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The rainbow trout (Oncorhynchus mykiss) is a typical cold-water species. However, due to global warming, it has experienced prolonged high-temperature stress. Research indicates that thermotolerance in rainbow trout varies by sex at multiple physiological levels. Specifically, females exhibit higher thermotolerance, which may be attributed to estrogen-mediated signal transduction pathways. This study involved culturing primary hepatocytes from rainbow trout and exposing them to estradiol and estrogen receptor antagonists to assess estradiol's protective effects. The analysis focused on expression of ER, HSPs genes, hepatocyte viability, and antioxidant indices. Four experimental groups were treated with 17-βE2 at concentrations of 0, 0.1, 1, and 10 μM/mL for durations of 4, 8, 12, 24, and 48 h at 18 °C. 17-βE2 treatment led to increased hepatocyte viability and enhanced SOD, GSH-Px, and CAT levels but decreased MDA levels. hsp70a, hsp90β, era1, and erβ1 levels were notably higher, with the optimal 17-βE2 concentration being 1.0 μM/mL. Following heat stress (24 °C), the addition of 1.0 μM/mL 17-βE2 improved hepatocyte viability and increased SOD, GSH-Px, and CAT levels, while MDA content initially decreased before rising. The gene expression of hsp70a, hsp90β, era1, and erβ1 was significantly elevated compared to controls. Flow cytometry analysis showed increased apoptosis after heat exposure; however, 17-βE2 treatment significantly reduced the heat stress-induced effects (p < 0.05). In conclusion, 17-βE2 and mild heat stress collaboratively enhanced the expression of HSPs and estrogen receptors, thereby providing protection to hepatocytes from heat stress damage, indicating a beneficial protective role of estradiol in rainbow trout hepatocytes. [ABSTRACT FROM AUTHOR]

Simple Summary: The role of the GPER in cancer is controversial due to its dual anti and protumor effects. Elevated GPER expression in cervical cancer has been associated with improved survival outcomes. In cervical cancer cell lines, the selective GPER agonist G-1 induces cell cycle arrest and apoptosis, although the precise molecular mechanisms behind these effects are not fully understood. This study explores the impact of GPER activation by G-1 on the transcriptome, cell migration, and invasion in SiHa cells, as well as in non-tumorigenic keratinocytes transduced with HPV16 E6 or E7 oncogenes. G-1 has been shown to exert antitumor effects by activating apoptotic pathways and modulating migration and invasion processes. The findings support the GPER as a promising prognostic marker and suggest that G-1 could be a valuable therapeutic tool for treating cervical cancer. Background/Objectives: Estrogens and HPV are necessary for cervical cancer (CC) development. The levels of the G protein-coupled estrogen receptor (GPER) increase as CC progresses, and HPV oncoproteins promote GPER expression. The role of this receptor is controversial due to its anti- and pro-tumor effects. This study aimed to determine the effect of GPER activation, using its agonist G-1, on the transcriptome, cell migration, and invasion in SiHa cells and non-tumorigenic keratinocytes transduced with the HPV16 E6 or E7 oncogenes. Methods: Transcriptome analysis was performed to identify G-1-enriched pathways in SiHa cells. We evaluated cell migration, invasion, and the expression of associated proteins in SiHa, HaCaT-16E6, and HaCaT-16E7 cells using various assays. Results: Transcriptome analysis revealed pathways associated with proliferation/apoptosis (TNF-α signaling, UV radiation response, mitotic spindle formation, G2/M cell cycle, UPR, and IL-6/JAK/STAT), cellular metabolism (oxidative phosphorylation), and cell migration (angiogenesis, EMT, and TGF-α signaling) in SiHa cells. Key differentially expressed genes included PTGS2 (pro/antitumor), FOSL1, TNFRSF9, IL1B, DIO2, and PHLDA1 (antitumor), along with under-expressed genes with pro-tumor effects that may inhibit proliferation. Additionally, DKK1 overexpression suggested inhibition of cell migration. G-1 increased vimentin expression in SiHa cells and reduced it in HaCaT-16E6 and HaCaT-16E7 cells. However, G-1 did not affect α-SMA expression or cell migration in any of the cell lines but increased invasion in HaCaT-16E7 cells. Conclusions: GPER is a promising prognostic marker due to its ability to activate apoptosis and inhibit proliferation without promoting migration/invasion in CC cells. G-1 could potentially be a tool in the treatment of this neoplasia. [ABSTRACT FROM AUTHOR]

Fertility treatment, including assisted reproductive technology (ART), is increasingly used. Sex hormones influence seizure control as well as interacting with antiseizure medications, and so the hormonal manipulation involved in fertility treatments has direct implications for people with epilepsy. Here, we summarise the various fertility treatments and consider their important influences on epilepsy care. While early observations raised concerns about seizure exacerbation associated with ART, there are limited data to guide best practice in people with epilepsy, and further research is needed. [ABSTRACT FROM AUTHOR]

Melatonin (N‐acetyl‐5‐methoxytryptamine, MLT) is suggested as a preventive agent and potential therapeutic option for breast cancer via its antioxidant as well as anticancer effects by modulating estrogen dependent and independent pathways. However, its rapid metabolic inactivation led scientists to discover novel MLT analogues. Therefore, a series of new indole‐based hydrazide/hydrazone derivatives were synthesized and characterized as MLT analogues in the present study. The initial aim is to investigate the cytotoxicity of novel 1‐ethyl indole hydrazone derivatives against two human breast cancer cells (MCF‐7 and MDA‐MB‐231) as well as a non‐tumorigenic human breast epithelial cell (MCF‐10A). Selective cytotoxic compounds for cancer cells are further investigated for their effects on selected targets; agonist/antagonist activity on estrogen receptor (ER) and inhibitory effects on aromatase and CYP1B1. Their potential antioxidant activity was also investigated by both cell based and cell free in vitro assays. Possible binding of the compounds to the selected targets is also explored by molecular modelling studies. Nonsubstituted compound E1 inhibited human aromatase and the CYP1B1 enzyme with IC50 values of 0.89 μM and 0.5 μM, respectively. Compounds EI 4 and EI 11 exhibited ER antagonist activity with IC50 values of 2.88 μM and 5.29 μM, respectively. Additionally, both EI 4 and EI 11 inhibited CYP1B1 enzyme within 60–100 nanomolar range. In conclusion among 19 tested derivatives EI 1, EI 4 and EI 11 affected either one or more targets besides their selective cytotoxic effect for MCF‐7 cells suggesting that they can be promising candidates in prevention/treatment of ER‐positive breast cancer. Further studies are needed to elucidate their metabolism, in vivo effects, and safety. [ABSTRACT FROM AUTHOR]

Purpose: Giredestrant is a potent, orally bioavailable, small-molecule selective estrogen receptor antagonist and degrader (SERD) that is being developed for the treatment of patients with estrogen receptor (ER)-positive breast cancer. In vitro, giredestrant was primarily metabolized by UGT1A4. The goal of this study was to investigate if UGT1A4 polymorphism had a clinically relevant impact on giredestrant exposure. Methods: Genotyping and pharmacokinetic data were obtained from 118 and 61 patients in two clinical studies, GO39932 [NCT03332797] and acelERA Breast Cancer [NCT04576455], respectively. Results: The overall allelic frequencies of UGT1A4*2 and UGT1A4*3 were 3.3% and 11%, respectively. Giredestrant exposure was consistent between patients with wild-type UGT1A4 and UGT1A4*2 and *3 polymorphisms, with no clinically relevant difference observed. In addition, haplotype analysis indicated that no other UGT1A4 variants were significantly associated with giredestrant exposure. Conclusion: Therefore, this study indicates that UGT1A4 polymorphism status is unlikely a clinically relevant factor to impact giredestrant exposure and giredestrant can be administered at the same dose level regardless of patients' UGT1A4 polymorphism status. [ABSTRACT FROM AUTHOR]

Background In women, ovarian cancer is the eighth most frequent cancer in incidence and mortality. It is often diagnosed at advanced stages; relapses are frequent, with a poor prognosis. When platinum resistant, subsequent lines of chemotherapy are of limited effect and often poorly tolerated, leading to quality of life deterioration. Various studies suggest a hormonal role in ovarian carcinogenesis, with a rationale for endocrine therapy in these cancers. Patients and Methods This multicenter, retrospective study assessed the use of endocrine treatment for high-grade ovarian epithelial carcinomas treated between 2010 and 2020. Results Eighty-one patients with ovarian cancers were included. The median duration of platinum sensitivity was 29 months. We observed a 35% disease control rate with endocrine therapy, and 10% reported symptom improvement. For 19 patients (23.5%), the disease was stabilized for more than 6 months. Median overall survival from diagnosis was 62.6 months. Regarding endocrine therapy predictive factors of response, in a multivariate analysis, 3 factors were statistically significant in favoring progression-free survival: platinum sensitivity (P  = .021), an R0 surgical resection (P  = .020), and the indication for hormone therapy being maintenance therapy (P  = .002) Conclusion This study shows real-life data on endocrine therapy in ovarian cancer. As it is a low-cost treatment with many advantages such as its oral administration and its safety, it may be an option to consider. A perspective lies in the search for cofactors to aim as future therapeutic targets to improve the effectiveness of hormone treatment by means of combination therapy. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to enhance the understanding of the role of estrogen in lymphangioleiomyomatosis(LAM) and to conclude the impact of estrogen-altering events on the condition and recent advances in estrogen-based treatments for LAM. Results: LAM development is strongly linked to mutations in the tuberous sclerosis gene (TSC1/2) and the presence of estrogen. Estrogen plays a significant role in the spread of TSC2-deficient uterine leiomyoma cells to the lungs and the production of pulmonary LAM. Menstruation, pregnancy, estrogen medication, and other events that cause an increase in estrogen levels can trigger the disorder, leading to a sudden worsening of symptoms. Current findings do not support using estrogen-blocking therapy regimens. However, Faslodex, which is an estrogen receptor antagonist, presents new possibilities for future therapeutic approaches in LAM. Conclusion: Estrogen is crucial in the development and spread of LAM. The use of estrogen inhibitors or estrogen receptor antagonists alone does not provide good control of the disease or even poses a greater risk, and the use of a combination of mTOR receptor inhibitors, complete estrogen receptor antagonists, estrogen inhibitors, and autophagy inhibitors targeting important signaling pathways in LAM pathogenesis may be of greater benefit to the patient. [ABSTRACT FROM AUTHOR]

Anxiety disorders are the most prevalent psychiatric disorders, exhibiting strong female bias. Clinical studies implicate declining estradiol levels in the exacerbation of anxiety symptoms in the premenstrual phase of the menstrual cycle. This study aimed to simulate estradiol fluctuation-linked anxiety behavior in larval zebrafish, using an estradiol treatment withdrawal model. Contrary to model aims, estradiol treatment withdrawal decreased both basal activity and anxiety-like hyperlocomotion (ANOVA main effect of dose, P < 0.0001 and P < 0.01, respectively) in the light/dark transition test. The accuracy of the estradiol washout model was not improved by longer durations of treatment or withdrawal. Basal activity was slightly altered by supraphysiological concentrations of WAY-200070 in the absence of added estradiol. Estrogen receptor (ER) β expression was not upregulated in larvae exposed to physiologically relevant, low concentrations of estradiol. Longer exposure to low concentrations of estradiol increased antioxidant capacity (P < 0.01). In addition, acute exposure to low concentrations of estradiol increased basal activity. Data suggest that in the current models, estradiol-associated altered activity levels were linked to more favorable redox status, rather than reflecting altered anxiety levels. As such, it is recommended that zebrafish larval behavioral analysis be conducted in parallel with mechanistic studies such as redox indicators, for investigations focused on ER signaling. [ABSTRACT FROM AUTHOR]

Evidence shows stereotactic ablative body radiotherapy (SABR) is used as a non-invasive ablative therapy in the treatment of multisite oligometastatic (OM) and oligoprogressive (OP) diseases originating from metastatic breast cancer. This study aims to report the treatment outcomes and to investigate what factors that are prognostic in terms of local control, progression-free survival (PFS) and overall survival (OS) in patients receiving SABR for extracranial OM and OP diseases originating from metastatic breast cancer. A retrospective review on treatment records of patients with OM and OP from metastatic breast cancer who underwent SABR at a single was carried out. SABR was performed with daily image-guided radiotherapy (IGRT) using a dedicated robotic SABR machine. Local control, PFS and OS were calculated using Kaplan-Meier statistics and the post-treatment toxicity data was scored following the CTCAE v4.0 protocol. Univariate and multivariate Cox regression tests were used in the subgroup analysis of prognostic factors on PFS and OS including patients' age, types of follow-up imaging (staging CT only vs whole-body MR/PET), metastases status (OM vs OP), primary breast cancer tumour grade, hormone receptors (ER/PR/HER2) status, change of systemic treatments at SABR, number of metastases, SABR treatment sites and doses. 56 metastatic breast cancer patients (38 patients with OM and 18 patients with OP) were involved in this retrospective review. The median follow-up was 35.6 months (range 4.0–132.9 months). The estimated local control at 1 , 2 and 5 years were 90.9%, 88.7% and 88.7%, respectively. The estimated median PFS was 19.2 months (95%CI 10.3–28.1 months); the PFS at 1, 2 and 5 years were 63.3%, 44.4% and 33.2%. The estimated OS at 1, 2 and 5 years were 98.0%, 91.9% and 74.3%, respectively with the estimated median OS of 105.1 months (95%CI 51.5–158.7 months). The vast majority of patients tolerated the treatment well with the commonest acute side effects as grade 1 fatigue. There were no statistically significant factors found in OS regression analysis. The types of follow-up imaging, metastases status, oestrogen receptor status, and number of metastases for SABR were statistically significant factors (p < 0.05) in the multivariate Cox regression analysis on PFS. There are limited studies published on the efficacy and post-treatment toxicities of metastatic breast cancer OM and OP SABR with adequate length of follow-up. This study confirmed that SABR was a safe, non-invasive treatment option for patients with extracranial OM and OP diseases originated from primary breast cancer in terms of the acceptable post-treatment toxicities. • This study reported SABR treatment outcomes for multisite OM and OP diseases originating from metastatic breast cancer • It showed modest local control and post-treatment toxicities on the SABR of extracranial OM and OP from metastatic breast cancer. • The types of follow-up imaging, OM vs OP, oestrogen receptor status, and number of metastases for SABR can be used as PFS prognostic factors. [ABSTRACT FROM AUTHOR]

The ethanol extract of Persea americana seeds was found to inhibit the development of estrogen-dependent conditions in female Wistar rats, suggesting the ability of its secondary metabolites to interact with estrogen receptors (ERs), either as partial agonists or as antagonists. To test this hypothesis, the abovementioned extract was assessed for its ability to mimic and/or antagonize estradiol effects. Two experiments were conducted in ovariectomized (OVX) rats: (1) animals were treated with estradiol valerate (E2V; 1 mg/kg) or P. americana at doses of 25 and 50 mg/kg; (2) animals were treated with E2V alone (0.75 mg/kg) or in combination with P. americana at the abovementioned doses. Treatments were given orally for 3 days and animals were sacrificed for biochemical and histological analyses of the uterus and vagina. When administered alone, P. americana did not change the histomorphology of both organs (uterus and vagina). In combination with E2V, P. americana decreased uterine weight [30 % decrease (p<0.001) at 25 mg/kg and 24 % (p<0.01) at 50 mg/kg] and epithelium height (37 % decrease). This was associated with decreased estradiol levels (at least 86 % decrease, p<0.001) in the uterus. Similarly, vagina epithelium height decreased by at least 34 % (p<0.05) when E2V was co-administered with P. americana. The seed extract of P. americana contains ER antagonist secondary metabolites accounting for its ability to inhibit the development of estrogen-dependent conditions in female rats. [ABSTRACT FROM AUTHOR]

Simple Summary: Head and neck tumors (HNTs) represent a diverse group of malignancies that originate from the lining tissue of organs in the upper parts of the respiratory and digestive tracts. Given that these include parts of the body that enable breathing, speech, and feeding, these tumors cause a great reduction in the quality of life. The main risk factors are consumption of tobacco products and alcohol, as well as infection with human papillomaviruses. However, regardless of the risk factors, men have a significantly higher risk of developing HNTs than women. It is, therefore, presumed that exposure to the female sex hormone estrogen in women could provide protection against the development of those tumors in women. In this scientific literature survey, we provide a comprehensive overview of the role of estrogen and its receptors in HNTs and assess the possible benefits of therapy with either exogenous estrogen or anti-estrogens. Head and neck squamous cell carcinoma (HNSCC) is the most common histological form of head and neck tumors (HNTs), which originate from the epithelium of the lips and oral cavity, pharynx, larynx, salivary glands, nasal cavity, and sinuses. The main risk factors include consumption of tobacco in all forms and alcohol, as well as infections with high-risk human papillomaviruses or the Epstein–Barr virus. Regardless of the etiological agent, the risk of developing different types of HNTs is from two to more than six times higher in males than in females. The reason for such disparities probably lies in a combination of both biological and psychosocial factors. Therefore, it is hypothesized that exposure to female sex hormones, primarily estrogen, provides women with protection against the formation and metastasis of HNTs. In this review, we synthesized available knowledge on the role of estrogen and estrogen receptors (ERs) in the development and progression of HNTs, with special emphasis on membrane ERs, which are much less studied. We can summarize that in addition to epidemiologic studies unequivocally pointing to the protective effect of estrogen in women, an increased expression of both nuclear ERs, ERα, and ERβ, and membrane ERs, ERα36, GPER1, and NaV1.2, was present in different types of HNSCC, for which anti-estrogens could be used as an effective therapeutic approach. [ABSTRACT FROM AUTHOR]

Background: Anxiety as an important psychological disorder that has affected many people and has made them to spend a lot of money for its treatment. Objectives: This study aims to assess the anxiolytic effect of the hydro-alcoholic extract of Anethum Graveolens L. seed (AGS) combined with the antagonist of estrogen receptor in female rats with anxiety. Materials & Methods: In this study, 66 female Wistar rats were divided into eight groups as follow as: Negative control (10 ml/kg saline), positive control (0.6 mg/kg diazepam), five groups of AGS extract (0.1, 1, 10, 100 and 1000 mg/kg) and tamoxifen+AGS extract (10 mg/kg). Anxiety indicators were measured by the elevated plus maze (EPM) test. Results: The percentage of time spent open arms (%OAT) and percentage open arms entry (%OAE) significantly increased after using 10 mg/Kg dose of AGS extract compared to control group. Tamoxifen could significantly reduce this increase caused by AGS extract on anxiety indices. Conclusion: Considering the anxiolytic effect of the hydro-alcoholic extract of AGS and the reduction of this effect by the antagonist of estrogen receptor (tamoxifen), it can be concluded that the extract's anxiolytic effect may be due to interaction with estrogen receptor. [ABSTRACT FROM AUTHOR]

Isoflavonoids have a wide range of biological effects. The majority of them could be helpful, while some could be dangerous, depending on the circumstances. These are plant secondary metabolites that, through a variety of metabolic pathways, mediate numerous biological functions. They are structurally related to estrogen and progesterone and have estrogenic and antiestrogenic effects in various tissues. Legumes are rich in proestrogenic isoflavones such Biochanin A and Formononetin, which are the starting points for the methylation of genistein and daidzein. In the current study, the effects of solid matrix priming (SMP), which uses nano-chitosan to treat salt stress in mung bean sprouts, were assessed. The findings demonstrated that isoflavone concentration in mung bean sprouts considerably increased after SMP with nano-chitosan. The chosen isoflavones also underwent an in-silico drug trial and toxicity assessment. [ABSTRACT FROM AUTHOR]

HER2-positive breast cancer is associated with aggressive behavior and reduced survival rates. Calcitriol restores the antiproliferative activity of antiestrogens in estrogen receptor (ER)-negative breast cancer cells by re-expressing ERα. Furthermore, calcitriol and its analog, EB1089, enhance responses to standard anti-cancer drugs. Therefore, we aimed to investigate EB1089 effects when added to the combined treatment of lapatinib and antiestrogens on the proliferation of HER2-positive breast cancer cells. BT-474 (ER-positive/HER2-positive) and SK-BR-3 (ER-negative/HER2-positive) cells were pre-treated with EB1089 to modulate ER expression. Then, cells were treated with EB1089 in the presence of lapatinib with or without the antiestrogens, and proliferation, phosphorylation array assays, and Western blot analysis were performed. The results showed that EB1089 restored the antiproliferative response to antiestrogens in SK-BR-3 cells and improved the inhibitory effects of the combination of lapatinib with antiestrogens in the two cell lines. Moreover, EB1089, alone or combined, modulated ERα protein expression and reduced Akt phosphorylation in HER2-positive cells. EB1089 significantly enhanced the cell growth inhibitory effect of lapatinib combined with antiestrogens in HER2-positive breast cancer cells by modulating ERα expression and Akt phosphorylation suppression. These results highlight the potential of this therapeutic approach as a promising strategy for managing HER2-positive breast cancer. [ABSTRACT FROM AUTHOR]

Background: Spironolactone (SPI) is a diuretic widely used to treat cardiovascular diseases (CVD) and is non-specific for mineralocorticoid receptors (MR) and with an affinity for progesterone (PR) and androgen (AR) receptors. Since 2009, it has been suggested that pharmaceuticals are emerging contaminants (called EDC), and recently, it was reported that most EDC are AR and MR antagonists and estrogen receptors (ER) agonists. Concerning SPI, endocrine-disrupting effects were observed in female western mosquitofish, but there are still no data regarding the SPI effects as a possible human EDC. Methods: In this work, aortic rings were used to analyze the contractility effects of SPI and the mode of action concerning the involvement of Ca2+ channels and endothelial pathways. Moreover, cytotoxic effects were analyzed by MTT assays. Results: SPI induces vasodilation in the rat aorta by endothelium-dependent mechanisms involving NO and by endothelium-independent mechanisms blocking Ca2+ channels. Moreover, a non-monotonic effect characteristic of EDC was observed for SPI-induced decrease in cell viability. Conclusions: Our findings suggest that SPI may act as an EDC at a human level. However, ex vivo studies with human arteries should be carried out to better understand this drug's implications for human health and future generations. [ABSTRACT FROM AUTHOR]

The article discusses the genitourinary syndrome of menopause (GSM), a condition where estrogen is absent in genital tissues postmenopausal. It reports a randomized controlled trial comparing vaginal estrogen, vaginal moisturizer, and placebo for treatment. It mentions that the most common symptom is vaginal dryness and pain with penetration. It emphasizes that treatment options include over-the-counter lubricants and vaginal estrogen.

Studies suggest that both genomic and nongenomic pathways are involved in mediating the salutary effects of steroids following traumatic brain injury (TBI). This study investigated the nongenomic effects of 17β-estradiol (E2) mediated by the PI3K/p-Akt pathway after TBI. Ovariectomized rats were apportioned to E2, E2-BSA (E2 conjugated to bovine serum albumin), G1 [G-protein-coupled estrogen receptor agonist (GPER)] or their vehicle was injected following TBI, whereas ICI (classical estrogen receptor antagonist), G15 (GPER antagonist), ICI + G15, and their vehicles were injected before the induction of TBI and injection of drugs. Diffuse TBI was induced by the Marmarou model. Evans blue (EBC, 5 h), brain water contents (BWC), histopathological changes, and brain PI3K and p-Akt protein expressions were measured 24 h after TBI. The veterinary comma scale (VCS) was assessed before and at different times after TBI. The results showed a reduction in BWC and EBC and increased VCS in the E2, E2-BSA, and G1 groups. Also, E2, E2-BSA, and G1 reduced brain edema, inflammation, and apoptosis. The ICI and G15 inhibited the beneficial effects of E2, E2-BSA, and G1 on these parameters. All drugs, following TBI, prevented the reduction of brain PI3K/p-Akt expression. The individual or combined use of ICI and G15 eliminated the beneficial effects of E2, E2-BSA, and G1 on PI3K/p-Akt expressions. These findings indicated that PI3K/p-Akt pathway plays a critical role in mediating the salutary effects of estradiol on histopathological changes and neurological outcomes following TBI, suggesting that GPER and classic ERs are involved in regulating the expression of PI3K/p-Akt. [ABSTRACT FROM AUTHOR]

Across the globe, metabolic syndrome, hyperuric acid, and their related diseases, such as cardiovascular disease, diabetes, and insulin resistance, are increasing in incidence due to metabolic imbalances. Due to the pathogenesis, women are more prone to these diseases than men. As estrogen levels decrease after menopause, obesity and metabolic disorders are more likely to occur. Men are also affected by hyperuric acid. To provide ideas for the prevention and treatment of metabolic syndrome and hyperuricemia, this article reviews and analyzes the relationship between estrogen receptors, metabolic syndrome, and hyperuricemia. Plain language summary: Influence of estrogen receptor on metabolic syndrome and hyperuricemia A narrative review discusses the mechanism of estrogen and estrogen receptors for metabolic syndrome and hyperuric acid, and highlights the important for prevention and treatment of metabolic balances. [ABSTRACT FROM AUTHOR]

Background: Rheumatoid arthritis (RA) is a prevalent autoimmune disease marked by chronic synovitis as well as cartilage and bone destruction. Halofuginone hydrobromide (HF), a bioactive compound derived from the Chinese herbal plant Dichroa febrifuga Lour., has demonstrated substantial anti-arthritic effects in RA. Nevertheless, the molecular mechanisms responsible for the anti-RA effects of HF remain unclear. Methods: This study employed a combination of network pharmacology, molecular docking, and experimental validation to investigate potential targets of HF in RA. Results: Network pharmacology analyses identified 109 differentially expressed genes (DEGs) resulting from HF treatment in RA. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses unveiled a robust association between these DEGs and the IL-17 signaling pathway. Subsequently, a protein-protein interaction (PPI) network analysis revealed 10 core DEGs, that is, EGFR, MMP9, TLR4, ESR1, MMP2, PPARG, MAPK1, JAK2, STAT1, and MAPK8. Among them, MMP9 displayed the greatest binding energy for HF. In an in vitro assay, HF significantly inhibited the activity of inflammatory macrophages, and regulated the IL-17 signaling pathway by decreasing the levels of IL-17 C, p-NF-κB, and MMP9. Conclusion: In summary, these findings suggest that HF has the potential to inhibit the activation of inflammatory macrophages through its regulation of the IL-17 signaling pathway, underscoring its potential in the suppression of immune-mediated inflammation in RA. [ABSTRACT FROM AUTHOR]

Simple Summary: The estrogen receptor (ER) plays a critical role in the initiation and progression of breast cancer. Utilizing specialized therapies aimed at the ER has been effective in many instances and is commonly employed in breast cancer treatment protocols. The selection of therapy depends on multiple factors, including the menopausal status, breast cancer stage, and unique tumor attributes. These therapies can function independently as monotherapy, or in conjunction or sequential alignment with other treatments, based on the distinct characteristics of the breast cancer and the patient's overall health. Furthermore, current research endeavors are focused on producing newer and more precise therapies for breast cancer, which include strategies to combat resistance mechanisms. The objective of this review is to provide a snapshot of the existing landscape and sketch out future paths for the progression of HR+ breast cancer treatments currently under clinical development. The hormone receptor-positive (HR+) type is the most frequently identified subtype of breast cancer. HR+ breast cancer has a more positive prognosis when compared to other subtypes, such as human epidermal growth factor protein 2-positive disorder and triple-negative disease. The advancement in treatment outcomes for advanced HR+ breast cancer has been considerably elevated due to the discovery of cyclin-dependent kinase 4/6 inhibitors and their combination effects with endocrine therapy. However, despite the considerable effectiveness of tamoxifen, a selective estrogen receptor modulator (SERMs), and aromatase inhibitors (AI), the issue of treatment resistance still presents a significant challenge for HR+ breast cancer. As a result, there is a focus on exploring new therapeutic strategies such as targeted protein degradation and covalent inhibition for targeting ERα. This article discusses the latest progress in treatments like oral selective ER degraders (SERDs), complete estrogen receptor antagonists (CERANs), selective estrogen receptor covalent antagonists (SERCAs), proteolysis targeting chimera (PROTAC) degraders, and combinations of CDK4/6 inhibitors with endocrine therapy. The focus is specifically on those compounds that have transitioned into phases of clinical development. [ABSTRACT FROM AUTHOR]

Sophora flavescens is a medicinal herb distributed widely in Japan and it has been used to treat various diseases and symptoms. To explore its pharmacological use, we examined the estrogenic activity of four prenylated flavonoids, namely kurarinone, kushenols A and I, and sophoraflavanone G, which are characterized by the lavandulyl group at position 8 of ring A, but have variations in the hydroxyl group at positions 3 (ring C), 5 (ring A) and 4' (ring B). These prenylated flavonoids were examined via cell proliferation assays using sulforhodamine B, Western blotting, and RT-PCR, corresponding to cell, protein, and transcription assays, respectively, based on estrogen action mechanisms. All the assays employed here found weak but clear estrogenic activities for the prenylated flavonoids examined. Furthermore, the activities were inhibited by an estrogen receptor antagonist, suggesting that the activities were likely being mediated by the estrogen receptors. However, there were differences in the activity, attributable to the hydroxyl group at position 4', which is absent in kushenol A. While the estrogenic activity of kurarinone and sophoraflavanone G has been reported before, to the best of our knowledge, there are no such reports on kushenols A and I. Therefore, this study represents the first report of their estrogenic activity. [ABSTRACT FROM AUTHOR]

Patients with estrogen receptor-positive (ER+) breast cancer, the most common subtype, remain at risk for lethal metastatic disease years after diagnosis. Recurrence arises partly because tumor cells in bone marrow become resistant to estrogen-targeted therapy. Here, we utilized a co-culture model of bone marrow mesenchymal stem cells (MSCs) and ER+ breast cancer cells to recapitulate interactions of cancer cells in bone marrow niches. ER+ breast cancer cells in direct contact with MSCs acquire cancer stem-like (CSC) phenotypes with increased resistance to standard antiestrogenic drugs. We confirmed that co-culture with MSCs increased labile iron in breast cancer cells, a phenotype associated with CSCs and disease progression. Clinically approved iron chelators and in-house lysosomal iron-targeting compounds restored sensitivity to antiestrogenic therapy. These findings establish iron modulation as a mechanism to reverse MSC-induced drug resistance and suggest iron modulation in combination with estrogen-targeted therapy as a promising, translatable strategy to treat ER+ breast cancer.

Background: 6-Gingerol (6-G) is the primary active phytocomponent of ginger and has been shown to regulate multiple targets against cancer and its treatment. Androgen receptors (ARs) remain critical in the progression of prostate cancer (PCa). This study focuses on investigating 6-G as a promising anti-cancerous agent that inhibits AR activity significantly. Methods: In this study, molecular docking simulation was done to investigate the binding affinity of 6-G and control drug Bicalutamide (BT) against oncogenic AR and tumor suppressor estrogen receptor β (ERβ). The crystal structure of AR and ERβ was retrieved from Protein Data Bank (PDB) and docked with 3D Pubchem structures of 6-G using iGEMDOCK and AutoDock. Further in vitro study was done to evaluate the antioxidant, anti-cancerous, apoptotic, and wound healing potential of 6-G. Results: The result displays that 6-G shows good binding affinity with AR and ERβ. Condensation of the nucleus, change in mitochondrial membrane potential (MMP) and the ability to induce reactive oxygen species (ROS) were done in human PCa PC-3 cells. Results from the MTT assay demonstrated that 6-G and control drug BT showed significant (p < 0.01) dose and time dependent inhibition of human PCa PC-3 cells. 6-G increased the ROS generation intracellularly and decreased the MMP, and cell migration in treated PCa PC-3 cells. 6-G treated cells showed fragmented, condensed chromatin and nuclear apoptotic bodies. Conclusions: Thus, this study validates 6-G as a potential drug candidate against human PCa. However, further study of the anticancer potency of 6-G has to be done before its use for PCa treatment. [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]

Background: At the end of the 19th century, Sir George Thomas Beatson first discovered the positive influence of a bilateral oophorectomy on the development of breast cancer lesions in women with advanced disease. Since then, endocrine therapy has been a key component of the treatment of both early (EBC) and advanced-stage (MBC) hormone receptor (HR)-positive breast cancer. Summary: This review discusses the evolution of this therapeutic approach from the introduction of high-dose estrogen therapy leading to the development of several antiestrogen therapies. Recently, the new generation of drugs includes selective estrogen receptor modulators, orally administered selective estrogen receptor degraders (SERDs), as well as more unique agents such as complete estrogen receptor antagonists, proteolysis targeting chimeric, and selective estrogen receptor covalent antagonists. These drugs are under evaluation in various levels of randomized clinical trials (RCTs) being evaluated in both early and metastatic settings. As of today, the options in EBC are ranging from short-term neoadjuvant endocrine therapy to monitor the responsiveness of Ki-67 to combined endocrine therapy in MBC, introducing the combination of endocrine therapy and CDK4/6 inhibition as well as PARP inhibition in patients with luminal breast cancer presenting with germline BRCA1/2 mutations. The results of global RCTs are settled in global and local guidelines to optimize the individual therapy of our patients with luminal EBC. Key Messages: Endocrine intervention in hormone-sensitive breast cancer remains one of the most important options in all settings of early and metastatic breast cancer. [ABSTRACT FROM AUTHOR]

Memories are rarely acquired under ideal conditions, rendering them vulnerable to profound omissions, errors, and ambiguities. Consistent with this, recent work using context fear conditioning has shown that memories formed after inadequate learning time display a variety of maladaptive properties, including overgeneralization to similar contexts. However, the neuronal basis of such poor learning and memory imprecision remains unknown. Using c-fos to track neuronal activity in male mice, we examined how these learning-dependent changes in context fear memory precision are encoded in hippocampal ensembles. We found that the total number of c-fos-encoding cells did not correspond with learning history but instead more closely reflected the length of the session immediately preceding c-fos measurement. However, using a c-fos-driven tagging method (TRAP2 mouse line), we found that the degree of learning and memory specificity corresponded with neuronal activity in a subset of dentate gyrus cells that were active during both learning and recall. Comprehensive memories acquired after longer learning intervals were associated with more double-labeled cells. These were preferentially reactivated in the conditioning context compared with a similar context, paralleling behavioral discrimination. Conversely, impoverished memories acquired after shorter learning intervals were associated with fewer double-labeled cells. These were reactivated equally in both contexts, corresponding with overgeneralization. Together, these findings provide two surprising conclusions. First, engram size varies with learning. Second, larger engrams support better neuronal and behavioral discrimination. These findings are incorporated into a model that describes how neuronal activity is influenced by previous learning and present experience, thus driving behavior.SIGNIFICANCE STATEMENT Memories are not always formed under ideal circumstances. This is especially true in traumatic situations, such as car accidents, where individuals have insufficient time to process what happened around them. Such memories have the potential to overgeneralize to irrelevant situations, producing inappropriate fear and contributing to disorders, such as post-traumatic stress disorder. However, it is unknown how such poorly formed fear memories are encoded within the brain. We find that restricting learning time results in fear memories that are encoded by fewer hippocampal cells. Moreover, these fewer cells are inappropriately reactivated in both dangerous and safe contexts. These findings suggest that fear memories formed at brief periods overgeneralize because they lack the detail-rich information necessary to support neuronal discrimination.

Aim:Addressing the fertility preservation needs of breast cancer patients with receptor-positive presents considerable dilemmas and difficulties. Case description: Presenting a case of a 35-year-old unmarried female with receptor-positive breast malignancy who was referred for fertility preservation. Counseling regarding remote risk with controlled ovarian stimulation using antagonist protocol was done. Antiestrogen therapy with letrozole was added to minimize the risk with supraphysiologic estrogen levels. Five mature metaphase II (MII) oocytes were retrieved and cryopreserved for future use. Conclusion: Oocyte cryopreservation in unmarried cancer patients is an acceptable option. The addition of antiestrogen-like letrozole is advisable in estrogen receptor-positive cases. Fertility concerns of young patients should be addressed with a multidisciplinary approach. [ABSTRACT FROM AUTHOR]

The developing CNS is exposed to physiological hypoxia, under which hypoxia-inducible factor α (HIFα) is stabilized and plays a crucial role in regulating neural development. The cellular and molecular mechanisms of HIFα in developmental myelination remain incompletely understood. A previous concept proposes that HIFα regulates CNS developmental myelination by activating the autocrine Wnt/β-catenin signaling in oligodendrocyte progenitor cells (OPCs). Here, by analyzing a battery of genetic mice of both sexes, we presented in vivo evidence supporting an alternative understanding of oligodendroglial HIFα-regulated developmental myelination. At the cellular level, we found that HIFα was required for developmental myelination by transiently controlling upstream OPC differentiation but not downstream oligodendrocyte maturation and that HIFα dysregulation in OPCs but not oligodendrocytes disturbed normal developmental myelination. We demonstrated that HIFα played a minor, if any, role in regulating canonical Wnt signaling in the oligodendroglial lineage or in the CNS. At the molecular level, blocking autocrine Wnt signaling did not affect HIFα-regulated OPC differentiation and myelination. We further identified HIFα-Sox9 regulatory axis as an underlying molecular mechanism in HIFα-regulated OPC differentiation. Our findings support a concept shift in our mechanistic understanding of HIFα-regulated CNS myelination from the previous Wnt-dependent view to a Wnt-independent one and unveil a previously unappreciated HIFα-Sox9 pathway in regulating OPC differentiation.SIGNIFICANCE STATEMENT Promoting disturbed developmental myelination is a promising option in treating diffuse white matter injury, previously called periventricular leukomalacia, a major form of brain injury affecting premature infants. In the developing CNS, hypoxia-inducible factor α (HIFα) is a key regulator that adapts neural cells to physiological and pathologic hypoxic cues. The role and mechanism of HIFα in oligodendroglial myelination, which is severely disturbed in preterm infants affected with diffuse white matter injury, is incompletely understood. Our findings presented here represent a concept shift in our mechanistic understanding of HIFα-regulated developmental myelination and suggest the potential of intervening with an oligodendroglial HIFα-mediated signaling pathway to mitigate disturbed myelination in premature white matter injury.

Maternal endocrine homeostasis is vital to a successful pregnancy, regulated by several hormones such as human chorionic gonadotropin, estrogen, leptin, glucocorticoid, insulin, prostaglandin, and others. Endocrine stress during pregnancy can modulate nutrient availability from mother to fetus, alter fetoplacental growth and reproductive functions. Endocrine disrupters such as bisphenols (BPs) and phthalates are exposed in our daily life's highest volume. Therefore, they are extensively scrutinized for their effects on metabolism, steroidogenesis, insulin signaling, and inflammation involving obesity, diabetes, and the reproductive system. BPs have their structural similarity to 17-β estradiol and their ability to bind as an agonist or antagonist to estrogen receptors to elicit an adverse response to the function of the endocrine and reproductive system. While adults can negate the adverse effects of these endocrine-disrupting chemicals (EDCs), fetuses do not equip themselves with enzymatic machinery to catabolize their conjugates. Therefore, EDC exposure makes the fetoplacental developmental window vulnerable to programming in utero. On the one hand prenatal BPs and phthalates exposure can impair the structure and function of the ovary and uterus, resulting in placental vascular defects, inappropriate placental expression of angiogenic growth factors due to altered hypothalamic response, expression of nutrient transporters, and epigenetic changes associated with maternal endocrine stress. On the other, their exposure during pregnancy can affect the offspring's metabolic, endocrine and reproductive functions by altering fetoplacental programming. This review highlights the latest development in maternal metabolic and endocrine modulations from exposure to estrogenic mimic chemicals on subcellular and transgenerational changes in placental development and its effects on fetal growth, size, and metabolic & reproductive functions. [ABSTRACT FROM AUTHOR]

The estrogen receptor (ER) is a classical receptor protein that plays a crucial role in mediating multiple signaling pathways in various target organs. It has been shown that ER-targeting therapies inhibit breast cancer cell proliferation, enhance neuronal protection, and promote osteoclast formation. Several drugs have been designed to specifically target ER in ER-positive (ER+) breast cancer, including selective estrogen receptor modulators (SERM) such as Tamoxifen. However, the emergence of drug resistance in ER+ breast cancer and the potential side effects on the endometrium which has high ER expression has posed significant challenges in clinical practice. Recently, novel ER-targeted drugs, namely, selective estrogen receptor degrader (SERD) and selective estrogen receptor covalent antagonist (SERCA) have shown promise in addressing these concerns. This paper provides a comprehensive review of the structural functions of ER and highlights recent advancements in SERD and SERCA-related small molecule drugs, especially focusing on their structural optimization strategies and future optimization directions. Additionally, the therapeutic potential and challenges of novel SERDs and SERCAs in breast cancer and other ER-related diseases have been discussed. [ABSTRACT FROM AUTHOR]

Two previously undescribed flavonoid thioglucosides lepidiumflavonosides A and B (1–2) and two known megastigmane compounds (7E,9S)-9-hydroxy-5,7-megastigmadien-4-one 9-O-β-D-glucopyranoside (3) and (9S)-4-oxo-β-inol β-D-glucopyranoside (4) were isolated from the water extract of the seeds of Lepidium apetalum Willd. The structural elucidation of isolated compounds was unambiguously determined based on extensive 1D and 2D NMR spectroscopic analyses. All compounds were evaluated for their estrogen-like effects on MCF-7 cells in vitro. The results showed that compounds 1–4 significantly promoted the proliferation of MCF-7 cells, and the proliferation was antagonized by the specific ER antagonist ICI182,780, suggesting that compounds 1–4 might have the estrogen-like effect in vitro potentially. [ABSTRACT FROM AUTHOR]

Background: Based on previous studies of vaginal lubrication as well as our own previously reported interview study of women who self-reported methamphetamine (meth)–induced vaginal lubrication, in the current study we sought to determine the potential dose-response relationship leading to meth-induced vaginal lubrication. We also developed an animal model to study the reported effects and examine potential mechanisms mediating this phenomenon. Aim: We sought to characterize the effects of meth on vaginal lubrication in an animal model with the aim of providing a potential framework for new mechanisms that incorporate novel therapeutic agents for the treatment of vaginal dryness. Methods: Vaginal lubrication was measured via insertion of a preweighed, cotton-tipped swab into the vaginal canal of anesthetized rats following treatment with various doses of intravenous (IV) meth, up to 0.96 mg/kg, and after additional pharmacological manipulations, including administration of a nitric oxide synthase inhibitor and an estrogen receptor antagonist. Plasma signaling molecules, including estradiol, progesterone, testosterone, nitric oxide, and vasoactive intestinal polypeptide, were measured immediately before and at 9 time points after IV meth administration. Blood was collected via a previously implanted chronic indwelling jugular catheter and analyzed by use of commercially available kits per the manufacturer's instructions. Outcomes: Outcomes for this study include the measurement of vaginal lubrication in anesthetized rats following various pharmacological manipulations and plasma levels of various signaling molecules. Results: Meth dose-dependently increased vaginal lubrication in anesthetized female rats. Meth significantly increased plasma levels compared to baseline of estradiol (2 and 15 minutes after meth infusion) as well as progesterone, testosterone, and nitric oxide (10 minutes after meth infusion). Also, vasoactive intestinal polypeptide decreased significantly compared to baseline for 45 minutes following meth infusion. Our data further suggest that nitric oxide, but not estradiol, is critical in the production of vaginal secretions in response to meth. Clinical Implications: This study has far-reaching implications for women who are suffering from vaginal dryness and for whom estrogen therapy is unsuccessful, as the investigation has demonstrated that meth presents a novel mechanism for producing vaginal lubrication that can be targeted pharmacologically. Strengths and Limitations: This study is, to our knowledge, the first performed to measure the physiological sexual effects of meth in an animal model. Animals were anesthetized when they were administered meth. In an ideal situation, animals would be self-administering the drug to recapitulate better the contingent nature of drug taking; however, this method was not feasible for the study reported here. Conclusion: Methamphetamine increases vaginal lubrication in female rats through a nitric oxide–dependent mechanism. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the effect of estrogen pre-treatment in patients with different ovarian response in antagonist protocol. Methods: Randomized controlled trials (RCTs) and retrospective studies about the effect of estrogen pre-treatment in antagonist prorocol were searched in PubMed, Web of Science, China National Knowledge Infrastructure, Wanfang Database. R software was used for meta-analysis. Results: Seven RCTs and two retrospective studies were included. In order to explore the source of heterogeneity, subgroup analysis was used, which was mainly conducted according to the ovarian response of the included population, which were divided into low responders, non-low responders and mixed responders. In the study about gonadotropin hormone (Gn) days, patients were divided into wash-out subgroup and non-wash-out subgroup according to drug use-pattern. Meta-results showed that the number of Gn days increased significantly in the non-wash-out subgroup (WMD=1.07, 95%CI[0.83; 1.31], I²= 66%). The number of Gn days in the wash-out subgroup were not affected (WMD = -0.12, 95%CI [-0.45; 0.21], I² = 0%). In the low-response subgroup, the number of oocytes retrieved (WMD = 0.46, 95% CI [-0.23;1.16], I² = 81%), the fresh cycle clinical pregnancy rate (RR = 0.77, 95%CI [0.55; 1.06], I² = 73%) and the cycle cancellation rate (RR = 0.80, 95%CI [0.40; 1.61], I² =83%) were not significantly changed with estrogen pre-treatment. In the non-low-response subgroup, the number of oocytes obtained (WMD = 0.21, 95%CI [-0.69; 1.11], I²=2%), fresh cycle clinical pregnancy rate (RR=0.94, 95% CI [0.77; 1.14], I²=41%), live birth rate (RR=0.82, 95% CI [0.62; 1.08], I²=0%) and cycle cancellation rate (RR=0.89, 95%CI [0.54; 1.47], I²=2%) were not significantly changed with estrogen pretreatment. Conclusions: Estrogen pre-treatment (with non-wash-out period) in antagonist protocol increases Gn days, dose not improve IVF outcomes in non-low responders and low responders. [ABSTRACT FROM AUTHOR]

GDC‐9545 (giredestrant) is a highly potent, nonsteroidal, oral selective estrogen receptor antagonist and degrader that is being developed as a best‐in‐class drug candidate for early‐stage and advanced drug‐resistant breast cancer. GDC‐9545 was designed to improve the poor absorption and metabolism of its predecessor GDC‐0927, for which development was halted due to a high pill burden. This study aimed to develop physiologically‐based pharmacokinetic/pharmacodynamic (PBPK‐PD) models to characterize the relationships between oral exposure of GDC‐9545 and GDC‐0927 and tumor regression in HCI‐013 tumor‐bearing mice, and to translate these PK‐PD relationships to a projected human efficacious dose by integrating clinical PK data. PBPK and Simeoni tumor growth inhibition (TGI) models were developed using the animal and human Simcyp V20 Simulator (Certara) and adequately described each compound's systemic drug concentrations and antitumor activity in the dose‐ranging xenograft experiments in mice. The established PK‐PD relationship was translated to a human efficacious dose by substituting mouse PK for human PK. PBPK input values for human clearance were predicted using allometry and in vitro in vivo extrapolation approaches and human volume of distribution was predicted from simple allometry or tissue composition equations. The integrated human PBPK‐PD model was used to simulate TGI at clinically relevant doses. Translating the murine PBPK‐PD relationship to a human efficacious dose projected a much lower efficacious dose for GDC‐9545 than GDC‐0927. Additional sensitivity analysis of key parameters in the PK‐PD model demonstrated that the lower efficacious dose of GDC‐9545 is a result of improvements in clearance and absorption. The presented PBPK‐PD methodology can be applied to support lead optimization and clinical development of many drug candidates in discovery or early development programs. [ABSTRACT FROM AUTHOR]

Breast cancer is globally associated with majority of the women. Indeed, high estrogen levels are the most common subtype of breast cancer. Three different classes of estrogen receptor antagonists are frequently used to treat such kinds of breast cancers. Each of these interacts directly with the initiation and activation of the estrogen signalling pathway. However, new medicines must be developed because resistance limits the therapeutic effectiveness. In silico studies for drug discovery have become popular in recent years due to their low cost and quick execution. To develop novel therapeutics for breast cancer, three different series of benzimidazole compounds targeting the estrogen receptor were docked. Among these three series, benzimidazole fused with pyrazole showed significant results and the leading compound was 32 based on docking results. The docking data was further validated by executing molecular dynamics (MD) simulations for the stability of designed leads within the macromolecular cavity in relation to time. Therefore, it is proposed that the pyrazole fused benzimidazole nucleus can be a promising pharmacophore for developing novel anticancer therapeutics for breast cancer. [ABSTRACT FROM AUTHOR]