), the recommended dilution range is 1:50 to 1:200 . This application enables the visualization of ESR1 expression and localization within tissue sections, providing valuable spatial information about receptor distribution in normal and pathological samples.
ELISA
The antibody has also been validated for enzyme-linked immunosorbent assay (ELISA) applications , allowing for quantitative detection of ESR1 in solution-based samples.
ESR1 Mutations and Clinical Implications
Recent research has highlighted the clinical significance of ESR1 mutations in breast cancer treatment and prognosis. A comprehensive study analyzed ESR1 mutation status in baseline serum samples from patients with advanced breast cancer, finding mutations in approximately 30% (115/383) of baseline samples .
Impact on Treatment Response
The presence of ESR1 mutations significantly affects treatment outcomes. In patients with detectable ESR1 mutations, median progression-free survival (PFS) was 2.4 months on exemestane compared to 3.9 months on fulvestrant (HR, 0.59; 95% CI, 0.39–0.89; P = 0.01) . This difference was not observed in patients without ESR1 mutations, indicating that mutation status may predict differential response to these therapies.
Patient Characteristics Based on ESR1 Mutation Status
The following table summarizes key patient characteristics based on ESR1 mutation status from clinical research:
| Characteristic | ESR1 Mutant (N=115) | ESR1 Wild-Type (N=268) | P Value |
|---|---|---|---|
| Age <50 years | 9.6% | 5.6% | 0.09 |
| Visceral Involvement | 63.5% | 57.8% | 0.31 |
| Aromatase Inhibitor Status: Sensitive | 83.5% | 72.4% | 0.02 |
| Time on NSAI >2 years in ABC | 42.6% | 32.5% | 0.01 |
This data reveals important correlations between ESR1 mutation status and clinical factors, with mutations more frequently observed in patients with sensitivity to prior aromatase inhibitor therapy .
Product Specs
Target Background
- Estrogen-induced miR-191 was identified as a direct upstream regulator of DAB2 in ER-positive breast cancer cells. PMID: 29247596
- This study provides whole-genome insights that can help fully understand the biological roles of ER1 in breast cancer. PMID: 30301189
- A relationship was found between rs2046210 and rs3803662, and the risk of developing breast cancer in Vietnamese women. The A allele is the risk allele for both rs2046210 (OR [95% CI] = 1.43 [1.14 - 1.78], P = 0.0015) and rs3803662 (OR [95% CI] = 1.45 [1.16 - 1.83], P = 0.001). In conclusion, these two polymorphisms, rs2046210 in ESR1 and rs3803662 in TNRC9, are associated with breast cancer risk in the Vietnamese population. PMID: 30078824
- This study demonstrates that estrogen receptor alpha can enhance the odonto/osteogenic differentiation of stem cells from apical papilla via ERK and JNK MAPK pathways. PMID: 30069950
- No association between polymorphisms in genes encoding estrogen receptors (ESR1 and ESR2) and excreted BPA levels was found in orthodontic patients after bracket bonding. PMID: 29961922
- Analysis of genome-wide ER binding sites identified mutant ER unique recruitment mediating the allele-specific transcriptional program. PMID: 29438694
- This study describes RNF8 as a co-activator of ERalpha that increases ERalpha stability via a post-transcriptional pathway, providing new insight into the mechanisms by which RNF8 promotes cell growth in ERalpha-positive breast cancer. PMID: 28216286
- Reduced expression of ERbeta1 in female ERalpha-negative papillary thyroid carcinoma patients is associated with greater progression of the disease. PMID: 29655286
- ERbeta exhibits a heterogeneous distribution in deep infiltrating endometriosis. PMID: 29383962
- ER-alpha36/EGFR signaling loop promotes the growth of hepatocellular carcinoma cells. PMID: 29481815
- This study aimed to determine the presence and localization of estrogen receptors (ERs), progesterone receptors (PRs), and androgen receptors (ARs) in both healthy and varicose vein wall cells and their relationship with gender. PMID: 30250632
- Estrogen receptor-alpha was expressed only in women and showed a positive correlation with the amount of fungi in oral paracoccidioidomycosis, while progesterone receptor was observed in both genders and exhibited no correlation with estrogen receptor-alpha or fungi counting. PMID: 29796757
- ERalpha upregulates vinculin expression in breast cancer cells. Loss of vinculin promotes amoeboid features of cancer cells. PMID: 28266545
- Polymorphisms in the ERalpha gene do not predict in vitro fertilization outcome. PMID: 29916276
- High ESR1 expression is associated with metastasis in breast cancer. PMID: 29187405
- The G/G XbaI genotype of the ESR1 gene is associated with breast cancer risk. PMID: 29893332
- miR-221 may impair the protective effect of estrogen in degenerated cartilaginous endplate cells through targeting estrogen receptor alpha. PMID: 29529124
- Results showed that NAT1 and ESR1 expression were increased in primary breast tumor samples compared with normal breast tissue samples, and in ER+ primary breast tumors compared with ER- tumors. Additionally, NAT1 and ESR1 expression seems to have overlapping regulation. PMID: 29901116
- All the patients without mutations detected by molecular barcode next-generation sequencing (MB-NGS) were found to have no mutations by ddPCR. In conclusion, MB-NGS could successfully detect ESR1 mutations in cfDNA with a higher sensitivity of 0.1% than conventional NGS and was considered as clinically useful as ddPCR. PMID: 28905136
- An association between the presence of particular genotypes at three ESR1 polymorphisms (rs2234693, rs6902771, rs7774230) and one ESR2 polymorphism (rs3020449), and the presence of metabolic syndrome in postmenopausal women was found. PMID: 30049354
- A higher frequency of ESR1 and PIK3CA mutations was found in plasma than in the serum in 33 MBC patients, indicating that serum samples should not be considered the preferred source of cfDNA. PMID: 29689710
- These results suggest that miR-125a-3p can function as a novel tumor suppressor in ER(+) breast cancer by targeting CDK3, which may be a potential therapeutic approach for TamR breast cancer therapy. PMID: 28939591
- A major finding of this study is that one out of five (20%) patients with breast cancer BM had a receptor discrepancy between the primary tumor and the subsequent BM, with loss of hormone receptors (ER and/or PR) expression, and gain of HER2 overexpression as the most commonly observed changes. PMID: 28975433
- This study reports a nodal role of IGF-IR in the regulation of ERalpha-positive breast cancer cell aggressiveness and the regulation of expression levels of several extracellular matrix molecules. PMID: 28079144
- Associations between PvuII (T>C) and XbaI (A>G) polymorphisms of the estrogen receptor alpha (ESR1) gene with type 2 diabetes mellitus (T2DM) or metabolic syndrome (MetS) are reported. PMID: 29883973
- The ERalpha gene seems to play a key role in stress urinary incontinence in the premenopausal period. PMID: 29769420
- This study reports the first discovery of naturally occurring ESR1 (Y537C) and ESR1 (Y537S) mutations in MCF7 and SUM44 ESR1-positive cell lines after acquisition of resistance to long-term-estrogen-deprivation (LTED) and subsequent resistance to fulvestrant (ICIR). These mutations were enriched with time, impacted on ESR1 binding to the genome, and altered the ESR1 interactome. PMID: 29192207
- Concomitant high expression of ERalpha36, GRP78, and GRP94 is associated with aggressive papillary thyroid cancer behavior and may be used as a predictor for extrathyroid extension, lymph node metastasis, and distant metastasis. PMID: 29368272
- Estrogen receptor-1 is a key regulator of HIV-1 latency that imparts gender-specific restrictions on the latent reservoir. PMID: 30061382
- Down-regulation of ESR1 gene expression was enhanced by the development of breast cancer. PMID: 29543921
- The aim of this study was to assess whether fibrosis markers, estrogen receptor (ER)alpha, and the stromal derived factor (SDF)1/CXC chemokine receptor type 4 (CXCR4) axis are abnormally expressed in Intrauterine adhesions endometrium. PMID: 29568895
- The frequency of alleles and genotypes of polymorphisms FSHR(-29G/A) and ESRI (XbaI A/G) in women with normal to poor response did not have a significant correlation. PMID: 29526845
- Each estrogen receptor alpha and estrogen receptor beta gene polymorphism might have a different impact on postmenopausal osteoporosis risk and bone mineral density in various ethnicities. PMID: 29458346
- The results suggest that the minor allele A of the ESR1 gene is associated with the development of arterial hypertension in men. PMID: 29658078
- This study found that tamoxifen treatment induced a decrease in PRMT2 and an increase in ER-alpha36, as well as ER-alpha36-mediated non-genomic effect in the MDA-MB-231 breast cancer cell line. PMID: 29620287
- ESR1 mutations are not associated with clinical resistance to fulvestrant in breast cancer patients. PMID: 27174596
- Overexpression of COPS5, through its isopeptidase activity, leads to ubiquitination and proteasome-mediated degradation of NCoR, a key corepressor for ERalpha and tamoxifen-mediated suppression of ERalpha target genes. PMID: 27375289
- ESR alpha PvuII and XbaI polymorphisms have no association with systemic lupus erythematosus. The combination of the TC/AA and CC/GG genotypes were associated with SLE susceptibility. PMID: 29356461
- Estrogen receptor (ER) and progesterone receptor (PR) expression in endometrial carcinoma (EC) were significantly higher than those in the paracarcinoma tissue and control. PMID: 29081408
- ESR1 promoter methylation was an independent risk factor and had a high value to predict 28-day mortality from acute-on-chronic hepatitis B liver failure. PMID: 29082740
- By analyzing different estrogen receptor-alpha(ER-a)-positive and ER-a-negative breast cancer cell lines, we defined the role of CCN5 in the leptin-mediated regulation of growth and invasive capacity. PMID: 29370782
- This study identified ESR1 as a direct target of miR-301a-3p. PMID: 29763890
- This study reports for the first time the presence of ESR1 methylation in plasma ctDNA of patients with HGSC. The agreement between ESR1 methylation in primary tumors and paired ctDNA is statistically significant. PMID: 29807696
- This study reports the development of a novel class of ERa AF2 inhibitors, which have the potential to effectively inhibit ERa activity by a unique mechanism and to circumvent the issue of mutation-driven resistance in breast cancer. PMID: 29462880
- The P2X7R rs3751143 and ER-alpha PvuII two-locus interaction confers a significantly high susceptibility to osteoporosis in Chinese postmenopausal women. PMID: 28884379
- Alcohol consumption may have differential effects on concordant and discordant receptor subtypes of breast cancer. PMID: 29353824
- ERalpha and ERbeta mRNA expression was significantly higher (p < 0.05) in tumor tissues relative to their paired normal mucosa and correlated inversely with survival outcome. PMID: 29390981
- High ESR1 expression is associated with Papillary Thyroid Carcinoma. PMID: 28124274
- Oral administration of RAD140 substantially inhibited the growth of AR/ER(+) breast cancer patient-derived xenografts (PDX). Activation of the AR and suppression of the ER pathway, including the ESR1 gene, were seen with RAD140 treatment. PMID: 28974548
- Polymorphism in the ERalpha gene is associated with an increased risk for advanced Pelvic Organ Prolapse. However, polymorphism in the LAMC1 gene does not seem to be associated with such risk. PMID: 29241914
