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Cancer remains a significant global health concern. Breast cancer is a multifaceted and prevalent disease influenced by several factors, among which estrogen receptors (ERs) and the extracellular matrix (ECM) play pivotal roles. ERs, encompassing ERα and ERβ, exert significant diversity on tumor behavior, cell signaling, invasion, and metastatic potential, thus guiding breast cancer prognosis. Understanding the multifunctional connections between ERs and ECM that mediate the dynamics of tumor microenvironment is vital for unraveling the complexity of breast cancer pathobiology and identifying novel therapeutic targets. This critical review delves into the intricate nature of ERs, emphasizing their structural isoforms and the consequential impact on breast cancer outcomes. A detailed examination of ER‐mediated cell signaling pathways reveals how differential expression of ERα and ERβ isoforms influence breast cancer cell behavior. The functional ERs‐matrix interactions emerge as a pivotal factor in modulating epigenetic mechanisms of breast cancer cells, orchestrating changes in cellular phenotype and expression patterns of matrix modulators. Specifically, ERα isoforms are shown to regulate ECM signaling cascades, while the effects of ECM components on ERα activity highlight a bidirectional regulatory axis. The diversity of ERβ isoforms is also highlighted, illustrating their distinct contribution to ECM‐mediated cellular responses. This review underscores the complex interplay between ERα/β isoforms and the ECM, shedding light onto the potential therapeutic strategies targeting these interactions to improve breast cancer management. [ABSTRACT FROM AUTHOR]

UNLABELLED: Transcriptionally active ESR1 fusions (ESR1-TAF) are a potent cause of breast cancer endocrine therapy (ET) resistance. ESR1-TAFs are not directly druggable because the C-terminal estrogen/anti-estrogen-binding domain is replaced with translocated in-frame partner gene sequences that confer constitutive transactivation. To discover alternative treatments, a mass spectrometry (MS)-based kinase inhibitor pulldown assay (KIPA) was deployed to identify druggable kinases that are upregulated by diverse ESR1-TAFs. Subsequent explorations of drug sensitivity validated RET kinase as a common therapeutic vulnerability despite remarkable ESR1-TAF C-terminal sequence and structural diversity. Organoids and xenografts from a pan-ET-resistant patient-derived xenograft model that harbors the ESR1-e6>YAP1 TAF were concordantly inhibited by the selective RET inhibitor pralsetinib to a similar extent as the CDK4/6 inhibitor palbociclib. Together, these findings provide preclinical rationale for clinical evaluation of RET inhibition for the treatment of ESR1-TAF-driven ET-resistant breast cancer. SIGNIFICANCE: Kinome analysis of ESR1 translocated and mutated breast tumors using drug bead-based mass spectrometry followed by drug-sensitivity studies nominates RET as a therapeutic target. See related commentary by Wu and Subbiah, p. 3159.

The stabilization of protein-protein interactions (PPIs) has emerged as a promising strategy in chemical biology and drug discovery. The identification of suitable starting points for stabilizing native PPIs and their subsequent elaboration into selective and potent molecular glues lacks structure-guided optimization strategies. We have previously identified a disulfide fragment that stabilized the hub protein 14-3-3σ bound to several of its clients, including ERα and C-RAF. Here, we show the structure-based optimization of the nonselective fragment toward selective and highly potent small-molecule stabilizers of the 14-3-3σ/ERα complex. The more elaborated molecular glues, for example, show no stabilization of 14-3-3σ/C-RAF up to 150 μM compound. Orthogonal biophysical assays, including mass spectrometry and fluorescence anisotropy, were used to establish structure-activity relationships. The binding modes of 37 compounds were elucidated with X-ray crystallography, which further assisted the concomitant structure-guided optimization. By targeting specific amino acids in the 14-3-3σ/ERα interface and locking the conformation with a spirocycle, the optimized covalent stabilizer 181 achieved potency, cooperativity, and selectivity similar to the natural product Fusicoccin-A. This case study showcases the value of addressing the structure, kinetics, and cooperativity for molecular glue development.

Small-molecule stabilization of protein-protein interactions (PPIs) is a promising strategy in chemical biology and drug discovery. However, the systematic discovery of PPI stabilizers remains a largely unmet challenge. Herein we report a fragment-linking approach targeting the interface of 14-3-3 and a peptide derived from the estrogen receptor alpha (ERα) protein. Two classes of fragments-a covalent and a noncovalent fragment-were co-crystallized and subsequently linked, resulting in a noncovalent hybrid molecule in which the original fragment interactions were largely conserved. Supported by 20 crystal structures, this initial hybrid molecule was further optimized, resulting in selective, 25-fold stabilization of the 14-3-3/ERα interaction. The high-resolution structures of both the single fragments, their co-crystal structures and those of the linked fragments document a feasible strategy to develop orthosteric PPI stabilizers by linking to an initial tethered fragment.

This work examined the potential benefit of curcumin in breast cancer patients as a supplementary drug in ER-positive cancers. The results indicated that in the MCF-7 human breast cancer cell line, E2 and curcumin decreased cell proliferation and the colony-forming capacity and down-regulated protein expression as well as important molecules associated with cell proliferation, such as PCNA and estrogen receptor alpha; genes associated with the epithelial-mesenchymal transition, such as β-catenin, Vimentin, and E-cadherin; and molecules associated with apoptosis. Clinical studies in bioinformatics have indicated a positive correlation between ESR1 and either CCND1 or BCL2 gene expression in all breast cancer patients. Thus, curcumin could become a potential natural adjuvant treatment for patients with estrogen receptor alpha-positive breast cancer and those with resistance or a poor response to endocrine therapy since the reactivation of estrogen receptor alpha is inevitable. [ABSTRACT FROM AUTHOR]

Women are more prone to develop rheumatoid arthritis, with peak incidence occurring around menopause. Estrogen has major effects on the immune system and is protective against arthritis. We have previously shown that treatment with estrogen inhibits inflammation and joint destruction in murine models of arthritis, although the mechanisms involved remain unclear. Fibroblastic reticular cells (FRCs) are specialized stromal cells that generate the three‐dimensional structure of lymph nodes (LNs). FRCs are vital for coordinating immune responses from within LNs and are characterized by the expression of the chemokine CCL19, which attracts immune cells. The aim of this study was to determine whether the influence of estrogen on innate and adaptive immune cells in arthritis is mediated by estrogen signaling in FRCs. Conditional knockout mice lacking estrogen receptor α (ERα) in CCL19‐expressing cells (Ccl19‐CreERαfl/fl) were generated and tested. Ccl19‐CreERαfl/fl mice and littermate controls were ovariectomized, treated with vehicle or estradiol and subjected to the 28‐day‐long antigen‐induced arthritis model to enable analyses of differentiated T‐ and B‐cell populations and innate cells in LNs by flow cytometry. The results reveal that while the response to estradiol treatment in numbers of FRCs per LN is significantly reduced in mice lacking ERα in FRCs, estrogen does not inhibit joint inflammation or markedly affect immune responses in this arthritis model. Thus, this study validates the Ccl19‐CreERαfl/fl strain for studying estrogen signaling in FRCs within inflammatory diseases, although the chosen arthritis model is deemed unsuitable for addressing this question. [ABSTRACT FROM AUTHOR]

Postmenopausal osteoporosis (PMOP) is a public health issue that needs to be addressed urgently. Patients are with decreased estrogen level, decreased estrogen receptor α (ERα) expression level, decreased osteoblast function, increased osteoclast activity, and imbalance of bone metabolic. ERα plays an important role in the occurrence and development of PMOP. In this paper, literature in the field of osteoporosis in recent ten years (2013-2023) are retrieved from PubMed, Web of Science, and CNKI. The role of ERα in bone mesenchymal stem cells, osteoblast progenitors, osteoblast progenitors, mature osteoblasts, osteoclasts, and osteocytes is summarized. The relevant anti-PMOP mechanism of ERα is expounded based on an example of icariin, a flavonoid component that significantly relieves PMOP. [ABSTRACT FROM AUTHOR]

Forkhead box P2 (FOXP2) regulates expression of various genes and is associated with language, speech and neural development as well as cancer. Since there may be a putative link between sex and language and because transcription factors rarely function in isolation, this study aims to investigate whether FOXP2 directly associates with oestrogen receptor α (ER1), a nuclear receptor responsible for sexual differentiation that is also associated with cancer. Isothermal titration calorimetry and fluorescence anisotropy were used to investigate the interaction between the DNA-binding forkhead domain (FHD) of FOXP2, the N-terminal region (NT) of FOXP2, and the ligand-binding domain (LBD) of ER1. ER1 LBD does not interact with FOXP2 NT but associates with apo-FOXP2 FHD in an enthalpically favourable manner. The affinity of this interaction is inversely correlated to the salt concentration. Additionally, FOXP2 FHD that is bound to ER1 LBD, has reduced ability to interact with its cognate DNA. This research identifies a novel interaction between ER1 LBD and FOXP2 FHD and shows that the interaction is regulated by salt. Moreover, FOXP2 FHD cannot bind to both ER1 LBD and DNA simultaneously, suggesting that this interaction could be involved in regulating the transcriptional pathway of FOXP2 should the interaction be found in vivo. This study could serve as a foundation for uncovering the basis of sexual dimorphism in speech and language development and related disorders and potentially offers an alternate for targeted cancer therapies. • A novel interaction is identified in vitro between FOXP2 FHD and ER1 LBD. • This interaction has both an electrostatic and hydrophobic interface and involves the DNA-binding Helix 3 of FOXP2 FHD. • The ligand binding region and the LXXLL-binding AF-2 region of ER1 LBD is not involved in the protein-protein interaction. • FOXP2 FHD can bind either to DNA or to ER1 but not to both simultaneously. • The identified FOXP2-ER1 interaction could be involved in regulating FOXP2's transcriptional activity. [ABSTRACT FROM AUTHOR]

A quantitative assessment of the expression of estrogen receptors alpha (ERα) is carried out in 115 samples of non-small cell lung cancer (NSCLC) by an immunofluorescent assay and flow cytometry. It is shown that a high level of ERα of ≥20% predicts a higher aggressiveness of NSCLC than at a low level of <20%: median survival based on a follow-up period of 78 months increases by 1.5 times; the risk of death is reduced by a factor of almost 2.0 (p = 0.04). The time to death increases on average by 18 months in about 20% of patients with a low ERα expression. The results validate the informative value of the immunofluorescence analysis and flow cytometry for quantifying the ERα expression and substantiate the prospects of antiestrogen therapy as a new option for NSCLC treatment, in particular, by analogy with breast cancer—in a long-term adjuvant therapy in ERα+ NSCLC patients. [ABSTRACT FROM AUTHOR]

Estradiol (E2) affects both reproductive and non-reproductive tissues, and the sensitivity to different doses of E2 varies between tissues. Membrane estrogen receptor α (mERα)-initiated signaling plays a tissue-specific role in mediating E2 effects, however, it is unclear if mERα signaling modulates E2 sensitivity. To determine this, we treated ovariectomized C451A females, lacking mERα signaling, and wildtype (WT) littermates with physiological (0.05 μg/mouse/day (low); 0.6 μg/mouse/day (medium)) or supraphysiological (6 μg/mouse/day (high)) doses of E2 (17β-estradiol-3-benzoate) for three weeks. Low-dose treatment increased uterus weight in WT, but not C451A mice, while non-reproductive tissues (gonadal fat, thymus, trabecular and cortical bone) were unaffected in both genotypes. Medium-dose treatment increased uterus weight and bone mass and decreased thymus and gonadal fat weights in WT mice. Uterus weight was also increased in C451A mice, but the response was significantly attenuated (- 85%) compared to WT mice, and no effects were triggered in non-reproductive tissues. High-dose treatment effects in thymus and trabecular bone were significantly blunted (- 34% and - 64%, respectively) in C451A compared to WT mice, and responses in cortical bone and gonadal fat were similar between genotypes. Interestingly, the high dose effect in uterus was enhanced (+ 26%) in C451A compared to WT mice. In conclusion, loss of mERα signaling reduces the sensitivity to physiological E2 treatment in both non-reproductive tissues and uterus. Furthermore, the E2 effect after high-dose treatment in uterus is enhanced in the absence of mERα, suggesting a protective effect of mERα signaling in this tissue against supraphysiological E2 levels.

Background: Growing evidence has indicated that women with type 2 diabetes mellitus are at an increased risk of developing breast cancer. However, as a major adjuvant treatment, the influence of hormone therapy such as exogenous insulin on type 2 diabetes mellitus in primary breast-cancer remains controversial. Objective: To explore the relationship between different types of hypoglycemic medications for diabetes and the factors that may contribute to the initiation of breast cancer. Methods: The study included 80 blood samples taken from 80 females recruited from Ibn Al-Bitar Center for Cardiac Surgery Hospital in Baghdad, Iraq, between November 2022 and February 2023. They were within the age range of 40 to 70 years. They were divided into three groups according to the treatment strategy and duration of disease as follows: Group 1: (20) patients who take insulin only, Group 2: (20) patients who take metformin with insulin, and G 3: (40) patients on metformin only for less than one year. An enzymatic oxidation technique was used to test the following biochemical parameters for all research groups: Total cholesterol, triglycerides, fasting blood glucose, and high-density lipoprotein cholesterol. Using the Friedewald formula, the very low-density lipoprotein cholesterol and low-density lipoprotein cholesterol were determined. Using an enzymatic process, Insulin levels and Insulin like growth factor-1(IGF-1), Estrogen receptor alpha (ERα) levels, and breast cancer susceptibility protein 1 (BRCA1) were measured with an enzyme-linked immunosorbent assay (ELISA). Glycated hemoglobin (HbA1c) level was measured with a sandwich immunodetection method. Finally, The Homeostasis Model Assessment for insulin resistance (HOMA-IR) was calculated according to the specific formula. Results: The values for HbA1C%, FBS, and lipid profile showed non-significant differences when compared between study groups. While BRCA-1, estrogen receptor alpha (ERα), insulin, insulin growth factor IGF-1, and HOMA IR All showed significant differences among all groups. Conclusion: Taking metformin only for less than one year seemed to contribute to higher levels of BRCA-1.

Although sex differences in learning behaviors are well documented, sexual dimorphism in the synaptic processes of encoding is only recently appreciated. Studies in male rodents have built upon the discovery of long-term potentiation (LTP), and acceptance of this activity-dependent increase in synaptic strength as a mechanism of encoding, to identify synaptic receptors and signaling activities that coordinate the activity-dependent remodeling of the subsynaptic actin cytoskeleton that is critical for enduring potentiation and memory. These molecular substrates together with other features of LTP, as characterized in males, have provided an explanation for a range of memory phenomena including multiple stages of consolidation, the efficacy of spaced training, and the location of engrams at the level of individual synapses. In the present report, we summarize these findings and describe more recent results from our laboratories showing that in females the same actin regulatory mechanisms are required for hippocampal LTP and memory but, in females only, the engagement of both modulatory receptors such as TrkB and synaptic signaling intermediaries including Src and ERK1/2 requires neuron-derived estrogen and signaling through membrane-associated estrogen receptor α (ERα). Moreover, in association with the additional ERα involvement, females exhibit a higher threshold for hippocampal LTP and spatial learning. We propose that the distinct LTP threshold in females contributes to as yet unappreciated sex differences in information processing and features of learning and memory.

Highlights Following in vitro ischemia, the nerve growth factor receptor TrkB is activated in the presence of the TrkB agonist 7,8-DHF only in female and not in male cultured hippocampal neurons, leading to increased neuronal survival. Expression of ERα is increased following in vitro ischemia in female but not male hippocampal neurons. The female hippocampal neuronal specific responses to in vitro ischemia are blocked by pre-treatment with testosterone. The data support a model for a female-specific a neuroprotective pathway in hippocampal neurons. The pathway is activated by a TrkB agonist, dependent on ERα and blocked by testosterone.

Context: Breast cancer expresses high levels of the estrogen receptor alpha (ER-α). Aims: To investigate the potential anticancer activity of nanoliposome Hedyotis corymbosa in breast cancer cells by specifically targeting the ER-α through a combination of in silico and in vitro studies. Methods: This study used molecular docking to analyze the interaction between ER-α and active compounds from H. corymbosa. In vitro studies, the H. corymbosa extract was converted into nanoliposomes. The nanoliposomes' characteristics were examined, combined with tamoxifen, and applied to breast cancer cell cultures. Viability, proliferation, and ER-α expression were assessed, and statistical analysis was performed (p

Elevated endogenous estrogens stimulate human uterine artery endothelial cell (hUAEC) hydrogen sulfide (H2S) production by selectively upregulating the expression of H2S synthesizing enzyme cystathionine β-synthase (CBS), but the underlying mechanisms are underdetermined. We hypothesized that CBS transcription mediates estrogen-stimulated pregnancy-dependent hUAEC H2S production. Estradiol-17β (E2β) stimulated CBS but not cystathionine γ-lyase (CSE) expression in pregnant human uterine artery ex vivo, which was attenuated by the estrogen receptor (ER) antagonist ICI 182,780. E2β stimulated CBS mRNA/protein and H2S production in primary hUAEC from nonpregnant and pregnant women, but with greater responses in pregnant state; all were blocked by ICI 182,780. Human CBS promoter contains multiple estrogen-responsive elements (EREs), including one ERE preferentially binding ERα (αERE) and three EREs preferentially binding ERβ (βERE), and one full ERE (α/βERE) and one half ERE (½α/βERE) binding both ERα and ERβ. Luciferase assays using reporter genes driven by human CBS promoter with a series of 5'-deletions identified the α/βEREs binding both ERα and ERβ (α/βERE and ½α/βERE) to be important for baseline and E2β-stimulated CBS promoter activation. E2β stimulated ERα/ERβ heterodimerization by recruiting ERα to α/βEREs and βERE, and ERβ to βERE, α/βEREs, and αERE. ERα or ERβ agonist alone trans-activated CBS promoter, stimulated CBS mRNA/protein and H2S production to levels comparable to that of E2β-stimulated, while ERα or ERβ antagonist alone abrogated E2β-stimulated responses. E2β did not change human CSE promoter activity and CSE mRNA/protein in hUAEC. Altogether, estrogen-stimulated pregnancy-dependent hUAEC H2S production occurs by selectively upregulating CBS expression via ERα/ERβ-directed gene transcription.

Purpose: Breast cancer heterogeneity contributes to chemotherapy resistance and decreased patient survival. To improve patient outcomes it is essential to develop a technology that is able to rapidly select the most efficacious therapy that targets the diverse phenotypes present within the tumor. Breast cancer organoid technologies are proposed as an attractive approach for evaluating drug responses prior to patient therapy. However, there remain challenges in evaluating the effectiveness of organoid cultures to recapitulate the heterogeneity present in the patient tumor in situ. Method: Organoids were generated from seven normal breast and nineteen breast cancer tissues diagnosed as estrogen receptor positive or triple negative. The Jensen-Shannon divergence index, a measure of the similarity between distributions, was used to compare and evaluate heterogeneity in starting tissue and their resultant organoids. Heterogeneity was analyzed using cytokeratin 8 and cytokeratin 14, which provided an easily scored readout. Results: In the in vitro culture system HER1 and FGFR were able to drive intra-tumor heterogeneity to generate divergent phenotypes that have different sensitivities to chemotherapies. Conclusion: Our methodology, which focuses on quantifiable cellular phenotypes, provides a tractable system that complements omics approaches to provide an unprecedented view of heterogeneity and will enhance the identification of novel therapies and facilitate personalized medicine. [ABSTRACT FROM AUTHOR]

Highlights: Following in vitro ischemia, the nerve growth factor receptor TrkB is activated in the presence of the TrkB agonist 7,8-DHF only in female and not in male cultured hippocampal neurons, leading to increased neuronal survival. Expression of ERα is increased following in vitro ischemia in female but not male hippocampal neurons. The female hippocampal neuronal specific responses to in vitro ischemia are blocked by pre-treatment with testosterone. The data support a model for a female-specific a neuroprotective pathway in hippocampal neurons. The pathway is activated by a TrkB agonist, dependent on ERα and blocked by testosterone. Background: Neonatal hypoxia ischemia (HI) related brain injury is one of the major causes of learning disabilities and memory deficits in children. In both human and animal studies, female neonate brains are less susceptible to HI than male brains. Phosphorylation of the nerve growth factor receptor TrkB has been shown to provide sex-specific neuroprotection following in vivo HI in female mice in an estrogen receptor alpha (ERα)-dependent manner. However, the molecular and cellular mechanisms conferring sex-specific neonatal neuroprotection remain incompletely understood. Here, we test whether female neonatal hippocampal neurons express autonomous neuroprotective properties and assess the ability of testosterone (T) to alter this phenotype. Methods: We cultured sexed hippocampal neurons from ERα+/+ and ERα−/− mice and subjected them to 4 h oxygen glucose deprivation and 24 h reoxygenation (4-OGD/24-REOX). Sexed hippocampal neurons were treated either with vehicle control (VC) or the TrkB agonist 7,8-dihydroxyflavone (7,8-DHF) following in vitro ischemia. End points at 24 h REOX were TrkB phosphorylation (p-TrkB) and neuronal survival assessed by immunohistochemistry. In addition, in vitro ischemia-mediated ERα gene expression in hippocampal neurons were investigated following testosterone (T) pre-treatment and TrkB antagonist therapy via q-RTPCR. Multifactorial analysis of variance was conducted to test for significant differences between experimental conditions. Results: Under normoxic conditions, administration of 3 µM 7,8-DHF resulted an ERα-dependent increase in p-TrkB immunoexpression that was higher in female, as compared to male neurons. Following 4-OGD/24-REOX, p-TrkB expression increased 20% in both male and female ERα+/+ neurons. However, with 3 µM 7,8-DHF treatment p-TrkB expression increased further in female neurons by 2.81 ± 0.79-fold and was ERα dependent. 4-OGD/24-REOX resulted in a 56% increase in cell death, but only female cells were rescued with 3 µM 7,8-DHF, again in an ERα dependent manner. Following 4-OGD/3-REOX, ERα mRNA increased ~ 3 fold in female neurons. This increase was blocked with either the TrkB antagonist ANA-12 or pre-treatment with T. Pre-treatment with T also blocked the 7,8-DHF- dependent sex-specific neuronal survival in female neurons following 4-OGD/24-REOX. Conclusions: OGD/REOX results in sex-dependent TrkB phosphorylation in female neurons that increases further with 7,8-DHF treatment. TrkB phosphorylation by 7,8-DHF increased ERα mRNA expression and promoted cell survival preferentially in female hippocampal neurons. The sex-dependent neuroprotective actions of 7,8-DHF were blocked by either ANA-12 or by T pre-treatment. These results are consistent with a model for a female-specific neuroprotective pathway in hippocampal neurons in response to hypoxia. The pathway is activated by 7,8-DHF, mediated by TrkB phosphorylation, dependent on ERα and blocked by pre-exposure to T. Plain english summary: In the clinical setting, it is well known that in neonates who suffer brain injury due to lack of blood flow and oxygen to the brain, the resulting damage is less severe in females compared to males. Furthermore, males sustaining brain injuries are more likely to exhibit learning and memory deficits as they mature. However, the underlying cellular mechanisms that lead to these sex differences in brain injury outcomes are poorly understood. In this report, we cultured hippocampal neurons from neonatal female and male mice and subjected them to reduced oxygen and glucose to mimic neonatal hypoxia ischemia. We found that the nerve growth factor receptor TrkB in females, as compared to males, is activated following the insult and more responsive to an exogenous nerve growth factor which leads to cell survival. In addition, expression of the estrogen receptor alpha is increased following the insult in females but not in males. Interestingly, the nerve growth factor receptor response in females is dependent on the presence of the estrogen receptor alpha. Both the nerve growth factor response and the increase in estrogen receptor alpha are abolished in females when treated with the male androgen, testosterone. Thus, our results support a model for a female-specific neuroprotective pathway in hippocampal neurons. The pathway is activated by nerve growth factors, dependent on estrogen receptor alpha, and is likely rendered inoperative in males by exposure to neonatal testosterone. [ABSTRACT FROM AUTHOR]

Background: In the year 2020, breast cancer was the most common form of cancer worldwide. Roughly 70% of breast cancers are estrogen receptor–positive (ER+). MicroRNA-190b (miR-190b) has previously been reported to be upregulated in ER+ breast cancers. Previously, we have demonstrated that miR-190b is hypomethylated in ER+ breast cancers, potentially leading to its upregulation. Objectives: To further study the role of miR-190b in ER+ breast cancer and to identify its clinically relevant targets in breast cancer. Design: Patient cohort and cell line–based RNA-sequencing analysis. Methods: The Cancer Genome Atlas was used to obtain gene expression data and clinical information on patients with breast cancer. To identify messenger RNA (mRNA) targets for miR-190b, the ER+ breast cancer cell line T-47D was used to immunoprecipitate biotin-labeled miR-190b followed by RNA sequencing. Western blot was used to confirm miR-190b target. Patient survival based on miR-190b and selected target was studied using the Cancer Genome Atlas. Results: In this study, we confirm that miR-190b is overexpressed in breast cancer via differential expression analysis and show that high expression of miR-190b results in more favorable outcomes in Luminal A patients, hazard ratio (HR) = 0.29, 95% confidence interval [CI] = 0.12-0.71, P =.0063. MicroRNA-190b target analysis identified RING finger and WD repeat domain 3 (RFWD3) as one of miR-190b regulatory targets in ER+ breast cancer. Survival analysis of RFWD3 showed that elevated levels result in poorer overall survival in patients with Luminal A breast cancer (HR = 2.22, 95% CI = 1.33-3.71, P =.002). Gene ontology analysis of our sequencing results indicates that miR-190b may have a role in breast cancer development and/or tumorigenesis and that it may be a suitable tool in characterization between the ER+ subtypes, Luminal A, and Luminal B. Conclusions: We show that miR-190b targets RFWD3 in ER+ breast cancers leading to lower RFWD3 protein expression. Low levels of RFWD3 are associated with better outcomes in patients with Luminal A breast cancer but not in patients with Luminal B breast cancer. These findings provide novel insights into miR-190b role in breast cancer and that its clinical relevance is subtype specific. Plain Language Summary: MicroRNA-190b targets RFWD3 in ER-positive Breast Cancer Breast cancer is the most common diagnosed type of cancer worldwide. Most of them, or 70%, overexpressed the estrogen receptor (ER) which can be targeted with drugs. MicroRNA-190b (miR-190b) is known to be overexpressed in these types of breast cancers, and we have shown that loss of DNA methylation within the genomic region of miR-190b occurs in these ER+ cancers as well, which potentially is the cause for its overexpression. We, therefore, aimed at understanding miR-190b further. To do so, we used a technique called immunoprecipitation to capture miR-190b targets and performed RNA sequencing to identify potential targets. Of the targets, we identified RFWD3 and performed a western blot to confirm whether it was a true target. Finally, we performed survival analysis using data from the Cancer Genome Atlas to see whether RFWD3 was important for patient prognosis. In summary, we identified RFWD3 to be a target of miR-190b in ER+ breast cancers and that its expression is lower when miR-190b is elevated. We also saw that lower levels of RFWD3 are linked to better outcomes in a subgroup of ER+ breast cancers called Luminal A. These findings help in understanding miR-190b and its role in breast cancer and show that its clinical relevance is subgroup specific. [ABSTRACT FROM AUTHOR]

Introduction: Estrogens are crucial regulators of ovarian function, mediating their signaling through binding to estrogen receptors. The disruption of the estrogen receptor 1 (Esr1) provokes infertility associated with a hemorrhagic, cystic phenotype similar to that seen in diseased or aged ovaries. Our previous study indicated the possibility of altered iron metabolism in Esr1-deficient ovaries showing massive expression of lipocalin 2, a regulator of iron homeostasis. Methods: Therefore, we examined the consequences of depleting Esr1 in mouse ovaries, focusing on iron metabolism. For that reason, we compared ovaries of adult Esr1-deficient animals and age-matched wild type littermates. Results and discussion: We found increased iron accumulation in Esr1-deficient animals by using laser ablation inductively coupled plasma mass spectrometry. Western blot analysis and RT-qPCR confirmed that iron overload alters iron transport, storage and regulation. In addition, trivalent iron deposits in form of hemosiderin were detected in Esr1-deficient ovarian stroma. The depletion of Esr1 was further associated with an aberrant immune cell landscape characterized by the appearance of macrophage-derived multinucleated giant cells (MNGCs) and increased quantities of macrophages, particularly M2-like macrophages. Similar to reproductively aged animals, MNGCs in Esr1-deficient ovaries were characterized by iron accumulation and strong autofluorescence. Finally, deletion of Esr1 led to a significant increase in ovarian mast cells, involved in iron-mediated foam cell formation. Given that these findings are characteristics of ovarian aging, our data suggest that Esr1 deficiency triggers mechanisms similar to those associated with aging. [ABSTRACT FROM AUTHOR]

Breast cancer remains a significant public health concern, necessitating the discovery of novel therapeutic agents. This study investigates the potential of thiourea derivatives, specifically HU, HTMX, and BMPTU compounds, as estrogen receptor alpha (ERα) inhibitors using computational approaches. Drug-likeness assessments using Lipinski's Ro5 confirmed the oral bioavailability of all compounds. Additionally, ADMET analysis indicated favorable pharmacokinetic properties, with minimal metabolic interactions and acceptable safety profiles, except for BMPTU2, which showed potential hepatotoxicity. Molecular docking simulations revealed strong binding affinities between BMPTU derivatives, particularly BMPTU2, BMPTU3, and BMPTU4, and key ERα residues. These interactions suggest their potential as ERα modulators, warranting further in silico and experimental validation. In conclusion, the findings highlight the potential of BMPTU derivatives, especially BMPTU2, BMPTU3, and BMPTU4, as promising lead compounds for developing novel ERα-targeted breast cancer therapies. Further optimization and validation are crucial to fully elucidate their therapeutic potential.

The development of oestrogen positive feedback is a hallmark of female puberty. Both oestrogen and progesterone signalling are required for the functioning of this neuroendocrine feedback loop but the physiological changes that underlie the emergence of positive feedback remain unknown. Only after puberty does oestradiol (E2) facilitate progesterone synthesis in the rat female hypothalamus (neuroP), an event critical for positive feedback and the LH surge. We hypothesize that prior to puberty, these astrocytes have low levels of membrane oestrogen receptor alpha (ERα), which is needed for facilitation of neuroP synthesis. Thus, we hypothesized that prepubertal astrocytes are unable to respond to E2 with increased neuroP synthesis due a lack of membrane ERα. To test this, hypothalamic tissues and enriched primary hypothalamic astrocyte cultures were acquired from prepubertal (postnatal week 3) and post-pubertal (week 8) female mice. E2-facilitated neuroP was measured in the hypothalamus pre- and post-puberty, and hypothalamic astrocyte responses were measured after treatment with E2. Prior to puberty, E2-facilitated neuroP synthesis did not occur in the hypothalamus, and mERα expression was low in hypothalamic astrocytes, but E2-facilitated neuroP synthesis in the rostral hypothalamus and mERα expression increased post-puberty. The increase in mERα expression in hypothalamic astrocytes corresponded with a post-pubertal increase in caveolin-1 protein, PKA phosphorylation, and a more rapid [Ca2+ ]i flux in response to E2. Together, results from the present study indicate that E2-facilitated neuroP synthesis occurs in the rostral hypothalamus, develops during puberty, and corresponds to a post-pubertal increase in mERα levels in hypothalamic astrocytes.

Problem: Reproductive performance of animals gets affected by nutritional restrictions which act as potential stressors leading to hormonal imbalance and testicular inflammation, the major causes of infertility. Withania somnifera (WS), well‐known traditional medicinal plant, has been used as antistress and infertility treatment. Therefore, the present study looks into the ameliorative effects of WS on the reproductive and immune system of male Coturnix coturnix japonica in stressed conditions like water and food restriction focussing on the modulation in estrogen receptor alpha (ERα). Method of study: Biochemical estimations for oxidative stress, histological alterations, immuno‐fluorescent localization of ERα, interleukin (IL)‐1β, IL‐4, and interferon gamma (IFN‐γ) in testicular cells were performed. Results: Nutritional restriction declines endogenous estradiol, ERα in testicular cells while it elevates corticosterone leading to oxidative stress in testis thereby reducing fertility by decrease in sperm. Results indicate significant reversal in all the parameters after the administration of WS by improving testicular cell morphology, increased superoxide and catalase activity thus reducing oxidative stress. WS increases spermatogenesis and enhances expression of ERα in testicular cells in quail. Further, WS increases IL‐4, decreases IL‐1β and IFN‐γ expression in testis, thereby improving immune profile contrary to stressed conditions. Conclusion: WS stimulates HPG‐axis even after stress resulting in increased endogenous estradiol which stimulates the expression of ERα in testis; increases sperm count and immunity thereby improving the reproductive performance. WS may be the best therapy against nutritional‐restriction stress induced reproductive toxicity by reducing oxidative stress mediated inflammatory response via increased testicular expression of ERα in quail. [ABSTRACT FROM AUTHOR]

Breast cancer is the most commonly diagnosed cancer globally, with the highest incidence of breast cancer occurring in Asian countries including Indonesia. Among the types of breast cancer, the estrogen receptor (ER)-positive subtype which is prominent with estrogen receptor alpha (ERα) and heat shock protein 90 (HSP90) overexpression genes becomes the most prevalent than the others, approximately 75% of all breast cancer cases. ERα and HSP90 play a role in breast cancer activities including breast tumor growth, invasion, and metastasis mechanism. Propolis, a natural bee product, has been explored for its anticancer activity. However, there is lack of studies that evaluated the potential inhibitor from propolis compounds to the ERα and HSP90 proteins. Therefore, this article focuses on examining the correlation between ERα and HSP90's role in breast cancer and investigating the potential of 93 unique propolis compositions in inhibiting these genes in breast cancer using in silico approaches. This study revealed the positive correlation between ERα and HSP90 genes in breast cancer disease development. Furthermore, we also found novel potential bioactive compounds of propolis against breast cancer through binding with ERα and HSP90; they were 3',4',7-trihydroxyisoflavone and baicalein-7-O-β-D glucopyranoside, respectively. Further research on these compounds is needed to elucidate deeper mechanisms and activity in the real biological system to develop new breast cancer drug treatments. [ABSTRACT FROM AUTHOR]

Head and neck squamous cell carcinoma (HNSCC) is associated with high morbidity and mortality. New personalized treatment strategies represent an unmet medical need to improve the overall survival and the quality of life of patients, which are often limited by the toxicity of established multimodal treatment protocols. Several studies have reported an increased expression of the estrogen receptor 1 (ESR1) in HNSCC, but its potential role in the disease outcome of these tumors remains elusive. Using an integrative analysis of multiomics and clinical data from The Cancer Genome Atlas (TCGA)-HNSC, we established a prognostic risk model based on an ESR1-related 25-gene set. The prognostic value was confirmed in an independent cohort of HNSCC and other solid tumors from TCGA. Finally, we performed in silico drug sensitivity modeling to explore potential vulnerabilities for both risk groups. This approach predicted a higher sensitivity for HNSCC, with prominent ESR1 pathway activity under treatment with specific estrogen receptor modulators. In conclusion, our data confirm the involvement of ESR1-related pathway activity in the progression of a defined subset of HNSCC, provide compelling evidence that these tumors share a specific vulnerability to endocrine therapy, and pave the way for preclinical studies and clinical trials to demonstrate the efficacy of this new therapeutic option. [ABSTRACT FROM AUTHOR]

In the skin, estradiol (E2) promotes profibrotic and proinflammatory cytokines, contributing to extracellular matrix (ECM) deposition. However, the magnitude of the response differs. Using the human skin organ culture model, we evaluated donor characteristics and correlations that contribute to E2-induced interleukin-6 (IL-6), transforming growth factor beta 1 and 2 (TGFB1 and TGFB2), collagen IA2 (Col IA2), collagen IIIA1 (Col IIIA1), and fibronectin (FN) expressions. In vehicle- and E2-treated dermal skin tissue transcripts, we confirm differences in the magnitude; however, there were positive correlations between profibrotic mediators and ECM components 48 h after E2 treatment. Also, positive correlations exist between baseline and E2-induced TGFB1, IL-6, Col IIIA1, and FN transcripts. Since estrogen receptor alpha (ERA) can propagate E2′s signal, we measured and detected differences in its baseline and fold change transcript levels, with a significant decline in baseline levels 48 h after incubation and an increase 48 h after E2 treatment. There was a trend to higher transcript levels in African American donors 24 h earlier. Finally, E2-induced ERA transcript levels negatively correlated with its own baseline levels and positively correlated with FN, TGFB1, and Col IA2 transcript levels. Therefore, our data suggest ERA, E2 exposure time, and race/ethnicity contribute to E2-induced dermal fibrosis. [ABSTRACT FROM AUTHOR]

Simple Summary: Most women diagnosed with breast cancer (BC) have estrogen receptor-alpha positive (ER+) disease. The current mouse models of ER+ BC often rely on supplemented estrogen to encourage metastasis, which modifies the immune system and the function of some tissues (like bone), or use genetically modified or immunocompromised mouse strains, which do not accurately replicate the clinical disease. We developed a mouse model of triple-negative (TN) breast cancer with virally transduced ER expression that metastasizes spontaneously without exogenous estrogen stimulation and is responsive to antiestrogen drugs. Our mouse model exhibited upregulated ER-responsive genes and multi-organ metastasis without exogenous estrogen administration. Following antiestrogen treatment (tamoxifen, ICI 182,780, or vehicle control), tumor volumes and weights were significantly decreased, exemplifying antiestrogen responsivity. This tumor model, which expresses the estrogen receptor, metastasizes spontaneously, and responds to antiestrogen treatment, will allow for further investigation into the biology and potential treatment of metastasis. Most women diagnosed with breast cancer (BC) have estrogen receptor alpha-positive (ER+) disease. The current mouse models of ER+ BC often rely on exogenous estrogen to encourage metastasis, which modifies the immune system and the function of some tissues like bone. Other studies use genetically modified or immunocompromised mouse strains, which do not accurately replicate the clinical disease. To create a model of antiestrogen responsive BC with spontaneous metastasis, we developed a mouse model of 4T1.2 triple-negative (TN) breast cancer with virally transduced ER expression that metastasizes spontaneously without exogenous estrogen stimulation and is responsive to antiestrogen drugs. Our mouse model exhibited upregulated ER-responsive genes and multi-organ metastasis without exogenous estrogen administration. Additionally, we developed a second TN BC cell line, E0771/bone, to express ER, and while it expressed ER-responsive genes, it lacked spontaneous metastasis to clinically important tissues. Following antiestrogen treatment (tamoxifen, ICI 182,780, or vehicle control), 4T1.2- and E0771/bone-derived tumor volumes and weights were significantly decreased, exemplifying antiestrogen responsivity in both cell lines. This 4T1.2 tumor model, which expresses the estrogen receptor, metastasizes spontaneously, and responds to antiestrogen treatment, will allow for further investigation into the biology and potential treatment of metastasis. [ABSTRACT FROM AUTHOR]

This article discusses a study on DNA methylation changes in hormone-responsive breast cancer cells. The researchers inhibited two proteins, ERα and DOT1L, and analyzed the resulting DNA methylation patterns using bioinformatics and functional annotation analyses. They found that the differentially methylated CpGs were mainly located in gene promoters and enhancers, and these changes were associated with estrogen response gene pathways. The study provides valuable data for future research on the role of DNA methylation in breast cancer. The article also includes information about funding sources, conflicts of interest, and references to other relevant articles. [Extracted from the article]

Introduction: The molecular mapping of cancers by the Cancer Genome Atlas Project has accelerated the quest for new therapeutic targets for urinary bladder cancer, including sex steroid receptors. Previous studies have demonstrated conflicting results on their relationship with bladder cancer, and there is sparse data on their expression in the Indian population. The aim of our study is to examine the expression of androgen receptors (AR) and estrogen receptors (ERα and ERβ) in patients with bladder cancer and their correlation with clinicopathologic features. Materials and methods: In this retrospective cohort study, a total of 132 patients, who were surgically managed for urinary bladder mass by transurethral resection or radical cystectomy in our institute, with transitional cell carcinoma on histopathology and with at least two years of follow-up were included. Their demographic and treatment details were obtained, histopathology blocks were retrieved and immunohistochemical staining for androgen and estrogen receptors was performed. Then, the relationship between their expression and clinicopathologic features was studied. Results: A total of 3.79% of patients showed estrogen receptor alpha positivity, 51.52% estrogen receptor beta positivity and 63.64% androgen receptor positivity. No statistically significant correlation was found between age of patients (p = 0.75/0.52/0.87), tumour stage and grade (0.71/0.3/0.21), pathological variant (p = 1/0.58/0.38) and overall survival (p = 0.70/0.052/0.45 for NMIBC and p = 0.82/0.36/0.22) and estrogen receptor alpha, estrogen receptor beta and androgen receptor-positive status, respectively. Estrogen receptor beta positivity was significantly higher in patients with unifocal (p = 0.015) and small tumours (< 5 cm) (p = 0.03), and its expression was associated with better disease-free survival (DFS) (p = 0.046) in patients of non-muscle invasive bladder cancer (NMIBC). Conclusion: Our study has the largest sample size conducted on Indian population with results differing from previous studies conducted on western population. Estrogen receptor beta expression was significantly associated with small unifocal tumours and better DFS. Estrogen receptor alpha and androgen receptor expression were not found to be associated with the clinicopathologic features of the study population. [ABSTRACT FROM AUTHOR]

This study investigated the effects of estrogen and estrogen receptor alpha (ERα) on the pathogenesis of primary biliary cholangitis (PBC) in human intrahepatic bile duct epithelial cells (HiBECs). The researchers measured serum levels of ERα, oxidative stress indicators, and cytokines in PBC patients and healthy controls. They examined the expression of ERα, pyruvate dehydrogenase complex E2‐component (PDC‐E2), and apoptosis‐related proteins in the small bile ducts. In vitro experiments with HiBECs showed that estrogen had a dual effect on cell viability, increasing it at low concentrations but reducing it at higher concentrations. ERα activation led to mitochondrial damage, apoptosis, and upregulation of ERα and PDC‐E2 expression. These findings suggest that the high expression of ERα in the bile ducts contributes to mitochondrial damage, inflammation, and apoptosis in PBC. The study highlights ERα as a potential target for understanding and treating estrogen‐mediated PBC pathogenesis. [ABSTRACT FROM AUTHOR]

BACKGROUND: Menopausal hormone therapy (MHT) is recommended for only five years to treat vasomotor symptoms and vulvovaginal atrophy because of safety concerns with long-term treatment. We investigated the ability of 2,3,4-trihydroxychalcone (2,3,4-THC) to modulate estrogen receptor (ER)-mediated responses in order to find drug candidates that could potentially prevent the adverse effects of long-term MHT treatment. METHODS: Transfection assays, real time-polymerase chain reaction, and microarrays were used to evaluate the effects of 2,3,4-THC on gene regulation. Radioligand binding studies were used to determine if 2,3,4-THC binds to ERα. Cell proliferation was examined in MCF-7 breast cancer cells by using growth curves and flow cytometry. Western blots were used to determine if 2,3,4-THC alters the E2 activation of the MAPK pathway and degradation of ERα. Chromatin immunoprecipitation was used to measure ERα binding to genes. RESULTS: The 2,3,4-THC/E2 combination produced a synergistic activation with ERα on reporter and endogenous genes in human U2OS osteosarcoma cells. Microarrays identified 824 genes that we termed reprogrammed genes because they were not regulated in U2OS-ERα cells unless they were treated with 2,3,4-THC and E2 at the same time. 2,3,4-THC blocked the proliferation of MCF-7 cells by preventing the E2-induced activation of MAPK and c-MYC transcription. The antiproliferative mechanism of 2,3,4-THC differs from selective estrogen receptor modulators (SERMs) because 2,3,4-THC did not bind to the E2 binding site in ERα like SERMs. CONCLUSION: Our study suggests that 2,3,4-THC may represent a new class of ERα modulators that do not act as a direct agonists or antagonists. We consider 2,3,4-THC to be a reprogramming compound, since it alters the activity of ERα on gene regulation and cell proliferation without competing with E2 for binding to ERα. The addition of a reprogramming drug to estrogens in MHT may offer a new strategy to overcome the adverse proliferative effects of estrogen in MHT by reprogramming ERα as opposed to an antagonist mechanism that involves blocking the binding of estrogen to ERα.

Selective estrogen receptor modulators (SERMs) act as estrogen receptor (ER) agonists or antagonists in a tissue-specific manner. ERs exert effects via nuclear actions but can also utilize membrane-initiated signaling pathways. To determine if membrane-initiated ERα (mERα) signaling affects SERM action in a tissue-specific manner, C451A mice, lacking mERα signaling due to a mutation at palmitoylation site C451, were treated with Lasofoxifene (Las), Bazedoxifene (Bza), or estradiol (E2), and various tissues were evaluated. Las and Bza treatment increased uterine weight to a similar extent in C451A and control mice, demonstrating mERα-independent uterine SERM effects, while the E2 effect on the uterus was predominantly mERα-dependent. Las and Bza treatment increased both trabecular and cortical bone mass in controls to a similar degree as E2, while both SERM and E2 treatment effects were absent in C451A mice. This demonstrates that SERM effects, similar to E2 effects, in the skeleton are mERα-dependent. Both Las and E2 treatment decreased thymus weight in controls, while neither treatment affected the thymus in C451A mice, demonstrating mERα-dependent SERM and E2 effects in this tissue. Interestingly, both SERM and E2 treatments decreased the total body fat percent in C451A mice, demonstrating the ability of these treatments to affect fat tissue in the absence of functional mERα signaling. In conclusion, mERα signaling can modulate SERM responses in a tissue-specific manner. This novel knowledge increases the understanding of the mechanisms behind SERM effects and may thereby facilitate the development of new improved SERMs.

Abstract Background Ras-GTPase-activating protein binding protein 1 (G3BP1) is an oncogenic factor, which highly expressed in a variety of cancers. In recent years, G3BP1 has been reported to promote the development of prostate cancer by inhibiting the degradation of AR through inhibiting SPOP. However, whether G3BP1 contributes in a similar manner to the abnormal accumulation of ERα, which is also an important target for hormone therapy, remains unknown. This article addresses this issue and explores potential mechanisms. Methods Bioinformatics tools were used for G3BP1 expression analysis, survival analysis, and clinical association analysis. Immunohistochemical staining was used to examine the correlation between G3BP1 and ERα in EC patients. In addition, western blot and co-immunoprecipitation were used to detect the half-life of G3BP1 and mutant, and the effect of G3BP1 and mutant on the ubiquitination and degradation of ERα mediated by SPOP. Then, the oncogenic functions of G3BP1 dependent on the SPOP/ERα axis were determined by CCK8 cell proliferation assay, colony formation assay and cell migration assay. Finally, we established the EC cells treated or untreated with fulvestrant, exploring the possibility of fulvestrant combined with the reduction of G3BP1 to improve the efficacy of fulvestrant. Results G3BP1 is abnormally high expressed and characterized by high-frequency mutation in EC. In addition, there is a positive correlation between G3BP1 protein and ERα protein. Mechanistically, both G3BP1 and mutant, the latter is displaying the longer half-life, competitively bind SPOP with ERα, thereby inhibiting SPOP-mediated ubiquitination and degradation of ERα. Functionally, G3BP1 and mutant promote the proliferation and migration of EC cells by regulating the G3BP1/SPOP/ERα axis. However, fulvestrant can reverse the cancer-promoting effects of G3BP1 and mutant. Conclusions G3BP1 and its mutant positively regulate ERα signaling pathway by inhibiting SPOP-mediated ubiquitination and degradation of ERα, indicating the promising effect of fulvestrant on the suppression the occurrence and development of EC with high expressed G3BP1 and G3BP1 mutants. Video Abstract

Abstract Background Cancer cells may develop resistance to cisplatin by various mechanisms. Yet, the exact mechanism of cisplatin in ovarian cancer remains unclear. Recent studies have shown that 3’-phospoadenosine 5’-phosphosulfate synthase 1 (PAPSS1) inhibition combined with low-dose cisplatin increases DNA damage. The aim of this study was to determine the value of targeting PAPSS1 as a cisplatin modulator in epithelial ovarian cancer (EOC). Results Increased expression of PAPSS1 was observed in both EOC cells and tissues. Also, its higher nuclear expression was distinctly associated with FIGO (The International Federation of Gynecology and Obstetrics) stage, histological subtype, metastasis, and recurrence. Down-regulation of the PAPSS1 gene increased the cisplatin sensitivity of EOC in vitro and in vivo. Expression of PAPSS1 was negatively correlated with estrogen receptor α (ERα) in EOC. Also, low nuclear PAPSS1 and high nuclear ERα expression in EOC were associated with longer overall survival and progression-free survival in all ovarian cancer and ovarian cancer patients who received platinum-based chemotherapy. PAPSS1 silencing increased the activity of ERα-signaling in EOC cells, thus sensitizing tumors to cisplatin. Conclusions These findings characterize a novel interplay between PAPSS1-mediated sulfation and ERα-signaling in EOC cisplatin resistance. PAPSS1 may be exploited as a cisplatin-sensitizing therapeutic target.

The role of central estrogen in cognitive, metabolic, and reproductive health has long fascinated the lay public and scientists alike. In the last two decades, insight into estrogen signaling in the brain and its impact on female physiology is beginning to catch up with the vast information already established for its actions on peripheral tissues. Using newer methods to manipulate estrogen signaling in hormone-sensitive brain regions, neuroscientists are now identifying the molecular pathways and neuronal subtypes required for controlling sex-dependent energy allocation. However, the immense cellular complexity of these hormone-sensitive brain regions makes it clear that more research is needed to fully appreciate how estrogen modulates neural circuits to regulate physiological and behavioral end points. Such insight is essential for understanding how natural or drug-induced hormone fluctuations across lifespan affect women's health.

Extensive knowledge has been gained on the transcription network controlled by ERα, however, the mechanism underlying ESR1 (encoding ERα) expression is less understood. We recently discovered that the Hippo pathway is required for the proper expression of ESR1. YAP/TAZ are transcription coactivators that are phosphorylated and inhibited by the Hippo pathway kinase LATS. Here we delineated the molecular mechanisms underlying ESR1 transcription repression by the Hippo pathway. Mechanistically, YAP binds to TEAD to increase local chromatin accessibility to stimulate transcription of nearby genes. Among the YAP target genes, Vestigial-Like Protein 3 (VGLL3) competes with YAP/TAZ for binding to TEAD transcription factor and recruits the NCOR2/SMRT repressor to the super-enhancer of ESR1 gene, leading to epigenetic alteration and transcriptional silencing. We developed a potent LATS inhibitor VT02956. Targeting the Hippo pathway by VT02956 represses ESR1 expression and inhibits the growth of ER+ breast cancer cells as well as patient-derived tumour organoids. Moreover, histone deacetylase inhibitors, such as Entinostat, induce VGLL3 expression to inhibit ER+ breast cancer cells. Our study suggests LATS as unexpected cancer therapeutic targets, especially for endocrine-resistant breast cancers.

Genomic analysis has recently identified multiple ESR1 gene translocations in estrogen receptor alpha-positive (ERα+) metastatic breast cancer (MBC) that encode chimeric proteins whereby the ESR1 ligand binding domain (LBD) is replaced by C-terminal sequences from many different gene partners. Here we functionally screened 15 ESR1 fusions and identified 10 that promoted estradiol-independent cell growth, motility, invasion, epithelial-to-mesenchymal transition, and resistance to fulvestrant. RNA sequencing identified a gene expression pattern specific to functionally active ESR1 gene fusions that was subsequently reduced to a diagnostic 24-gene signature. This signature was further examined in 20 ERα+ patient-derived xenografts and in 55 ERα+ MBC samples. The 24-gene signature successfully identified cases harboring ESR1 gene fusions and also accurately diagnosed the presence of activating ESR1 LBD point mutations. Therefore, the 24-gene signature represents an efficient approach to screening samples for the presence of diverse somatic ESR1 mutations and translocations that drive endocrine treatment failure in MBC. SIGNIFICANCE: This study identifies a gene signature diagnostic for functional ESR1 fusions that drive poor outcome in advanced breast cancer, which could also help guide precision medicine approaches in patients harboring ESR1 mutations.

This work examined the potential benefit of curcumin in breast cancer patients as a supplementary drug in ER-positive cancers. The results indicated that in the MCF-7 human breast cancer cell line, E2 and curcumin decreased cell proliferation and the colony-forming capacity and down-regulated protein expression as well as important molecules associated with cell proliferation, such as PCNA and estrogen receptor alpha; genes associated with the epithelial-mesenchymal transition, such as β-catenin, Vimentin, and E-cadherin; and molecules associated with apoptosis. Clinical studies in bioinformatics have indicated a positive correlation between ESR1 and either CCND1 or BCL2 gene expression in all breast cancer patients. Thus, curcumin could become a potential natural adjuvant treatment for patients with estrogen receptor alpha-positive breast cancer and those with resistance or a poor response to endocrine therapy since the reactivation of estrogen receptor alpha is inevitable.

Oestrogen depletion in rodents and humans leads to inactivity, fat accumulation and diabetes1,2, underscoring the conserved metabolic benefits of oestrogen that inevitably decrease with age. In rodents, the preovulatory surge in 17β-oestradiol (E2) temporarily increases energy expenditure to coordinate increased physical activity with peak sexual receptivity. Here we report that a subset of oestrogen-sensitive neurons in the ventrolateral ventromedial hypothalamic nucleus (VMHvl)3-7 projects to arousal centres in the hippocampus and hindbrain, and enables oestrogen to rebalance energy allocation in female mice. Surges in E2 increase melanocortin-4 receptor (MC4R) signalling in these VMHvl neurons by directly recruiting oestrogen receptor-α (ERα) to the Mc4r gene. Sedentary behaviour and obesity in oestrogen-depleted female mice were reversed after chemogenetic stimulation of VMHvl neurons expressing both MC4R and ERα. Similarly, a long-term increase in physical activity is observed after CRISPR-mediated activation of this node. These data extend the effect of MC4R signalling - the most common cause of monogenic human obesity8 - beyond the regulation of food intake and rationalize reported sex differences in melanocortin signalling, including greater disease severity of MC4R insufficiency in women9. This hormone-dependent node illuminates the power of oestrogen during the reproductive cycle in motivating behaviour and maintaining an active lifestyle in women.

ObjectivesTumor HPV status is an established independent prognostic marker for oropharynx cancer (OPC). Recent studies have reported that tumor estrogen receptor alpha (ERα) positivity is also associated with prognosis independent of HPV. Little is known about the biologic and behavioral predictors of ERα positivity in head and neck squamous cell cancer (HNSCC). We therefore explored this in a multicenter prospective cohort study.Materials and methodsParticipants with HNSCC completed a survey and provided a blood sample. Tumor samples were tested for ERα using immunohistochemistry. ERα positivity was defined as ≥1%, standardized by the American Society of Clinical Oncology/College of American Pathologists in breast cancer. Characteristics were compared with χ2 and Fisher's exact test. Odds ratios (OR) were calculated using logistic regression.ResultsOf 318 patients with HNSCC, one third had ERα positive tumors (36.2%, n = 115). Odds of ERα expression were significantly increased in those with HPV-positive tumors (OR = 27.5, 95% confidence interval[CI] 12.1-62), smaller tumors (≤T2, OR = 3.6, 95% CI 1.9-7.1), male sex (OR = 2.0, 95% CI 1.1-3.6), overweight/obesity (BMI ≥ 25, OR = 1.9, 95% CI 1.1-3.3), and those married/living with a partner (OR = 1.7, 95% CI 1.0-3.0). In a multivariate model, HPV-positivity (aOR = 27.5, 95% CI 11.4-66) and small tumor size (≤T2, aOR = 2.2, 95% CI 1.0-4.8) remained independently associated with ERα status. When restricted to OPC (n = 180), tumor HPV status (aOR = 17.1, 95% CI 2.1-137) and small tumor size (≤T2, aOR = 4.0 95% CI 1.4-11.3) remained independently associated with ERα expression.ConclusionTumor HPV status and small tumor size are independently associated with ERα expression in HNSCC.

Estrogen receptor α (ERα) is a hormone receptor and key driver for over 70% of breast cancers that has been studied for decades as a transcription factor. Unexpectedly, we discover that ERα is a potent non-canonical RNA-binding protein. We show that ERα RNA binding function is uncoupled from its activity to bind DNA and critical for breast cancer progression. Employing genome-wide cross-linking immunoprecipitation (CLIP) sequencing and a functional CRISPRi screen, we find that ERα-associated mRNAs sustain cancer cell fitness and elicit cellular responses to stress. Mechanistically, ERα controls different steps of RNA metabolism. In particular, we demonstrate that ERα RNA binding mediates alternative splicing of XBP1 and translation of the eIF4G2 and MCL1 mRNAs, which facilitates survival upon stress conditions and sustains tamoxifen resistance of cancer cells. ERα is therefore a multifaceted RNA-binding protein, and this activity transforms our knowledge of post-transcriptional regulation underlying cancer development and drug response.

Abstract Background About one-third of patients with estrogen receptor alpha (ERα)-positive breast cancer have tumors which are progesterone receptor (PR) negative. PR is an important prognostic factor in breast cancer. Patients with ERα-positive/PR-negative tumors have shorter disease-free and overall survival than patients with ERα-positive/PR-positive tumors. New evidence has shown that progesterone (P4) has an anti-proliferative effect in ERα-positive breast cancer cells. However, the role of PR in breast cancer is only poorly understood. Methods We disrupted the PR gene (PGR) in ERα-positive/PR-positive T-47D cells using the CRISPR/Cas9 system. This resulted in cell pools we termed PR-low as P4 mediated effects were inhibited or blocked compared to control T-47D cells. We analyzed the gene expression profiles of PR-low and control T-47D cells in the absence of hormone and upon treatment with P4 alone or P4 together with estradiol (E2). Differentially expressed (DE) genes between experimental groups were characterized based on RNA-seq and Gene Ontology (GO) enrichment analyses. Results The overall gene expression pattern was very similar between untreated PR-low and untreated control T-47D cells. More than 6000 genes were DE in control T-47D cells upon stimulation with P4 or P4 plus E2. When PR-low pools were subjected to the same hormonal treatment, up- or downregulation was either blocked/absent or consistently lower. We identified more than 3000 genes that were DE between hormone-treated PR-low and control T-47D cells. GO analysis revealed seven significantly enriched biological processes affected by PR and associated with G protein-coupled receptor (GPCR) pathways which have been described to support growth, invasiveness, and metastasis in breast cancer cells. Conclusions The present study provides new insights into the complex role of PR in ERα-positive/PR-positive breast cancer cells. Many of the genes affected by PR are part of central biological processes of tumorigenesis.

IntroductionEstrogens are crucial regulators of ovarian function, mediating their signaling through binding to estrogen receptors. The disruption of the estrogen receptor 1 (Esr1) provokes infertility associated with a hemorrhagic, cystic phenotype similar to that seen in diseased or aged ovaries. Our previous study indicated the possibility of altered iron metabolism in Esr1-deficient ovaries showing massive expression of lipocalin 2, a regulator of iron homeostasis.MethodsTherefore, we examined the consequences of depleting Esr1 in mouse ovaries, focusing on iron metabolism. For that reason, we compared ovaries of adult Esr1-deficient animals and age-matched wild type littermates. Results and discussionWe found increased iron accumulation in Esr1-deficient animals by using laser ablation inductively coupled plasma mass spectrometry. Western blot analysis and RT-qPCR confirmed that iron overload alters iron transport, storage and regulation. In addition, trivalent iron deposits in form of hemosiderin were detected in Esr1-deficient ovarian stroma. The depletion of Esr1 was further associated with an aberrant immune cell landscape characterized by the appearance of macrophage-derived multinucleated giant cells (MNGCs) and increased quantities of macrophages, particularly M2-like macrophages. Similar to reproductively aged animals, MNGCs in Esr1-deficient ovaries were characterized by iron accumulation and strong autofluorescence. Finally, deletion of Esr1 led to a significant increase in ovarian mast cells, involved in iron-mediated foam cell formation. Given that these findings are characteristics of ovarian aging, our data suggest that Esr1 deficiency triggers mechanisms similar to those associated with aging.

In this study we present an inducible biosensor model for the Estrogen Receptor Beta (ERβ), GFP-ERβ:PRL-HeLa, a single-cell-based high throughput (HT) in vitro assay that allows direct visualization and measurement of GFP-tagged ERβ binding to ER-specific DNA response elements (EREs), ERβ-induced chromatin remodeling, and monitor transcriptional alterations via mRNA fluorescence in situ hybridization for a prolactin (PRL)-dsRED2 reporter gene. The model was used to accurately (Z’ = 0.58–0.8) differentiate ERβ-selective ligands from ERα ligands when treated with a panel of selective agonists and antagonists. Next, we tested an Environmental Protection Agency (EPA)-provided set of 45 estrogenic reference chemicals with known ERα in vivo activity and identified several that activated ERβ as well, with varying sensitivity, including a subset that is completely novel. We then used an orthogonal ERE-containing transgenic zebrafish (ZF) model to cross validate ERβ and ERα selective activities at the organism level. Using this environmentally relevant ZF assay, some compounds were confirmed to have ERβ activity, validating the GFP-ERβ:PRL-HeLa assay as a screening tool for potential ERβ active endocrine disruptors (EDCs). These data demonstrate the value of sensitive multiplex mechanistic data gathered by the GFP-ERβ:PRL-HeLa assay coupled with an orthogonal zebrafish model to rapidly identify environmentally relevant ERβ EDCs and improve upon currently available screening tools for this understudied nuclear receptor.

Pituitary neuroendocrine tumors (PitNETs) are divided into multiple histological subtypes, which determine their clinical and biological variable behavior. Despite their benign evolution, in some cases, prolactin (PRL) and growth hormone (GH)-secreting PitNETs may have aggressive behavior. In this study, we investigated the potential predictive role of ER∝, alongside the clinicopathological classification of PitNETs (tumor diameter, tumor type, and tumor grade). A retrospective study was conducted with 32 consecutive cases of PRL- and mixed GH- and PRL-secreting PitNETs (5 patients with prolactinomas and 27 with acromegaly, among them, 7 patients with GH- and PRL- co-secretion) who underwent transsphenoidal intervention. Tumor specimens were histologically and immunohistochemical examined: anterior pituitary hormones, ki-67 labeling index, CAM 5.2, and ER∝; ER∝ expression was correlated with basal PRL levels at diagnosis (rho = 0.60, p < 0.01) and postoperative PRL levels (rho = 0.58, p < 0.001). In our study, the ER∝ intensity score was lower in female patients. Postoperative maximal tumor diameter correlated with Knosp grade (p = 0.02); CAM 5.2 pattern (densely/sparsely granulated/mixed densely and sparsely granulated) was correlated with postoperative PRL level (p = 0.002), and with ki-67 (p < 0.001). The IGF1 level at diagnosis was correlated with the postoperative GH nadir value in the oral glucose tolerance test (OGTT) (rho = 0.52, p < 0.05). Also, basal PRL level at diagnosis was correlated with postoperative tumor diameter (p = 0.63, p < 0.001). At univariate logistic regression, GH nadir in OGTT test at diagnostic, IGF1, gender, and invasion were independent predictors of remission for mixed GH- and PRL-secreting Pit-NETs; ER∝ can be used as a prognostic marker and loss of ER∝ expression should be considered a sign of lower differentiation and a likely indicator of poor prognosis. A sex-related difference can be considered in the evolution and prognosis of these tumors, but further studies are needed to confirm this hypothesis. [ABSTRACT FROM AUTHOR]

Simple Summary: Our previous work established that organophosphorus pesticides increased acetylcholine (ACh) levels and promoted mammary gland tumor development in rats. This suggests that ACh could modulate ERα activity. In this study, we demonstrated that ACh has functional effects in breast cancer cell lines—specifically, activating the MAPK/ERK and PI3K/Akt pathways, inducing p-ERα, and eliciting its nuclear translocation. However, ACh did not induce the upregulation of estrogen-responsive genes, suggesting a mechanistic distinction from the effects of 17β-estradiol. Furthermore, ACh enhanced cell viability and induced the overexpression of specific EMT markers. These findings suggest that ACh and muscarinic receptors could be emerging regulators of breast cancer. Acetylcholine (ACh) is a neurotransmitter that regulates multiple functions in the nervous system, and emerging evidence indicates that it could play a role in cancer progression. However, this function is controversial. Previously, we showed that organophosphorus pesticides decreased the levels of the enzyme acetylcholinesterase in vivo, increasing ACh serum levels and the formation of tumors in the mammary glands of rats. Furthermore, we showed that ACh exposure in breast cancer cell lines induced overexpression of estrogen receptor alpha (ERα), a key protein described as the master regulator in breast cancer. Therefore, here, we hypothesize that ACh alters the ERα activity through a ligand-independent mechanism. The results here reveal that the physiological concentration of ACh leads to the release of Ca+2 and the activity of MAPK/ERK and PI3K/Akt pathways. These changes are associated with an induction of p-ERα and its recruitment to the nucleus. However, ACh fails to induce overexpression of estrogen-responsive genes, suggesting a different activation mechanism than that of 17ß-estradiol. Finally, ACh promotes the viability of breast cancer cell lines in an ERα-dependent manner and induces the overexpression of some EMT markers. In summary, our results show that ACh promotes breast cancer cell proliferation and ERα activity, possibly in a ligand-independent manner, suggesting its putative role in breast cancer progression. [ABSTRACT FROM AUTHOR]

Background: Ras-GTPase-activating protein binding protein 1 (G3BP1) is an oncogenic factor, which highly expressed in a variety of cancers. In recent years, G3BP1 has been reported to promote the development of prostate cancer by inhibiting the degradation of AR through inhibiting SPOP. However, whether G3BP1 contributes in a similar manner to the abnormal accumulation of ERα, which is also an important target for hormone therapy, remains unknown. This article addresses this issue and explores potential mechanisms. Methods: Bioinformatics tools were used for G3BP1 expression analysis, survival analysis, and clinical association analysis. Immunohistochemical staining was used to examine the correlation between G3BP1 and ERα in EC patients. In addition, western blot and co-immunoprecipitation were used to detect the half-life of G3BP1 and mutant, and the effect of G3BP1 and mutant on the ubiquitination and degradation of ERα mediated by SPOP. Then, the oncogenic functions of G3BP1 dependent on the SPOP/ERα axis were determined by CCK8 cell proliferation assay, colony formation assay and cell migration assay. Finally, we established the EC cells treated or untreated with fulvestrant, exploring the possibility of fulvestrant combined with the reduction of G3BP1 to improve the efficacy of fulvestrant. Results: G3BP1 is abnormally high expressed and characterized by high-frequency mutation in EC. In addition, there is a positive correlation between G3BP1 protein and ERα protein. Mechanistically, both G3BP1 and mutant, the latter is displaying the longer half-life, competitively bind SPOP with ERα, thereby inhibiting SPOP-mediated ubiquitination and degradation of ERα. Functionally, G3BP1 and mutant promote the proliferation and migration of EC cells by regulating the G3BP1/SPOP/ERα axis. However, fulvestrant can reverse the cancer-promoting effects of G3BP1 and mutant. Conclusions: G3BP1 and its mutant positively regulate ERα signaling pathway by inhibiting SPOP-mediated ubiquitination and degradation of ERα, indicating the promising effect of fulvestrant on the suppression the occurrence and development of EC with high expressed G3BP1 and G3BP1 mutants. 7zf14ZtBi1KWa6qjVt88Zx Video Abstract [ABSTRACT FROM AUTHOR]

Breast cancer is a significant global concern, with tamoxifen, the standard treatment, raising long-term safety issues due to side effects. In this study, we evaluated the potential of five onoceranoid triterpenes from Lansium domesticum Corr. cv. kokosan against estrogen receptor alpha (ERα) using in silico techniques. Utilizing molecular docking, Lipinski's rule of five, in silico ADMET, and molecular dynamics simulations, we assessed the potency of five onoceranoid triterpenes against ERα. Molecular docking indicated competitive binding energies for these triterpenes relative to the active form of tamoxifen (4OHT) and estradiol, an ERα native ligand. Three triterpenes met drug-likeness criteria with favorable ADMET profiles. Notably, 2 demonstrated superior binding affinity in molecular dynamics simulations, outperforming estradiol, closely followed by 3 and 4. Hierarchical clustering on principal components (HCPC) and the spatial distribution of contact surface area (CSA) analyses suggest that these triterpenes, especially 2, may act as antagonist ligands akin to 4OHT. These findings highlight the potential of onoceranoid triterpenes in treating ERα-related breast cancer. [ABSTRACT FROM AUTHOR]

Background: There are many studies which strongly suggest that the pathophysiology of Temporomandibular joint Disorder (TMD) may also be influenced by genetic conditions. The current study was aimed to evaluate the hypothesis that the polymorphism of estrogen receptor genes, estrogen receptor 1 and 2 (ESR1 and ESR2), and the gene Catechol-O-Methyl-Transferase (COMT) could be Predisposing factor for TMD. Methods: In this case-control study, blood sample were taken from 100 TMD diagnosed patients based on Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) and 103 healthy individuals as the control group. Tetra ARMS-PCR method was used to amplify and identify COMT rs4680, ESR1 rs1643821, and ESR2 rs1676303 gene polymorphism. Results: ESR1 genotype AA and GA showed significantly increase probability (OR= 4.80, OR=2.98, respectively) of TMD. ESR2 T/T homozygosity was associated with decreased risk for TMD (OR=0.41). The relationship between COMT and TMD was not statistically significant (p>00.05). The relationship between the severity of TMD and ESR1 was significant (p=0.003). According to the inheritance pattern the COMT and ESR1 gene, in the dominant pattern can be susceptible to TMD and in ESR2 gene, in the recessive pattern can be protective to TMD. Conclusion: It seems that SNPs of ESR1 rs1643821 has a susceptible role and ESR2 rs1676303 has a protective role against TMD. Also, we add evidences that various genotype of COMT rs4680 were not statistically different between case and control, but allele A in the dominant inherence pattern can be susceptible to TMD. [ABSTRACT FROM AUTHOR]