ESR2-HDA6 complex negatively regulates auxin biosynthesis to delay callus initiation in Arabidopsis leaf explants during tissue culture

Plants exhibit an astonishing ability to regulate organ regeneration upon wounding. Excision of leaf explants promotes the biosynthesis of indole-3-acetic acid (IAA), which is polar-transported to excised regions, where cell fate transition leads to root founder cell specification to induce de novo root regeneration. The regeneration capacity of plants has been utilized to develop in vitro tissue culture technologies. Here, we report that IAA accumulation near the wounded site of leaf explants is essential for callus formation on 2,4-dichlorophenoxyacetic acid (2,4-D)-rich callus-inducing medium (CIM). Notably, a high concentration of 2,4-D does not compensate for the action of IAA because of its limited efflux; rather, it lowers IAA biosynthesis via a negative feedback mechanism at an early stage of in vitro tissue culture, delaying callus initiation. The auxin negative feedback loop in CIM-cultured leaf explants is mediated by an auxin-inducible APETALA2 transcription factor, ENHANCER OF SHOOT REGENERATION 2 (ESR2), along with its interacting partner HISTONE DEACETYLASE 6 (HDA6). The ESR2-HDA6 complex binds directly to, and removes the H3ac mark from, the YUCCA1 (YUC1), YUC7, and YUC9 loci, consequently repressing auxin biosynthesis and inhibiting cell fate transition on 2,4-D-rich CIM. These findings indicate that negative feedback regulation of auxin biosynthesis by ESR2 and HDA6 interferes with proper cell fate transition and callus initiation.

Regulation of Follicular Development in Chickens: WIF1 Modulates Granulosa Cell Proliferation and Progesterone Synthesis via Wnt/β-Catenin Signaling Pathway

Proliferation, apoptosis, and steroid hormone secretion by granulosa cells (GCs) and theca cells (TCs) are essential for maintaining the fate of chicken follicles. Our previous study showed that the Wnt inhibitor factor 1 (WIF1) plays a role in follicle selection. However, the significance of WIF1 in GC- and TC-associated follicular development was not explicitly investigated. This study found that WIF1 expression was strongly downregulated during follicle selection (p < 0.05) and was significantly higher in GCs than in TCs (p < 0.05). WIF1 inhibits proliferation and promotes apoptosis in GCs. Additionally, it promotes progesterone secretion in prehierarchal GCs (pre-GCs, 1.16 ± 0.05 ng/mg vs. 1.58 ng/mg ± 0.12, p < 0.05) and hierarchal GCs (hie-GCs, 395.00 ng/mg ± 34.73 vs. 527.77 ng/mg ± 27.19, p < 0.05) with the participation of the follicle-stimulating hormone (FSH). WIF1 affected canonical Wnt pathways and phosphorylated β-catenin expression in GCs. Furthermore, 604 upregulated differentially expressed genes (DEGs) and 360 downregulated DEGs in WIF1-overexpressed GCs were found through RNA-seq analysis (criteria: |log2⁡(FoldChange)| > 1 and p_adj < 0.05). Cytokine-cytokine receptor interaction and the steroid hormone biosynthesis pathway were identified. In addition, the transcript of estrogen receptor 2 (ESR2) increased significantly (log2⁡(FoldChange) = 1.27, p_adj < 0.05). Furthermore, we found that WIF1 regulated progesterone synthesis by upregulating ESR2 expression in GCs. Additionally, WIF1 suppressed proliferation and promoted apoptosis in TCs. Taken together, these results reveal that WIF1 stimulates follicle development by promoting GC differentiation and progesterone synthesis, which provides an insight into the molecular mechanism of follicle selection and egg-laying performance in poultry.

Effects of BXSMD on ESR1 and ESR2 expression in CSD female mice

ETHNIC PHARMACOLOGICAL RELEVANCE

Due to the rapid pace of modern society, chronic insomnia has become universal phenomenon. In China, Banxia Shumi Decoction (BXSMD) has been used in treating chronic insomnia for thousands of years, but its chemical composition and action mechanism are still unknown.

AIM OF THE STUDY

This study aims to explore the chemical composition of BXSMD and its effects on Estrogen receptor 1 (ESR1) and Estrogen receptor 2 (ESR2) in mice with chronic sleep deprivation (CSD).

MATERIALS AND METHODS

UHPLC-Q-Orbitrap-MS/MS was applied in determining the chemical composition of BXSMD. After 21-day sleep deprivation (SD) in platform water environment, CSD mice model was prepared. By conducting open field test, 24-h autonomic diurnal and nocturnal activity of mice in each group was detected. ELISA was employed to measure the contents of 5-HT, DA, NE, GABA, Glu, and MT. With RT-PCR, Western blot (WB), and immunohistochemistry (IHC), mRNA and protein expressions of ESR1 and ESR2 in the hypothalamus and hippocampus were tested.

RESULTS

BXSMD included ferulic acid, kaverol, daidzein, apigenin, berberine, adenosine, aesculin, vanillin, naringin, and glycine, which might constitute the material basis forthe improvement of chronic insomnia. With BXSMD, the total moving distance and the rest time in dark period of CSD mice were shortened, while its rest time in light period was increased. Besides, BXSMD enhanced the contents of 5-HT, GABA, and MT in CSD mice, and decreased the contents of Glu, NE, and DA. BXSMD elevated the mRNA of Esr1 and Esr2, and elevated the protein expressions of ESR1 and ESR2 in the hypothalamus and hippocampus of CSD mice.

CONCLUSIONS

BXSMD contains various chemical components for sleep-wake regulation, with the mechanism of stimulating estrogen signaling pathway by regulating the expressions of ESR1 and ESR2, ultimately realizing the regulation to sleep-wake disorder caused by CSD.

Isoliquiritigenin Inhibits the Growth of Colorectal Cancer Cells through the ESR2/PI3K/AKT Signalling Pathway

Colorectal cancer (CRC) is one of the most common malignancies. Isoliquiritigenin (ISL), a flavonoid phytoestrogen, has shown anti-tumour activities against various cancers. However, its anti-CRC mechanism has not been clarified. In this study, the potential molecular mechanism of ISL against CRC was investigated through network pharmacological prediction and experimental validation. The results of the network prediction indicate that ESR2, PIK3CG and GSK3β might be the key targets of ISL against CRC, which was verified by molecular docking, and that its anti-tumour mechanisms might be related to the oestrogen and PI3K/AKT signalling pathway. The experimental results show that ISL reduced the viability of SW480 and HCT116 cells, induced apoptosis, blocked the cell cycle in the G2 phase in vitro, and suppressed xenograft tumour growth in vivo. In addition, ISL significantly down-regulated the protein expression of PIK3CG, AKT, p-AKT, p-GSK3β, CDK1, NF-κB and Bcl-2; up-regulated ESR2 and Bax; decreased the ratio of p-AKT/AKT and p-GSK3β/GSK3β; and increased the Bax/Bcl-2 ratio. This study indicates that ISL can inhibit the growth of CRC cells and induce apoptosis, which may be related to the up-regulation of ESR2 and inhibition of the PI3K/Akt signalling pathway.

Sex and interspecies differences in ESR2-expressing cell distributions in mouse and rat brains

BACKGROUND

ESR2, a nuclear estrogen receptor also known as estrogen receptor β, is expressed in the brain and contributes to the actions of estrogen in various physiological phenomena. However, its expression profiles in the brain have long been debated because of difficulties in detecting ESR2-expressing cells. In the present study, we aimed to determine the distribution of ESR2 in rodent brains, as well as its sex and interspecies differences, using immunohistochemical detection with a well-validated anti-ESR2 antibody (PPZ0506).

METHODS

To determine the expression profiles of ESR2 protein in rodent brains, whole brain sections from mice and rats of both sexes were subjected to immunostaining for ESR2. In addition, to evaluate the effects of circulating estrogen on ESR2 expression profiles, ovariectomized female mice and rats were treated with low or high doses of estrogen, and the resulting numbers of ESR2-immunopositive cells were analyzed. Welch's t-test was used for comparisons between two groups for sex differences, and one-way analysis of variance followed by the Tukey-Kramer test were used for comparisons among multiple groups with different estrogen treatments.

RESULTS

ESR2-immunopositive cells were observed in several subregions of mouse and rat brains, including the preoptic area, extended amygdala, hypothalamus, mesencephalon, and cerebral cortex. Their distribution profiles exhibited sex and interspecies differences. In addition, low-dose estrogen treatment in ovariectomized female mice and rats tended to increase the numbers of ESR2-immunopositive cells, whereas high-dose estrogen treatment tended to decrease these numbers.

CONCLUSIONS

Immunohistochemistry using the well-validated PPZ0506 antibody revealed a more localized expression of ESR2 protein in rodent brains than has previously been reported. Furthermore, there were marked sex and interspecies differences in its distribution. Our histological analyses also revealed estrogen-dependent changes in ESR2 expression levels in female brains. These findings will be helpful for understanding the ESR2-mediated actions of estrogen in the brain.

Calponin 2 harnesses metabolic reprogramming to determine kidney fibrosis

OBJECTIVE

In the fibrotic kidneys, the extent of a formed deleterious microenvironment is determined by cellular mechanical forces. This process requires metabolism for energy. However, how cellular mechanics and metabolism are connected remains unclear.

METHODS

A multi-disciplinary approach was employed: the fibrotic kidney disease models were induced by renal ischemia-reperfusion injury and unilateral ureteral obstruction in Calponin 2 (CNN2) knockdown mice. Proteomics, bioinformatics, and in vivo and in vitro molecular experimental pathology studies were performed.

RESULT

Our proteomics revealed that actin filament binding and cell metabolism are the two most dysregulated events in the fibrotic kidneys. As a prominent actin stabilizer, CNN2 was predominantly expressed in fibroblasts and pericytes. In CKD patients, CNN2 levels was markedly induced in blood. In mice, CNN2 knockdown preserves kidney function and alleviates fibrosis. Global proteomics profiled that CNN2 knockdown enhanced the activities of the key rate-limiting enzymes and regulators of fatty acid oxidation (FAO) in the diseased kidneys. Inhibiting carnitine palmitoyltransferase 1α in the FAO pathway resulted in lipid accumulation and extracellular matrix deposition in the fibrotic kidneys, which were restored after CNN2 knockdown. Bioinformatics and chromatin immunoprecipitation showed that CNN2 interactor, estrogen receptor 2 (ESR2), binds peroxisome proliferator-activated receptor-α (PPARα) to transcriptionally regulate FAO downstream target genes expression amid kidney fibrosis. In vitro, ESR2 knockdown repressed the mRNA levels of PPARα and the key genes in the FAO pathway. Conversely, activation of PPARα reduced CNN2-induced matrix inductions.

CONCLUSIONS

Our results suggest that balancing cell mechanics and metabolism is crucial to develop therapeutic strategies to halt kidney fibrosis.

Bisphenol A and Di(2-Ethylhexyl) Phthalate promote pulmonary carcinoma in female rats via estrogen receptor beta: In vivo and in silico analysis

The prevalence of lung cancer in women currently merits our attentions. However, cigarette exposure alone does not tell the whole story that lung cancer is more prevalent among non-smoking women. Since female lung cancer is closely linked to estrogen levels, many of endocrine disrupting chemicals (EDCs), as the substances similar to estrogen, affect hormone levels and become a potential risk of female lung cancer. Additionally, the combined toxicity of EDCs in daily environment has only been discussed on a limited scale. Consequently, this study explored the cancer-promoting effect of two representative substances of EDCs namely Bisphenol A (BPA) and Di(2-Ethylhexyl) Phthalate (DEHP) after their exposure alone or in combination, using a rat pulmonary tumor model published previously, combining bioinformatics analysis based on The Comparative Toxicogenomics Database (CTD) and The Cancer Genome Atlas (TCGA) databases. It demonstrated that BPA and DEHP enhanced the promotion of pulmonary tumor in female rats, either alone or in combination. Mechanistically, BPA and DEHP mainly directly bound and activated ESR2 protein, phosphorylated CREB protein, activated HDAC6 transcriptionally, induced the production of the proto-oncogene c-MYC, and accelerated the formation of pulmonary tumor in female rats. Remarkably, BPA, rather than DEHP, exhibited a much more critical effect in female lung cancer. Additionally, the transcription factor ESR2 was most affected in carcinogenesis, causing genetic disruption. Furthermore, the TCGA database revealed that ESR2 could enhance the promotion and progression of non-small cell lung cancer in females via activating the WNT/β-catenin pathway. Finally, our findings demonstrated that BPA and DEHP could enhance the promotion of pulmonary carcinoma via ESR2 in female rats and provide a potential and valuable insight into the causes and prevention of lung cancer in non-smoking women due to EDCs exposure.

Unhatched bovine blastocysts express all transcripts of the estrogen biosynthetic pathway, but steroid hormone synthesis could not yet be demonstrated

Early embryos of rodent species and rabbits but also farm animals such as pigs, horses and cattle produce estrogens, which are considered important regulators of the implantation process. In cattle, the exact stage at which embryonic estrogen synthesis commences is yet unknown. However, this information is regarded as important to consider a possible role of embryonic estrogens in preimplantation development. Therefore, in this study, we first used quantitative reverse transcription PCR to examine the mRNA expression of the enzymes required for the conversion of cholesterol into free and sulfonated estrogens (CYP11A1, CYP17A1, HSD3B, CYP19A1, and SULT1E1), the cholesterol carrier protein STAR, and the estrogen receptors ESR1 and ESR2 in in vitro produced morulae and unhatched blastocysts (d 6-9). Only in the blastocysts, were the mRNAs of the entire estrogen biosynthesis chain and of both estrogen receptors clearly present, whereas mRNA specific to ESRs was already detectable in the morulae. We also examined the expression of the corresponding enzymes in blastocysts at the protein level. None of the enzymes were detectable by capillary-based western analysis. Immunofluorescence methods were established for the detection of CYP17A1, CYP19A1, and SULT1E1. CYP17A1 was observed in the inner cell mass and trophectoderm, whereas CYP19A1 and SULT1E1 were present only in trophectoderm. An attempt to detect estrogen sulfotransferase activity was unsuccessful. Despite clear evidence that some elements of the estrogen biosynthetic pathway are also present at the protein level, it remains to be clarified whether the enzyme cascade underlying estrogen production is already functional in unhatched blastocysts.

Optimized Mouse-on-mouse Immunohistochemical Detection of Mouse ESR2 Proteins with PPZ0506 Monoclonal Antibody

Despite the physiological significance of ESR2, a lack of well-validated detection systems for ESR2 proteins has hindered progress in ESR2 research. Thus, recent identification of a specific anti-human ESR2 monoclonal antibody (PPZ0506) and its specific cross-reactivity against mouse and rat ESR2 proteins heightened momenta toward development of appropriate immunohistochemical detection systems for rodent ESR2 proteins. Building upon our previous optimization of ESR2 immunohistochemical detection in rats using PPZ0506, in this study, we further aimed to optimize mouse-on-mouse immunohistochemical detection using PPZ0506. Our assessment of several staining conditions using paraffin-embedded ovary sections revealed that intense heat-induced antigen retrieval, appropriate blocking, and appropriate antibody dilutions were necessary for optimization of mouse-on-mouse immunohistochemistry. Subsequently, we applied the optimized immunostaining method to determine expression profiles of mouse ESR2 proteins in peripheral tissues and brain subregions. Our analyses revealed more localized distribution of mouse ESR2 proteins than previously assumed. Moreover, comparison of these results with those obtained in humans and rats using PPZ0506 revealed interspecies differences in ESR2 expression. We expect that our optimized methodology for immunohistochemical staining of mouse ESR2 proteins will help researchers to solve multiple lines of controversial evidence concerning ESR2 expression.

Association of ESR1 and ESR2 Polymorphisms with Osteoporosis: A Meta-Analysis from 36 Studies

BACKGROUND

Recently, the roles of ESR1 and ESR2 polymorphisms in osteoporosis have been extensively reported, with conflicting findings. Therefore, we performed this present study to evaluate the potential associations between ESR1 and ESR2 polymorphisms and osteoporosis risk.

METHODOLOGY

All included literatures published up to April 2021 were identified by searching Pubmed, Embase, Web of Science, Cochrane Library, Chinese National Knowledge Infrastructure (CNKI) and Wanfang databases. Pooled odds ratio (OR) and 95% confidence interval (CI) were calculated the associations using a fixed or random effects model.

RESULTS

36 observational studies involving five gene polymorphisms (ESR1 PvuII, ESR1 XbaI, ESR1 G2014A, ESR2 AluI and ESR2 RsaI) covering 12507 cases and 18487 controls were included. The results of our meta-analysis demonstrated the variant A allele of ESR2 RsaI polymorphism might play a remarkable protective role in developing osteoporosis under all genetic models. However, no associations were observed between ESR1 PvuII, ESR1 XbaI, ESR1 G2014A and ESR2 AluI polymorphisms with the risk of osteoporosis under all genetic models.

CONCLUSIONS

Our meta-analysis suggests that genetic polymorphism in ESR2 RsaI may lead to decreased risk for osteoporosis. Further larger studies are needed to confirm this conclusion.

ESR2 Drives Mesenchymal-to-Epithelial Transition in Triple-Negative Breast Cancer and Tumorigenesis In Vivo

Estrogen receptors (ERs) have pivotal roles in the development and progression of triple-negative breast cancer (TNBC). Interactions among cancer cells and tumor microenvironment are orchestrated by the extracellular matrix that is rapidly emerging as prominent contributor of fundamental processes of breast cancer progression. Early studies have correlated ERβ expression in tumor sites with a more aggressive clinical outcome, however ERβ exact role in the progression of TNBC remains to be elucidated. Herein, we introduce the functional role of ERβ suppression following isolation of monoclonal cell populations of MDA-MB-231 breast cancer cells transfected with shRNA against human ESR2 that permanently resulted in 90% reduction of ERβ mRNA and protein levels. Further, we demonstrate that clone selection results in strongly reduced levels of the aggressive functional properties of MDA-MB-231 cells, by transforming their morphological characteristics, eliminating the mesenchymal-like traits of triple-negative breast cancer cells. Monoclonal populations of shERβ MDA-MB-231 cells undergo universal matrix reorganization and pass on a mesenchymal-to-epithelial transition state. These striking changes are encompassed by the total prevention of tumorigenesis in vivo following ERβ maximum suppression and isolation of monoclonal cell populations in TNBC cells. We propose that these novel findings highlight the promising role of ERβ targeting in future pharmaceutical approaches for managing the metastatic dynamics of TNBC breast cancer.

ESR2 gene variants (rs1256049, rs4986938, and rs1256030) and their association with breast cancer risk

Background

Variants of the estrogen receptor b (ESR2) gene have been associated with different types of cancer. However, these associations have been inconsistent. We genotyped the ESR2 variants (rs1256049, rs4986938, and rs1256030) in breast cancer (BC) patients and in healthy women.

Results

The variants rs1256049 and rs4986938 in the ESR2 gene were not associated with risk susceptibility in BC patients. However, the rs1256030 variant had an association as a risk factor for BC patients when compared with controls and BC patients for the TT genotype (odds ratio (OR) 1.86, 95% confidence intervals (CI) [1.05-3.28], p = 0.042). In addition, differences were observed in patients and controls carrying the TT genotype under 50 years of age (OR 1.85, 95% CI [1.05-3.27], p = 0.043). Thus, evident differences showed the rs1256030 variant in patients with TT, TC, and TC+TT genotypes with: (1) Stage IV (OR 1.60, 95% CI [1.06-2.54], p = 0.033), and (2) Luminal A (OR 1.60, 95% CI [0.47-0.21], p = 0.041), as well as in BC carriers of the TT genotype with indices of cellular proliferative (Ki-67) elevated (>20%) and overweight (OR 1.67, 95% CI [0.85-3.28], p = 0.041), respectively. In BC HER2 with lymph node metastasis, the TT genotype was a protective factor (OR 0.38, 95% CI [0.18-0.78], p = 0.005). The identification of haplotypes included two common GAT as risk factors (OR 3.1, 95% CI [1.31-7.72], p = 0.011) and GGC as a protective factor (OR 0.7, 95% CI [0.60-0.97], p = 0.034). The haplogenotype GGGATC was a risk factor (OR 2.5, 95% CI [1.28-5.0], p = 0.008).

Conclusion

The variant rs1256030 (TT) of the ESR2 gene and haplotype GAT were associated with susceptibility to BC as risk factors in this sample from the Mexican population.

Exogenous auxin-induced ENHANCER OF SHOOT REGENERATION 2 (ESR2) enhances femaleness of cucumber via activating CsACS2 gene

Cucumber (Cucumis sativus L.) is a model for the study of sex differentiation in the last two decades. In cucumber, sex differentiation is mainly controlled by genetic material, but plant growth regulators can also influence or even change it. However, the effect of exogenous auxin application on cucumber sex differentiation is mostly limited in physiological level. In this study, we explored the effects of different exogenous auxin concentrations on the varieties with different mutant sex-controlling genotypes and found that there was a dosage effect of exogenous indole-3-acetic acid (IAA) on the enhancement of cucumber femaleness. Several ACC synthetase (ACS) family members could directly respond to the induction of exogenous IAA to improve endogenous ethylene synthesis, and this process can be independent on the previously identified sex-related ACC oxidase CsACO2. We further demonstrated that ENHANCER OF SHOOT REGENERATION 2 (ESR2), responding to the induction of exogenous auxin, could directly activate CsACS2 expression by combining the ERE cis-acting element regions in the promoter, and then increase endogenous ethylene content, which may induce femaleness. These findings reveal that exogenous auxin improves cucumber femaleness via inducing sex-controlling gene and promoting ethylene synthesis.

Role of Single Nucleotide Variants in FSHR, GNRHR, ESR2 and LHCGR Genes in Adolescents with Polycystic Ovary Syndrome

Background: Polycystic ovary syndrome (PCOS) is the most common endocrinopathy in women, affecting up to 16.6% of reproductive-age women. PCOS symptoms in adolescents comprise oligomenorrhoea/amenorrhoea and biochemical and/or clinical hyperandrogenism. Long-term health risks of PCOS patients include infertility, metabolic syndrome, type 2 diabetes and cardiovascular disease. Genetic factors have been proven to play a role in development of the syndrome and its symptoms. Objective: To investigate single nucleotide variants (SNVs) in the GNRHR, ESR2, LHCGR and FSHR genes in adolescent patients with PCOS and their association with PCOS symptoms. Methods: We conducted a cross-sectional study comprising of 152 adolescents: 63 patients with PCOS, 22 patients at risk of developing PCOS and 67 healthy controls. Participants were recruited from out-patients attending a gynaecologist at the Children’s Clinical University Hospital, Riga, Latvia, between January 2017 and December 2020. Genomic DNA was extracted from whole blood, and SNVs in the GNRHR, ESR2, LHCGR and FSHR genes were genotyped. The distributions of SNV genotypes were compared among the three groups and genotype-phenotype associations within the PCOS group were evaluated. Results: No statistically significant differences were found in the distributions of genotypes for GNRHR (rs104893837), ESR2 (rs4986938), LHCGR (rs2293275) and FSHR (rs6166, rs6165, rs2349415) among PCOS patients, risk patients and healthy controls. Within the PCOS group, ESR2 rs4986938 minor allele homozygous patients had a significantly higher level of total testosterone than major allele homozygous patients and heterozygous patients. A significantly higher total testosterone level was also observed in PCOS patients carrying the LHCGR rs2293275 minor allele compared with major allele homozygous patients. Conclusions: The SNVs ESR2 rs4986938 and LHCGR rs2293275 play a role in the phenotypic characteristics of PCOS. To fully uncover their influence on the development of PCOS and its symptoms, further studies of larger cohorts and a follow up of this study sample through to adulthood are required. Furthermore, studies of adolescent PCOS patients conducted prior to the latest European Society of Human Reproduction and Embryology (ESHRE) criteria (2018) should be re-evaluated as the study groups might include risk patients according to these updated criteria, thereby potentially significantly impacting the published results.

Polymorphism analysis and expression profile of the estrogen receptor 2 gene in Leizhou black duck

Our previous study on the ovarian transcriptomic analysis in Leizhou black duck revealed that the ESR2 gene was involved in hormone regulation in reproduction and the estrogen signaling pathway related to reproductive performance was enriched. This suggested that ESR2 may have a functional role in the reproductive performance of the Leizhou black duck. Thus, this study aimed at evaluating the polymorphism of the ESR2 gene and its association with egg-laying traits and the distribution pattern of ESR2 mRNA in laying and non-laying Leizhou black ducks. In this study, genomic DNA was extracted from blood samples of 101 Leizhou black ducks to identify single nucleotide polymorphisms (SNPs) of the ESR2 gene to elucidate molecular markers highly associated with egg-laying traits. Four each of laying and non-laying Leizhou black ducks were selected to collect different tissues to analyze the ESR2 gene expression. A total of 23 SNPs were identified and association analysis of the single SNP sites showed that SNPs g.56805646 T>C and exon 3-20G>A were significantly (P < 0.05) associated with egg weight. Ducks with CT and AG genotypes had significantly higher (P < 0.05) egg weights than their respective other genotypes. Haplotype association analysis of g.56805646 T>C and exon 3-20G>A showed that the haplotypes were significantly associated with egg weight. Higher egg weight was seen in individuals with H3H4 haplotypes. In the hypothalamus-pituitary-gonadal (HPG) axis, the results of qRT/PCR showed that ESR2 mRNA was significantly (P < 0.05) expressed in the ovaries of both duck groups than in the hypothalamus and pituitary. In the oviduct, ESR2 was significantly (P < 0.05) higher in the infundibulum and magnum of laying and non-laying ducks respectively. This study provides a molecular marker for selecting Leizhou black ducks for egg production. In addition, it offers theoretical knowledge for studying the related biological functions of the ESR2 gene at the cellular level.

ESR2 regulates PINK1-mediated mitophagy via transcriptional repression of microRNA-423 expression to promote asthma development

Asthma represents an inflammatory airway disease related to the induction of airway eosinophilia, mucus overproduction, and bronchial hyperresponsiveness. This study explored the effects of microRNA-423 (miR-423) on mitophagy and inflammation in asthmatic mice challenged with house dust mites (HDMs) and rhinovirus (RV). By searching for differentially expressed miRNAs in the GSE25230 microarray, miR-423 was identified as our target. Moreover, miR-423 was expressed at low levels in the lung tissues from patients with asthma, and agomiR-423 significantly inhibited RV-induced inflammatory injury and activation of inflammasome signaling in mouse lung tissues. Additionally, miR-423 downregulated the expression of IL-1β/NLRP3/Caspase-1 inflammasome signaling by targeting phosphatase and tensin homolog-induced putative kinase 1 (PINK1). Furthermore, luciferase reporter experiments and ChIP-qPCR assays revealed that estrogen receptor 2 (ESR2) transcriptionally repressed miR-423 expression by coordinating with H3K9me2 modification of the miR-423 promoter histone. Overall, ESR2 synergized with the H3K9me2 modification of the miR-423 promoter histone to transcriptionally repress miR-423 expression and increase PINK1 expression in lung tissues, resulting in asthma exacerbation.

Estrogen receptor beta (ESR2) gene polymorphism and susceptibility to dementia

Strong evidence supports the involvement of sex steroid hormones in the development and progression of dementia. Attention has been largely focused on the association between genetic variants of estrogen receptor alpha (ERα, ESR1) with dementia, although several studies indicate that ERβ is predominantly expressed in the brain. Interestingly, however, a limited number of studies evaluate the role of ERβ (ESR2) in dementia. Therefore, a meta-analysis was conducted to clarify the association between ESR2 genetic polymorphisms and the risk of dementia. All the relevant studies evaluating ESR2 genetic polymorphisms and dementia were identified through online databases. In total, 14 studies including 20,609 subjects were analyzed. Collectively, it was found that a combined data set of ESR2 polymorphisms was not associated with dementia risk. Interestingly, ESR2 rs4986938 polymorphism is significantly associated with dementia in the Asian population (OR = 0.73, 95% CI 0.59-0.91, P = 0.006). The carrier of A allele in rs4986938 exhibits a protective effect against dementia (A vs. G, OR = 0.6633, P = 0.012; AA + GA vs. GG, OR = 0.6499, P = 0.014; GA vs. AA + GG, OR = 0.6672, P = 0.025; GA vs. GG, OR = 0.6617, P = 0.022). In conclusion, our study suggests that ESR2 genetic polymorphisms are not significantly associated with dementia risk. ESR2 rs4986938 may have potential as a genetic marker for dementia in the Asian population. However, further studies need to verify this conclusion.

miR-135a Suppresses Granulosa Cell Growth by Targeting Tgfbr1 and Ccnd2 during Folliculogenesis in Mice

The success of female reproduction relies on high quality oocytes, which is determined by well-organized cooperation between granulosa cells (GCs) and oocytes during folliculogenesis. GC growth plays a crucial role in maintaining follicle development. Herein, miR-135a was identified as a differentially expressed microRNA in pre-ovulatory ovarian follicles between Large White and Chinese Taihu sows detected by Solexa deep sequencing. We found that miR-135a could significantly facilitate the accumulation of cells arrested at the G1/S phase boundary and increase apoptosis. Mechanically, miR-135a suppressed transforming growth factor, beta receptor I (Tgfbr1) and cyclin D2 (Ccnd2) expression by targeting their 3′UTR in GCs. Furthermore, subcellular localization analysis and a chromatin immunoprecipitation-quantitative real-time PCR (ChIP-qPCR) assay demonstrated that the TGFBR1-SMAD3 pathway could enhance Ccnd2 promoter activity and thus upregulate Ccnd2 expression. Finally, estrogen receptor 2 (ESR2) functioned as a transcription factor by directly binding to the miR-135a promoter region and decreasing the transcriptional activity of miR-135a. Taken together, our study reveals a pro-survival mechanism of ESR2/miR-135a/Tgfbr1/Ccnd2 axis for GC growth, and also provides a novel target for the improvement of female fertility.

An Analysis of ESR2 and CYP19A1 Gene Expression Levels in Women With Endometriosis

AIM

The analysis of oestrogen receptor (ESR2) and cytochrome P450 family 19 subfamily A member (CYP19A1) gene expression in the context of the risk for endometriosis development.

MATERIALS AND METHODS

Tissue specimens, collected from patients with endometriosis (n=100) and from control patients (n=100) embedded into paraffin blocks, provided the material for genetic studies, oriented towards the expression of ESR2 and CYP19A1 genes. The gene expression was assessed by the reverse transcription-polymerase chain reaction technique.

RESULTS

Higher expression levels of ESR2 gene were demonstrated in the patients with endometriosis in comparison with the healthy controls. The expression intensity of CYP19A1 gene was associated with endometriosis, manifested as abdominal wall nodules. A relationship was observed between CYP19A1 gene expression and the Revised American Society for Reproductive Medicine classification in the group with ovarian endometrioid cysts, as well as in the group with peritoneal endometriosis.

CONCLUSION

This study suggests the significant role of ESR2 and CYP19A1 gene expression in the pathogenesis of endometriosis.

Association between single nucleotide polymorphism of the CYP19A1 and ESR2 genes and endometriosis

PURPOSE

Endometriosis is a frequent gynaecological condition, both in Poland and in the world. The development of this disease is supported by hormonal, immunological and environmental factors. During the recent years, a particular attention has been focused on the genetic polymorphisms which may be of particular significance for the increased incidence rates of endometriosis. According to literature data, Oestrogen Receptor 2 (ESR2) and Cytochrome P450 Family 19 Subfamily A Member 1 (CYP19A1) genes may be accounted to the potential risk factors of infertility associated with endometriosis. The reported research was aimed to evaluate the association between single nucleotide polymorphisms (SNPs) rs17179740 of ESR2 and rs2899470 of CYP19A1 genes and the incidence of endometriosis.

METHODS

The study material included blood specimens, collected from patients (n = 200) with endometriosis. Blood samples from age-matched, endometriosis-free women (n = 200) served as control. The High-Resolution Melter (HRM) technique was applied for polymorphism analysis.

RESULTS

Regarding rs2899470 polymorphism TT homozygotes was significantly more prevalent among the patients with endometriosis than in the controls (OR 2.19; p = 0.04). In case of rs17179740, GG homozygotes, as well as AG-AA genotypes, were significantly more prevalent among the endometriosis patients (OR 2.48, p = 0.04 and OR 2.36, p = 0.04, respectively).

CONCLUSION

Summing up, the investigated polymorphisms of ESR2 and CYP19A1 gene are associated with the observed incidence of endometriosis.

Genomic exploration of the targets of FOXL2 and ESR2 unveils their implication in cell migration, invasion, and adhesion

FOXL2 and ESR2 are key transcriptional regulators in ovarian granulosa cells. To explore their transcriptional roles and their interplay, we have depleted Foxl2 and Esr2 in mouse primary granulosa cells to assess their ability to bind their targets and/or to modulate gene expression and cellular functions. We show that FOXL2 is involved in a large number of regulatory actions essential for the maintenance of granulosa cell fate. A parallel ChIP-seq analysis showed that FOXL2 mainly binds to sites located in intergenic regions quite far from its targets. A bioinformatic analysis demonstrated that FOXL2-activated genes were enriched in peaks associated with the H3K27ac mark, whereas FOXL2-repressed genes were not, suggesting that FOXL2 can activate transcription through binding to enhancer sites. We also identified about 500 deregulated genes upon Esr2 silencing, of which one third are also targets of FOXL2. We provide evidence showing that both factors modulate, through a coherent feed-forward loop, a number of common targets. Many of the FOXL2/ESR2 targets are involved in cell motility and, consistently, granulosa cells depleted for either Foxl2 or Esr2 exhibit decreased migration, invasion and adhesion. This effect is paralleled by the depletion of their target Phactr1, involved in actin cytoskeleton dynamics. Our analysis expands the number of direct and indirect transcriptional targets of both FOXL2 and ESR2, which deserve investigation in the context of adult-type granulosa cell tumors whose molecular diagnostic hallmark is the presence of the C134W FOXL2 pathogenic variant.

Estrogen and Glycemic Homeostasis: The Fundamental Role of Nuclear Estrogen Receptors ESR1/ESR2 in Glucose Transporter GLUT4 Regulation

Impaired circulating estrogen levels have been related to impaired glycemic homeostasis and diabetes mellitus (DM), both in females and males. However, for the last twenty years, the relationship between estrogen, glycemic homeostasis and the mechanisms involved has remained unclear. The characterization of estrogen receptors 1 and 2 (ESR1 and ESR2) and of insulin-sensitive glucose transporter type 4 (GLUT4) finally offered a great opportunity to shed some light on estrogen regulation of glycemic homeostasis. In this manuscript, we review the relationship between estrogen and DM, focusing on glycemic homeostasis, estrogen, ESR1/ESR2 and GLUT4. We review glycemic homeostasis and GLUT4 expression (muscle and adipose tissues) in Esr1^−/− and Esr2^−/− transgenic mice. We specifically address estradiol-induced and ESR1/ESR2-mediated regulation of the solute carrier family 2 member 4 (Slc2a4) gene, examining ESR1/ESR2-mediated genomic mechanisms that regulate Slc2a4 transcription, especially those occurring in cooperation with other transcription factors. In addition, we address the estradiol-induced translocation of ESR1 and GLUT4 to the plasma membrane. Studies make it clear that ESR1-mediated effects are beneficial, whereas ESR2-mediated effects are detrimental to glycemic homeostasis. Thus, imbalance of the ESR1/ESR2 ratio may have important consequences in metabolism, highlighting that ESR2 hyperactivity assumes a diabetogenic role.

The Genetic Background of Endometriosis: Can ESR2 and CYP19A1 Genes Be a Potential Risk Factor for Its Development?

Endometriosis is defined as the presence of endometrial foci, localized beyond their primary site, i.e., the uterine cavity. The etiology of this disease is rather complex. Its development is supported by hormonal, immunological, and environmental factors. During recent years, particular attention has been focused on the genetic mechanisms that may be of particular significance for the increased incidence rates of endometriosis. According to most recent studies, ESR2 and CYP19A1 genes may account for the potential risk factors of infertility associated with endometriosis. The paper presents a thorough review of the latest reports and data concerning the genetic background of the risk for endometriosis development.

Estrogen Receptor Beta (ERβ): A Ligand Activated Tumor Suppressor

Estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ) belong to a superfamily of nuclear receptors called steroid hormone receptors, which, upon binding ligand, dimerize and translocate to the nucleus where they activate or repress the transcription of a large number of genes, thus modulating critical physiologic processes. ERβ has multiple isoforms that show differing association with prognosis. Expression levels of the full length ERβ1 isoform are often lower in aggressive cancers as compared to normal tissue. High ERβ1 expression is associated with improved overall survival in women with breast cancer. The promise of ERβ activation, as a potential targeted therapy, is based on concurrent activation of multiple tumor suppressor pathways with few side effects compared to chemotherapy. Thus, ERβ is a nuclear receptor with broad-spectrum tumor suppressor activity, which could serve as a potential treatment target in a variety of human cancers including breast cancer. Further development of highly selective agonists that lack ERα agonist activity, will be necessary to fully harness the potential of ERβ.

Accurate assessment of estrogen receptor profiles in non-functioning pituitary adenomas using RT-digital PCR and immunohistochemistry

BACKGROUND

Non-functioning pituitary adenomas (NFPAs) are common pituitary tumors, and surgery is generally the only treatment option. Few attempts have been made to explore target molecules for the development of NFPA pharmacological treatments.

METHOD

We quantitatively assessed the expression profiles of estrogen receptor (ER) transcripts and proteins in NFPA samples, using reverse transcription-digital polymerase chain reaction (RT-dPCR) and immunohistochemistry, and further investigated the correlations between the expression levels of ER and those of downstream responsive genes. All patients had undergone surgery at the same high-volume hospital. A total of 20 patients with NFPAs were included. All patients were new-onset, and none were diagnosed with intratumoral hemorrhages or cysts.

RESULTS

NFPA samples exhibited a bimodal ESR1 expression pattern and were categorized into significantly different high- and low-ESR1 expression level groups (P < 0.05). In contrast, expression levels of ESR1 variants and ESR2 could barely be detected. Similar results were obtained through the immunohistochemical staining of NFPAs, using well-validated antibodies against ERs. The expression levels of ESR1 positively correlated with those of GREB1, an estrogen-responsive gene [correlation coefficient (r) = 0.623, P = 0.003].

CONCLUSIONS

ESR1 expression levels in NFPAs exhibited a bimodal pattern and were positively correlated with GREB1 expression levels. The accurate assessment of ER expression levels may further advance future NFPA-related research.

Suppression of estrogen receptor-beta promotes gastric cancer cell apoptosis with induction of autophagy

Estrogen Receptor 2 (ESR2) is the protein-coding gene of estrogen receptor β (ERβ) and has been shown to be abundantly expressed in gastric carcinoma (GC), suggesting that it plays a role in GC pathogenesis. However, the underlying molecular mechanism remains elusive. In the present in vitro study, GC cell growth was found to be estrogen-dependent, and the expression level of ERβ was higher than that of ERα. Knocking down the endogenous expression of ESR2 in GC cells increased the apoptosis rate and the level of cleaved caspase-3, caspase-7 and poly ADP-ribose polymerase. The induced apoptosis was primarily related to GC cell growth arrest, accompanied with activation of DNA damage-inducible protein 45 alpha (GADD45α) in a p53-independent manner. Importantly, down-regulation of ESR2 also promoted autophagy. The autophagy inhibitor 3-MA or silencing ATG7 rescued the apoptosis by knocking down ESR2 via activation of the MAPK signaling pathway in AGS cells, leading to increased apoptosis. In conclusion, these results demonstrated that suppression of ESR2 gene expression could promote GC cell apoptosis, suggesting that it may prove to be a potential therapeutic target for GC.

Endometriosis and nuclear receptors

BACKGROUND

Endometriosis is recognized as a steroid-dependent disorder; however, the precise roles of nuclear receptors (NRs) in steroid responsiveness and other signaling pathways are not well understood.

OBJECTIVE AND RATIONALE

Over the past several years, a number of paradigm-shifting breakthroughs have occurred in the area of NRs in endometriosis. We review and clarify new information regarding the mechanisms responsible for: (i) excessive estrogen biosynthesis, (ii) estrogen-dependent inflammation, (iii) defective differentiation due to progesterone resistance and (iv) enhanced survival due to deficient retinoid production and action in endometriosis. We emphasize the roles of the relevant NRs critical for these pathological processes in endometriosis.

SEARCH METHODS

We conducted a comprehensive search using PubMed for human, animal and cellular studies published until 2018 in the following areas: endometriosis; the steroid and orphan NRs, estrogen receptors alpha (ESR1) and beta (ESR2), progesterone receptor (PGR), steroidogenic factor-1 (NR5A1) and chicken ovalbumin upstream promoter-transcription factor II (NR2F2); and retinoids.

OUTCOMES

Four distinct abnormalities in the intracavitary endometrium and extra-uterine endometriotic tissue underlie endometriosis progression: dysregulated differentiation of endometrial mesenchymal cells, abnormal epigenetic marks, inflammation activated by excess estrogen and the development of progesterone resistance. Endometriotic stromal cells compose the bulk of the lesions and demonstrate widespread epigenetic abnormalities. Endometriotic stromal cells also display a wide range of abnormal NR expression. The orphan NRs NR5A1 and NR2F2 compete to regulate steroid-synthesizing genes in endometriotic stromal cells; NR5A1 dominance gives rise to excessive estrogen formation. Endometriotic stromal cells show an abnormally low ESR1:ESR2 ratio due to excessive levels of ESR2, which mediates an estrogen-driven inflammatory process and prostaglandin formation. These cells are also deficient in PGR, leading to progesterone resistance and defective retinoid synthesis. The pattern of NR expression, involving low ESR1 and PGR and high ESR2, is reminiscent of uterine leiomyoma stem cells. This led us to speculate that endometriotic stromal cells may display stem cell characteristics found in other uterine tissues. The biologic consequences of these abnormalities in endometriotic tissue include intense inflammation, defective differentiation and enhanced survival.

WIDER IMPLICATIONS

Steroid- and other NR-related abnormalities exert genome-wide biologic effects via interaction with defective epigenetic programming and enhance inflammation in endometriotic stromal cells. New synthetic ligands, targeting PGR, retinoic acid receptors and ESR2, may offer novel treatment options.

Polymorphisms in the 3'UTR Region of ESR2 and CYP19A1 Genes in Women With Endometriosis

OBJECTIVE

ESR2 and CYP19A1 genes play a major role in the hormonal control of women with endometriosis. The aim of the study was to analyze single nucleotide polymorphisms (SNPs) in the 3'UTR region of ESR2 and CYP19A1 genes. The study aimed at localisation of new polymorphisms, the nucleotide variants of which determine the level of susceptibility to endometriosis.

STUDY DESIGN

The study included n = 200 patients: 100 with endometriosis and 100 healthy controls. The Sanger's sequencing method was applied for polymorphism analysis.

RESULTS

Statistically significant correlations were identified between new, not previously described, two SNPs of ESR2 gene and endometriosis: rs4986938 (G>A) and rs928554 (A>G). In the case of rs4986938 polymorphism, the genotype AA was found to decrease the risk of endometriosis (OR = 0.24 95 % PU 0.05-1.22, p = 0.04). Analysis of the rs928554 polymorphism revealed that the occurrence of the AG genotype reduced the risk of endometriosis (OR = 0.38 95 % PU 0.21-0.71, p = 0.002). There were no differences in the distribution of genotypes of the polymorphisms rs10046 (C>T) and rs4646 (C>A) of CYP19A1 gene between patients and control.

CONCLUSIONS

Further studies are necessary in groups with higher numbers of patients to explain whether the above-mentioned polymorphisms may be the risk factors for endometriosis.

Association of the polymorphisms of the genes APOC3 (rs2854116), ESR2 (rs3020450), HFE (rs1799945), MMP1 (rs1799750) and PPARG (rs1801282) with lipodystrophy in people living with HIV on antiretroviral therapy: a systematic review

The aim of this study was to perform a systematic review to identify data reported in the literature concerning the association of APOC3 (rs2854116), ESR2 (rs3020450), HFE (rs1799945), MMP1 (rs1799750) and PPARG (rs1801282) polymorphisms with lipodystrophy in people living with HIV (PLWHIV) on antirretroviral therapy. The research was conducted in six databases and the studies were selected in two steps. First, a search was undertaken in the following electronic databases: PubMed, Science Direct, Medline, World Wide Science, Directory of Open Access Journals, Scielo, Lilacs and Medcarib. The titles and abstracts of 24,859 articles were read to select those that match the elegibilty criteria. Five papers that addressed the association of HAART, lipodystrophy and polymorphisms were selected for the review. There was no association between the polymorphisms of the genes APOC3 and PPARG and lipodystrophy. Another study described an association between the variant allele (G) of HFE and protection concerning the development of lipoatrophy (0.02) when compared with the reference allele (C). On the other hand, the variant allele (T) of the ESR2 gene was associated with the development of lipoatrophy (p = 0.007) when compared with the reference allele (C). In addition, the genotype and the variant allele of the gene MMP1 (2G) were associated with lipodystrophy in PLWHIV on HAART (p = 0.0002 and p = 0.0008, respectively). Therefore, further studies with other populations, involving PLWHIV on HAART are necessary to better understand the role of genetic markers, which may be involved in a predisposition to lipodystrophy.

Structural analysis of estrogen receptors: interaction between estrogen receptors and cav-1 within the caveolae†

Pregnancy is a physiologic state of substantially elevated estrogen biosynthesis that maintains vasodilator production by uterine artery endothelial cells (P-UAECs) and thus uterine perfusion. Estrogen receptors (ER-α and ER-β; ESR1 and ESR2) stimulate nongenomic rapid vasodilatory responses partly through activation of endothelial nitric oxide synthase (eNOS). Rapid estrogenic responses are initiated by the ∼4% ESRs localized to the plasmalemma of endothelial cells. Caveolin-1 (Cav-1) interactions within the caveolae are theorized to influence estrogenic effects mediated by both ESRs. Hypothesis: Both ESR1 and ESR2 display similar spatial partitioning between the plasmalemma and nucleus of UAECs and have similar interactions with Cav-1 at the plasmalemma. Using transmission electron microscopy, we observed numerous caveolae structures in UAECs, while immunogold labeling and subcellular fractionations identified ESR1 and ESR2 in three subcellular locations: membrane, cytosol, and nucleus. Bioinformatics approaches to analyze ESR1 and ESR2 transmembrane domains identified no regions that facilitate ESR interaction with plasmalemma. However, sucrose density centrifugation and Cav-1 immunoisolation columns uniquely demonstrated very high protein-protein association only between ESR1, but not ESR2, with Cav-1. These data demonstrate (1) both ESRs localize to the plasmalemma, cytosol and nucleus; (2) neither ESR1 nor ESR2 contain a classic region that crosses the plasmalemma to facilitate attachment; and (3) ESR1, but not ESR2, can be detected in the caveolar subcellular domain demonstrating ESR1 is the only ESR bound in close proximity to Cav-1 and eNOS within this microdomain. Lack of protein-protein interaction between Cav-1 and ESR2 demonstrates a novel independent association of these proteins at the plasmalemma.

Transcriptome datasets of ESR2-regulated genes in rat granulosa cells during gonadotropin-induced follicle maturation

Disruption of estrogen receptor beta (ESR2) dysregulates granulosa cell genes essential for follicle maturation and ovulation. The datasets presented in this article depict gonadotropin-induced genes, which are differentially expressed in Esr2-null rat granulosa cells. Synchronized follicle development was initiated in four-week-old wildtype and Esr2-null female rats by administration of PMSG. Forty-eight hours after PMSG injection, further maturation of ovarian follicles was induced by hCG treatment. Granulosa cells were collected from the ovaries before gonadotropin administration, 48 h after PMSG treatment, and 4 h after hCG injection to the PMSG-treated rats. Total RNA was purified from granulosa cells and whole transcriptome was assessed by RNA-sequencing on an Illumina HiSeq X platform. RNA-seq data of wildtype and Esr2-null granulosa cells were analyzed and differentially expressed genes were identified by CLC Genomics Workbench. Gonadotropin-induced genes were identified by comparing the transcriptome data of PMSG- or hCG-induced wildtype granulosa cells with those without gonadotropin treatment. Furthermore, differentially expressed genes in Esr2-null granulosa cells were determined by comparing the transcriptome data with that of wildtype granulosa cells. These datasets can be used to recognize the gonadotropin-induced genes in granulosa cells that are Esr2-regulated and important for ovarian follicle maturation.

Association of estrogen receptor gene variants (ESR1 and ESR2) with polycystic ovary syndrome in Tunisia

SNV (single nucleotide variation) in estrogen receptor (ESR1 and ESR2) genes are susceptibility markers for complex diseases, such as cancer, metabolic disorders and women infertility. We explored six widely used SNVs in ESR1 (rs2234693, rs9340799, rs3798577, rs3020314) and ESR2 (rs1256049, rs4986938) in polycystic ovary syndrome (PCOS) in women from Tunisia (n = 254) compared to controls (n = 170). Genotyping was performed by RFLP-PCR or real-time PCR and analyzed in GoldenHelix statistical package. Logistic regression revealed association of rs2234693, rs3798577 and rs3020314 (ESR1) and rs1256049 (ESR2), the association of rs2234693 (C/T) being the strongest with P < 4.81 × 10^-6, 2.88 × 10^-5 after Bonferroni correction, OR 0.31, 95%CI (0.18-0.53)). Correlations were found with LH, LH/FSH or hyperandrogenism and even more significant with metabolic syndrome (rs9340799) and hyperglycemia (rs3798577). Among 14 haplotypes reconstructed in ESR1gene, four haplotypes (H1 to H4) were associated with PCOS the strongest being that of H1 (P < 0.002) supported by Bonferroni (P < 0.033) and permutation tests (P < 4 x10^-4). In haplotype trend regression, concordant correlations were found with insulin resistance (P < 0.033) for H2 and with high blood pressure for H3 (P < 0.048). While these data revealed influential role on metabolic rather and hormonal features of PCOS, the association of rs2234693 was the strongest among all ethnic populations studied thus far giving a new insight on estrogen receptor gene variation in distant North African populations and their role in metabolic alteration of PCOS.

The direct effects of gonadotropin-releasing hormone on proliferation of granulosa cells and development of follicles in goose

1. The study objectives were to determine the direct effects of gonadotropin-releasing hormone (GnRH) on the proliferation of ovarian granulosa cells (GCs) and the development of follicles in geese (Anser cygnoides) by colorimetry and ethynyl-2'-deoxyuridine (EdU) cell proliferation assays, in which primary GCs were treated with different concentrations of GnRH agonist (alarelin acetate) and an antagonist (cetrorelix acetate). Differently expressed genes (DEGs) were identified by RNA-sequencing and validated by quantitative reverse transcription polymerase chain reaction (RT-qPCR) and Western blotting. 2. The EdU assays showed that the proliferation of GCs was affected by the GnRH agonist and antagonist in a dose-dependent manner. The effect of treatment on cell proliferation was statistically significant at the concentrations of 10^-5 mol/l alarelin and 1 mg/l cetrorelix acetate. A total of 134 DEGs (76 downregulated and 58 upregulated for alarelin treatment) and 226 DEGs (90 downregulated and 136 upregulated for cetrorelix) were identified by RNA-sequencing analysis, respectively. Enrichment analysis indicated that DEGs were enriched in the GO terms of cell-cell signalling and cell junctions. The pathways that regulate the development of follicles were identified, including the biological progress of cAMP accumulation, ovulation cycle and vasculature that are essential to follicular selection. 3. The results suggested that GnRH might directly regulate GC proliferation via autocrine or paracrine pathways related to cell junctions. In particular, it was confirmed that the mRNA and protein expression levels of the oestrogen receptor 2 (ESR2) gene, a negative transcription factor involved in follicular maturation and ovulation, were affected by GnRH agonist or antagonist in GCs. 4. In conclusion, GnRH might play an important role in follicular development by changing the expression of genes that participate in cAMP accumulation, ovulation cycle and cell junctions in ovarian GCs.

Applicability of Anti-Human Estrogen Receptor β Antibody PPZ0506 for the Immunodetection of Rodent Estrogen Receptor β Proteins

Several lines of controversial evidence concerning estrogen receptor β (ERβ) remain to be solved because of the unavailability of specific antibodies against ERβ. The recent validation analysis identified a monoclonal antibody (PPZ0506) with sufficient specificity against human ERβ. However, the specificity and cross-reactivity of PPZ0506 antibody against ERβ proteins from laboratory animals have not been confirmed. In the present study, we aimed to validate the applicability of PPZ0506 to rodent studies. The antibody exhibited specific cross-reactivity against mouse and rat ERβ proteins in immunoblot and immunocytochemical experiments using transfected cells. In immunohistochemistry for rat tissue sections, PPZ0506 showed immunoreactive signals in the ovary, prostate, and brain. These immunohistochemical profiles of rat ERβ proteins in rat tissues accord well with its mRNA expression patterns. Although the antibody was reported to show the moderate signals in human testis, no immunoreactive signals were observed in rat testis. Subsequent RT-PCR analysis revealed that this species difference in ERβ expression resulted from different expression profiles related to the alternative promoter usage between humans and rats. In conclusion, we confirmed applicability of PPZ0506 for rodent ERβ studies, and our results provide a fundamental basis for further examination of ERβ functions.

Evaluation of the epidemiological and prognosis significance of ESR2 rs3020450 polymorphism in ovarian cancer

AIM

To investigate the correlation between the polymorphism of estrogen receptor β gene (ESR2) rs3020450 and cancer susceptibility, and explore the epidemiological significance and the effect of ESR2 expression levels on the prognosis of ovarian cancer.

METHODS

Based on meta-analysis the association between ESR2 rs3020450 polymorphism and cancer susceptibility was estimated and a case-control design was used to verify this result in ovarian cancer. The epidemiological effect of ESR2 rs3020450 polymorphism was assessed by attributable risk percentage (ARP) and population attributable risk percentage (PARP). Kaplan Meier plotters were used to evaluate overall survival (OS) and progression-free survival (PFS) in ovarian cancer patients and GEPIA for the differential expression of ESR2 levels in ovarian cancer and adjacent normal tissues.

RESULTS

The pooled analysis indicated no significant correlation between the ESR2 rs3020450 polymorphism and the cancer susceptibility. In the stratified analysis by cancer types, significantly decreased risk was found in ovarian cancer (AG vs GG: OR = 0.73, 95%CI: 0.53-0.97, P = 0.03). Unconditional logistic regression results of case-control study in ovarian cancer observed significant differences in all comparisons (AG vs GG: OR = 0.81, 95%CI: 0.62-0.98, P = 0.04; AA vs GG: OR = 0.63, 95%CI: 0.42-0.92, P = 0.01 and AG + AA vs GG: OR = 0.73, 95%CI: 0.53-0.96, P < 0.001). Based on meta-analysis and case-control pooled results, ARP and PARP were evaluated respectively in allele (21.95% and7.97%), heterozygote (36.99% and 12.11%) and dominant model (36.84% and 12.97%) of rs3020450 polymorphism in ovarian cancer. The expression levels of ESR2 in normal tissues was significantly higher than that in cancer tissues (OV, Median, 4.7:0.21), and significant correlations were observed between high ESR2 expression levels and long OS (HR = 0.80, 95%CI: 0.70-0.92, P = 0.002) and PFS (HR = 0.767, 95%Cl: 0.67-0.88, P < 0.001).

CONCLUSION

Our results indicated that ESR2 rs3020450 polymorphism was associated with ovarian cancer risk from epidemiological perspective, and high ESR2 expression levels was associated with long survival in patients with ovarian cancer.

No Association between Estrogen Receptor-Β Rs4986938 and Cancer Risk: A Systematic Review and Meta-Analysis

BACKGROUND

The association between estrogen receptor-β (ESR2) rs4986938 polymorphism and the risk of various types of cancer have been investigated in previous studies. However, the results remained disputable. Here, we conducted a meta-analysis to investigate the association between ESR2 rs4986938 polymorphism and the risk of cancer.

METHODS

We searched for relevant articles collected by the PubMed, EMBASE, and Cochrane library up to March 30, 2018. The association was assessed using Odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

The meta-analysis involved a total of 23 studies in 20 papers, including 24,334 cases and 31,707 controls. No significant association was detected between the rs4986938 polymorphism and cancer risk in the additive model (A compared with G: OR=0.97, 95% CI=0.92-1.02, P=0.20), dominant model (AA+AG compared with GG: OR=0.96, 95% CI=0.93-1.03, P=1.00), recessive model (AA compared with AG + GG: OR=0.94, 95% CI=0.86-1.03, P=0.18), heterozygous model (AG compared with GG: OR=0.97, 95% CI=0.94-1.01, P=0.14), and homozygous model (AA compared with GG: OR=0.96, 95% CI=0.87-1.06, P=0.39). Results of subgroup analysis stratified by ethnicity and cancer types further validated the results.

CONCLUSION

We found no evidence of an association between rs4986938 and the risk of overall cancer.

Facial Sadness Recognition is Modulated by Estrogen Receptor Gene Polymorphisms in Healthy Females

Polymorphisms of the estrogen receptor ESR1 and ESR2 genes have been linked with cognitive deficits and affective disorders. The effects of these genetic variants on emotional processing in females with low estrogen levels are not well known. The aim was to explore the impact of the ESR1 and ESR2 genes on the responses to the facial emotion recognition task in females. Postmenopausal healthy female volunteers were genotyped for the polymorphisms Xbal and PvuII of ESR1 and the polymorphism rs1256030 of ESR2. The effect of these polymorphisms on the response to the facial emotion recognition of the emotions happiness, sadness, disgust, anger, surprise, and fear was analyzed. Females carrying the P allele of the PvuII polymorphism or the X allele of the Xbal polymorphism of ESR1 easily recognized facial expressions of sadness that were more difficult for the women carrying the p allele or the x allele. They displayed higher accuracy, fast response time, more correct responses, and fewer omissions to complete the task, with a large effect size. Women carrying the ESR2 C allele of ESR2 showed a faster response time for recognizing facial expressions of anger. These findings link ESR1 and ESR2 polymorphisms in facial emotion recognition of negative emotions.

ESR2 regulates granulosa cell genes essential for follicle maturation and ovulation

Estrogen receptor 2 (ESR2) plays a critical role in folliculogenesis and ovulation. Disruption of ESR2-function in the rats results in female infertility due to failure of ovulation. Ovulation failure occurred in two distinct rat models, a null mutant and a DNA binding domain (DBD) mutant of ESR2, indicating that transcriptional regulation by ESR2 is indispensable for ovulation. To define the regulatory role of ESR2 in preovulatory follicular maturation and ovulation, we investigated ovarian responsiveness to exogenous gonadotropins in prepubertal females. Granulosa cells (GCs) play a vital role in follicle maturation and ovulation, and ESR2-dependent estrogen signaling is predominant in GCs, therefore, we examined the differential expression of gonadotropin-induced genes in GCs. Of 32,623 genes detected by RNA-sequencing, 1696 were differentially expressed in Esr2-mutant rats (789 downregulated, and 907 upregulated, absolute fold change 2, FDR p < 0.05). Molecular pathway analyses indicated that these differentially expressed genes are involved in steroidogenesis, follicle maturation, and ovulation. Many of these genes are known regulators of ovarian function and a subset were also disrupted in Esr2-mutant mice. Interestingly, Kiss1 was identified as one of the differentially expressed genes implicating a potential role within the follicle and its regulation by ESR2. Our findings indicate that ESR2 regulates key genes in GCs that are essential for follicle maturation and ovulation in the rat.

Role of FSHR rs6165 and ESR2 rs4986938 polymorphisms in ovarian stimulation of Iranian women who underwent assisted reproduction treatment

BACKGROUND

Gonadotropin therapy was used to stimulate the ovary in infertile women who underwent assisted reproduction treatment (ART). Numerous studies indicated that infertile women showed different responses to gonadotropin therapy. Follicle stimulating hormone receptor (FSHR) and Oestrogen receptor (ER) polymorphisms have been reported to involve induction of folliculogenesis and ovarian response to treatment.

METHODS

In the present study, two polymorphisms, namely FSHR rs6165 and ESR2 rs4986938, were investigated in 198 Iranian infertile women aged less than 39 years who underwent ART. After DNA extraction, these polymorphisms were genotyped by TaqMan genotyping assay. According to the number of eggs released during ovulation, the patients were categorized into poor responders (PR) and good responders (GR). The results indicated that the good responders showed lower levels of FSH and LH than poor responders.

RESULTS

No association was observed between ESR2 rs4986938 and poor response in Iranian women patients. Instead, FSHR rs6165 showed a strong association with ovarian response to ART (p< 0.05).

CONCLUSION

The obtained results indicated that FSHR rs6165, not ESR2 rs4986938, could be suggested as a candidate marker to predict poor ovarian response.

Estrogen Receptor 1 (ESR1) Enhances Slc2a4/GLUT4 Expression by a SP1 Cooperative Mechanism

Background: Estrogens are involved in glycemic regulation, playing an important role in the development and/or progression of insulin resistance. For that, estrogens regulate the expression of the glucose transporter protein GLUT4 (codified by the solute carrier family 2 member 4 gene, Slc2a4), thus modulating adipose and muscle glucose disposal. This regulation is a balance between ESR1-mediated enhancer effect and ESR2-mediated repressor effect on Slc2a4 gene. However, molecular mechanisms involved in these effects are poorly understood. Since the specificity protein 1 (SP1) participates in several ESR-mediated genomic regulations, the aim of the present study is to investigate the participation of SP1 in the ESR1/2-mediated regulation of Slc2a4 gene. Methods: Differentiated 3T3-L1 adipocytes were 24-hour challenged with 10 nM estradiol (E2) and 10 nM ESR1 agonist (PPT) or 100 nM ESR2 agonist (DPN), added or not with E2. Slc2a4 and Sp1 mRNAs (RT-qPCR), total GLUT4 and nuclear ESR1, ESR2 and SP1 proteins (Western blotting), SP1 binding activity into Slc2a4 promoter (EMSA), and nuclear complexation of SP1/ESR1 (immunoprecipitation) were analyzed. Results: E2 and PPT increased (25-50%) whereas DPN reduced (20-45%) Slc2a4 and GLUT4 expression. Nuclear content of ESR1 and ESR2 remained unchanged. Nuclear content of SP1 increased (50 to 90%) by PPT and DPN added or not with E2; the highest effect observed with PPT alone. PPT also increased the nuclear content of SP1/ESR1 complex and the SP1 binding into the Slc2a4 promoter. Conclusions: ESR1 activation in adipocytes increased the nuclear content of SP1 protein, the SP1/ESR1 interaction and SP1 binding into the Slc2a4 gene promoter, culminating with increased Slc2a4/GLUT4 expression. No involvement of SP1 seems to occur in ESR2-mediated repressor effect on Slc2a4. We expect that this ESR1/SP1 cooperative effect can contribute to the development of new approaches for prevention or treatment of insulin resistance and diabetes mellitus.

The rs1256044 polymorphism in the ESR2 gene and the risk for osteoporosis in Polish postmenopausal women

Population association studies have demonstrated a strong association between ESR2 SNPs and BMD, indicating that ESR2 may influence attainment of bone mass. The aim of the study was to investigate the ESR2 gene, located on chromosome 14q linked with BMD, which demonstrates a correlation with changes in bone mass in healthy Caucasian women. The study included 675 unrelated Polish postmenopausal women, including 109 with osteopenia, 333 with osteoporosis and 233 healthy women. The women were classified into the following groups: osteopenia, osteoporosis and normal T-score. Analysis of genotype frequency for the ESR2 rs1256044 polymorphism revealed no statistically significant differences. No statistically significant differences were noted for the allele frequency. However, it is noticeable that the CT genotype occurred more often in women with osteopenia (50.4%, OR = 1.14) and osteoporosis (54.7%, OR = 1.33) than controls (47.7%). There were statistically significant differences between the clinical parameters and distribution of genotypes in patients with osteopenia but not osteoporosis. ESR2 polymorphisms demonstrate minimal influence on BMD changes in women. Identification of various genes with little impact on BMD, such as ESR2, might help design a screening panel for osteoporosis risk assessment in healthy subjects.

A transcriptomic comparison of theca and granulosa cells in chicken and cattle follicles reveals ESR2 as a potential regulator of CYP19A1 expression in the theca cells of chicken follicles

Previous studies have shown that theca and granulosa cell layers in follicles do not play the same roles in mammals and birds, especially regarding the synthesis of estrogen. The functions of these two cell types have been well characterized in cattle, but they remain unclear in chickens. To clarify this issue, a comparison of small yellow follicles (SYFs) in chickens and cattle at different follicular development stages was done by weighted gene co-expression network analysis (WGCNA). The modules obtained from WGCNA were used for further identification of the key genes associated with CYP19A1 expression. Module preservation analysis showed high similarity between cow_D (the follicular phase before the LH surge) and chicken_SYF (small yellow follicle between 6 and 8 mm in diameter) datasets, and 10 top hub genes highly associated with CYP19A1 expression in chicken SYFs were identified in each module. A comparison of the transcriptomes of theca and granulosa cells (TCs and GCs) between chicken SYFs and cattle follicles at the differentiation stage, as well as the aforementioned hub genes, revealed that ESR2 is a potential regulator of CYP19A1 expression in the theca cells of chicken SYFs. Furthermore, 197 cell-specific (179 in theca and 18 in granulosa) and 235 cell-biased expressed genes (196 in theca and 39 in granulosa) in chicken small yellow follicles were also identified by transcriptomic comparison of theca and granulosa cells.

Genetic association between HER2 and ESR2 polymorphisms and ovarian cancer: a meta-analysis

Objective

The estrogen receptor (ER) and the human epidermal growth factor receptor 2 (HER2) each play an important role in female cancers. This study aimed to investigate the genetic association between three common single nucleotide polymorphisms (SNPs) and the risk of ovarian cancer. The SNPs investigated in this study were ESR2 rs1271572 and rs3020450 and HER2 rs1801200.

Methods

In this study, databases were electronically searched in a meta-analysis. Databases used were PubMed, Embase, China National Knowledge Infrastructure (CNKI), Wanfang and Cochrane library. Case–control studies on the association between ESR2 and HER2 polymorphisms were selected according to inclusion and exclusion standard. Articles were evaluated for quality, and data were extracted.

Results

A total of 13 articles with 5,461 cases and 7,603 controls were included in this meta-analysis. The recessive model of ESR2 rs1271572 was shown to be significantly associated with the risk of ovarian cancer (p = 0.008, odds ratio [OR] [95% confidence interval {CI}] = 1.13 [1.03, 1.24]), and this significant association still existed in a subgroup analysis stratified by ethnicity (Asian: p = 0.04, OR [95% CI] = 1.92 [1.04, 3.56]; Caucasian: p = 0.02, OR [95% CI] = 1.12 [1.02, 1.23]). In addition, the distribution of the dominant model of ESR2 rs3020450 was significantly different in the total group (p = 0.02, OR [95% CI] = 0.71 [0.53, 0.95]) and the Caucasian subgroup (p = 0.02, OR [95% CI] = 0.67 [0.48, 0.94]). Furthermore, no significant association between allelic, dominant, codominant and recessive models of HER2 rs1801200 (V655I) and ovarian cancer was found (p > 0.05).

Conclusion

The recessive model of ESR2 rs1271572 and the dominant model of ESR2 rs3020450 might be susceptible factors for ovarian cancer.

Polymorphisms in sex steroid receptors: From gene sequence to behavior

Sex steroid receptors have received much interest as potential mediators of human behaviors and mental disorders. Candidate gene association studies have identified about 50 genetic variants of androgen and estrogen receptors that correlate with human behavioral phenotypes. Because most of these polymorphisms lie outside coding regions, discerning their effect on receptor function is not straightforward. Thus, although discoveries of associations improve our ability to predict risk, they have not greatly advanced our understanding of underlying mechanisms. This article is intended to serve as a starting point for psychologists and other behavioral biologists to consider potential mechanisms. Here, I review associations between polymorphisms in sex steroid receptors and human behavioral phenotypes. I then consider ways in which genetic variation can affect processes such as mRNA transcription, splicing, and stability. Finally, I suggest ways that hypotheses about mechanism can be tested, for example using in vitro assays and/or animal models.

Distribution and chemical composition of estrogen receptor β neurons in the paraventricular nucleus of the female and male mouse hypothalamus

Activation of estrogen receptor beta (ERβ)-expressing neurons regulates the mammalian stress response via the hypothalamic-pituitary-adrenal (HPA) axis. These neurons densely populate the paraventricular nucleus of the hypothalamus (PVN). Recent research has revealed striking differences between rat and mouse PVN cytochemistry, but careful exploration of PVN ERβ neurons in mice has been hindered by a lack of specific ERβ antisera. Therefore, we used male and female transgenic mice expressing EGFP under the control of the mouse ERβ promoter (ERβ-EGFP) to examine the chemical architecture of PVN ERβ cells. Using immunohistochemistry, we found that 90% of ERβ-immunoreactivity (-ir) colocalized with EGFP. Cellular colocalization of EGFP with neuropeptides, transcription modulators, and neuronal tracers was examined throughout the PVN. ERβ-EGFP cells expressed oxytocin more abundantly in the rostral (71 ± 3%) than caudal (33 ± 8%) PVN. Arginine vasopressin colocalized with EGFP more often in females (18 ± 3%) than males (4 ± 1%). Moreover, estrogen receptor α-ir colocalized with ERβ-EGFP at low levels (15 ± 3%). Using a corticotropin releasing hormone-cre driver X tdTomato reporter mouse, we found a moderate colocalization with ERβ-ir (48 ± 16%) in the middle PVN. Peripheral injection of fluorogold revealed that the rostral PVN ERβ-EGFP cells are neuroendocrine neurons whereas non-neuroendocrine (presumably pre-autonomic) ERβ-EGFP neurons predominated in the posterior PVN. These data demonstrate chemoarchitectural differences in ERβ neurons of the mouse PVN that are different from that previously described for the rat, thus, elucidating potential neuronal pathways involved in the regulation of the HPA axis in mice.

Oleic acid induces down-regulation of the granulosa cell identity marker FOXL2, and up-regulation of the Sertoli cell marker SOX9 in bovine granulosa cells

During negative energy balance, the concentration of different fatty acids, especially of oleic acid (OA) increases in the follicular fluid of cattle. Previously, we showed that OA induced morphological, physiological and molecular changes in cultured bovine granulosa cells. In our present study we analyzed effects of OA on the expression of markers for granulosa and Sertoli cell identity, FOXL2 and SOX9, respectively, in addition to effects on the FOXL2 regulated genes ESR2, FST, PTGS2 and PPARG. The results showed that OA down-regulated FOXL2, ESR2, FST and PPARG but up-regulated PTGS2 and SOX9. From these data we conclude that OA can compromise granulosa cell functionality and may initiate trans-differentiation processes in bovine granulosa cells. This novel mechanism may be causally involved in postpartum fertility problems of lactating dairy cows.

Understanding the Inguinal Sinus in Sheep (Ovis aries)-Morphology, Secretion, and Expression of Progesterone, Estrogens, and Prolactin Receptors

Post-parturient behavior of mammalian females is essential for early parent–offspring contact. After delivery, lambs need to ingest colostrum for obtaining the related immunological protection, and early interactions between the mother and the lamb are crucial. Despite visual and auditory cues, olfactory cues are decisive in lamb orientation to the mammary gland. In sheep, the inguinal sinus is located bilaterally near the mammary gland as a skin pouch (IGS) that presents a gland that secretes a strong-smelling wax. Sheep IGS gland functions have many aspects under evaluation. The objective of the present study was to evaluate sheep IGS gland functional aspects and mRNA transcription and the protein expression of several hormone receptors, such as progesterone receptor (PGR), estrogen receptor 1 (ESR1), and 2 (ESR2) and prolactin receptor (PRLR) present. In addition, another aim was to achieve information about IGS ultrastructure and chemical compounds produced in this gland. All hormone receptors evaluated show expression in IGS during the estrous cycle (follicular/luteal phases), pregnancy, and the post-partum period. IGS secretion is rich in triterpenoids that totally differ from the surrounding skin. They might be essential substances for the development of an olfactory preference of newborns to their mothers.

Seasonal variations of aromatase and estrogen receptors expression in the testis of free-ranging sand rats

An increasing number of studies revealed the importance of estrogen in male reproduction. However, most research was conducted in laboratory rodents subjected to standardized environmental conditions. Therefore, seasonal regulations of estrogen pathways remain poorly understood under natural conditions. Using immunohistochemistry, the expression of several molecules involved in the functioning of testis (i.e. 17-β estradiol [E2], P450 aromatase, estrogen receptors ESR1, ESR2, and GPER1 [also known as GPR30]) were investigated in free-ranging fat sand rats, Psammomys obesus, during the breeding and resting seasons. Leydig cells showed a strong immunoreactivity for aromatase in the testis sampled during the breeding season only; however, E2, ESR1, ESR2 and GPER1 were present during both seasons. Sertoli cells showed a positive signal for E2 and ESR2 during the breeding season; though, all molecules, except GPER1, were present during the resting season. Spermatogonia were reactive for E2, ESR2 and GPER1 during the breeding season and for ESR1 and GPER1 during the resting season. During both seasons, spermatocytes-I presented a moderate reactivity for E2, ESR1, ESR2 and a strong reactivity for GPER1; aromatase was detected during the resting season only. Spermatids and spermatozoa were present exclusively during breeding season and were reactive for all molecules; except round spermatids that were negative for aromatase. The functioning of the testis depends on finely tuned stimulation and inhibition systems. Our results suggest that differential expression of aromatase, ESR1, ESR2, and GPER1 across cells types is involved in the seasonal activation/inactivation cycle of spermatogenesis in a free-ranging species.

Regulation of submaxillary gland androgen-regulated protein 3A via estrogen receptor 2 in radioresistant head and neck squamous cell carcinoma cells

Background

Molecular mechanisms of intrinsic or acquired radioresistance serve as critical barrier for curative therapy of head and neck squamous cell carcinoma (HNSCC) and remain a major obstacle for progression-free and disease-specific survival.

Methods

HNSCC cell lines were treated with a protocol of fractionated irradiation (IR, 4× 2Gy) alone or in combination with antagonists of estrogen receptor signaling and viability was determined by a colony-forming assay (CFA). Expression of submaxillary gland androgen-regulated protein 3A (SMR3A) and estrogen receptor 2 (ESR2) were assessed in tumor cells in vitro by RQ-PCR, Western blot analysis and immunofluorescence staining, and by immunohistochemical staining of tissue microarrays containing tumor sections from patients with oropharyngeal squamous cell carcinoma (OPSCC), which were treated by definitive or adjuvant radiotherapy. Subgroups with distinct SMR3A and ESR2 expression patterns were correlated with clinical parameters and survival outcome including multivariable analysis.

Results

Fractionated irradiation (IR) revealed an accumulation of tumor cells with prominent SMR3A expression, which was accompanied by an up-regulation of the estrogen receptor 2 (ESR2). ESR2-dependent regulation of SMR3A was supported by induced expression after stimulation with estradiol (E2), which was impaired by co-treatment with 4-Hydroxytamoxifen (TAM) or Fulvestrant, respectively. Both drugs significantly sensitized FaDu cells to fractionated IR as determined by a CFA and accelerated apoptosis. These data suggest a critical role of ESR2 in radioresistance and that SMR3A might serve as a surrogate marker for active ESR2 signaling. In line with this assumption, ESR2-positive oropharyngeal squamous cell carcinoma (OPSCC) with high SMR3A expression had an unfavorable progression-free and disease-specific survival as compared to those tumors with low SMR3A expression.

Conclusions

In summary, our findings provide compelling experimental evidence that HNSCC with SMR3A and ESR2 co-expression have a higher risk for treatment failure and these patients might benefit from clinically well-established drugs targeting estrogen receptor signaling.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-017-0496-2) contains supplementary material, which is available to authorized users.

Variants of estrogen receptor alpha and beta genes modify the severity of sporadic breast cancer

INTRODUCTION

Reproductive factors pose a risk for sporadic breast cancer (BC) development owing to the lifetime exposure to estrogen, a hormone responsible for cell proliferation in the breast. Because variants of the estrogen receptor (ER) alpha and beta genes have been associated with BC risk in numerous populations, the objective of the study was to determine whether the risk and severity of sporadic BC was associated with the rs2228480 (ESR1) and rs4986938 (ESR2) variants in a Brazilian population.

METHODS

A total of 253 DNA samples from sporadic BC patients and 257 DNA samples from healthy controls were studied. The samples were genotyped by PCR-RFLP. Epidemiological, clinical, and reproductive factors were analyzed. Statistical tests conducted included the χ² test, Fisher's exact test, and Mann-Whitney and Kruskal-Wallis tests or their parametric equivalents.

RESULTS

There was a high frequency of the rs2228480*GG genotype among the ER-positive tumors (OR=2.13; 95% CI=1.189-3.816) and it showed minor association with clinical stage 0 (OR=0.324; 95% CI=0.116-0.904). The rs2228480*GA genotype was associated with minor ER expression, whereas rs2228480*GG was associated with high expression of the progesterone receptor (PR). The frequency of rs4986938*GA was high among women who breastfed (OR=2.11; 95% CI=1.203-3.702), and it showed high association with clinical stage 0 (OR=4.383; 95% CI=1.606-11.96) whereas it had minor association with systemic arterial hypertension (OR=0.53; 95% CI=0.319-0.880). The rs2228480*GG/rs4986938*GG haplotype occurred at a low frequency among women who breastfed (OR=0.525; 95% CI=0.298-0.924) but it was associated with a high expression of PR.

CONCLUSION

The rs2228480 and rs4986938 variants did not alter sporadic BC risk, but they did modulate the BC severity.