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Frontiers in Physiology 2024In addition to loss of sensory and motor function below the level of the lesion, traumatic spinal cord injury (SCI) may reduce circulating steroid hormones that are...
In addition to loss of sensory and motor function below the level of the lesion, traumatic spinal cord injury (SCI) may reduce circulating steroid hormones that are necessary for maintaining normal physiological function for extended time periods. For men, who comprise nearly 80% of new SCI cases each year, testosterone is the most abundant circulating sex steroid. SCI often results in significantly reduced testosterone production and may result in chronic low testosterone levels. Testosterone plays a role in respiratory function and the expression of respiratory neuroplasticity. When testosterone levels are low, young adult male rats are unable to express phrenic long-term facilitation (pLTF), an inducible form of respiratory neuroplasticity invoked by acute, intermittent hypoxia (AIH). However, testosterone replacement can restore this respiratory neuroplasticity. Complicating the interpretation of this finding is that testosterone may exert its influence in three possible ways: 1) directly through androgen receptor (AR) activation, 2) through conversion to dihydrotestosterone (DHT) by way of the enzyme 5α-reductase, or 3) through conversion to 17β-estradiol (E2) by way of the enzyme aromatase. DHT signals via AR activation similar to testosterone, but with higher affinity, while E2 activates local estrogen receptors. Evidence to date supports the idea that exogenous testosterone supplementation exerts its influence through estrogen receptor signaling under conditions of low circulating testosterone. Here we explored both recovery of breathing function (measured with whole body barometric plethysmography) and the expression of AIH-induced pLTF in male rats following C2-hemisection SCI. One week post injury, rats were supplemented with either E2 or DHT for 7 days. We hypothesized that E2 would enhance ventilation and reveal pLTF following AIH in SCI rats. To our surprise, though E2 did beneficially impact overall breathing recovery following C2-hemisection, both E2 supplementation and DHT restored the expression of AIH-induced pLTF 2 weeks post-SCI.
PubMed: 38803364
DOI: 10.3389/fphys.2024.1390777 -
Frontiers in Oncology 2024Breast cancer is the most prevalent malignancy in women, and is characterized by its heterogeneity; exhibiting various subgroups identifiable through molecular... (Review)
Review
Breast cancer is the most prevalent malignancy in women, and is characterized by its heterogeneity; exhibiting various subgroups identifiable through molecular biomarkers that also serve as predictive indicators. More than two thirds of breast tumors are classified as luminal with positive hormone receptors (HR), indicating that cancer cells proliferation is promoted by hormones. Endocrine therapies play a vital role in the effective treatment of breast cancer by manipulating the signaling of estrogen receptors (ER), leading to a reduction in cell proliferation and growth rate. Selective estrogen receptor modulators (SERMs), such as tamoxifen and toremifene, function by blocking estrogen's effects. Aromatase inhibitors (AI), including anastrozole, letrozole and exemestane, suppress estrogen production. On the other hand, selective estrogen receptor degraders (SERDs), like fulvestrant, act by blocking and damaging estrogen receptors. Tamoxifen and AI are widely used both in early- and advanced-stage disease, while fulvestrant is used as a single agent or in combination with other agents like the cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors (palbociclib, abemaciclib, ribociclib) or alpelisib for advanced-stage disease. Currently, SERDs are recognized as an effective therapeutic approach for the treatment of ER-positive breast cancer, showing proficiency in reducing and blocking ER signaling. This review aims to outline the ongoing development of novel oral SERDs from a practical therapeutic perspective, enhancing our understanding of the mechanisms of action underlying these compounds.
PubMed: 38800404
DOI: 10.3389/fonc.2024.1385577 -
General and Comparative Endocrinology Sep 2024The production of communication signals can be modulated by hormones acting on the brain regions that regulate these signals. However, less is known about how signal... (Review)
Review
The production of communication signals can be modulated by hormones acting on the brain regions that regulate these signals. However, less is known about how signal perception is regulated by hormones. The electrocommunication signals of weakly electric fishes are sexually dimorphic, sensitive to hormones, and vary across species. The neural circuits that regulate the production and perception of these signals are also well-characterized, and electric fishes are thus an excellent model to examine the neuroendocrine regulation of sensorimotor mechanisms of communication. We investigated (1) whether steroid-related genes are expressed in sensory brain regions that process communication signals; and (2) whether this expression differs across sexes and species that have different patterns of sexual dimorphism in their signals. Apteronotus leptorhynchus and Apteronotus albifrons produce continuous electric organ discharges (EODs) that are used for communication. Two brain regions, the electrosensory lateral line lobe (ELL) and the dorsal torus semicircularis (TSd), process inputs from electroreceptors to allow fish to detect and discriminate electrocommunication signals. We used qPCR to quantify the expression of genes for two androgen receptors (ar1, ar2), two estrogen receptors (esr1, esr2b), and aromatase (cyp19a1b). Four out of five steroid-related genes were expressed in both sensory brain regions, and their expression often varied between sexes and species. These results suggest that expression of steroid-related genes in the brain may differentially influence how EOD signals are encoded across species and sexes, and that gonadal steroids may coordinately regulate central circuits that control both the production and perception of EODs.
Topics: Animals; Female; Electric Fish; Male; Brain; Electric Organ; Sex Characteristics
PubMed: 38797340
DOI: 10.1016/j.ygcen.2024.114549 -
Cancers May 2024(1) Background: Abemaciclib combined with endocrine therapy is a standard first- or later-line of treatment for HR+/HER2- metastatic breast cancer (MBC). The aim of this...
(1) Background: Abemaciclib combined with endocrine therapy is a standard first- or later-line of treatment for HR+/HER2- metastatic breast cancer (MBC). The aim of this retrospective cohort study was to describe the outcomes of patients treated in a real-world setting, with particular focus on elderly patients. (2) Patients and methods: Patients treated with abemaciclib between November 2019 and February 2022 were included in the study. Data were collected from electronic medical records. The primary objective was to determine real-world progression-free survival (rwPFS), and secondary objectives included median overall survival (mOS) and safety. (3) Results: Analysis included 134 patients, with a median follow-up of 42 months. Median age was 62 years, with 29.9% aged 70+ years. A total of 51.5% of patients received abemaciclib in first-line, predominantly with aromatase inhibitor (68.1%). Median rwPFS was 21 in first-line and 20 months in the second-line, with no significant difference between treatment lines (HR 0.96; = 0.88). Patients treated in the third- or later-line had a significantly shorter rwPFS, at 7 months (HR 1.48, = 0.003). mOS was not reached in the first-line setting. For second- and third- or later-lines, mOS was 29 and 19 months, respectively. There was no significant difference in mOS between first- or second-line (HR 1.37, = 0.36). In the 70+ group, median rwPFS was 15 months and mOS was 25 months with no significant difference compared to younger patients (rwPFS HR 1.1; = 0.65; OS HR 1.4; = 0.21). Most common adverse events (AEs) were diarrhoea (68.7%), anaemia (64.9%), and increased serum creatinine (63.4%). Grade 3/4 AEs were reported in 21.6% of patients. Dose reductions occurred in 30.6% of patients and were more frequent in patients 70+ (40%) compared to younger patients (28%); the difference was not significant ( = 0.22). At study cut-off, 64.9% of patients discontinued abemaciclib, primarily due to disease progression (73.5%). (4) Conclusions: Our study provides valuable insights into the effectiveness and safety of abemaciclib for the treatment of MBC. We observed comparable outcomes in terms of rwPFS and OS between the first two lines, suggesting consistent effectiveness across treatment lines. In addition, our findings suggest that older age (70+) does not significantly impact the effectiveness and tolerability of abemaciclib, although the careful monitoring and management of AEs are warranted.
PubMed: 38791907
DOI: 10.3390/cancers16101828 -
Biomedicines Apr 2024Contamination by fungi and the toxins they secrete is a worldwide health concern. One such toxin is zearalenone (Zea), which is structurally similar to the hormone...
Contamination by fungi and the toxins they secrete is a worldwide health concern. One such toxin is zearalenone (Zea), which is structurally similar to the hormone estrogen, interferes with its action on the reproductive system, and is therefore classified as an endocrine disruptor. This study aims to determine the effectiveness of hispidin and magnesium nanoparticles (MgONPs) against zearalenone-induced myotoxicity, which causes polycystic ovary syndrome (PCOS) in rats. A three-month exposure study was performed using female Wistar rats ( = 42) with an average weight of 100-150 g. The animals were divided into six groups (I to VI) of seven rats each. Group I was administered distilled water as a negative control. Group II was exposed to Zea 0.1 mg/kg b.w. through gavage daily. Group III was treated with 0.1 mg/kg of hispidin through gavage daily. Group IV was given 150 µg/mL MgONPs orally each day. Group V was treated with Zea 0.1 mg/kg b.w. + 0.1 mg/kg hispidin orally each day. Group VI was treated with Zea 0.1 mg/kg b.w. and the combination treatment of 0.1 mg/kg hispidin + 150 µg/mL MgONPs through gavage every day. The effectiveness of hispidin and MgONPs against Zea toxicity was evaluated in terms of ovarian histological changes, gene expression, oxidative stress biomarkers, biochemical variables, and hormone levels. The findings showed that exposure to Zea promotes PCOS in rats, with Zea-treated rats displaying hyper-ovulation with large cysts; elevated testosterone, luteinizing hormone, insulin, and glucose; and reduced sex hormone-binding globulin. In addition, qRT-PCR for aromatase () showed it to be downregulated. Treatment with hispidin improved the histopathological and hormonal situation and rescued expression of . Our data indicate the potential therapeutic effects of hispidin against Zea-induced Fungal Toxicity.
PubMed: 38790905
DOI: 10.3390/biomedicines12050943 -
Genes May 2024The estrogen receptor signaling pathway plays an important role in vertebrate embryonic development and sexual differentiation. There are four major estrogen receptors...
The estrogen receptor signaling pathway plays an important role in vertebrate embryonic development and sexual differentiation. There are four major estrogen receptors in zebrafish: , , and . However, the specific role of different estrogen receptors in zebrafish is not clear. To investigate the role of in zebrafish development and reproduction, this study utilized TALENs technology to generate an knockout homozygous zebrafish line. The number of eggs laid by knockout female zebrafish did not differ significantly from that of wild zebrafish. The embryonic development process of wild-type and knockout zebrafish was observed, revealing a significant developmental delay in the knockout zebrafish. Additionally, mortality rates were significantly higher in knockout zebrafish than in their wild-type counterparts at 24 hpf. The reciprocal cross experiment between knockout zebrafish and wild-type zebrafish revealed that the absence of resulted in a decline in the quality of zebrafish oocytes, while having no impact on sperm cells. The knockout of also led to an abnormal sex ratio in the adult zebrafish population, with a female-to-male ratio of approximately 1:7. The quantitative PCR (qPCR) and in situ hybridization results demonstrated a significant downregulation of expression in knockout embryos compared to wild-type embryos throughout development (at 2 dpf, 3 dpf and 4 dpf). Additionally, the estrogen-mediated induction expression of was attenuated, while the estradiol-induced upregulated expression of was disrupted. These results suggest that is involved in regulating zebrafish oocyte development and sex differentiation.
Topics: Animals; Zebrafish; Female; Male; Zebrafish Proteins; Sex Ratio; Aromatase; Embryonic Development; Gene Expression Regulation, Developmental; Gene Knockout Techniques; Estrogen Receptor beta; Sex Differentiation; Oocytes
PubMed: 38790265
DOI: 10.3390/genes15050636 -
Clinical Breast Cancer May 2024Young women with breast cancer (BC) may experience bone mineral density (BMD) loss secondary to cancer treatment effects on estrogen levels. Studies assessing BMD in BC...
INTRODUCTION
Young women with breast cancer (BC) may experience bone mineral density (BMD) loss secondary to cancer treatment effects on estrogen levels. Studies assessing BMD in BC patients have had a limited representation of young women. This multicenter retrospective study analyzed the frequency of low BMD and associated factors in this age group.
METHODS
Women diagnosed with stage 0-III BC at ≤40 years, treated with chemotherapy and/or endocrine therapy between 2010 and 2020 at 5 Mexican BC referral centers were eligible. Demographic, clinical and treatment data were collected, as well as bone dual-energy X-ray absorptiometry (DEXA) results. Low BMD was defined as lumbar or femoral neck T-score < -1.0 or Z-score ≤ -2.0.
RESULTS
A total of 1259 patients were included; median age at diagnosis was 36 years (21-40). Overall, 93% received chemotherapy and 65% endocrine therapy (tamoxifen was received at some point by 61%, aromatase inhibitors by 17%, and GnRH agonists/bilateral oophorectomy by 21%). DEXA scans were documented in 254 (20%), of which 163 (64%; 95% confidence interval [CI] 58%-70%) had a low BMD report. Low BMD was associated with receiving aromatase inhibitors (Odds ratio [OR] 1.92; 95% CI 1.13-3.24), and GnRH agonists/bilateral oophorectomy (OR 2.25; 95% CI 1.21-4.21).
CONCLUSION
The suboptimal frequency of BMD monitoring observed displays an alarming disregard for bone health in young patients. Thus, a high proportion of women with low BMD are potentially being missed and precluded from the opportunity to receive timely interventions. Particular focus should be put on BMD monitoring among patients treated with aromatase inhibitors, GnRH agonists or bilateral oophorectomy.
PubMed: 38789360
DOI: 10.1016/j.clbc.2024.04.012 -
European Journal of Pharmaceutical... Aug 2024Letrozole, an aromatase inhibitor metabolised via CYP2A6 and CYP3A4/5 enzymes, is used as adjuvant therapy for women with hormone receptor (HR)-positive early breast...
BACKGROUND
Letrozole, an aromatase inhibitor metabolised via CYP2A6 and CYP3A4/5 enzymes, is used as adjuvant therapy for women with hormone receptor (HR)-positive early breast cancer. The objective of this study was to quantify the impact of CYP2A6 genotype on letrozole pharmacokinetics (PK), to identify non-adherent patients using a population approach and explore the possibility of a relationship between non-adherence and early relapse.
METHODS
Breast cancer patients enrolled in the prospective PHACS study (ClinicalTrials.gov NCT01127295) and treated with adjuvant letrozole 2.5 mg/day were included. Trough letrozole concentrations (C) were measured every 6 months for 3 years by a validated LC-MS/MS method. Concentration-time data were analysed using non-linear mixed effects modelling. Three methods were evaluated for identification of non-adherent subjects using the base PK model.
RESULTS
617 patients contributing 2534 plasma concentrations were included and led to a one-compartment PK model with linear absorption and elimination. Model-based methods identified 28 % of patients as non-adherent based on high fluctuations of their C compared to 3 % based on patient declarations. The covariate analysis performed in adherent subjects revealed that CYP2A6 intermediate (IM) and slow metabolisers (SM) had 21 % (CI95 % = 12 - 30 %) and 46 % (CI95 % = 41 - 51 %) lower apparent clearance, respectively, compared to normal and ultrarapid metabolisers (NM+UM). Early relapse (19 patients) was not associated with model-estimated, concentration-based or declared adherence in the total population (p = 0.41, p = 0.37 and p = 0.45, respectively).
CONCLUSIONS
These findings will help future investigations focusing on the exposure-efficacy relationship for letrozole in adjuvant setting.
Topics: Humans; Letrozole; Female; Breast Neoplasms; Middle Aged; Aged; Medication Adherence; Aromatase Inhibitors; Adult; Chemotherapy, Adjuvant; Models, Biological; Prospective Studies; Receptors, Estrogen; Antineoplastic Agents; Aged, 80 and over
PubMed: 38788907
DOI: 10.1016/j.ejps.2024.106809 -
Breast Cancer Research and Treatment Jul 2024Vaginal oestrogens can be used to treat genitourinary symptoms in women with early breast cancer. Studies evaluating vaginal oestrogens have commonly measured serum...
PURPOSE
Vaginal oestrogens can be used to treat genitourinary symptoms in women with early breast cancer. Studies evaluating vaginal oestrogens have commonly measured serum oestrogen levels as a surrogate marker of safety, but methods vary. We sought to summarise the data on serum oestrogen measurement in women with breast cancer using vaginal oestrogens to better understand the methods, levels and reliability.
METHODS
We searched Medline, Embase, CENTRAL, SCOPUS and CINAHL from inception to October 2023 for clinical studies where serum oestrogen was measured in women with a history of early breast cancer using vaginal oestrogens. Studies with a reported testing methodology were included.
RESULTS
Nine studies met the inclusion criteria for this systematic review. Methods used to measure oestradiol and oestriol in selected studies included mass spectrometry and immunoassays; several studies used more than one with variable concordance. Mass spectrometry detected oestradiol levels down to a lower limit between 1.0 pg/mL and 3.0 pg/mL. Immunoassays such as ELISA (enzyme-linked immunosorbent assay), ECLIA (enhanced chemiluminiscence immunoassay) and RIA (radioimmunoassay) had lower detection limits ranging between 0.8 pg/mL and 10 pg/mL. Studies were heterogeneous in testing techniques used, timing of testing, and the population including with subsequent varying results in the effect on oestrogens reported.
CONCLUSIONS
Adopting consistent and standardised methods of measuring oestrogens in clinical trials involving women with early breast cancer on vaginal oestrogens is critical. Serum oestrogens are used as a surrogate marker of safety in this population, and good-quality data are necessary to enable clinicians and patients to feel confident in prescribing and taking vaginal oestrogens. Mass spectrometry, although more expensive, gives more reliable results when dealing with very low levels of oestrogens often found in women on aromatase inhibitors, compared to immunoassays.
Topics: Female; Humans; Administration, Intravaginal; Breast Neoplasms; Cancer Survivors; Estradiol; Estriol; Estrogens; Vagina
PubMed: 38780887
DOI: 10.1007/s10549-024-07364-0 -
PM & R : the Journal of Injury,... May 2024Aromatase inhibitors are prescribed in breast cancer due to their associated lower rate of cancer recurrence compared to tamoxifen. However, aromatase inhibitor-induced... (Review)
Review
Aromatase inhibitors are prescribed in breast cancer due to their associated lower rate of cancer recurrence compared to tamoxifen. However, aromatase inhibitor-induced arthralgia (AIIA) is one of the leading causes of treatment nonadherence, increasing the risk of cancer recurrence. The pathophysiology of AIIA is poorly understood, and although current recommendations for AIIA include lifestyle changes and analgesics depending on the severity of symptoms, there is no established effective treatment. The aim of this study is to explore the presentation and mechanism of AIIA and investigate the feasibility and efficacy of different exercise interventions (aerobic, resistance, aerobic and resistance combined, and yoga or tai chi) in patients with AIIA to guide the development of formal exercise prescription guidelines. Findings indicate that a mixed-modality regimen of aerobic and resistance exercises is feasible and safe and may serve the most benefit in improving joint pain, functionality, and quality of life. More specifically, the weekly regimen should consist of 150 min of aerobic exercise with two sessions of at least six resistance exercises, 8 to 12 repetitions, three sets each. Supplementary yoga and tai chi may be recommended twice a week depending on a patient's target symptoms. Yoga was associated with improved physical functionality, whereas tai chi was related to improvements in mental health. However, the feasibility and impact of combined aerobic and resistance exercise protocols with yoga or tai chi in our target population were not investigated in this review. The use of large, randomized controlled trials is recommended for future studies.
PubMed: 38780410
DOI: 10.1002/pmrj.13193