Search Results (4,701)

Cardiac fibrosis is a central determinant of heart failure progression and arises from pathological remodeling characterized by fibroblast activation, myofibroblast differentiation, and excessive extracellular matrix deposition. In contrast, physiological remodeling permits adaptive cardiac growth without net fibrosis. Pregnancy represents an underexplored physiological model of reversible cardiac remodeling. In response to hemodynamic load, the maternal heart undergoes hypertrophic growth that resolves postpartum, constituting a natural paradigm of fibrosis-resistant cardiac adaptation. Pregnancy and lactation are accompanied by profound endocrine and immune reprogramming of maternal tissues. We propose that this hormonal milieu orchestrates coordinated crosstalk among endothelial cells, fibroblasts, and immune cell populations to suppress profibrotic pathways and preserve extracellular matrix homeostasis. Candidate regulators include estrogen, progesterone, prolactin family peptides, relaxin, oxytocin, and components of the renin–angiotensin–aldosterone system. During the postpartum and lactational period, prolactin and oxytocin may further promote reverse remodeling. These hormones likely act by modulating local cytokine and growth factor networks that otherwise drive fibroblast activation. By focusing on non-myocyte cardiac cells and extracellular matrix dynamics, this review positions pregnancy as a translational model to uncover endogenous anti-fibrotic mechanisms and identify novel therapeutic strategies for cardiac fibrosis. Full article

(1) Background: Advances in machine learning (ML)-based survival modeling enable the analysis of high-dimensional biomedical data. However, many approaches rely on the proportional hazards (PH) assumption, which is frequently violated in oncology and can limit the interpretability of hazard ratio-based results. Using Estrogen Receptor (ER) status in the METABRIC breast cancer cohort as a case study, we propose a framework that integrates machine learning survival models with Restricted Mean Survival Time (RMST) to provide a more robust and clinically interpretable approach for survival analysis under non-proportional hazards. (2) Methods: Overall survival was analyzed in 1104 patients. PH violations were confirmed using Schoenfeld residuals and Kaplan–Meier inspection. We compared four models: stratified Cox Elastic Net (Cox E-Net), Random Survival Forest (RSF), Gradient Boosting Survival Analysis (GBSA), and DeepHit. Performance was assessed using Harrell’s C-index, time-dependent IPCW C-index, and Integrated Brier Score (IBS). RMST at 180 months was utilized to quantify absolute survival differences between ER subgroups. To improve the stability of the estimates, 200 bootstrap resamples were performed, and 95% confidence intervals were derived from the bootstrap distribution. (3) ER status demonstrated significant PH violation (p < 0.005) with crossing survival curves. Discrimination (C-index 0.664–0.725) and calibration (IBS 0.149–0.169) were comparable across models, with RSF achieving the highest overall performance. Despite similar accuracy, survival curve structures differed substantially. Cox E-Net and RSF reproduced the observed crossing pattern, whereas GBSA generated smoother trajectories and DeepHit showed marked compression of subgroup separation. In the independent test cohort, the empirical RMST difference at 180 months was 16.6 months (ER-positive: 130.4; ER-negative: 113.8). Model-based RMST differences ranged from 1 month (DeepHit) to 27 months (Cox E-Net), with RSF and GBSA (12.8 and 13.8 months) most closely approximating the empirical benchmark. (4) Conclusions: We propose a novel, model-agnostic ML + RMST framework that addresses non-proportional hazards while providing quantifiable, time-specific clinical benefit. Moreover, models with similar discrimination and calibration produced markedly different survival curve behavior and absolute RMST estimates, demonstrating that accuracy metrics alone are insufficient for clinical interpretation. By linking prognostic modeling with absolute survival quantification, this framework advances survival evaluation beyond relative risk ranking toward individualized, clinically meaningful decision support. Full article

Premature ovarian insufficiency (POI) is a clinical condition characterized by loss of ovarian function indicated by amenorrhea or irregular menstrual cycles for at least 4 months and elevated gonadotrophins (FSH > 25 IU/L, measured on one occasion) and low estrogen serum levels in women under the age of 40. Premature ovarian insufficiency can be non-iatrogenic or spontaneous (idiopathic or due to genetic, autoimmune, or metabolic reasons, or infections) and iatrogenic (a consequence of oophorectomy, chemotherapy, radiotherapy, or uterine artery embolization). Women with POI are faced not only with estrogen deficiency but also with infertility and psychological implications. Hormonal replacement therapy is effective in treating the symptoms of premature ovarian insufficiency as well as in lowering the health risk of long-term consequences of premature ovarian insufficiency. Currently, oocyte donation is the standard treatment for patients with POI desiring pregnancy. Recently developed methods for the regeneration of ovarian tissue, such as stem cell therapy, platelet-reach plasma therapy and in vitro activation of ovarian tissue, are still under research and further adequate multicentric clinical studies are needed to develop standardized effective and safe protocols for the infertility treatment of patients with premature ovarian insufficiency. Full article

Formalin-fixed paraffin-embedded (FFPE) tissues represent an invaluable resource for both basic and clinical research due to their stable preservation of tissue architecture and molecular integrity. Multiplex immunofluorescence (mIF) using tyramide signal amplification (TSA) enables the simultaneous detection of multiple antigens within a single FFPE section. Here, we describe a kit-independent and customizable TSA-based mIF protocol that utilizes commercially available horseradish peroxidase (HRP)-conjugated secondary antibodies and tyramide–fluorophore reagents. The method was applied using FFPE endometriosis tissue, targeting estrogen receptor alpha (ERα), progesterone receptor (PR), α-smooth muscle actin (αSMA), CD20 and CD31. Each staining round was followed by heat-induced epitope removal (HIER) of the bound antibodies while preserving covalently deposited signals. Fluorescence imaging was performed using a multi-channel slide scanner with carefully selected fluorophores to enable optical separation between detection channels. Under the conditions described, the protocol enabled clear visualization of maker-specific staining patterns with preserved tissue morphology. This study provides a practical and flexible TSA-based mIF protocol as a qualitative proof of concept, offering an accessible alternative to commercial kit-based approaches. Further studies will be required to establish quantitative performance and a broader applicability across tissue types. Full article

Hormonal fluctuations across female life stages drive numerous transcriptomic and epigenetic changes, yet the effects of sex hormones on mucosal immunity, particularly in the vaginal epithelium, remain poorly understood. The vaginal mucosa undergoes cyclical remodeling during the ovulatory cycle under the influence of estrogens and progesterone produced mainly in the ovary. The ovary can also be a source of testosterone, and in postmenopausal women, as well as transgender men receiving hormone therapy, phenotypic changes in the vagina due to increased testosterone have been observed. However, the consequences of testosterone dominance in this tissue in terms of resilience and inflammation have not been well characterized. The goal of this study was to identify the histological and immunological changes within the vaginal epithelial cell barrier in an estrogen- vs. testosterone-dominant environment using an established in vitro reconstructed vaginal epithelial tissue model. Compared to estradiol, exposure to testosterone resulted in a thinner tissue with alterations in the cornification, although no impairment in the epithelial barrier was detected. Each hormone also resulted in a unique RNA expression profile, including increased expression of tight junction genes and decreased expression of chemokines and their receptors in testosterone compared to estradiol exposure. These data have implications for women’s health, including menopause, transgender men using gender-affirming hormone therapy, and other conditions associated with high testosterone in the vaginal compartment. Full article

Zearalenone (ZEA) is a potent estrogenic mycotoxin known to disrupt reproductive functions, but its precise central neuroendocrine mechanisms remain unclear. This study investigated the effects of ZEA on the hypothalamic-pituitary Kiss1/GPR54 signaling pathway in weaned gilts. A total of 32 gilts were randomly assigned to four dietary treatments contained with 0, 0.15, 1.5, or 3.0 mg/kg ZEA for a 32-day feeding trial. Histopathology, immunohistochemistry, and mRNA/protein expression analyses of GPR30, Kiss1, GPR54, GnRH, and GnRHR in the hypothalamus and pituitary gland were conducted. ZEA exposure induced significant histological damage in both tissues. In the hypothalamus, Kiss1, GPR54, GnRH, and GnRHR exhibited a non-linear response, increasing at moderate doses and decreasing at 3.0 mg/kg ZEA, whereas GPR30 expression was continuously upregulated. In the pituitary gland, GnRHR showed a similar non-linear pattern. Furthermore, high-dose ZEA down-regulated pituitary Kiss1 and GPR54 while up-regulating GnRH and GPR30 expressions. In conclusion, ZEA induces reproductive neuroendocrine toxicity through a complex, dose-dependent modulation of the Kiss1/GPR54 signaling axis. The persistent upregulation of GPR30 suggests it acts as a crucial mediator in disrupting this endocrine feedback loop within the hypothalamus and pituitary gland. Full article

Trastuzumab is the first humanised monoclonal antibody (Mab) developed for breast cancer (BC) therapy. The high affinity of Trastuzumab Fab-domain binding to the human epidermal growth factor receptor 2 (HER2) receptor, with a K_d value of <1 nM, is also accompanied by Fc domain interaction with Fc-receptors in natural killer cells and leukocytes, enabling the killing of tumour cells through antibody-directed cellular cytotoxicity (ADCC). Trastuzumab blocks the over-expressed HER2 receptor-mediated dimerization and consequent intracellular signalling, leading to cancerous growth. However, the trastuzumab resistance (TR) became the major problem within 1 year of treatment. The mutation in phosphatidylinositol 3′-kinase (PI3K) pathway, cross-talk with estrogen receptors, over-expression of Mucin 1 (MUC1) protein, insulin-like growth factor I receptor, etc., are key pathways involved in TR. In this review, we have provided a molecular view of TR and the possible remedies for overcoming TR using BC stem cell (BCSC)-based therapy, PI3K pathway inhibitors, MUC1-based treatment, etc. We have also analysed the patents and clinical trials from the pre-TR and post-TR era to rationalise the possible steps to overcome TR. Our analysis implies that Trastuzumab monotherapy no longer applies to HER2+ BC treatment. Further, combination therapy using other antibodies like pertuzumab and protein kinase inhibitors and targeting pathways like the ubiquitin proteasome pathway will be the future option for BC Treatment. Overall, this review provides a detailed summary of the molecular mechanisms involving TR and its potential ways of evasion, based on updated information from published research articles, clinical trial outcomes, and patent data. Full article

Steroid-sensitive cancers (e.g., breast, ovarian, uterine, and prostate cancers) are difficult to control and frequently metastasize to lymph nodes, bone, or lung. Although endocrine research has greatly advanced our identification of the direct roles of steroid sex hormones such as androgens and estrogens on tumor cells in promoting metastasis or recurrence (e.g., treatment with gonadotropin releasing hormone agonists/antagonists, aromatase inhibitors, and estrogen and androgen receptor antagonists), mechanistic insight regarding indirect effects of steroid hormones, including how the innate immune system responds to cancer and is influenced by steroid hormones, is lacking. Despite technological advances in engineering more robust adaptive immunity to combat tumor growth (e.g., CART or checkpoint inhibitors), there remains a relative lack of investigation into the role of innate immunity as a key defense system. Here we discuss recent studies that highlight the significance of neutrophils and their response to tumorigenic conditions with or without steroid hormones in animal models of cancer. We will describe relationships between steroid hormones and neutrophils, with a specific focus on neutrophil extracellular traps (NETs), and how these interactions modulate tumor growth and invasion. Together, these data indicate that combinatorial regulation of both innate and adaptive immunity in the context of tumorigenesis may improve outcomes in cancer therapies. Full article

Endocrine therapy is the mainstay for estrogen receptor (ER) α-positive breast cancer (BC), yet many patients display acquired resistance. We then screened natural compounds using human ERα-positive BC cells and identified perillyl alcohol (POH), a monoterpene from perilla, that reduces ERα protein levels. Chemoproteome analysis using POH-immobilized nanomagnetic beads revealed adenine nucleotide translocase 2 (ANT2), a mitochondrial inner membrane protein, as a direct target of POH. Molecular dynamics (MD) simulations predicted POH binding to the central pore of ANT2, which functions in ATP transport. ANT2 depletion reduced ERα levels, and public datasets indicate that high ANT2 expression correlates with poor prognosis in ERα-positive BC. POH also inhibited the growth of Tamoxifen- and Fulvestrant-resistant BC cells. RNA sequencing showed that fatty acid elongation-related genes were upregulated in Fulvestrant-resistant cells but downregulated by ANT2 depletion. Both ANT2 depletion and POH treatment led to the accumulation of intracellular lipid droplets in Fulvestrant-resistant cells, consistent with impaired fatty acid elongation. Finally, in silico screening using MD simulations identified venetoclax and nystatin as potential ANT2 pore binders. Both compounds reduced ERα levels in ERα-positive BC cells and increased lipid droplet formation in Fulvestrant-resistant cells. These findings highlight ANT2 as a druggable target against endocrine-resistant BC. Full article

The search for new anticancer agents with improved efficacy and reduced toxicity has intensified interest in metal-based compounds. In this study, two novel palladium(II) complexes, synthesized from Schiff base ligands derived from 5-chloro-salicylaldehyde and p-hydroxybenzylamine or tyramine, were chemically characterized and biologically evaluated. Both complexes exhibited significant cytotoxic activity against the MCF-7 breast cancer cell line in a dose- and time-dependent manner, with Pd2 showing slightly higher potency. Morphological analysis of treated cells indicated that apoptosis is the predominant mechanism of cell death. To gain deeper insight into the potential mechanisms underlying the observed anticancer activity, several biologically relevant targets were investigated. Enzyme kinetics revealed that the complexes act as uncompetitive inhibitors of liver catalase, suggesting a possible role in the induction of oxidative stress. Fluorescence studies demonstrated that Pd2 interacts with CT-DNA through combined intercalative and minor groove binding modes and exhibits significant binding affinity toward human serum albumin, predominantly at Sudlow’s site I. Molecular docking analysis further supported favorable interactions with catalase, estrogen receptor α, and B-form DNA, providing structural insight into the experimentally observed biological effects. Overall, the study explores multiple potential mechanisms of anticancer action, underscoring the promising therapeutic potential of these palladium(II) complexes, while antitumor activity has been initially assessed using a MCF-7 cell line as a preliminary model. Full article

The protective effect of physical activity on breast cancer recurrence may be mediated changes in by sex hormone levels. In this study, we examined the association between habitual physical activity and estrogen and androgen plasma levels in postmenopausal women with localised breast cancer. We conducted a cross-sectional study among 47 postmenopausal women who were breast cancer survivors with estrogen receptor-positive tumours (enrolled at the Medical Oncology Department of University Hospital Dr. Peset, Valencia, Spain). Habitual physical activity was assessed using the International Physical Activity Questionnaire (IPAQ), and a weighted estimate of total physical activity per week (MET∙min∙wk⁻¹) was calculated. Total plasma levels of estrone, 17β-estradiol, progesterone, androstenedione, testosterone, and dehydroepiandrosterone-sulphate (DHEA-sulphate) were measured. Bivariate analyses by the Spearman correlation test were done between physical activity and each hormone concentration. Multivariate analyses (linear regression) using concentration of each hormone as the dependent variable and physical activity, age, marital status, BMI, Charlson Comorbidity Index, tumour stage, previous radiotherapy, or previous chemotherapy as predictor variables. Estrone concentration was positively and significantly correlated with BMI (ρ = 0.332, p = 0.022), but no other correlations were found between BMI and the other hormone concentrations, nor were concentrations of any hormone associated with age or Charlson Comorbidity Index (p > 0.05 in all cases). Physical activity was significantly and inversely correlated with estrone concentration (ρ = −0.308; p = 0.035). Linear regression analysis confirmed a statistically significant association between estrone concentration and BMI and physical activity, after adjusting for all potential confounders (for BMI: standardised β coefficient = 0.407; non-standardised β coefficient = 1.054; t = 2.898; p = 0.006; 95% CI for non-standardised beta: 0.318- to 1.790; for physical activity: standardised β coefficient = −0.300; non-standardised β coefficient = −0.005; t = −2.135; p = 0.039; 95% CI for non-standardised beta: −0.010- to 0.000). The relationship between estrone concentration and physical activity may be further explored as a biomarker for evaluating the protective effect of physical activity against breast cancer recurrence in women receiving anti-estrogen therapies. Full article

Background and Objectives: Tamoxifen, a cornerstone selective estrogen receptor modulator in breast cancer therapy, is increasingly recognized to be associated with retinal toxicity characterized by mitochondrial dysfunction, oxidative stress, lipid peroxidation, and oxidative DNA injury. By targeting mitochondrial bioenergetic dysfunction and redox disequilibrium, adenosine triphosphate (ATP) emerges as a biologically plausible candidate for retinal cytoprotection. This study aimed to evaluate the protective effect of ATP against tamoxifen-induced retinal toxicity in a rat model. Materials and Methods: Twenty-four male albino Wistar rats were randomly assigned to four groups: healthy control (HG), ATP-alone (ATPG, 4 mg/kg, intraperitoneally), tamoxifen-alone (TAMG, 5 mg/kg, orally), and tamoxifen plus ATP-treated (ATAG; ATP, 4 mg/kg, intraperitoneally; tamoxifen, 5 mg/kg, orally). Treatments were administered once daily for 30 days. Oxidative stress markers (malondialdehyde, total glutathione), antioxidant enzyme activities (superoxide dismutase, catalase), and oxidative DNA damage (8-hydroxy-2′-deoxyguanosine) were assessed in ocular tissues. Retinal histopathological evaluation included hematoxylin–eosin staining with semiquantitative assessment of edema, vascular congestion, polymorphonuclear leukocyte infiltration, and cytoplasmic vacuolization, together with quantitative measurements of retinal layer thicknesses and ganglion cell layer (GCL) cell counts. Results: Tamoxifen administration induced marked oxidative stress, antioxidant depletion, and increased oxidative DNA damage in ocular tissues, accompanied by significant thickening of retinal layers, reduced GCL cell counts, and pronounced disruption of retinal architecture. By comparison, ATP co-administration significantly suppressed lipid peroxidation and restored antioxidant defenses, thereby reducing oxidative DNA damage and preserving retinal structural integrity, as reflected by partial normalization of retinal layer thicknesses, preservation of GCL cell counts, and the presence of only mild residual edema. Conclusions: These findings indicate that ATP attenuates tamoxifen-induced retinal toxicity by supporting mitochondrial energy balance and redox homeostasis. Accordingly, ATP administration may represent a promising protective approach for reducing retinal injury associated with long-term tamoxifen therapy. Full article

Maternal nutrition during critical windows of development plays a pivotal role in shaping long-term disease susceptibility, including cancer risk. This study investigated whether maternal exposure to lipotropes (methyl donor nutrients) during pregnancy and lactation modulates gene expression in 7,12-dimethylbenzanthracene (DMBA)-induced mammary tumors in adult female offspring. Timed-pregnant Sprague-Dawley rats were fed with either a control or lipotrope-supplemented diet, with or without vitamin B6. Female offspring were exposed to DMBA at puberty, and mammary tumors were evaluated histologically and molecularly. DMBA-induced tumors displayed ductal carcinoma in situ-like morphology and significant upregulation of fetal mammary developmental genes (Tbx2 and Tbx3), the tumorigenesis-associated gene Tp53, and key epigenetic regulators (Hdac1, Dnmt1, and Mthfr). Estrogen receptor 1 (Esr1) mRNA expression also showed a significant increase. Maternal lipotropes supplementation significantly attenuated the expression of these genes in offspring tumors. Collectively, these findings demonstrate that maternal methyl donor nutrition modulates tumor-associated gene expression patterns, potentially by limiting the reactivation of developmental and epigenetic pathways in adulthood. This study highlights maternal nutrition as a modifiable early-life factor with important implications for long-term health programming. Full article

Background/Objectives: Vasomotor symptoms (hot flashes) affect 70–80% of menopausal women, significantly impairing quality of life. Current treatments include hormone therapy, which is contraindicated for many patients, and non-hormonal alternatives with limited efficacy or adverse effects. Cannabidiol (CBD), a non-psychoactive phytocannabinoid, has emerged as a potential therapeutic candidate due to its interaction with the endocannabinoid system. This study aimed to investigate whether a standardized Cannabis sativa extract containing isolated CBD attenuates heat dissipation in ovariectomized rats, a preclinical model of estrogen deficiency. Methods: Female Wistar rats were randomly assigned to sham-operated vehicle-treated (SHAM-V), ovariectomized vehicle-treated (OVX-V), or ovariectomized CBD-treated (OVX-CBD; 10 mg/kg/day, oral gavage) groups. Treatment began on postoperative day 2 and continued for 21 days. Tail-skin temperature, a surrogate marker of heat dissipation, was assessed by infrared thermography on day 14. Energy metabolism was evaluated by indirect calorimetry on day 21. Uterine weight was measured as a biomarker of estrogen depletion. Results: Ovariectomy significantly increased tail temperature compared to SHAM-V. CBD treatment completely prevented this effect, with OVX-CBD animals exhibiting thermographic profiles similar to SHAM-V. Uterine atrophy was not reversed by CBD. No differences in the calorimetry parameter were observed among groups. Conclusions: This study provides novel preclinical evidence that cannabidiol attenuates ovariectomy-induced heat dissipation in rats, without detectable effects on uterine weight or metabolic parameters. These findings suggest that CBD may represent a potential non-hormonal approach for the management of menopausal vasomotor symptoms; however, further studies are required to elucidate the underlying mechanisms and to determine its translational and clinical relevance. Full article

Uterine fibroids (leiomyomas) are common benign smooth muscle tumors that impose substantial symptom burden and healthcare costs worldwide. Although uterine fibroid (leiomyoma) pathogenesis is multifactorial, hypoxia has emerged as a key feature of the uterine fibroid (leiomyoma) microenvironment, particularly within poorly perfused tumor cores. Hypoxia-inducible factor-1α (HIF-1α) is a central transcriptional regulator of cellular adaptation to low oxygen and coordinates downstream programs that support angiogenesis, metabolic reprogramming, cell survival, and extracellular matrix (ECM) remodeling. In uterine fibroids (leiomyomas), these HIF-1α–dependent processes intersect with steroid hormone signaling, growth factor pathways, inflammatory mediators, and redox imbalance, together promoting tumor persistence and progressive fibrosis. This review synthesizes the molecular regulation of HIF-1α, highlights major HIF-linked effector pathways relevant to uterine fibroid (leiomyoma) biology, and emphasizes mechanistic crosstalk with estrogen- and progesterone-responsive signaling, TGF-β/SMAD-driven fibrosis, NF-κB-mediated inflammation, and metabolic checkpoint pathways including mTOR and AMPK. Finally, we evaluate emerging therapeutic strategies that target HIF-1α directly or indirectly through upstream regulators. Full article