Search Results (264)

Hormone-dependent breast cancer, particularly in its treatment-resistant forms, remains a significant therapeutic challenge. In this study, we applied a fully computational strategy to design steroid-based compounds capable of simultaneously targeting three key receptors involved in disease progression: progesterone receptor (PR), estrogen receptor alpha (ER-α), and HER2. Using a robust 3D-QSAR model (R² = 0.86; Q²_LOO = 0.86) built from 52 steroidal structures, we identified molecular features associated with high anticancer potential, specifically increased polarizability and reduced electronegativity. From a virtual library of 271 DFT-optimized analogs, 31 compounds were selected based on predicted potency (pIC₅₀ > 7.0) and screened via molecular docking against PR (PDB 2W8Y), HER2 (PDB 7JXH), and ER-α (PDB 6VJD). Seven candidates showed strong binding affinities (ΔG ≤ −9 kcal/mol for at least two targets), with Estero-255 emerging as the most promising. This compound demonstrated excellent conformational stability, a robust hydrogen-bonding network, and consistent multitarget engagement. Molecular dynamics simulations over 100 nanoseconds confirmed the structural integrity of the top ligands, with low RMSD values, compact radii of gyration, and stable binding energy profiles. Key interactions included hydrophobic contacts, π–π stacking, halogen–π interactions, and classical hydrogen bonds with conserved residues across all three targets. These findings highlight Estero-255, alongside Estero-261 and Estero-264, as strong multitarget candidates for further development. By potentially disrupting the PI3K/AKT/mTOR signaling pathway, these compounds offer a promising strategy for overcoming resistance in hormone-driven breast cancer. Experimental validation, including cytotoxicity assays and ADME/Tox profiling, is recommended to confirm their therapeutic potential. Full article

Estrogen receptor alpha (ERα) plays a vital role in the development and progression of breast cancer by regulating the expression of genes associated with cell proliferation in breast tissue. ERα inhibition is a key strategy in the prevention and treatment of breast cancer. Previous research modified chalcone compounds into pyrazoline benzenesulfonamide derivatives (Modifina) which show activity as an ERα inhibitor. This study aimed to design novel pyrazoline benzenesulfonamide derivatives (PBDs) as ERα antagonists using in silico approaches. Structure-based and ligand-based drug design approaches were used to create drug target molecules. A total of forty-five target molecules were initially designed and screened for drug likeness (Lipinski’s rule of five), cytotoxicity, pharmacokinetics and toxicity using a web-based prediction tools. Promising candidates were subjected to molecular docking using AutoDock 4.2.6 to evaluate their binding interaction with ERα, followed by molecular dynamics simulations using AMBER20 to assess complex stability. A pharmacophore model was also generated using LigandScout 4.4.3 Advanced. The molecular docking results identified PBD-17 and PBD-20 as the most promising compounds, with binding free energies (ΔG) of −11.21 kcal/mol and −11.15 kcal/mol, respectively. Both formed hydrogen bonds with key ERα residues ARG394, GLU353, and LEU387. MM-PBSA further supported these findings, with binding energies of −58.23 kJ/mol for PDB-17 and −139.46 kJ/mol for PDB-20, compared to −145.31 kJ/mol, for the reference compound, 4-OHT. Although slightly less favorable than 4-OHT, PBD-20 demonstrated a more stable interaction with ERα than PBD-17. Furthermore, pharmacophore screening showed that both PBD-17 and PBD-20 aligned well with the generated model, each achieving a match score of 45.20. These findings suggest that PBD-17 and PBD-20 are promising lead compounds for the development of a potent ERα inhibitor in breast cancer therapy. Full article

Long-chain fatty acids (LCFAs) have emerged as important regulators of cancer metabolism, but their impact on hormone receptor expression in breast cancer (BCA) remains poorly understood. In this study, we investigated the effects of five LCFAs—linoleic acid (LA), oleic acid (OA), elaidic acid (EA), palmitic acid (PA), and α-linolenic acid (LNA)—on two BCA cell lines: luminal-type MCF7 and triple-negative MDA-MB-231 (MB231). All LCFAs suppressed cell viability and mitochondrial function in a dose-dependent manner, accompanied by decreased membrane potential, increased reactive oxygen species production, and a metabolic shift. Notably, OA reduced both mRNA and nuclear protein levels of estrogen receptor alpha (ERα) in MCF7 cells, leading to impaired responses to estradiol and tamoxifen. In contrast, PA induced nuclear ERα expression in MB231 cells, although ER signaling remained inactive. MicroRNA profiling revealed that OA upregulated ER-suppressive miR-22 and miR-221 in MCF7, while PA increased miR-34a in MB231, contributing to ERα induction. These findings suggest that specific LCFAs modulate ER expression through epigenetic and post-transcriptional mechanisms, altering hormonal responsiveness in BCA. Our results offer new insights into how dietary lipids may influence therapeutic efficacy and tumor behavior by regulating nuclear receptor signaling. Full article

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

Marine tunicates are a very attractive and abundant source of secondary metabolites with chemical diversity and biological activity. Fractionation and purification of the organic extract of the Red Sea tunicate Didemnum species resulted in the isolation and identification of three new compounds, didemnosides A and B (1 and 2) and 1,1′,3,3′-bisuracil (3), together with thymidine (4), 2′-deoxyuridine (5), homarine (6), and acetamide (7). Planar structures of the compounds were explained through analyses of their 1D (¹H and ¹³C) and 2D (¹H–¹H COSY, HSQC, and HMBC) NMR spectra and high-resolution mass spectral determinations. Compound 1 exhibited the highest growth inhibition toward the MCF-7 cancer cell line with IC₅₀ values of 0.597 μM, while other compounds were inactive (≥50 μM) against this cell line. On the other hand, compounds 1, 2, and 4–7 moderately inhibited SW-1222 and PC-3 cells with IC₅₀ values ranging between 5.25 and 9.36 μM. Molecular docking analyses of the top three active compounds on each tested cell line exposed stable interactions into the active pockets of estrogen receptor alpha (ESR1), human topoisomerase II alpha (TOP2A), and cyclin-dependent kinase 5 (CDK5) which are contemplated as essential targets in cancer treatments. Thus, compound 1 represents a scaffold for the development of more effective anticancer drugs. Full article

Genistein, a natural isoflavone, exerts anticancer effects on human breast cancer cells by modulating the unfolded protein response (UPR). However, the effect of genistein on UPR in canine mammary gland tumor (CMT) cells remains unknown. The aim of the present study was to investigate the anticancer effects of genistein on CMT-U27 cells, focusing on the regulation of UPR-related pathways and the associated cell death mechanisms. CMT-U27 cells were treated with genistein. Cell viability, apoptosis, and UPR-related protein expression were analyzed using MTS assay, Annexin V-Propidium Iodide (PI) staining, Western blotting, and immunocytochemistry. Genistein treatment significantly reduced cell viability and induced apoptosis, accompanied by an increased Bcl-2-associated X (Bax) ratio of B-cell lymphoma-2 (Bcl-2) and cleaved caspase-8 and caspase-3. On regulation of the UPR system, genistein treatment showed a dual-function by enhancing the protein kinase R-like endoplasmic reticulum kinase (PERK) signaling while suppressing the inositol-requiring enzyme 1 alpha (IRE1α)–X-box-binding protein 1 (XBP1) axis. Furthermore, genistein downregulated estrogen receptor alpha (ERα), which may contribute to the inhibition of IRE1α signaling through a disrupted positive feedback loop. These findings suggested that genistein modulates the UPR to induce apoptosis in CMT-U27 cells, highlighting its potential as a therapeutic or adjuvant agent for CMTs. 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

Transcription factors (TFs) play central roles in gene regulation and disease progression but have long been considered undruggable due to the absence of well-defined binding pockets and their reliance on protein–protein or protein–DNA interactions. Proteolysis-targeting chimeras (PROTACs) offer a novel strategy to overcome these limitations by inducing selective degradation of TFs via the ubiquitin–proteasome system. This review highlights recent advances in TF-targeting PROTACs, focusing on key oncogenic TFs such as androgen receptor (AR), estrogen receptor alpha (ERα), BRD4, c-Myc, and STAT family members. Strategies for ligand design—including small molecules, peptides, and nucleic acid-based elements—are discussed alongside the use of various E3 ligases such as VHL, CRBN, and IAP. Several clinically advanced PROTACs, including ARV-110 and ARV-471, demonstrate the therapeutic potential of this technology. Despite challenges in pharmacokinetics and E3 ligase selection, emerging data suggest that PROTACs can successfully target TFs, paving the way for new treatment strategies across oncology and other disease areas. Full article

Background: Ammonia (NH₃), a harmful gas, reduces livestock productivity, threatens their health, and causes economic losses. Luteolin (Lut), an anti-inflammatory flavonoid, may counteract these effects. Methods: Our study explored luteolin’s protective mechanisms on chicken splenic lymphocytes under ammonia stress using a simulation model and four-dimensional fast data-independent acquisition (4D-FastDIA) proteomics. We identified 316 proteins, with 69 related to ammonia’s negative effects and 247 to Lut’s protection. Thirty differentially expressed proteins (DEPs) were common to both groups, with 27 showing counter-regulation with Lut. Results: Gene Ontology (GO) analysis showed DEPs enriched in molecular responses to interferons and the negative regulation of immune responses, mainly located extracellularly. Molecular function analysis revealed DEPs in antigen binding and synthase activity. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis linked DEPs to pathways like estrogen signaling, NOD-like receptor signaling, cytokine–cytokine receptor interaction, and JAK-STAT signaling. The quantitative real-time polymerase chain reaction (qRT-PCR) results indicated that the mRNA levels of Interferon Alpha and Beta Receptor subunit 2 (IFNAR2) and Signal Transducer and Activator of Transcription 1 (STAT1) were trending downward. This observation was in strong agreement with the downregulation noted in the proteomics analysis. Conclusions: Lut’s protective role against ammonia’s adverse effects on chicken splenic lymphocytes is linked to the modulation of key signaling pathways, offering insights for further research on treating ammonia exposure with Lut. Full article

Molecular imaging probes play a pivotal role in assaying molecular events in various physiological systems. In this study, we demonstrate a new genre of bioluminescent probes for imaging protein–protein interactions (PPIs) in mammalian cells, named the molecular association assay (MAA) probe. The MAA probe is designed to be as simple as a full-length marine luciferase fused to a protein of interest with a flexible linker. This simple fusion protein alone surprisingly works by recognizing a specific ligand, interacting with a counterpart protein of the PPI, and developing bioluminescence (BL) in mammalian cells. We made use of an artificial intelligence (AI) tool to simulate the binding modes and working mechanisms. Our AlphaFold-based analysis on the binding mode suggests that the hinge region of the MAA probe is flexible before ligand binding but becomes stiff after ligand binding and protein association. The sensorial properties of representative MAA probes, FRB-ALuc23 and FRB-R86SG, are characterized with respect to the quantitative feature, BL spectrum, and in vivo tumor imaging using xenografted mice. Our AI-based simulation of the working mechanisms reveals that the association of MAA probes with the other proteins works in a way to facilitate the substrate’s access to the active sites of the luciferase (ALuc23 or R86SG). We prove that the concept of MAA is generally applicable to other examples, such as the ALuc16- or R86SG-fused estrogen receptor ligand-binding domain (ER LBD). Considering the versatility of this conceptionally unique and distinctive molecular imaging probe compared to conventional ones, we are expecting the widespread application of these probes as a new imaging repertoire to determine PPIs in living organisms. Full article

The interaction of estrogen receptor alpha (ERα) with various metabolites—both endogenous and exogenous, such as those present in food products, as well as gut microbiota-derived metabolites—plays a critical role in modulating the hormonal balance in the human body. In this study, we evaluated a suite of 27 machine learning models and, following systematic optimization and rigorous performance comparison, identified linear discriminant analysis (LDA) as the most effective predictive approach. A meticulously curated dataset comprising 75 molecular descriptors derived from compounds with known ERα activity was assembled, enabling the model to achieve an accuracy of 89.4% and an F1 score of 0.93, thereby demonstrating high predictive efficacy. Feature importance analysis revealed that both topological and physicochemical descriptors—most notably FractionCSP3 and AromaticProportion—play pivotal roles in the potential binding to ERα. Subsequently, the model was applied to chemicals commonly encountered in food products, such as indole and various phenolic compounds, indicating that approximately 70% of these substances exhibit activity toward ERα. Moreover, our findings suggest that food processing conditions, including fermentation, thermal treatment, and storage parameters, can significantly influence the formation of these active metabolites. These results underscore the promising potential of integrating predictive modeling into food technology and highlight the need for further experimental validation and model refinement to support innovative strategies for developing healthier and more sustainable food products. Full article

Background/Objectives: Breast cancer is the most prevalent cancer in adult women. Currently, new therapies and protein determinations with prognostic value are under development. Fascin (encoded by the FSCN1 gene) is an actin-binding protein that is critical for the development of cytoplasmic projections that are essential for tumor invasion. DNA topoisomerase 2-alpha (TOP2A) is a nuclear protein crucial for ATP-dependent breakage, passage, and rejoining of double-stranded DNA and cell division. Both proteins are associated with higher proliferation rates and worse prognosis in breast cancer and together can provide comprehensive information on prognosis and treatment response. Methods: We simultaneously assessed fascin expression and TOP2A/CEP17 DNA copy number ratios in various histological and molecular subtypes. Additionally, these markers were analyzed along with previously established diagnostic markers and other relevant clinical data. Results: Our series included 265 patients, four of whom were male, and all of which were diagnosed with breast carcinoma. Of the 265 patients initially included, sufficient material for analysis was available for 175 cases, as some samples were excluded because of insufficient tissue quantity, poor preservation, or lack of hybridization in certain assays. Immunohistochemical (IHC) expression of fascin, both in its aggregated form and by category, showed no association with the TOP2A gene alteration ratio. Fascin expression was significantly associated with histological subtype (p < 0.001), molecular subtype (p < 0.001), hormone receptor (HR) (p < 0.001), BCL2 (p = 0.003), Ki67 (p = 0.002), and histological grade (p < 0.001). TOP2A was significantly associated with molecular subtype (p = 0.041), Ki67 (p = 0.048), and histological grade (p = 0.033). In our study, molecular subtype (p = 0.037) emerged as an independent variable for the complete histological response to neoadjuvant treatment. Multivariate analysis linked pathological stage (p = 0.002) and estrogen receptor (ER) expression (p = 0.004) to overall survival (OS) and disease-free survival (DFS). Conclusions: No statistical relationship was evident between fascin expression (IHC) and the TOP2A copy ratio. The results of this study suggested that the mechanisms of increased cell proliferation associated with alterations in fascin and TOP2A are independent. Full article

Background/Objectives: Glucocorticoid-induced osteonecrosis of the femoral head (GIOFH) is a debilitating condition resulting from impaired bone metabolism and vascular disruption due to prolonged glucocorticoid use. This study aimed to explore the therapeutic potential of salvigenin, a flavonoid with antioxidative and estrogen-like properties, in alleviating GIOFH by modulating estrogen receptor alpha (ESR1) pathways. Methods: A network pharmacology approach was utilized to identify salvigenin’s potential targets and their association with GIOFH. Protein–protein interaction networks, along with Gene Ontology and KEGG pathway analyses, were conducted to clarify salvigenin’s multi-target mechanisms. Molecular docking and dynamics simulations assessed the interaction between salvigenin and ESR1. Experimental validation included in vitro assays on MG63 cells treated with dexamethasone (Dex) to mimic GIOFH, evaluating oxidative stress, apoptosis, osteogenic differentiation, and ESR1 expression. Results: Network analysis identified ESR1, NOS3, and MMP9 as key hub targets of salvigenin. Molecular docking and dynamics simulations confirmed stable binding of salvigenin to ESR1. Salvigenin significantly reduced Dex-induced oxidative stress and apoptosis in osteoblasts while restoring osteogenic differentiation and ESR1 expression. Functional assays showed improved mineralized nodule formation, ALP activity, and mitochondrial integrity in salvigenin-treated cells. Conclusions: Salvigenin exhibits significant therapeutic potential in addressing GIOFH through ESR1-mediated pathways. These results offer a strong foundation for future translational studies and the development of salvigenin-based therapies for glucocorticoid-induced bone disorders. Full article

Background/Objectives: Metabolic dysfunction-associated steatotic liver disease (MASLD) is associated with cardiometabolic risk. Although studies have shown that estradiol positively contributes to energy metabolism via estrogen receptor alpha (ERα), its role specifically in the liver is not defined. Therefore, this study aimed to evaluate the effects of ERα overexpression, specifically in the liver in mice fed a high-fat diet (HFD). Methods: Male C57BL/6J mice were divided into four groups, vehicle fed with regular chow (RC) (RC-Vehicle); vehicle fed an HFD (HFD-Vehicle); AAV-treated fed with RC (RC-AAV); and AAV-treated fed an HFD (HFD-AAV), for 6 weeks (8–10 mice per group). AAV was administered intravenously to induce ERα overexpression. Results: We demonstrate that overexpression of ERα in RC-fed mice reduces body fat (28%). These mice show increased oxygen consumption in cultured primary hepatocytes, both in basal (19%) and maximal respiration (34%). In HFD-fed mice, we showed a decrease in hepatic TAG content (43%) associated with improved hepatic insulin sensitivity (145%). Conclusions: From this perspective, our results prove that hepatic ERα signaling is responsible for some of the metabolic protective effects of estrogen in mice. Overexpression of ERα improves hepatocyte mitochondrial function, consequently reducing hepatic lipid accumulation and protecting animals from hepatic steatosis and hepatic insulin resistance. Further investigations will be needed to determine the exact molecular mechanism by which ERα improves hepatic metabolic health. Full article

Breast cancer is a heterogeneous disease characterized by a wide range of biomarker expressions, resulting in varied progression, behavior, and prognosis. While traditional biopsy-based molecular classification is the gold standard, it is invasive and limited in capturing tumor heterogeneity, especially in deep or metastatic lesions. Molecular imaging, particularly positron emission tomography (PET) imaging, offering a non-invasive alternative, potentially plays a crucial role in the classification and management of breast cancer by providing detailed information about tumor location, heterogeneity, and progression. This narrative review, which focuses on both clinical patients and preclinical studies, explores the latest advancements in PET imaging for breast cancer, emphasizing the development of new tracers targeting hormone receptors such as the estrogen alpha receptor, progesterone receptor, androgen receptor, estrogen beta receptor, as well as the ErbB family of receptors, VEGF/VEGFR, PARP1, PD-L1, and markers for indirectly assessing Ki-67. These innovative radiopharmaceuticals have the potential to guide personalized treatment approaches based on the unique tumor profiles of individual patients. Additionally, they may improve the assessment of treatment efficacy, ultimately leading to better outcomes for those diagnosed with breast cancer. Full article