Search Results (47)

Background: Targeted therapies, such as endocrine agents, have significantly improved outcomes for patients with estrogen receptor alpha-positive (ERα+) breast cancer. Unfortunately, for patients with triple-negative breast cancer (TNBC), which lack expression of ERα and HER2, there remains a dearth of targeted adjuvant agents. We discovered that estrogen receptor beta (ERβ) is expressed in approximately 20% of TNBC cases, and its activation has been shown to inhibit proliferation, invasion, and migration in preclinical models. However, it remains unclear whether ERβ-targeted therapies maintain efficacy following the development of chemoresistance. Methods: To address this question, we generated ERβ+ TNBC cell line models with acquired resistance to paclitaxel or doxorubicin. We then assessed their response to ERβ-targeted therapies and analyzed transcriptomic changes associated with chemoresistance and ERβ ligand treatment. Results: Chemotherapy-resistant ERβ+ TNBC cells retained sensitivity to ERβ-targeted therapies and, in some cases, exhibited enhanced responsiveness. ERβ expression did not compromise chemotherapy efficacy in treatment-naïve cells. Chemotherapy-resistant cells had a vastly altered transcriptome and surprisingly, a heavily reduced ERβ transcriptome, compared to sensitive cells despite the maintenance of ERβ-driven anti-neoplastic activity. Conclusions: These findings suggest that ERβ remains a relevant drug target in chemotherapy-refractory disease and has aided in the refinement of a minimal ERβ transcriptomic signature associated with response to ERβ-targeting agents, further informing the primary mechanisms through which ERβ elicits its tumor suppressive effects. Full article

Oral inflammation and the immune response are distinct but related processes where Linum usitatissimum L., fam. Linaceae represents a possible use for localized relief. Oral lichen planus (OLP) is an oral potentially malignant disorder (OPMD) with an inflammatory background that mainly affects post- and peri-menopausal women. The presented methodology was threefold. Firstly, the plant extracts were made from flaxseeds of selected cultivars (Szafir [SZ] and Jantarol [JA]) containing plant lignans. In silico docking affinity was performed to verify the beta and alpha estrogen receptors of keratinocytes’ (ERα and ERβ) affinity for lignans from the plant extracts. Lastly, tests using living keratinocyte cell lines were performed. Adding the studied extracts from two cultivars of flaxseed—JA and SZ (10 µg/mL) reduced lipopolysaccharides (LPS)—induced cell inflammation markers levels of COX-2 and IL-6. The effect of JA was more pronounced than that of SZ, with statistical significance (p < 0.05). A high in silico affinity was provided during secoisolariciresinol diglucoside (SDG) docking to ERα and ERβ. Flaxseed’s action could be based on the docking affinity of its major components to the estrogen receptors and the overall concentration of the elements of the extracts. Full article

Background/Objectives: Gelsolin (GSN) is an actin-binding protein that helps maintain neuronal structure and shape, regulates neuronal growth, and apoptosis. Our previous work demonstrated that GSN associated with estrogen receptor beta (ERβ1) in the brains of female rats, but this association was lost in advanced age. GSN was also required for ERβ1-mediated transcriptional repression at activator protein-1 (AP-1) motifs upstream of a minimal gene promoter. However, the consequences of the loss of GSN:ERβ1 protein interaction on ERβ1 nuclear translocation and transcriptional repression at AP-1 sites located within complex endogenous gene promoters remained unclear. Methods: We used immunofluorescent super resolution microscopy and luciferase reporter assays to test the hypothesis that GSN facilitates ERβ1 nuclear translocation and transcriptional repression of two genes relevant for Alzheimer Disease: APP (amyloid-beta precursor protein) and ITPKB (inositol-1,4,5-trisphosphate 3-kinase B). Results: Our results revealed the novel finding that GSN is required for ERβ1 ligand-independent nuclear translocation in neuronal cells. Moreover, we show that GSN increased APP and ITPKB promoter activity, which was repressed by ERβ1. Conclusions: Together, these data revealed the importance of the cytoskeletal protein, GSN, in regulating intracellular trafficking of nuclear receptors and demonstrate the first evidence of ERβ1 directly regulating two genes that are implicated in the progression of AD. Full article

Lipedema is a chronic, idiopathic, and painful disease characterized by an excess of adipose tissue in the extremities. The goal of this study is to characterize the gene expression of estrogen receptors (ERα and ERβ), G protein-coupled estrogen receptor (GPER), and ER-metabolizing enzymes: hydroxysteroid 17-beta dehydrogenase (HSD17B1, 7, B12), cytochrome P450 (CYP19A1), hormone-sensitive lipase (LIPE), enzyme steroid sulfatase (STS), and estrogen sulfotransferase (SULT1E1), which are markers in Body Mass Index (BMI) and age-matched non-lipedema (healthy) and lipedema ASCs and spheroids. Flow cytometry and cellular proliferation assays, RT-PCR, and Western Blot techniques were used to determine the expression of ERs and estrogen-metabolizing enzymes. In 2D monolayer culture, estrogen increased the proliferation and the expression of the mesenchymal marker, CD73, in hormone-depleted (HD) healthy ASCs compared to lipedema ASCs. The expression of ERβ was significantly increased in HD lipedema ASCs and spheroids compared to corresponding healthy cells. In contrast, ERα and GPER gene expression was significantly decreased in estrogen-treated lipedema spheroids. CYP19A1 and LIPE gene expressions were significantly increased in estrogen-treated healthy ASCs and spheroids, respectively, while estrogen upregulated the expression of PPAR-ϒ2 and ERα in estrogen-treated lipedema-differentiated adipocytes and spheroids. These results indicate that estrogen may play a role in adipose tissue dysregulation in lipedema. Full article

The etiopathogenesis of preeclampsia, a leading hypertensive disorder of pregnancy, has been proposed to involve an abnormal circulating sex hormone profile and misexpression of placental estrogen and progesterone receptors (ER and PR, respectively). However, existing research is vastly confined to third trimester preeclamptic placentas. Consequently, the placental–uterine molecular crosstalk and the dynamic ER and PR expression pattern in the peri-conception period remain overlooked. Herein, our goal was to use the BPH/5 mouse to elucidate pre-pregnancy and early gestation Er and Pr dynamics in a preeclamptic-like uterus. BPH/5 females display low circulating estrogen concentration during proestrus, followed by early gestation hypoestrogenemia, hyperprogesteronemia, and a spontaneous preeclamptic-like phenotype. Preceding pregnancy, the gene encoding Er alpha (Erα, Esr1) is upregulated in the diestrual BPH/5 uterus. At the peak of decidualization, Esr1, Er beta (Erβ, Esr2), and Pr isoform B (Pr-B) were upregulated in the BPH/5 maternal–fetal interface. At the protein level, BPH/5 females display higher percentage of decidual cells with nuclear Erα expression, as well as Pr downregulation in the decidua, luminal and glandular epithelium. In conclusion, we provide evidence of disrupted sex hormone signaling in the peri-conception period of preeclamptic-like pregnancies, potentially shedding some light onto the intricate role of sex hormone signaling at unexplored timepoints of human preeclampsia. Full article

Canine-mammary-gland tumors (CMTs) are prevalent in female dogs, with approximately 50% of them being malignant and often presenting as inoperable owing to their size or metastasis. Owing to poor outcomes, effective alternatives to conventional chemotherapy for humans are necessary. Two estrogen receptors, estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ), which act in opposition to each other, are involved, and CMT growth involves ERα through the phosphoinositide 3-kinases (PI3K)/AKT pathway. In this study, we aimed to identify the synergistic anti-cancer effects of ERB-041, an ERβ agonist, and genistein, an isoflavonoid from soybeans known to have ERβ-specific pseudo-estrogenic actions, on CMT-U27 and CF41.Mg CMT cell lines. ERB-041 and genistein synergistically inhibited cell proliferation and increased the number of annexin V-positive cells in both cell lines. Furthermore, we observed a synergistic increase in the Bax/Bcl-2 ratio and cleaved caspase-3 expression. Additionally, cell-cycle arrest occurred through the synergistic regulation of cyclin D1 and cyclin-dependent kinase 4 (CDK4). We also found a synergistic decrease in the expression of ERα, and the expression of proteins involved in the PI3K/AKT pathway, including p-PI3K, phosphatase and tensin homolog (PTEN), AKT, and mechanistic target of rapamycin (mTOR). In conclusion, ERB-041 and genistein exhibited a synergistic anticancer effect on CMTs, suggesting that cotreatment with ERB-041 and genistein is a promising treatment for CMTs. Full article

This study investigated the interplay between transforming growth factor beta (TGF-β1/T1 and TGF-β3/T3), and sex hormone receptors using our 3D in vitro cornea stroma model. Primary human corneal fibroblasts (HCFs) from healthy donors were plated in transwells at 10⁶ cells/well and cultured for four weeks. HCFs were supplemented with stable vitamin C (VitC) and stimulated with T1 or T3. 3D construct proteins were analyzed for the androgen receptor (AR), progesterone receptor (PR), estrogen receptor alpha (ERα) and beta (ERβ), luteinizing hormone receptor (LHR), follicle-stimulating hormone receptor (FSHR), gonadotropin-releasing hormone receptor (GnRHR), KiSS1-derived peptide receptor (KiSS1R/GPR54), and follicle-stimulating hormone subunit beta (FSH-B). In female constructs, T1 significantly upregulated AR, PR, ERα, FSHR, GnRHR, and KiSS1R. In male constructs, T1 significantly downregulated FSHR and FSH-B and significantly upregulated ERα, ERβ, and GnRHR. T3 caused significant upregulation in expressions PR, ERα, ERβ, LHR, FSHR, and GNRHR in female constructs, and significant downregulation of AR, ERα, and FSHR in male constructs. Semi-quantitative Western blot findings present the interplay between sex hormone receptors and TGF-β isoforms in the corneal stroma, which is influenced by sex as a biological variable (SABV). Additional studies are warranted to fully delineate their interactions and signaling mechanisms. Full article

Estrogen receptor beta 1 (ERβ1) is a ligand-activated nuclear receptor, which has been shown to maintain tissue differentiation in the normal prostate, and regulate androgen response and increase expression of tumor suppressors in prostate cancer cell lines. There are three shorter isoforms of ERβ expressed in the human prostate, ERβ2, ERβ4, and ERβ5, which have already been implicated in chemotherapy resistance and disease progression, suggesting a possible oncogenic role. Their ligand-binding domain (LBD) is truncated, so they are unable to activate canonical ERβ1 signaling pathways; however, they were shown to participate in hypoxic signaling and to induce a gene expression signature associated with stemness and hypoxia. To elucidate the role of the truncated ERβ isoforms in prostate cancer, we created a knockout of all isoforms, as well as a truncation of the LBD, to remove the function of ERβ1. We showed that the removal of all isoforms leads to a decrease in the expression of cancer stem cell (CSC)-associated genes, decreased chemotherapy resistance, and a decrease in the CSC population, based on sphere formation ability and SORE6 (CSC reporter) activity, while removing the LBD function only had the opposite effect. Our results suggest a more aggressive phenotype in prostate cancer cell lines expressing ERβ variants. Full article

Obesity is a pandemic and a serious health problem in developed and undeveloped countries. Activation of estrogen receptor beta (ERβ) has been shown to promote weight loss without modifying caloric intake, making it an attractive target for developing new drugs against obesity. This work aimed to predict new small molecules as potential ERβ activators. A ligand-based virtual screening of the ZINC15, PubChem, and Molport databases by substructure and similarity was carried out using the three-dimensional organization of known ligands as a reference. A molecular docking screening of FDA-approved drugs was also conducted as a repositioning strategy. Finally, selected compounds were evaluated by molecular dynamic simulations. Compounds 1 (−24.27 ± 0.34 kcal/mol), 2 (−23.33 ± 0.3 kcal/mol), and 6 (−29.55 ± 0.51 kcal/mol) showed the best stability on the active site in complex with ERβ with an RMSD < 3.3 Å. RMSF analysis showed that these compounds do not affect the fluctuation of the Cα of ERβ nor the compactness according to the radius of gyration. Finally, an in silico evaluation of ADMET showed they are safe molecules. These results suggest that new ERβ ligands could be promising molecules for obesity control. Full article

Phytoestrogens have been suggested to have an anti-proliferative role in prostate cancer, potentially by acting through estrogen receptor beta (ERβ) and modulating several hormones. We primarily aimed to investigate the effect of a phytoestrogen intervention on hormone concentrations in blood depending on the ERβ genotype. Patients with low and intermediate-risk prostate cancer, scheduled for radical prostatectomy, were randomized to an intervention group provided with soybeans and flaxseeds (∼200 mg phytoestrogens/d) added to their diet until their surgery, or a control group that was not provided with any food items. Both groups received official dietary recommendations. Blood samples were collected at baseline and endpoint and blood concentrations of different hormones and phytoestrogens were analyzed. The phytoestrogen-rich diet did not affect serum concentrations of testosterone, insulin-like growth factor 1, or sex hormone-binding globulin (SHBG). However, we found a trend of decreased risk of increased serum concentration of estradiol in the intervention group compared to the control group but only in a specific genotype of ERβ (p = 0.058). In conclusion, a high daily intake of phytoestrogen-rich foods has no major effect on hormone concentrations but may lower the concentration of estradiol in patients with prostate cancer with a specific genetic upset of ERβ. Full article

Castration-resistant prostate cancer, or CRPC, is an aggressive stage of prostate cancer (PCa) in which PCa cells invade nearby or other parts of the body. When a patient with PCa goes through androgen deprivation therapy (ADT) and the cancer comes back or worsens, this is called CRPC. Instead of androgen-dependent signalling, recent studies show the involvement of the estrogen pathway through the regulation of estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ) in CRPC development. Reduced levels of testosterone due to ADT lead to low ERβ functionality in inhibiting the proliferation of PCa cells. Additionally, ERα, which possesses androgen independence, continues to promote the proliferation of PCa cells. The functions of ERα and ERβ in controlling PCa progression have been studied, but further research is needed to elucidate their roles in promoting CRPC. Finding new ways to treat the disease and stop it from becoming worse will require a clear understanding of the molecular processes that can lead to CRPC. The current review summarizes the underlying processes involving ERα and ERβ in developing CRPC, including castration-resistant mechanisms after ADT and available medication modification in mitigating CRPC progression, with the goal of directing future research and treatment. Full article

Hydrogen peroxide is one of the most important reactive oxygen species, which plays a vital role in many physiological and pathological processes. A dramatic increase in H₂O₂ levels is a prominent feature of cancer. Therefore, rapid and sensitive detection of H₂O₂ in vivo is quite conducive to an early cancer diagnosis. On the other hand, the therapeutic potential of estrogen receptor beta (ERβ) has been implicated in many diseases including prostate cancer, and this target has attracted intensive attention recently. In this work, we report the development of the first H₂O₂-triggered ERβ-targeted near-infrared fluorescence (NIR) probe and its application in imaging of prostate cancer both in vitro and in vivo. The probe showed good ERβ selective binding affinity, excellent H₂O₂ responsiveness and near infrared imaging potential. Moreover, in vivo and ex vivo imaging studies indicated that the probe could selectively bind to DU-145 prostate cancer cells and rapidly visualizes H₂O₂ in DU-145 xenograft tumors. Mechanistic studies such as high-resolution mass spectrometry (HRMS) and density functional theory (DFT) calculations indicated that the borate ester group is vital for the H₂O₂ response turn-on fluorescence of the probe. Therefore, this probe might be a promising imaging tool for monitoring the H₂O₂ levels and early diagnosis studies in prostate cancer research. Full article

The estrogen receptor beta (ERβ) is physiologically essential for reproductive biology and is implicated in various diseases. However, despite more than 20 years of intensive research on ERβ, there are still uncertainties about its distribution in tissues and cellular expression. Several studies show contrasts between mRNA and protein levels, and the use of knockout strategies revealed that many commercially available antibodies gave false-positive expression results. Recently, a specific monoclonal antibody against human ERβ (PPZ0506) showed cross-reactivity with rodents and was optimized for the detection of rat ERβ. Herein, we established an immunohistochemical detection protocol for ERβ protein in mouse tissue. Staining was optimized on murine ovaries, as granulosa cells are known to strongly express ERβ. The staining results were confirmed by western blot analysis and RT-PCR. To obtain accurate and reliable staining results, different staining conditions were tested in paraffin-embedded tissues. Different pitfalls were encountered in immunohistochemical detection. Strong heat-induced epitope retrieval (HIER) and appropriate antibody dilution were required to visualize specific nuclear expression of ERβ. Finally, the specificity of the antibody was confirmed by using ovaries from Esr2-depleted mice. However, in some animals, strong (non-specific) background staining appeared. These signals could not be significantly alleviated with commercially available additional blocking solutions and are most likely due to estrus-dependent expression of endogenous immunoglobulins. In summary, our study showed that the antibody PPZ0506, originally directed against human ERβ, is also suitable for reliable detection of murine ERβ. An established staining protocol mitigated ambiguities regarding the expression and distribution of ERβ in different tissues and will contribute to an improved understanding of its role and functions in murine tissues in the future. Full article

Women consistently show lower incidence and mortality rates for colorectal cancer (CRC) compared to men. Epidemiological evidence supports a pivotal role for estrogen in protecting women against CRC. Estrogen protective effects in CRC have been mainly attributed to the estrogen receptor beta (ERβ) however its expression is lost during CRC progression. The role of the G-protein coupled membrane estrogen receptor (GPER/GPER1/GPR30), which remains expressed after ERβ loss in CRC, is currently under debate. We hypothesise that estrogen can protect against CRC progression via GPER by modulating the Wnt/β-catenin proliferative pathway which is commonly hyperactivated in CRC. We sought evidence of sexual dimorphism within the Wnt/β-catenin pathway by conducting Kaplan–Meier analyses based on gene expression of the Wnt receptor FZD1 (Frizzled 1) in multiple public domain CRC patient data sets. High expression of FZD1 was associated with poor relapse-free survival rates in the male but not the female population. In female-derived HT29 CRC cell lines, we show that β-catenin nuclear translocation was not affected by treatment with the GPER agonist G1. However, G1 prevented the Wnt pathway-induced upregulation of the JUN oncogene. These novel findings indicate a mechanistic role for GPER in protecting against CRC progression by selectively reducing the tumorigenic effects of hyperactive Wnt/β-catenin signalling pathways in CRC. Full article

The estrogenic receptor beta (ERβ) protects against carcinogenesis by stimulating apoptosis. Bisphenol A (BPA) is related to promoting cancer, and naringenin has chemoprotective activities both can bind to ERβ. Naringenin in the colon is metabolized by the microbiota. Cancer involves genetic and epigenetic mechanisms, including miRNAs. The objective of the present study was to evaluate the co-exposure effect of colonic in vitro fermented extract of naringenin (FEN) and BPA, to elucidate molecular effects in HT-29 colon cancer cell line. For this, we quantified genes related to the p53 signaling pathway as well as ERβ, miR-200c, and miR-141. As an important result, naringenin (IC50 250 µM) and FEN (IC50 37%) promoted intrinsic pathways of apoptosis through phosphatase and tensin homolog (PTEN) (+2.70, +1.72-fold, respectively) and CASP9 (+3.99, +2.03-fold, respectively) expression. BPA decreased the expression of PTEN (−3.46-fold) gene regulated by miR-200. We suggest that once co-exposed, cells undergo a greater stress forcing them to mediate other extrinsic apoptosis mechanisms associated with death domain FASL. In turn, these findings are related to the increase of ERβ (5.3-fold with naringenin and 13.67-fold with FEN) gene expression, important in the inhibition of carcinogenic development. Full article