Connections and regulation of the human estrogen receptor

Electrochemical biosensors for early detection of breast cancer

Breast cancer continues to be a significant contributor to global cancer deaths, particularly among women. This highlights the critical role of early detection and treatment in boosting survival rates. While conventional diagnostic methods like mammograms, biopsies, ultrasounds, and MRIs are valuable tools, limitations exist in terms of cost, invasiveness, and the requirement for specialized equipment and trained personnel. Recent shifts towards biosensor technologies offer a promising alternative for monitoring biological processes and providing accurate health diagnostics in a cost-effective, non-invasive manner. These biosensors are particularly advantageous for early detection of primary tumors, metastases, and recurrent diseases, contributing to more effective breast cancer management. The integration of biosensor technology into medical devices has led to the development of low-cost, adaptable, and efficient diagnostic tools. In this framework, electrochemical screening platforms have garnered significant attention due to their selectivity, affordability, and ease of result interpretation. The current review discusses various breast cancer biomarkers and the potential of electrochemical biosensors to revolutionize early cancer detection, making provision for new diagnostic platforms and personalized healthcare solutions.

Drug discovery of N-methyl-pyrazole derivatives as potent selective estrogen receptor degrader (SERD) for the treatment of breast cancer

Nowadays, ERα is considered to be a primary target for the treatment of breast cancer, and selective estrogen receptor degraders (SERDs) are emerging as promising antitumor agents. By analysing ERα-SERDs complexes, the pharmacophore features of SERDs and the crucial protein-ligand interactions were identified. Then, by utilizing the scaffold-hopping and bioisosteres strategy, 23 novel derivatives were designed, synthesized and biologically evaluated. Among these derivatives, A20 exhibited potent ERα binding affinity (IC50 = 24.0 nM), degradation ability (EC50 = 5.3 nM), excellent ER selectivity, and outstanding anti-proliferative effects on MCF-7 cells (IC50 = 0.28 nM). Further biological studies revealed that A20 could degrade ERα through proteasome-mediated pathway, suppress signal transduction of MCF-7 cells, and arrest the cell cycle in G1 phase. Moreover, A20 showed excellent antitumor effect (TGI = 92.98 %, 30 mg kg-1 day-1) in the MCF-7 xenograft model in vivo with good safety and favorable pharmacokinetics (F = 39.6 %), making it a promising candidate for the treatment of breast cancer.

Unraveling the Dynamics of Estrogen and Progesterone Signaling in the Endometrium: An Overview

The endometrium is crucial for the perpetuation of human species. It is a complex and dynamic tissue lining the inner wall of the uterus, regulated throughout a woman's life based on estrogen and progesterone fluctuations. During each menstrual cycle, this multicellular tissue undergoes cyclical changes, including regeneration, differentiation in order to allow egg implantation and embryo development, or shedding of the functional layer in the absence of pregnancy. The biology of the endometrium relies on paracrine interactions between epithelial and stromal cells involving complex signaling pathways that are modulated by the variations of estrogen and progesterone levels across the menstrual cycle. Understanding the complexity of estrogen and progesterone receptor signaling will help elucidate the mechanisms underlying normal reproductive physiology and provide fundamental knowledge contributing to a better understanding of the consequences of hormonal imbalances on gynecological conditions and tumorigenesis. In this narrative review, we delve into the physiology of the endometrium, encompassing the complex signaling pathways of estrogen and progesterone.

Estrogen receptor beta suppresses the androgen receptor oncogenic effects in triple-negative breast cancer

BACKGROUND

Triple-negative breast cancer (TNBC) is an aggressive type of breast cancer associated with poor prognosis and limited treatment options. The androgen receptor (AR) has emerged as a potential therapeutic target for luminal androgen receptor (LAR) TNBC. However, multiple studies have claimed that anti-androgen therapy for AR-positive TNBC only has limited clinical benefits. This study aimed to investigate the role of AR in TNBC and its detailed mechanism.

METHODS

Immunohistochemistry and TNBC tissue sections were applied to investigate AR and nectin cell adhesion molecule 4 (NECTIN4) expression in TNBC tissues. Then, in vitro and in vivo assays were used to explore the function of AR and estrogen receptor beta (ERβ) in TNBC. Chromatin immunoprecipitation sequencing (ChIP-seq), co-immunoprecipitation (co-IP), molecular docking method, and luciferase reporter assay were performed to identify key molecules that affect the function of AR.

RESULTS

Based on the TNBC tissue array analysis, we revealed that ERβ and AR were positive in 21.92% (32/146) and 24.66% (36/146) of 146 TNBC samples, respectively, and about 13.70% (20/146) of TNBC patients were ERβ positive and AR positive. We further demonstrated the pro-tumoral effects of AR on TNBC cells, however, the oncogenic biology was significantly suppressed when ERβ transfection in LAR TNBC cell lines but not in AR-negative TNBC. Mechanistically, we identified that NECTIN4 promoter -42 bp to -28 bp was an AR response element, and that ERβ interacted with AR thus impeding the AR-mediated NECTIN4 transcription which promoted epithelial-mesenchymal transition in tumor progression.

CONCLUSIONS

This study suggests that ERβ functions as a suppressor mediating the effect of AR in TNBC prognosis and cell proliferation. Therefore, our current research facilitates a better understanding of the role and mechanisms of AR in TNBC carcinogenesis.

17β-estradiol biosensors based on different bioreceptors and their applications

17β-Estradiol (E2) is a critical sex steroid hormone, which has significant effects on the endocrine systems of both humans and animals. E2 is also believed to play neurotrophic and neuroprotective roles in the brain. Biosensors present a powerful tool to detect E2 because of their small, efficient, and flexible design. Furthermore, Biosensors can quickly and accurately obtain detection results with only a small sampling amount, which greatly meets the detection of the environment, food safety, medicine safety, and human body. This review focuses on previous studies of biosensors for detecting E2 and divides them into non-biometric sensors, enzyme biosensors, antibody biosensors, and aptamer biosensors according to different bioreceptors. The advantages, disadvantages, and design points of various bioreceptors for E2 detection are analyzed and summarized. Additionally, applications of different bioreceptors of E2 detection are presented and highlight the field of environmental monitoring, food and medicine safety, and disease detection in recent years. Finally, the development of E2 detection by biosensor is prospected.

Hot-Spot Residue-Based Virtual Screening of Novel Selective Estrogen-Receptor Degraders for Breast Cancer Treatment

The estrogen-receptor alfa (ERα) is considered pivotal for breast cancer treatment. Although selective estrogen-receptor degraders (SERDs) have been developed to induce ERα degradation and antagonism, their agonistic effect on the uterine tissue and poor pharmacokinetic properties limit further application of ERα; thus, discovering novel SERDs is necessary. The ligand preferentially interacts with several key residues of the protein (defined as hot-spot residues). Improving the interaction with hot-spot residues of ERα offers a promising avenue for obtaining novel SERDs. In this study, pharmacophore modeling, molecular mechanics/generalized Born surface area (MM/GBSA), and amino-acid mutation were combined to determine several hot-spot residues. Focusing on the interaction with these hot-spot residues, hit fragments A1-A3 and A9 were virtually screened from two fragment libraries. Finally, these hit fragments were linked to generate compounds B1-B3, and their biological activities were evaluated. Remarkably, compound B1 exhibited potent antitumor activity against MCF-7 cells (IC50 = 4.21 nM), favorable ERα binding affinity (Ki = 14.6 nM), and excellent ERα degradative ability (DC50 = 9.7 nM), which indicated its potential to evolve as a promising SERD for breast cancer treatment.

Regulation of mRNA translation by estrogen receptor in breast cancer

Breast cancer is one of the leading causes of cancer-related fatalities and the most often diagnosed malignancy in women globally. Dysregulation of sex hormone signaling pathways mediated by the estrogen receptor (ER) in breast cancer is well characterized. Although ER is known to promote cell growth and survival by altering gene transcription, recent research suggests that its effects in cancers are also mediated through dysregulation of protein synthesis. This implies that ER can coordinately affect gene expression through both translational and transcriptional pathways, leading to the development of malignancy. In this review, we will cover the current understanding of how the ER controls mRNA translation in breast cancer and discuss any potential clinical implications of this phenomenon.

The beneficial effects of tamoxifen on arteries: a key player for cardiovascular health of breast cancer patient

Breast cancer is the most common cancer in women. Over the past few decades, advances in cancer detection and treatment have significantly improved survival rate of breast cancer patients. However, due to the cardiovascular toxicity of cancer treatments (chemotherapy, anti-HER2 antibodies and radiotherapy), cardiovascular diseases (CVD) have become an increasingly important cause of long-term morbidity and mortality in breast cancer survivors. Endocrine therapies are prescribed to reduce the risk of recurrence and specific death in estrogen receptor-positive (ER+) early breast cancer patients, but their impact on CVD is a matter of debate. Whereas aromatase inhibitors and luteinizing hormone-releasing hormone (LHRH) analogs inhibit estrogen synthesis, tamoxifen acts as a selective estrogen receptor modulator (SERM), opposing estrogen action in the breast but mimicking their actions in other tissues, including arteries. This review aims to summarize the main clinical and experimental studies reporting the effects of tamoxifen on CVD. In addition, we will discuss how recent findings on the mechanisms of action of these therapies may contribute to a better understanding and anticipation of CVD risk in breast cancer patients.

Structure-guided identification of novel dual-targeting estrogen receptor α degraders with aromatase inhibitory activity for the treatment of endocrine-resistant breast cancer

Drug resistance is a major challenge in conventional endocrine therapy for estrogen receptor (ER) positive breast cancer (BC). BC is a multifactorial disease, in which simultaneous aromatase (ARO) inhibition and ERα degradation may effectively inhibit the signal transduction of both proteins, thus potentially overcoming drug resistance caused by overexpression or mutation of target proteins. In this study, guided by the X-ray structure of a hit compound 30a in complex with ER-Y537S, a structure-based optimization was performed to get a series of multiacting inhibitors targeting both ERα and ARO, and finally a novel class of potent selective estrogen receptor degraders (SERDs) based on a three-dimensional oxabicycloheptene sulfonamide (OBHSA) scaffold equipped with aromatase inhibitor (AI) activity were identified. Of these dual-targeting SERD-AI hybrids, compound 31q incorporating a 1H-1,2,4-triazole moiety showed excellent ERα degradation activity, ARO inhibitory activity and remarkable antiproliferative activity against BC resistant cells. Furthermore, 31q manifested efficient tumor suppression in MCF-7 tumor xenograft models. Taken together, our study reported for the first time the highly efficient dual-targeting SERD-AI hybrid compounds, which may lay the foundation of translational research for improved treatment of endocrine-resistant BC.

Stearoyl-CoA Desaturases1 Accelerates Non-Small Cell Lung Cancer Metastasis by Promoting Aromatase Expression to Improve Estrogen Synthesis

Metastases contribute to the low survival rate of non-small cell lung cancer (NSCLC) patients. Targeting lipid metabolism for anticancer therapies is attractive. Accumulative evidence shows that stearoyl-CoA desaturases1 (SCD1), a key enzyme in lipid metabolism, enables tumor metastasis and the underlying mechanism remains unknown. In this study, immunohistochemical staining of 96 clinical specimens showed that the expression of SCD1 was increased in tumor tissues (p < 0.001). SCD1 knockdown reduced the migration and invasion of HCC827 and PC9 cells in transwell and wound healing assays. Aromatase (CYP19A1) knockdown eliminated cell migration and invasion caused by SCD1 overexpression. Western blotting assays demonstrated that CYP19A1, along with β-catenin protein levels, was reduced in SCD1 knocked-down cells, and estrogen concentration was reduced (p < 0.05) in cell culture medium measured by enzyme-linked immunosorbent assay. SCD1 overexpression preserving β-catenin protein stability was evaluated by coimmunoprecipitation and Western blotting. The SCD1 inhibitor A939572, and a potential SCD1 inhibitor, grape seed extract (GSE), significantly inhibited cell migration and invasion by blocking SCD1 and its downstream β-catenin, CYP19A1 expression, and estrogen concentration. In vivo tumor formation assay and a tail vein metastasis model indicated that knockdown of SCD1 blocked tumor growth and metastasis. In conclusion, SCD1 could accelerate metastasis by maintaining the protein stability of β-catenin and then promoting CYP19A1 transcription to improve estrogen synthesis. SCD1 is expected to be a promised therapeutic target, and its novel inhibitor, GSE, has great therapeutic potential in NSCLC.

Glyphosate mimics 17β-estradiol effects promoting estrogen receptor alpha activity in breast cancer cells

Glyphosate, the active ingredient in several broad-spectrum herbicide formulations, has been validated and widely used throughout the world. Recent reports have questioned its safety, showing that glyphosate may act as an endocrine disruptor by promoting estrogenic activity. However, the molecular mechanism involved in this phenomenon remains unclear. Therefore, here we aimed to elucidate the mechanism by which glyphosate induces estrogenic activity using estrogen-sensitive breast cancer cell line models. Our results show that glyphosate mimics the cell effects of 17β-estradiol (E2), promoting estrogen receptor α (ERα) phosphorylation, its degradation, and transcriptional activity at high concentrations. The molecular mechanism seems involved in the ERα ligand-binding domain (LBD). Molecular simulations suggest a plausible interaction between glyphosate and the LBD through a coordinated complex involving divalent cations such as Zn (II). In addition, glyphosate exposure alters the level of Cyclin-dependent kinase 7 that contribute to ERα phosphorylation. Finally, glyphosate increases cell proliferation rate and levels of cell cycle regulators, accompanied by an increase in anchorage-independent growth capacity. These findings suggest that glyphosate at high concentrations, induces estrogen-like effects through an ERα ligand binding site-dependent mechanism, leading to cellular responses resulting from a complex interplay of genomic and non-genomic events.

Estrogen Receptor Signaling in the Immune System

The immune system functions in a sexually dimorphic manner, with females exhibiting more robust immune responses than males. However, how female sex hormones affect immune function in normal homeostasis and in autoimmunity is poorly understood. In this review, we discuss how estrogens affect innate and adaptive immune cell activity and how dysregulation of estrogen signaling underlies the pathobiology of some autoimmune diseases and cancers. The potential roles of the major circulating estrogens, and each of the 3 estrogen receptors (ERα, ERβ, and G-protein coupled receptor) in the regulation of the activity of different immune cells are considered. This provides the framework for a discussion of the impact of ER modulators (aromatase inhibitors, selective estrogen receptor modulators, and selective estrogen receptor downregulators) on immunity. Synthesis of this information is timely given the considerable interest of late in defining the mechanistic basis of sex-biased responses/outcomes in patients with different cancers treated with immune checkpoint blockade. It will also be instructive with respect to the further development of ER modulators that modulate immunity in a therapeutically useful manner.

Mathematically Modeling the Effect of Endocrine and Cdk4/6 Inhibitor Therapies on Breast Cancer Cells

Mathematical modeling of cancer systems is beginning to be used to design better treatment regimens, especially in chemotherapy and radiotherapy. The effectiveness of mathematical modeling to inform treatment decisions and identify therapy protocols, some of which are highly nonintuitive, is because it enables the exploration of a huge number of therapeutic possibilities. Considering the immense cost of laboratory research and clinical trials, these nonintuitive therapy protocols would likely never be found by experimental approaches. While much of the work to date in this area has involved high-level models, which look simply at overall tumor growth or the interaction of resistant and sensitive cell types, mechanistic models that integrate molecular biology and pharmacology can contribute greatly to the discovery of better cancer treatment regimens. These mechanistic models are better able to account for the effect of drug interactions and the dynamics of therapy. The aim of this chapter is to demonstrate the use of ordinary differential equation-based mechanistic models to describe the dynamic interactions between the molecular signaling of breast cancer cells and two key clinical drugs. In particular, we illustrate the procedure for building a model of the response of MCF-7 cells to standard therapies used in the clinic. Such mathematical models can be used to explore the vast number of potential protocols to suggest better treatment approaches.

Estrogen Receptor Function: Impact on the Human Endometrium

The physiological role of estrogen in the female endometrium is well established. On the basis of responses to steroid hormones (progesterone, androgen, and estrogen), the endometrium is considered to have proliferative and secretory phases. Estrogen can act in the endometrium by interacting with estrogen receptors (ERs) to induce mucosal proliferation during the proliferative phase and progesterone receptor (PR) synthesis, which prepare the endometrium for the secretory phase. Mouse knockout studies have shown that ER expression, including ERα, ERβ, and G-protein-coupled estrogen receptor (GPER) in the endometrium is critical for normal menstrual cycles and subsequent pregnancy. Incorrect expression of ERs can produce many diseases that can cause endometriosis, endometrial hyperplasia (EH), and endometrial cancer (EC), which affect numerous women of reproductive age. ERα promotes uterine cell proliferation and is strongly associated with an increased risk of EC, while ERβ has the opposite effects on ERα function. GPER is highly expressed in abnormal EH, but its expression in EC patients is paradoxical. Effective treatments for endometrium-related diseases depend on understanding the physiological function of ERs; however, much less is known about the signaling pathways through which ERs functions in the normal endometrium or in endometrial diseases. Given the important roles of ERs in the endometrium, we reviewed the published literature to elaborate the regulatory role of estrogen and its nuclear and membrane-associated receptors in maintaining the function of endometrium and to provide references for protecting female reproduction. Additionally, the role of drugs such as tamoxifen, raloxifene, fulvestrant and G-15 in the endometrium are also described. Future studies should focus on evaluating new therapeutic strategies that precisely target specific ERs and their related growth factor signaling pathways.

Estradiol Signaling at the Heart of Folliculogenesis: Its Potential Deregulation in Human Ovarian Pathologies

Estradiol (E2) is a major hormone controlling women fertility, in particular folliculogenesis. This steroid, which is locally produced by granulosa cells (GC) within ovarian follicles, controls the development and selection of dominant preovulatory follicles. E2 effects rely on a complex set of nuclear and extra-nuclear signal transduction pathways principally triggered by its nuclear receptors, ERα and ERβ. These transcription factors are differentially expressed within follicles, with ERβ being the predominant ER in GC. Several ERβ splice isoforms have been identified and display specific structural features, which greatly complicates the nature of ERβ-mediated E2 signaling. This review aims at providing a concise overview of the main actions of E2 during follicular growth, maturation, and selection in human. It also describes the current understanding of the various roles of ERβ splice isoforms, especially their influence on cell fate. We finally discuss how E2 signaling deregulation could participate in two ovarian pathogeneses characterized by either a follicular arrest, as in polycystic ovary syndrome, or an excess of GC survival and proliferation, leading to granulosa cell tumors. This review emphasizes the need for further research to better understand the molecular basis of E2 signaling throughout folliculogenesis and to improve the efficiency of ovarian-related disease therapies.

ERα-independent NRF2-mediated immunoregulatory activity of tamoxifen

Sex differences in immune-mediated diseases are linked to the activity of estrogens on innate immunity cells, including macrophages. Tamoxifen (TAM) is a selective estrogen receptor modulator (SERM) used in estrogen receptor-alpha (ERα)-dependent breast cancers and off-target indications such as infections, although the immune activity of TAM and its active metabolite, 4-OH tamoxifen (4HT), is poorly characterized. Here, we aimed at investigating the endocrine and immune activity of these SERMs in macrophages. Using primary cultures of female mouse macrophages, we analyzed the expression of immune mediators and activation of effector functions in competition experiments with SERMs and 17β-estradiol (E2) or the bacterial endotoxin LPS. We observed that 4HT and TAM induce estrogen antagonist effects when used at nanomolar concentrations, while pharmacological concentrations that are reached by TAM in clinical settings regulate the expression of VEGFα and other immune activation genes by ERα- and G protein-coupled receptor 1 (GPER1)-independent mechanisms that involve NRF2 through PI3K/Akt-dependent mechanisms. Importantly, we observed that SERMs potentiate cell phagocytosis and modify the effects of LPS on the expression of inflammatory cytokines, such as TNFα and IL1β, with an overall increase in cell inflammatory phenotype, further sustained by potentiation of IL1β secretion through caspase-1 activation. Altogether, our data unravel a novel molecular mechanism and immune functions for TAM and 4HT, sustaining their repurposing in infective and other estrogen receptors-unrelated pathologies.

Endocrine resistance in breast cancer: from molecular mechanisms to therapeutic strategies

Estrogen receptor-positive (ER +) breast cancer accounts for approximately 75% of all breast cancers. Endocrine therapies, including selective ER modulators (SERMs), aromatase inhibitors (AIs), and selective ER down-regulators (SERDs) provide substantial clinical benefit by reducing the risk of disease recurrence and mortality. However, resistance to endocrine therapies represents a major challenge, limiting the success of ER + breast cancer treatment. Mechanisms of endocrine resistance involve alterations in ER signaling via modulation of ER (e.g., ER downregulation, ESR1 mutations or fusions); alterations in ER coactivators/corepressors, transcription factors (TFs), nuclear receptors and epigenetic modulators; regulation of signaling pathways; modulation of cell cycle regulators; stress signaling; and alterations in tumor microenvironment, nutrient stress, and metabolic regulation. Current therapeutic strategies to improve outcome of endocrine-resistant patients in clinics include inhibitors against mechanistic target of rapamycin (mTOR), cyclin-dependent kinase (CDK) 4/6, and the phosphoinositide 3-kinase (PI3K) subunit, p110α. Preclinical studies reveal novel therapeutic targets, some of which are currently tested in clinical trials as single agents or in combination with endocrine therapies, such as ER partial agonists, ER proteolysis targeting chimeras (PROTACs), next-generation SERDs, AKT inhibitors, epidermal growth factor receptor 1 and 2 (EGFR/HER2) dual inhibitors, HER2 targeting antibody-drug conjugates (ADCs) and histone deacetylase (HDAC) inhibitors. In this review, we summarize the established and emerging mechanisms of endocrine resistance, alterations during metastatic recurrence, and discuss the approved therapies and ongoing clinical trials testing the combination of novel targeted therapies with endocrine therapy in endocrine-resistant ER + breast cancer patients.

Estrogen receptor gets a grip on RNA

The nuclear hormone receptor estrogen receptor alpha (ERα) is a well-known transcription factor present in many breast cancers, where it promotes cancer progression. In this issue of Cell, Xu et al. report that ERα is also an RNA-binding protein and that its post-transcriptional activity enables cancer cell fitness and survival.

Role of estrogen receptor coregulators in endocrine resistant breast cancer

Breast cancer (BC) is the most ubiquitous cancer in women. Approximately 70–80% of BC diagnoses are positive for estrogen receptor (ER) alpha (ERα). The steroid hormone estrogen [17β-estradiol (E2)] plays a vital role both in the initiation and progression of BC. The E2-ERα mediated actions involve genomic signaling and non-genomic signaling. The specificity and magnitude of ERα signaling are mediated by interactions between ERα and several coregulator proteins called coactivators or corepressors. Alterations in the levels of coregulators are common during BC progression and they enhance ligand-dependent and ligand-independent ERα signaling which drives BC growth, progression, and endocrine therapy resistance. Many ERα coregulator proteins function as scaffolding proteins and some have intrinsic or associated enzymatic activities, thus the targeting of coregulators for blocking BC progression is a challenging task. Emerging data from in vitro and in vivo studies suggest that targeting coregulators to inhibit BC progression to therapy resistance is feasible. This review explores the current state of ERα coregulator signaling and the utility of targeting the ERα coregulator axis in treating advanced BC.

Hi-C profiling of cancer spheroids identifies 3D-growth-specific chromatin interactions in breast cancer endocrine resistance

BACKGROUND

Organoids or spheroids have emerged as a physiologically relevant in vitro preclinical model to study patient-specific diseases. A recent study used spheroids of MCF10 cells to model breast cancer progression and identified targetable alterations more similar to those in vivo. Thus, it is practical and essential to explore and characterize the spheroids of the commonly used human breast cancer (BC) cells.

METHODS

In this study, we conducted Hi-C analyses in three-dimensional (3D) spheroids of MCF10A, MCF7 and MCF7TR cells and compared TADs and looping genes with those in 2D monolayers. Furthermore, we performed in silico functional analysis on 3D-growth-specific looping genes and to compare patient outcomes with or without endocrinal therapy. Finally, we performed 3C/RT-qPCR validations in 3D spheroids and 3D-FISH confirmations in organoids of breast cancer patient tissues.

RESULTS

We found that chromatin structures have experienced drastic changes during the 3D culture growth of BC cells although there is not much change in the quantity of chromatin domains. We also observed that the strengths of looping genes were statistically different between 2D monolayers and 3D spheroids. We further identified novel 3D growth-specific looping genes within Hippo relevant pathways, of which two genes showed potential prognostic values in measuring the outcome of the endocrine treatment. We finally confirmed a few selected genes in Hippo relevant pathways with enhanced looping in organoids of breast cancer patient tissues.

CONCLUSIONS

Hence, our work has provided significant insights into our understanding of 3D-growth-specific chromatin architecture in tamoxifen-resistant breast cancer. Our analyses suggest that the strengthened looping-mediated Hippo relevant pathways may contribute to endocrine therapy resistance in breast cancer patients.

Combined endocrine and targeted therapy in luminal breast cancer

Introduction: For decades, endocrine therapy has been the cornerstone of management for luminal breast cancer. Despite the substantial benefit derived by patients from endocrine therapy, primary and secondary resistances to endocrine therapy are serious clinical issues.Areas covered: Today, in the advanced setting, three distinct classes of targeted agents mTOR, CDK 4/6, and PI3K inhibitors, are approved for use. CDK 4/6 inhibitors have improved outcomes substantially, changing the natural history of advanced luminal breast cancer. Current studies seek to bring CDK 4/6 inhibitors to the early setting. This review will cover all available data on target therapy combinations with endocrine therapy for both the early and advanced settings, including approved drugs and agents in development.Expert opinion: Combined endocrine and target therapy has changed the landscape in advanced disease. In early disease, it is possible to have a large impact, particularly in patients with higher risk of relapse. Trials like ADAPTCYCLE seek to leverage neoadjuvant data to de-escalate treatment, substituting chemotherapy for CDK 4/6 inhibitors. In advanced diseases, studies such as PADA-1 point toward a future in which ctDNA will be used to define management before clinical progression occurs.

HOTAIR Facilitates Endocrine Resistance in Breast Cancer Through ESR1/miR-130b-3p Axis: Comprehensive Analysis of mRNA-miRNA-lncRNA Network

Background

To summarize the regulatory role of mRNA-miRNA-lncRNA network associated with endocrine therapy resistance (ETR) in breast cancer.

Methods

We analyzed the differentially expressed genes (DEGs), differentially expressed lncRNAs (DELs), and differentially expressed miRNAs (DEMs) in long-term estrogen-deprived (LTED) estrogen receptor (ER)-positive breast cancer cells (LTED MCF7) (modeling relapse on endocrine therapy) and MCF7 cells in the presence of estrogen (E2) (modeling a patient at primary diagnosis) by mining GSE120929 and GSE120930 datasets. The mRNA-miRNA-lncRNA network was constructed by multiple bioinformatic tools. The prognosis of genes from the network was validated in breast cancer patients with following systemic treatment (endocrine therapy) by GEPIA, Kaplan–Meier plotter and UALCAN database.

Results

Totally, 769 DEGs, 33 DEMs, and 10 DELs were selected. The mRNA-miRNA-lncRNA network was established including 60 mRNA nodes, 6 miRNA nodes and 3 lncRNA nodes. A significant module containing 3 nodes and 3 edges was calculated based on the mRNA-miRNA-lncRNA network. The hub genes in the network are ABCG2, ESR1 and GJA1. ESR1/miR-130b-3p/HOTAIR are significantly correlated with the prognosis of breast cancer patients with endocrine therapy.

Conclusion

This study provides a novel ETR-related mRNA-miRNA-lncRNA network. Further, we suggest that ESR1/miR-130b-3p/HOTAIR may be promising targets for clinical treatment of endocrine therapy-resistant breast cancer.

The Role of Gut Microbial β-Glucuronidase in Estrogen Reactivation and Breast Cancer

Over the past decade, the gut microbiota has received considerable attention for its interactions with the host. Microbial β-glucuronidase generated by this community has hence aroused concern for its biotransformation activity to a wide range of exogenous (foreign) and endogenous compounds. Lately, the role of gut microbial β-glucuronidase in the pathogenesis of breast cancer has been proposed for its estrogen reactivation activity. This is plausible considering that estrogen glucuronides are the primary products of estrogens' hepatic phase II metabolism and are subject to β-glucuronidase-catalyzed hydrolysis in the gut via bile excretion. However, research in this field is still at its very preliminary stage. This review outlines the biology of microbial β-glucuronidase in the gastrointestinal tract and elaborates on the clues to the existence of microbial β-glucuronidase-estrogen metabolism-breast cancer axis. The research gaps in this field will be discussed and possible strategies to address these challenges are suggested.

GDC-9545 (Giredestrant): A Potent and Orally Bioavailable Selective Estrogen Receptor Antagonist and Degrader with an Exceptional Preclinical Profile for ER+ Breast Cancer

Breast cancer remains a leading cause of cancer death in women, representing a significant unmet medical need. Here, we disclose our discovery efforts culminating in a clinical candidate, 35 (GDC-9545 or giredestrant). 35 is an efficient and potent selective estrogen receptor degrader (SERD) and a full antagonist, which translates into better antiproliferation activity than known SERDs (1, 6, 7, and 9) across multiple cell lines. Fine-tuning the physiochemical properties enabled once daily oral dosing of 35 in preclinical species and humans. 35 exhibits low drug-drug interaction liability and demonstrates excellent in vitro and in vivo safety profiles. At low doses, 35 induces tumor regressions either as a single agent or in combination with a CDK4/6 inhibitor in an ESR1^Y537S mutant PDX or a wild-type ERα tumor model. Currently, 35 is being evaluated in Phase III clinical trials.

Oestrogen receptor alpha in papillary thyroid carcinoma: association with clinical features and BRAFV600E mutation

BACKGROUND

Papillary thyroid cancer cells can express oestrogen receptor alpha, which is encoded by the ESR1 gene and may bind to oestrogen to induce the occurrence and development of papillary thyroid cancer. The BRAFV600E mutation is also an important biomarker for the occurrence and progression of papillary thyroid cancer. However, the association between the BRAFV600E mutation and oestrogen receptor alpha expression has not been identified. This study aims to investigate the association between ESR1 expression and the BRAFV600E mutation and its clinical significance.

METHODS

Oestrogen receptor alpha and BRAFV600E proteins were detected by immunohistochemical staining of formalin-fixed paraffin-embedded thyroid tissues from 1105 patients with papillary thyroid cancer at our institution. Messenger RNA expression counts of ESR1 and clinicopathologic information were obtained from The Cancer Genome Atlas database.

RESULTS

Oestrogen receptor alpha protein expression was significantly associated with BRAFV600E protein. The positive rate of oestrogen receptor alpha protein in papillary thyroid cancer patients was significantly higher in males, younger patients and patients with the multifocal type. In papillary thyroid cancer patients with positive BRAFV600E protein, oestrogen receptor alpha expression was significantly correlated with central lymph node metastasis. Data from the The Cancer Genome Atlas database also suggested that the ESR1 messenger RNA level was associated with the BRAFV600E mutation. Furthermore, classification analysis performed according to a tree-based classification method demonstrated that higher ESR1 messenger RNA expression indicated poorer overall survival in papillary thyroid cancer patients with the BRAFV600E mutation.

CONCLUSIONS

The percentage of BRAFV600E mutations is increased in patients with higher ESR1 messenger RNA levels, and the BRAFV600E protein might be co-expressed with oestrogen receptor alpha, which could be an indicator of cervical lymph node metastasis and poor overall survival in patients with papillary thyroid cancer.

Physiologically Relevant Estrogen Receptor Alpha Pathway Reporters for Single-Cell Imaging-Based Carcinogenic Hazard Assessment of Estrogenic Compounds

Estrogen receptor alpha (ERα) belongs to the nuclear hormone receptor family of ligand-inducible transcription factors and regulates gene networks in biological processes such as cell growth and proliferation. Disruption of these networks by chemical compounds with estrogenic activity can result in adverse outcomes such as unscheduled cell proliferation, ultimately culminating in tumor formation. To distinguish disruptive activation from normal physiological responses, it is essential to quantify relationships between different key events leading to a particular adverse outcome. For this purpose, we established fluorescent protein MCF7 reporter cell lines for ERα-induced proliferation by bacterial artificial chromosome-based tagging of 3 ERα target genes: GREB1, PGR, and TFF1. These target genes are inducible by the non-genotoxic carcinogen and ERα agonist 17β-estradiol in an ERα-dependent manner and are essential for ERα-dependent cell-cycle progression and proliferation. The 3 GFP reporter cell lines were characterized in detail and showed different activation dynamics upon exposure to 17β-estradiol. In addition, they demonstrated specific activation in response to other established reference estrogenic compounds of different potencies, with similar sensitivities as validated OECD test methods. This study shows that these fluorescent reporter cell lines can be used to monitor the spatial and temporal dynamics of ERα pathway activation at the single-cell level for more mechanistic insight, thereby allowing a detailed assessment of the potential carcinogenic activity of estrogenic compounds in humans.

Interactions of neuroimmune signaling and glutamate plasticity in addiction

Chronic use of drugs of abuse affects neuroimmune signaling; however, there are still many open questions regarding the interactions between neuroimmune mechanisms and substance use disorders (SUDs). Further, chronic use of drugs of abuse can induce glutamatergic changes in the brain, but the relationship between the glutamate system and neuroimmune signaling in addiction is not well understood. Therefore, the purpose of this review is to bring into focus the role of neuroimmune signaling and its interactions with the glutamate system following chronic drug use, and how this may guide pharmacotherapeutic treatment strategies for SUDs. In this review, we first describe neuroimmune mechanisms that may be linked to aberrant glutamate signaling in addiction. We focus specifically on the nuclear factor-kappa B (NF-κB) pathway, a potentially important neuroimmune mechanism that may be a key player in driving drug-seeking behavior. We highlight the importance of astroglial-microglial crosstalk, and how this interacts with known glutamatergic dysregulations in addiction. Then, we describe the importance of studying non-neuronal cells with unprecedented precision because understanding structure-function relationships in these cells is critical in understanding their role in addiction neurobiology. Here we propose a working model of neuroimmune-glutamate interactions that underlie drug use motivation, which we argue may aid strategies for small molecule drug development to treat substance use disorders. Together, the synthesis of this review shows that interactions between glutamate and neuroimmune signaling may play an important and understudied role in addiction processes and may be critical in developing more efficacious pharmacotherapies to treat SUDs.

The relationship between NFKB, HER2, ER expression and anthracycline -based neoadjuvan chemotherapy response in local advanced stadium breast cancer: A cohort study in Eastern Indonesia

Introduction

Neoadjuvant chemotherapy has become the standard form of treatment for locally advanced breast cancer. Chemoresistence is a problem that limits the effectiveness of chemotherapy. Therefore, predictive biomarkers are needed to choose the appropriate chemotherapy to the right patient. The role of NF-кb expression as a predictive biomarker of neoadjuvant chemotherapy response needs to be investigated in patients with locally advanced breast cancer who are treated with a regimen of cyclophosphamide-doxorubicin-5FU (CAF).

Methods

This observational study used the prospective cohort method to examine 62 samples. CAF was administered at 3-week intervals for 3 cycles of chemotherapy. The data utilized in this study include the positive and negative expression of NF-κB, ER, and HER2 overexpression. The cases were divided into groups that were responsive and non-responsive to the neoadjuvant chemotherapy.

Results

The average age in the youngest group was 26 years, and that in the oldest was 66 years. The highest age group was subjects in their 50s, which had 26 cases (41.9%). The majority of the cases were moderate grade with 38 cases (61.3%). The percentage of responsive subjects was higher in the groups with negative NF-κB expression (82.5%), positive HER2 status (85.7%), and negative ER status (71.9%). It was found that 37 cases (59.7%) were responsive to CAF, while 25 cases (40.3%) were non-responsive. There was a significant relationship between NF-κB expression and chemotherapy response (p < 0.05), and the percentage of responsive subjects was higher among those with negative NF-κB expression (82.5%) than positive NF-κB expression (18.2%).

Conclusion

NF-κB expression, ER status, and HER2 have a significant relationship with the response to anthracycline-based neoadjuvant chemotherapy for local advanced breast cancer, and NF-κB expression has the most significant relationship with the chemotherapy response. Therefore, NF-κB expression should be considered as a predictive biomarker for the response to CAF regimens.

Estrogen-induced circRNA, circPGR, functions as a ceRNA to promote estrogen receptor-positive breast cancer cell growth by regulating cell cycle-related genes

Estrogen and estrogen receptor (ER)-regulated gene transcriptional events have been well known to be involved in ER-positive breast carcinogenesis. Meanwhile, circular RNAs (circRNAs) are emerging as a new family of functional non-coding RNAs (ncRNAs) with implications in a variety of pathological processes, such as cancer. However, the estrogen-regulated circRNA program and the function of such program remain uncharacterized. Methods: CircRNA sequencing (circRNA-seq) was performed to identify circRNAs induced by estrogen, and cell proliferation, colony formation, wound healing, transwell and tumor xenograft experiments were applied to examine the function of estrogen-induced circRNA, circPGR. RNA sequencing (RNA-seq) and ceRNA network analysis wereperformed to identify circPGR's target genes and the microRNA (miRNA) bound to circPGR. Anti-sense oligonucleotide (ASO) was used to assess circPGR's effects on ER-positive breast cancer cell growth. Results: Genome-wide circRNA profiling by circRNA sequencing (circRNA-seq) revealed that a large number of circRNAs were induced by estrogen, and further functional screening for the several circRNAs originated from PGR revealed that one of them, which we named as circPGR, was required for ER-positive breast cancer cell growth and tumorigenesis. CircPGR was found to be localized in the cytosol of cells and functioned as a competing endogenous RNA (ceRNA) to sponge miR-301a-5p to regulate the expression of multiple cell cycle genes. The clinical relevance of circPGR was underscored by its high and specific expression in ER-positive breast cancer cell lines and clinical breast cancer tissue samples. Accordingly, anti-sense oligonucleotide (ASO) targeting circPGR was proven to be effective in suppressing ER-positive breast cancer cell growth. Conclusions: These findings reveled that, besides the well-known messenger RNA (mRNA), microRNA (miRNA), long non-coding RNA (lncRNA) and enhancer RNA (eRNA) programs, estrogen also induced a circRNA program, and exemplified by circPGR, these estrogen-induced circRNAs were required for ER-positive breast cancer cell growth, providing a new class of therapeutic targets for ER-positive breast cancer.

Histone deacetylase inhibitors enhance estrogen receptor beta expression and augment agonist-mediated tumor suppression in glioblastoma

BACKGROUND

Glioblastomas (GBMs) are the most lethal primary brain tumors. Estrogen receptor β (ESR2/ERβ) function as a tumor suppressor in GBM, however, ERβ expression is commonly suppressed during glioma progression. In this study, we examined whether drugs that reverse epigenetic modifications will enhance ERβ expression and augment ERβ agonist-mediated tumor suppression.

METHODS

We tested the utility of epigenetic drugs which act as an inhibitor of histone deacetylases (HDACs), histone methylases, and BET enzymes. Mechanistic studies utilized RT-qPCR, chromatin immunoprecipitation (ChIP), and western blotting. Cell viability, apoptosis, colony formation, and invasion were measured using in vitro assays. An orthotopic GBM model was used to test the efficacy of in vivo.

RESULTS

Of all inhibitors tested, HDACi (panobinostat and romidepsin) showed the potential to increase the expression of ERβ in GBM cells. Treatment with HDACi uniquely upregulated ERβ isoform 1 expression that functions as a tumor suppressor but not ERβ isoform 5 that drives oncogenic functions. Further, combination therapy of HDACi with the ERβ agonist, LY500307, potently reduced cell viability, invasion, colony formation, and enhanced apoptosis. Mechanistic studies showed that HDACi induced ERβ is functional, as it enhanced ERβ reporter activities and ERβ target genes expression. ChIP analysis confirmed alterations in the histone acetylation at the ERβ and its target gene promoters. In orthotopic GBM model, combination therapy of panobinostat and LY500307 enhanced survival of tumor-bearing mice.

CONCLUSIONS

Our results suggest that the combination therapy of HDACi and LY500307 provides therapeutic utility in overcoming the suppression of ERβ expression that commonly occurs in GBM progression.

Microenvironmental Determinants of Breast Cancer Metastasis: Focus on the Crucial Interplay Between Estrogen and Insulin/Insulin-Like Growth Factor Signaling

The development and progression of the great majority of breast cancers (BCs) are mainly dependent on the biological action elicited by estrogens through the classical estrogen receptor (ER), as well as the alternate receptor named G-protein–coupled estrogen receptor (GPER). In addition to estrogens, other hormones and growth factors, including the insulin and insulin-like growth factor system (IIGFs), play a role in BC. IIGFs cooperates with estrogen signaling to generate a multilevel cross-communication that ultimately facilitates the transition toward aggressive and life-threatening BC phenotypes. In this regard, the majority of BC deaths are correlated with the formation of metastatic lesions at distant sites. A thorough scrutiny of the biological and biochemical events orchestrating metastasis formation and dissemination has shown that virtually all cell types within the tumor microenvironment work closely with BC cells to seed cancerous units at distant sites. By establishing an intricate scheme of paracrine interactions that lead to the expression of genes involved in metastasis initiation, progression, and virulence, the cross-talk between BC cells and the surrounding microenvironmental components does dictate tumor fate and patients’ prognosis. Following (i) a description of the main microenvironmental events prompting BC metastases and (ii) a concise overview of estrogen and the IIGFs signaling and their major regulatory functions in BC, here we provide a comprehensive analysis of the most recent findings on the role of these transduction pathways toward metastatic dissemination. In particular, we focused our attention on the main microenvironmental targets of the estrogen-IIGFs interplay, and we recapitulated relevant molecular nodes that orientate shared biological responses fostering the metastatic program. On the basis of available studies, we propose that a functional cross-talk between estrogens and IIGFs, by affecting the BC microenvironment, may contribute to the metastatic process and may be regarded as a novel target for combination therapies aimed at preventing the metastatic evolution.

Age, gender, and racial/ethnic differences in the association of triclocarban with adulthood obesity using NHANES 2013-2016

This study examined the association between triclocarban and obesity among US adults and compared the pattern of this association across age, gender, and racial/ethnic groups. Study found triclocarban to be associated with obesity (OR: OR:1.123 95% CI: 1.046, 1.205) and this association remained among women (OR:1.14 95% CI: 1.031, 1.261). Study participants aged 60 years and older were more likely to be overweight (OR:1.131 95% CI: 1.022 1.251) and obese (OR:1.192 95% CI: 1.079, 1.317) when compared to other age groups. Likewise, non-Hispanic whites (OR:1.126 95% CI: 1.003, 1.263) and "other race including multi-racial" (OR:1.431 95% CI: 1.219, 1.679) were more likely to be obese when compared to other racial/ethnic groups. In conclusion, triclocarban is associated with obesity among US adults and there is evidence of gender, age, and racial/ethnicity differences in the association.

Differential regulation of osteopontin and CD44 correlates with infertility status in PCOS patients

Endometrial receptivity is mediated by adhesion molecules at the endometrium-trophoblast interface where osteopontin (OPN) and CD44 form a protein complex that plays an important role in embryo recognition. Here, we undertook a prospective study investigating the expression and regulation of OPN and CD44 in 50 fertile and 31 infertile ovulatory polycystic ovarian syndrome (PCOS) patients in the proliferative and secretory phases of the natural menstrual cycle and in 12 infertile anovulatory PCOS patients. Endometrial biopsies and blood samples were evaluated for expression of OPN and CD44 using RT-PCR, immunohistochemistry and ELISA analysis to determine circulating levels of OPN, CD44, TNF-α, IFN-γ and OPN and CD44 levels in biopsy media. Our findings highlighted an increased level of circulating OPN and CD44 in serum from infertile patients that inversely correlated with expression levels in endometrial tissue and positively correlated with levels secreted into biopsy media. OPN and CD44 levels positively correlated to each other in serum and media from fertile and PCOS patients, as well as to circulating TNF-α and IFN-γ. In vitro analysis revealed that hormone treatment induced recruitment of ERα to the OPN and CD44 promoters with a concomitant increase in the expression of these genes. In infertile patients, inflammatory cytokines led to recruitment of NF-κB and STAT1 proteins to the OPN and CD44 promoters, resulting in their overexpression. These observations suggest that the endometrial epithelial OPN-CD44 adhesion complex is deficient in ovulatory PCOS patients and displays an altered stoichiometry in anovulatory patients, which in both cases may perturb apposition. This, together with elevated circulating and local secreted levels of these proteins, may hinder endometrium-trophoblast interactions by saturating OPN and CD44 receptors on the surface of the blastocyst, thereby contributing to the infertility associated with ovulating PCOS patients. KEY MESSAGES: • Endometrial epithelial OPN-CD44 adhesion complex levels are deficient in ovulatory PCOS patients contributing to the endometrial infertility associated with ovulating PCOS patients. • Circulating levels of OPN, CD44 and inflammatory cytokines TNF-α and IFN-γ are altered in infertile PCOS patients. • Increased levels of both OPN and CD44 in biopsy media and serum inversely correlate with endometrial expression of these markers in endometrial tissue. • In infertile PCOS patients, high levels of oestrogens and inflammatory cytokines stimulate the recruitment of transcription factors to the OPN and CD44 promoters to enhance gene transcription. • Our study identifies a novel crosstalk between the CD44-OPN adhesion complex, ERα, STAT1 and NF-κB pathways modulating endometrial receptivity.

An H3K4me3 reader, BAP18 as an adaptor of COMPASS-like core subunits co-activates ERα action and associates with the sensitivity of antiestrogen in breast cancer

Estrogen receptor alpha (ERα) signaling pathway is essential for ERα-positive breast cancer progression and endocrine therapy resistance. Bromodomain PHD Finger Transcription Factor (BPTF) associated protein of 18kDa (BAP18) has been recognized as a crucial H3K4me3 reader. However, the whole genomic occupation of BAP18 and its biological function in breast cancer is still elusive. Here, we found that higher expression of BAP18 in ERα-positive breast cancer is positively correlated with poor prognosis. ChIP-seq analysis further demonstrated that the half estrogen response elements (EREs) and the CCCTC binding factor (CTCF) binding sites are the significant enrichment sites found in estrogen-induced BAP18 binding sites. Also, we provide the evidence to demonstrate that BAP18 as a novel co-activator of ERα is required for the recruitment of COMPASS-like core subunits to the cis-regulatory element of ERα target genes in breast cancer cells. BAP18 is recruited to the promoter regions of estrogen-induced genes, accompanied with the enrichment of the lysine 4-trimethylated histone H3 tail (H3K4me3) in the presence of E2. Furthermore, BAP18 promotes cell growth and associates the sensitivity of antiestrogen in ERα-positive breast cancer. Our data suggest that BAP18 facilitates the association between ERα and COMPASS-like core subunits, which might be an essential epigenetic therapeutic target for breast cancer.

The phthalate DEHP modulates the estrogen receptors α and β increasing lactotroph cell population in female pituitary glands

Humans are exposed to numerous endocrine disruptors on a daily basis, which may interfere with endogenous estrogens, with Di-(2-ethylhexyl) phthalate (DEHP) being one of the most employed. The anterior pituitary gland is a target of 17β-estradiol (E2) through the specific estrogen receptors (ERs) α and β, whose expression levels fluctuate in the gland under different contexts, and the ERα/β index is responsible for the final E2 effect. The aim of the present study was to evaluate in vivo and in vitro the DEHP effects on ERα and β expression in the pituitary cell population, and also its impact on lactotroph and somatotroph cell growth. Our results revealed that perinatal exposure to DEHP altered the ERα and β expression pattern in pituitary glands from prepubertal and adult female rats and increased the percentage of lactotroph cells in adulthood. In the in vitro system, DEHP down-regulated ERα and β expression, and as a result increased the ERα/β ratio and decreased the percentages of lactotrophs and somatotrophs expressing ERα and β. In addition, DEHP increased the S + G2M phases, Ki67 index and cyclin D1 in vitro, leading to a rise in the lactotroph and somatotroph cell populations. These results showed that DEHP modified the pituitary ERα and β expression in lactotrophs and somatotrophs from female rats and had an impact on the pituitary cell growth. These changes in ER expression may be a mechanism underlying DEHP exposure in the pituitary gland, leading to cell growth deregulation.

A mutant form of ERα associated with estrogen insensitivity affects the coupling between ligand binding and coactivator recruitment

A homozygous missense mutation in the gene encoding the estrogen receptor α (ERα) was previously identified in a female patient with estrogen insensitivity syndrome. We investigated the molecular features underlying the impaired transcriptional response of this mutant (ERα-Q375H) and four other missense mutations at this position designed to query alternative mechanisms. The identity of residue 375 greatly affected the sensitivity of the receptor to agonists without changing the ligand binding affinity. Instead, the mutations caused changes in the affinity of coactivator binding and alterations in the balance of coactivator and corepressor recruitment. Comparisons among the transcriptional regulatory responses of these six ERα genotypes to a set of ER agonists showed that both steric and electrostatic factors contributed to the functional deficits in gene regulatory activity of the mutant ERα proteins. ERα-coregulator peptide binding in vitro and RIME (rapid immunoprecipitation mass spectrometry of endogenous) analysis in cells showed that the degree of functional impairment paralleled changes in receptor-coregulator binding interactions. These findings uncover coupling between ligand binding and coregulator recruitment that affects the potency rather than the efficacy of the receptor response without substantially altering ligand binding affinity. This highlights a molecular mechanism for estrogen insensitivity syndrome involving mutations that perturb a bidirectional allosteric coupling between ligand binding and coregulator binding that determines receptor transcriptional output.

Role of GPER-Mediated Signaling in Testicular Functions and Tumorigenesis

Estrogen signaling plays important roles in testicular functions and tumorigenesis. Fifteen years ago, it was discovered that a member of the G protein-coupled receptor family, GPR30, which binds also with high affinity to estradiol and is responsible, in part, for the rapid non-genomic actions of estrogens. GPR30, renamed as GPER, was detected in several tissues including germ cells (spermatogonia, spermatocytes, spermatids) and somatic cells (Sertoli and Leydig cells). In our previous review published in 2014, we summarized studies that evidenced a role of GPER signaling in mediating estrogen action during spermatogenesis and testis development. In addition, we evidenced that GPER seems to be involved in modulating estrogen-dependent testicular cancer cell growth; however, the effects on cell survival and proliferation depend on specific cell type. In this review, we update the knowledge obtained in the last years on GPER roles in regulating physiological functions of testicular cells and its involvement in neoplastic transformation of both germ and somatic cells. In particular, we will focus our attention on crosstalk among GPER signaling, classical estrogen receptors and other nuclear receptors involved in testis physiology regulation.

ESR1 Mutations Associated With Estrogen Insensitivity Syndrome Change Conformation of Ligand-Receptor Complex and Altered Transcriptome Profile

Estrogen insensitivity syndrome (EIS) arises from rare mutations in estrogen receptor-α (ERα, encoded by ESR1 gene) resulting in the inability of estrogen to exert its biological effects. Due to its rarity, mutations in ESR1 gene and the underlying molecular mechanisms of EIS have not been thoroughly studied. Here, we investigate known ESR1 mutants, Q375H and R394H, associated with EIS patients using in vitro and in vivo systems. Comparison of the transcriptome and deoxyribonucleic acid methylome from stable cell lines of both Q375H and R394H clinical mutants shows a differential profile compared with wild-type ERα, resulting in loss of estrogen responsiveness. Molecular dynamic simulation shows that both ESR1 mutations change the ERα conformation of the ligand-receptor complexes. Furthermore, we generated a mouse model Esr1-Q harboring the human mutation using CRISPR/Cas9 genome editing. Female and male Esr1-Q mice are infertile and have similar phenotypes to αERKO mice. Overall phenotypes of the Esr1-Q mice correspond to those observed in the patient with Q375H. Finally, we explore the effects of a synthetic progestogen and a gonadotropin-releasing hormone inhibitor in the Esr1-Q mice for potentially reversing the impaired female reproductive tract function. These findings provide an important basis for understanding the molecular mechanistic consequences associated with EIS.

Structure and Characterization of a Covalent Inhibitor of Src Kinase

Unregulated Src activity promotes malignant processes in cancer, but no Src-directed targeted therapies are used clinically, possibly because early Src inhibitors produce off-target effects leading to toxicity. Improved selective Src inhibitors may enable Src-directed therapies. Previously, we reported an irreversible Src inhibitor, DGY-06-116, based on the hybridization of dasatinib and a promiscuous covalent kinase probe SM1-71. Here, we report biochemical and biophysical characterization of this compound. An x-ray co-crystal structure of DGY-06-116: Src shows a covalent interaction with the kinase p-loop and occupancy of the back hydrophobic kinase pocket, explaining its high potency, and selectivity. However, a reversible analog also shows similar potency. Kinetic analysis shows a slow inactivation rate compared to other clinically approved covalent kinase inhibitors, consistent with a need for p-loop movement prior to covalent bond formation. Overall, these results suggest that a strong reversible interaction is required to allow sufficient time for the covalent reaction to occur. Further optimization of the covalent linker may improve the kinetics of covalent bond formation.

Racial Differences in the Association Between Luminal Master Regulator Gene Expression Levels and Breast Cancer Survival

PURPOSE

Compared with their European American (EA) counterparts, African American (AA) women are more likely to die from breast cancer in the United States. This disparity is greatest in hormone receptor-positive subtypes. Here we uncover biological factors underlying this disparity by comparing functional expression and prognostic significance of master transcriptional regulators of luminal differentiation.

EXPERIMENTAL DESIGN

Data and biospecimens from 262 AA and 293 EA patients diagnosed with breast cancer from 2001 to 2010 at a major medical center were analyzed by IHC for functional biomarkers of luminal differentiation, including estrogen receptor (ESR1) and its pioneer factors, FOXA1 and GATA3. Integrated comparison of protein levels with network-level gene expression analysis uncovered predictive correlations with race and survival.

RESULTS

Univariate or multivariate HRs for overall survival, estimated from digital IHC scoring of nuclear antigen, show distinct differences in the magnitude and significance of these biomarkers to predict survival based on race: ESR1 [EA HR = 0.47; 95% confidence interval (CI), 0.31-0.72 and AA HR = 0.77; 95% CI, 0.48-1.18]; FOXA1 (EA HR = 0.38; 95% CI, 0.23-0.63 and AA HR = 0.53; 95% CI, 0.31-0.88), and GATA3 (EA HR = 0.36; 95% CI, 0.23-0.56; AA HR = 0.57; CI, 0.56-1.4). In addition, we identify genes in the downstream regulons of these biomarkers highly correlated with race and survival.

CONCLUSIONS

Even within clinically homogeneous tumor groups, regulatory networks that drive mammary luminal differentiation reveal race-specific differences in their association with clinical outcome. Understanding these biomarkers and their downstream regulons will elucidate the intrinsic mechanisms that drive racial disparities in breast cancer survival.

Aromatase Inhibitors for Ovarian Stimulation in Patients with Breast Cancer

BACKGROUND

Breast cancer is the most common malignancy diagnosed in women, and its treatment has a high probability of loss of fertility. Oocyte vitrification is the most commonly used technique to preserve fertility before starting oncological treatment. Aromatase inhibitors induce hypoestrogenemia while promoting the release of gonadotropins and constitute an alternative drug for ovarian stimulation in patients with breast cancer.

OBJECTIVE

In this mini-review, we update and describe the current status of aromatase inhibitor use in controlled ovarian stimulation for oocyte vitrification in patients with breast cancer.

RESULTS

Aromatase inhibitors are commonly used in combination with gonadotropins for ovarian stimulation in patients with breast cancer who preserve their fertility through oocyte vitrification. They achieve similar ovarian responses as conventional ovarian stimulation protocols in regards to the number of oocytes, and no additional complications after their use have been reported. Furthermore, aromatase inhibitors seem to be safe not only for offspring, as no more congenital defects occur in newborns from pregnancies achieved after their use, but also for the patients, as no more malignancy recurrence or increased mortality was found in cohort studies.

CONCLUSION

Aromatase inhibitors are elective drugs for ovarian stimulation in patients with breast cancer who decide to preserve their fertility through oocyte vitrification.

Estrogenic, Antiestrogenic and Antiproliferative Activities of Euphorbia bicolor (Euphorbiaceae) Latex Extracts and Its Phytochemicals

Estrogen receptor antagonists are effective in breast cancer treatment. However, the side effects of these treatments have led to a rise in searching for alternative therapies. The present study evaluated the estrogenic, antiestrogenic, and antiproliferative activities of Euphorbiabicolor (Euphorbiaceae), a plant native to south-central USA. Estrogenic and antiestrogenic activities of latex extract and its phytochemicals were evaluated with a steroid-regulated yeast system expressing the human estrogen receptor α and antiproliferative properties were assessed in the ER-positive MCF-7 and T47-D and triple-negative MDA-MB-231 and MDA-MB-469 breast carcinomas. Genistein and coumestrol identified in the latex extract induced higher estrogenic and antiestrogenic activities compared to diterpenes and flavonoids. The latex extract, resiniferatoxin (RTX) and rutin induced antiproliferative activities in all cell lines in a dose-dependent manner, but not in human normal primary dermal fibroblast cultures. A biphasic effect was observed with MDA-MB-468 breast carcinoma in which the latex extract at low concentrations increased and at high concentrations decreased cell proliferation. Treatments with latex extract in combination with RTX or rutin reduced even more the proliferation of MCF-7 breast carcinoma compared to the individual latex, RTX, and rutin treatments. E. bicolor latex phytochemicals could contribute to developing commercial therapeutic agents for breast cancer treatment.

The emerging role of mediator complex subunit 12 in tumorigenesis and response to chemotherapeutics

Transcriptional dysregulation induced by disease-defining genetic alterations of proteins in transcriptional machinery is a key feature of cancers. Mediator complex subunit 12 (MED12) is the central architectural subunit in the kinase module of Mediator, a large transcriptional regulatory complex that controls essential steps of transcription. Emerging evidence links deregulated MED12 to human cancers. MED12 is frequently mutated in benign tumors and cancers. Although the missense mutations of MED12 in benign tumors disrupt the kinase activity of Mediator, MED12 mutations in cancers could eliminate the interaction between Mediator complex and RNA polymerase II, leading to severe transcriptional misregulation. Aberrant expression of MED12 is associated with the prognosis of various types of human cancers. Loss of MED12 function has been associated with the development of resistance to chemotherapeutics. Moreover, MED12 is modified by posttranscriptional regulations. Arginine methylation of MED12 has been shown to regulate MED12-mediated transcriptional regulation and response to chemotherapeutics in human cancer cell lines. In this mini-review, the authors provide an overview of the roles of MED12 in the development of benign and malignant tumors as well as its roles in chemoresistance. The studies of MED12 exemplify that aberrant transcriptional programming is a therapeutic vulnerability for certain types of cancer.

In vivo and in vitro pharmacological activities of Tacca integrifolia rhizome and investigation of possible lead compounds against breast cancer through in silico approaches

Background

The study was conducted to evaluate the analgesic, anti-inflammatory, antipyretic properties of ethanolic extract of Tacca integrifolia rhizome (EETI) in mice and cytotoxic effects in brine shrimp nauplii followed by a PASS prediction study for some isolated compounds of T. integrifolia. Additionally, this experiment included the in silico molecular docking and ADME/T property analyses of some phytochemicals.

Methods

Formalin- induced paw licking test and acetic acid-induced writhing test for analgesic activity, carrageenan-induced paw edema test for anti-inflammatory potential and Brewer’s yeast-induced pyrexia test for antipyretic activity were applied. Antinociceptive and antineoplastic activity for breast cancer were revealed with PASS program. Schrodinger suite 2015 was used to evaluate the binding interaction and ADME/T properties of selected phytoconstituents with estrogen receptor alpha.

Results

In formalin-induced paw licking test, EETI at the doses of 200 and 400 mg/kg BW showed highly significant inhibition of writhing in both neurogenic and inflammatory phases. While EETI also exhibited highly significant, compared to control, writhing inhibition for both the doses in acetic acid-induced writhing test. Moderate anti-inflammatory effect at a dose of 400 mg/kg BW was noticed in paw-edema test. It also showed 77.51% of maximum antipyretic effect which was significantly effective compared to standard drug paracetamol (150 mg/kg) in Brewer’s yeast-induced pyrexia test. The EETI showed potential cytotoxic activity with LC50 value of 114.46 μg/mL. The PASS prediction revealed the potential antinociceptive and antineoplastic activity of target compounds. The compounds betulinic acid, quercetin-3-α-arabinoside, catsanogenin were found to be effective in molecular docking study.

Conclusion

It is evident that the EETI possesses highly significant analgesic activity with remarkable anti-inflammatory and antipyretic activity. The phytoconstituents have potential antinociceptive and antineoplastic (breast cancer) activity.

Graphical abstract

Lavender Products Associated With Premature Thelarche and Prepubertal Gynecomastia: Case Reports and Endocrine-Disrupting Chemical Activities

CONTEXT

Previous case reports associated prepubertal gynecomastia with lavender-containing fragrances, but there appear to be no reports of premature thelarche.

OBJECTIVE

To add to a case series about lavender-fragranced product use and breast growth in children and to measure endocrine-disrupting chemical activity of essential oil components.

DESIGN, SETTING, AND PATIENTS

Patients experiencing premature thelarche or prepubertal gynecomastia with continuous exposure to lavender-fragranced products were evaluated in the pediatric endocrinology departments of two institutions. Mechanistic in vitro experiments using eight components of lavender and other essential oils were performed at National Institute of Environmental Health Sciences.

MAIN OUTCOME MEASURES

Case reports and in vitro estrogen and androgen receptor gene expression activities in human cell lines with essential oils.

RESULTS

Three prepubertal girls and one boy with clinical evidence of estrogenic action and a history of continuous exposure to lavender-containing fragrances were studied. Breast growth dissipated in all patients with discontinuation of the fragranced products. Some of the components tested elicited estrogenic and antiandrogenic properties of varying degrees.

CONCLUSION

We report cases of premature thelarche that resolved upon cessation of lavender-containing fragrance exposure commonly used in Hispanic communities. The precise developmental basis for such conditions could be multifactorial. In vitro demonstration of estrogenic and antiandrogenic properties of essential oil components suggests essential oils in these cases could be considered a possible source and supports a possible link with idiopathic prepubertal breast development. Whether the level of lavender oil estrogenic potency is sufficient to cause these effects is unknown.

The prognostic values of estrogen receptor alpha and beta in patients with gastroesophageal cancer: A meta-analysis

BACKGROUND

Published studies have investigated the prognostic roles of estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ) in gastroesophageal cancer patients with the controversial results. The aim of the study was to systematically evaluate the impacts of ERα and ERβ on the overall survival (OS) in patients.

METHOD

Relevant eligible studies were extracted from PubMed, Embase, Web of Science, CNKI and Wanfang databases (from the start date to November 2018) following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. HR (hazard ratio) with 95% confidence intervals (CIs) were used to assess the prognostic values of ERα and ERβ for OS in patients.

RESULTS

High ERα expression was associated with poor OS (HR = 1.58, 95% CI = 1.29-1.94, P < .001) and ERβ with better OS (HR = 0.56, 95% CI = 0.37-0.83, P = .004) in gastroesophageal cancer. Furthermore, unfavorable OS was found in Chinese gastroesophageal patients with higher ERα expression (HR = 1.57, 95% CI = 1.25-1.96, P < .001) and better OS with higher ERβ expression (HR = 0.51, 95% CI = 0.31-0.83, P < .01) in our subgroup analysis. Meanwhile, worse OS was found in esophageal squamous cell carcinoma (ESCC) patients with high ERα expression (HR = 1.74, 95% CI = 1.33-2.26, P < .001), and favorable OS in ESCC with ERβ overexpression (HR = 0.40, 95% CI = 0.31-0.52, P < .001). Besides, high ERα expression was associated with lower tumor differentiation in ESCC (OR = 1.64; 95% CI = 1.02-2.64, P = .04) and ERβ was linked with better tumor differentiation in gastric adenocarcinoma (GCA) (OR = 0.49; 95% CI = 0.26-0.94, P = .03).

CONCLUSIONS

ERα and ERβ might serve as potential prognostic biomarkers for gastroesophageal cancer patients. ERα overexpression predicted poor OS and lower tumor differentiation, and ERβ suggested favorable OS and better tumor differentiation. Further related studies should be performed to test these results.

Focus on the glycerophosphocholine pathway in choline phospholipid metabolism of cancer

Activated choline metabolism is a hallmark of carcinogenesis and tumor progression, which leads to elevated levels of phosphocholine and glycerophosphocholine in all types of cancer tested so far. Magnetic resonance spectroscopy applications have played a key role in detecting these elevated choline phospholipid metabolites. To date, the majority of cancer-related studies have focused on phosphocholine and the Kennedy pathway, which constitutes the biosynthesis pathway for membrane phosphatidylcholine. Fewer and more recent studies have reported on the importance of glycerophosphocholine in cancer. In this review article, we summarize the recent literature on glycerophosphocholine metabolism with respect to its cancer biology and its detection by magnetic resonance spectroscopy applications.

Crumbs protein homolog 3 (CRB3) expression is associated with oestrogen and progesterone receptor positivity in breast cancer

The crumbs protein homolog 3 (CRB3) regulates the tight junction to help maintain epithelial polarity. Altered CRB3 expression was associated with carcinogenesis of epithelial cells. This study detected CRB3 expression in 192 cases of breast cancer tissues and in the Molecular Taxonomy of Breast Cancer International Consortium (Metabric) and The Cancer Genome Atlas (TCGA) datasets for association with triple negative breast cancer (TNBC) phenotypes. The in vitro experiments confirm the ex vivo data. The data showed that levels of both CRB3 mRNA and protein were associated with TNBC phenotypes, ie, 41.1% (39/95) of ER+ breast cancer was CRB3-positive, whereas 26.9% (25/93) ER- tumour was CRB3-positive (P = 0.046). Moreover, 47.6% (30/63) of PR+ breast cancer was CRB3-positive vs 28.4% (33/116) PR- tumours positive for CRB3 (P = 0.013). In addition, 40.1% (27/66) of ER+/PR+ tumour was CRB3-positive, but only 22.4% (19/85) of TNBC showed CRB3 expression (P = 0.048). Indeed, levels of CRB3 mRNA were higher in non-TNBC than TNBC in both Metabric (P = 3.682e-10) and TCGA datasets (P = 2.501e-07). The in vitro data showed that CRB3 expression was higher in luminal (MCF7 and T47D) than in HER2 (MDA-MB-453 and SK-BR-3) and basal (MDA-MB-231 and BT-549) breast cancer cell lines. More interestingly, ERα regulated expression of CRB3 protein in MCF7 and BT-549 cells and ERα expression was associated with CRB3 expression in breast cancer tissues specimens. This study demonstrated that ERα could be a novel regulator for CRB3 expression in breast cancer.