Estrogen Suppression Research Articles

In Silico Based Approach to Investigate Plant Lignans as Inhibitor Candidates for Estrogen Receptor in Breast Cancer

Background: In the last decades, growing evidence demonstrates interest in phytoestrogen intake to modulate targets in different types of cancer. Plant lignans have proven efficacious in blocking estrogen receptors of breast cancer cells. Among them, four phytoestrogen lignans: pinoresinol, matairesinol, lariciresinol, and secoisolariciresinol have been most studied. However, available studies have mostly dealt with the anti-cancer effects of groups of lignans in certain foods or plants and the effects of specific lignans, especially from a molecular interaction viewpoint, have been rarely addressed in the literature. Objective: We aimed to in silico predict pharmacological properties, binding ability and binding strength of pinoresinol, matairesinol, lariciresinol and secoisolariciresinol as possible inhibitors of estrogen receptor alpha which is the most important biomarker in breast cancer. Methods: Firstly, we evaluated the pharmacological properties of four lignans using SwissADME. Then we investigated the ligand-receptor interactions of these molecules as positively appraised ligands for ER-positive breast cancer targeted therapy using docking method. We finally compared the inhibitory effect possibility of the lignans against endoxifen which is the active metabolite of tamoxifen. Results: The best binding affinity of endoxifen, matairesinol, pinoresinol, lariciresinol and secoisolariciresinol were respectively -9.2, -7.5, -6.7, -6.7, -5.8 kcal/mol. In the meantime, matairesinol showed a minimum binding energy than other studied lignans in addition to the most similar interactions to endoxifen with conserved domain residues of the active site pocket in Leu:391, Ala:350, Met:421, and Phe:404. Conclusion: Among the studied lignans, matairesinol showed favorable pharmacokinetics and drug-likeliness properties, the least binding energy as well as the most common interactions in conserved residues of the active site pocket with estrogens. This makes it a molecule with low number of nonspecific interactions, better target selectivity, and hence fewer side effects. Thus, our results introduce matairesinol as a possibly effective anti-estrogen receptor inhibitor candidate.

Perils of prolonged ovarian suppression and hypoestrogenism in the treatment of breast cancer: Is the risk of treatment worse than the risk of recurrence?

Premenopausal breast cancer is usually estrogen receptor positive, and hence, prolonged ovarian suppression by medical or surgical means to prevent recurrence has become standard of management to improve disease-free survival. Ten-year adjuvant tamoxifen therapy is associated with 3.5% fewer recurrences compared to five years. The SOFT trial demonstrated small but statistically significant incremental improvements in long-term disease-free survival by the addition of gonadotropin-releasing hormone analog treatment (triptorelin) to an aromatase inhibitor (exemestane). Profound hypoestrogenism in the premenopausal age group may not be well tolerated due to a host of bothersome side effects (primarily vasomotor symptoms, musculoskeletal complaints, genitourinary syndrome of menopause, and mood disorders). Prolonged hypoestrogenism in younger women is associated with premature development of cardiovascular disease, bone loss, cognitive decline, and all-cause mortality. This paper explores multi-system consequences of prolonged hypoestrogenism in premenopausal women derived from studies of women with and without breast cancer. Pretreatment counseling in estrogen receptor positive breast cancer should emphasize the benefit of prolonged estrogen suppression on breast cancer recurrence and established risks of lifelong hypoestrogenism on quality of life and all-cause mortality. Future genomic research may help identify the best candidates for extended ovarian suppression to avoid treating many women when only a minority benefit.

MiRNA320a-3p/RUNX2 signal programming mediates the transgenerational inheritance of inhibited ovarian estrogen synthesis in female offspring rats induced by prenatal dexamethasone exposure

Our previous studies found that prenatal dexamethasone exposure could cause abnormal follicular development in fetal rats. This study intends to observe the transgenerational inheritance effects of ovarian estrogen inhibition in offspring exposed to dexamethasone (0.2 mg/kg • d) from gestational day 9 (GD9) to GD20 in Wistar rats, and explore the intrauterine programming mechanisms. Prenatal dexamethasone exposure reduced the expression of ovarian cytochrome P450 aromatase (P450arom), the level of serum estradiol (E2) and the number of primordial follicles, while increased the number of atresia follicles before and after birth in F1 offspring rats. At the same time, the expression of miRNA320a-3p in F1 ovaries was down-regulated, and RUNX2 expression increased significantly. These changes were continued to F2 and F3 generations, accompanied by consistently down-regulated miRNA320a-3p expression in oocyte of F1 and F2 adult offspring. In vitro, fetal rat ovaries and KGN human ovarian granulosa cells were treated with dexamethasone. It showed that dexamethasone decreased miRNA320a-3p and P450arom expression, as well as E2 synthesis, and increased RUNX2 expression. All these effects could be reversed by the GR antagonist RU486. The overexpression of miRNA320a-3p in vitro could also reverse the effects of dexamethasone on RUNX2, P450arom, and E2 levels. The dual-luciferase reporter gene experiment further confirmed the direct targeted regulation of miRNA320a-3p on RUNX2. These results indicate that prenatal dexamethasone exposure induces ovarian E2 synthesis inhibition mediated by the GR/miRNA320a-3p/RUNX2/P450arom cascade signal in fetal rat ovary, which has transgenerational inheritance effects and may related to the inhibited miRNA320a-3p expression in oocyte.

Impact of obesity on clinical outcomes in hormone receptor-positive breast cancer: a systematic review.

The relationship between obesity and prognosis of early breast cancer is complex. Increased levels of aromatase present in adipose tissue of obese postmenopausal women may lead to suboptimal suppression of systemic estrogens. However, studies have been mixed with respect to the association between use of aromatase inhibitors (AIs) and clinical outcomes in obese women with early breast cancer. We conducted a systematic literature review following PRISMA guidelines to examine the impact of obesity on the efficacy of AIs in early-stage hormone receptor-positive breast cancer. Primary outcome measures included disease-free survival, relapse-free survival, distant recurrence-free survival, breast cancer-free survival, and overall survival. Of 491 studies identified, eight studies met criteria for inclusion: three retrospective cohort studies, one prospective cohort study and four randomized controlled trials. Four studies limited eligibility to postmenopausal women. Percentage of obese patients in studies ranged from 10 to 30%. Two studies examined use of AIs alone while the remainder included patients treated with either AIs or tamoxifen. Five out of seven studies suggested a negative impact of obesity on AI efficacy. The results of our systematic review highlight a need for further research exploring the optimal endocrine therapies for obese women. There is insufficient evidence at present to recommend tailoring adjuvant endocrine therapy with use of specific AIs or for dosing modifications of AIs in this patient population.

Recent Development in Indole Derivatives as Anticancer Agent: A Mechanistic Approach.

Cancer accounts for several deaths each year. There are multiple FDA approved drugs for cancer treatments. Due to the severe side effects and multiple drug resistance, the current drug therapies become ineffective. So, the newer moieties with fewer toxic effects are necessary for the development. The mechanism of indole derivatives as anti-cancer agents with their major target is explored in detail in this article. Recent advances and mechanism of indole derivatives as anti-cancer agents are reviewed. This review suggests a detailed explanation of multiple mechanisms of action of various indole derivatives: cell cycle arrest, aromatase inhibitor estrogen receptor regulator, tubulin inhibitor, a tyrosine kinase inhibitor, topoisomerase inhibitors, and NFkB/PI3/Akt/mTOR pathway inhibitors, through which these derivatives have shown promising anti-cancer potential. A full literature review showed that the indole derivatives are associated with the properties of inducing apoptosis, aromatase inhibition, regulation of estrogen receptor and inhibition of tyrosine kinase, tubulin assembly, NFkB/PI3/Akt/mTOR pathway, and HDACs. These derivatives have shown significant activity against cancer cell lines. Indole derivatives seem to be important in cancer via acting through various mechanisms. This review has shown that the indole derivatives can further be explored for the betterment of cancer treatment, and to discover the hidden potential of indole derivatives.

Fatty Liver in Hormone Receptor-Positive Breast Cancer and Its Impact on Patient's Survival.

PurposeLong-term estrogen inhibition may cause fatty liver disease (non-alcoholic fatty liver disease; NAFLD) among other adverse conditions such as osteoporosis, climacteric symptoms, thromboembolism, dyslipidemia, and metabolic syndrome. The prevalence of NAFLD among breast cancer patients ranges from 2.3%–45.2%. This study aimed to determine the risk factors for newly developed NAFLD among breast cancer patients after hormonal treatment and whether it influences survival outcomes.MethodsThis retrospective study investigated hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative (HR+/HER2−), nonmetastatic breast cancer patients diagnosed between January 2010 and December 2018. All patients received adjuvant hormonal treatment for at least 6 months. Clinical data on metabolic profile indicators such as body mass index (BMI), waist circumference, serum cholesterol, triglycerides, low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C), diabetes, and presence of metabolic syndrome (MetS) were collected. In total, 160 eligible patients with complete covariate data and survival follow-up were included.ResultsNAFLD was diagnosed in 35% of patients. There were significant associations of being overweight (BMI ≥ 25 kg/m2), waist circumference > 80 cm, triglycerides ≥ 150 mg/dL, HDL-C ≤ 50 mg/dL, LDL-C < 150 mg/dL, and presence of MetS with the development of NAFLD. However, unlike other factors, MetS and HDL-C were not independently associated with NAFLD. Patients with breast cancer who developed NAFLD had longer disease-free survival (DFS). The median DFS was not reached in the NAFLD group, whereas it was 59.3 (45.6–73.0) months in the non-NAFLD group. No worsening of overall survival was observed in patients with breast cancer and NAFLD.ConclusionThe development of NAFLD during treatment in patients with HR+/HER2− breast cancer was associated with several independent risk factors: being overweight, waist circumference, triglycerides, and LDL-C. Interestingly, breast cancer patients with NAFLD during treatment had longer DFS than those without NAFLD.

Effects of estrogen inhibition formula herbal mixture for danazol-induced precocious puberty in female rats: An experimental study with network pharmacology

BackgroundThis study aimed at determining the effect of the herbal mixture estrogen inhibition formula (EIF) and its possible mechanisms by precocious puberty animal models and network pharmacology-based analysis. MethodsPrecocious puberty animal models were established by a single injection of 300 μg danazol, then female rats were administered EIF, vaginal openings were monitored, uterus and pituitary indices were determined. The levels of ALP, E2, LH, and FSH were measured using ELISA kits. Real-time PCR was performed to evaluate the mRNA expression of GnRH, UNC5C, and netrin-1 in hypothalamic tissues. We applied network pharmacological analysis to predict potential targets and pathways of EIF. ResultsEIF delayed danazol-induced early vaginal opening. In the onset model, EIF reduced the increased levels of serum ALP, E2, LH, and FSH; as well as mRNA expressions of GnRH, Netrin-1, and UNC5C. Moreover, long-term administration of EIF not only diminished all impaired factors but also had no effect on the normal development of the animals. The gene set enrichment analysis showed that the targets of EIF are mainly associated with the GnRH signaling and ovarian steroidogenesis pathways. ConclusionEIF could be used in preclinical research for the treatment of precocious puberty by the inhibition of HPGA pre-maturation.

A Case of Nonalcoholic Steatohepatitis in Central Precocious Puberty Aggravated by Gonadotropin-releasing Hormone Analog

We report the case of a girl with central precocious puberty (CPP) and nonalcoholic steatohepatitis (NASH) aggravated by gonadotropin-releasing hormone analog (GnRHa). She was diagnosed with CCP and began treatment with GnRHa at the age of 8 years and 9 months. She already had mild liver dysfunction and was obese at that time; however, liver dysfunction was aggravated during GnRHa initiation. Her liver dysfunction improved after the discontinuation of GnRHa. Liver biopsy was performed twice during GnRHa initiation and findings suggested NASH. In this case, NASH may have been aggravated by the mechanism of estrogen suppression by GnRHa besides obesity. In conclusion, NASH should be ruled out in obese CPP patients with abnormal liver function before starting GnRHa therapy. CPP patients treated with GnRHa require close examination for the early diagnosis of NASH or its progression.

Proline rich 11 (PRR11) overexpression amplifies PI3K signaling and promotes antiestrogen resistance in breast cancer

The 17q23 amplicon is associated with poor outcome in ER+ breast cancers, but the causal genes to endocrine resistance in this amplicon are unclear. Here, we interrogate transcriptome data from primary breast tumors and find that among genes in 17q23, PRR11 is a key gene associated with a poor response to therapeutic estrogen suppression. PRR11 promotes estrogen-independent proliferation and confers endocrine resistance in ER+ breast cancers. Mechanistically, the proline-rich motif-mediated interaction of PRR11 with the p85α regulatory subunit of PI3K suppresses p85 homodimerization, thus enhancing insulin-stimulated binding of p110-p85α heterodimers to IRS1 and activation of PI3K. PRR11-amplified breast cancer cells rely on PIK3CA and are highly sensitive to PI3K inhibitors, suggesting that PRR11 amplification confers PI3K dependence. Finally, genetic and pharmacological inhibition of PI3K suppresses PRR11-mediated, estrogen-independent growth. These data suggest ER+/PRR11-amplified breast cancers as a novel subgroup of tumors that may benefit from treatment with PI3K inhibitors and antiestrogens.

Bazedoxifene inhibits PDGF-BB induced VSMC phenotypic switch via regulating the autophagy level

There is increasing evidence that Bazedoxifene, as an FDA-approved selective estrogen inhibitor, approved by FDA, not only inhibits estrogen receptors, but also has other pharmacological effects. The purpose of this study was to investigate the effects of Bazedoxifene on the functional changes of vascular smooth muscle cells (VSMCs) after PDGF-BB stimulation. VSMCs were divided into control group, PDGF-BB treatment group, and PDGF-BB treatment group with different concentrations of Bazedoxifene. CCK-8 and EdU staining were used to determine the VSMCs viability and proliferation. Western blot was used to detect the expressions of vimentin, SMA, ERK, p-ERK, STAT3, p-STAT3, AKT, p-AKT, and LC3 I/II. Wound healing method was used to detect the migration of VSMCs. PDGF-BB treatment significantly enhanced the viability and proliferation of VSMCs as indicated by CCK-8 and EdU assays (P < 0.01), while Bazedoxifene pretreatment could reduce the increased viability and proliferation of VSMCs caused by PDGF-BB (P < 0.05). Wound healing test also showed Bazedoxifene significantly attenuated the migration in the PDGF-BB stimulated VSMCs (P < 0.01). PDGF-BB also induced the phenotypic switch and decreased the autophagy level in VSMCs, manifested as a reduction in vimentin, SMA, and LC3 II (P < 0.01). These effects of PDGF-BB were partially reversed by Bazedoxifene (P < 0.05). Bazedoxifene may inhibit the proliferation and migration of VSMCs through up-regulate the autophagy level after PDGF-BB stimulation.

ASSOCIATION BETWEEN ESTRADIOL LEVELS AND OBSTETRIC OUTCOMES IN LETROZOLE-STIMULATED FROZEN EMBRYO TRANSFER CYCLES

Letrozole-stimulated frozen embryo transfer (LTZ-FET) cycles are increasingly utilized due to growing evidence of improved success rates in multiple populations, including patients with polycystic ovary syndrome, diminished ovarian reserve, tubal factor, or unexplained infertility. The degree of estrogen suppression is variable between patients, and the impact of low estradiol (E2) levels in the follicular phase is unknown. Thus, the goal of this study was to assess the impact of low estradiol on outcomes of LTZ- FET cycles.

Abstract 4384: Quantitative assessment of drug combination effects in NSCLC cell lines through network-based analysis of functional protein activity

Abstract Non-small cell lung cancer (NSCLC) is the most prevalent type of lung cancer, which is the leading cause of cancer death worldwide. The KRAS oncogene is one of the most common driver mutations in NSCLC patients but, despite that, there are no approved targeted therapies for tumors harboring this mutation. The MEK inhibitor Selumetinib (SE) turned out to be an ineffective drug against KRAS mutated lung cancer. Since combination therapy has shown to be beneficial in many tumors, we wanted to investigate the combination of MEK inhibition with other targeted therapies. Thus, we measured the proteomic response of KRAS mutant (MUT) and wild-type (WT) NSCLC cell lines (CLs) to the combination of SE with Everolimus (EV), an mTOR inhibitor, and Tamoxifen (TA), an Estrogen inhibitor. The expression level of 183 proteins was measured through Reverse Phase Protein Array (RPPA) in eight NSCLC CLs treated with SE, SE plus EV and SE plus TA at 6 time points: 5 minutes (min), 30 min, 1, 2, 6 and 24 hours (h). As control, measures were taken in baseline CLs and in CLs with only dimethyl sulfoxide. To study the drug combination effects, we applied a computational workflow centered on two algorithms initially developed for gene expression data. We analyzed the CLs with the Algorithm for the Reconstruction of Accurate Cellular Networks (ARACNe) to reconstruct a context specific signaling network of 2635 interactions between 73 kinases and 6 phosphatases and their substrates. Then, we analyzed the obtained network with the Virtual Inference of Protein activity by Enriched Regulon analysis (VIPER) algorithm to assess the mechanism of action of the drug compounds and how they dysregulate the activity of kinases and phosphatases over time. With respect to SE alone and apart from the drug targets, VIPER predicted the following proteins as highly inhibited over time across all CLs : 1) Aurora and LKB1 in SE+EV, 2) AMPK, c-RAF and ATR in SE+TA, 3) mTOR, p90, p70S6K, c-MET and GSK-3 in both combinations. On the other hand, Akt, ETK, Axl and FAK are all activated in SE+EV as well as PP2A, SGK1 and IGF1R in SE+TA, after 1h from the treatment. By running Gene Set Enrichment Analysis on the VIPER output against the primary drug target pathways, we found that mTOR signaling pathway exhibits a quite different evolution between KRAS MUT and WT CLs. On the other hand, other pathways revealed mechanisms of response that are CL specific. For instance, the main MEK pathways in H1734 CL (KRAS MUT) treated with SE+TA are all insensitive to the drug compounds. In conclusion, this computational approach successfully predicted protein-protein interactions and elucidated both proteomic mechanisms of drug combinations and CL specific dependencies. It allows to develop effective predictive and quantitative models reproducing each CL behavior, in order to realize the fullest potential of a targeted therapeutic approach. Citation Format: Chiara Antonini, George Rosenberger, Fortunato Bianconi, Lorenzo Tomassoni, Vienna Ludovini, Sara Baglivo, Sara Calandrini, Elisa Baldelli, Mariaelena Pierobon, Emanuel F. Petricoin, Andrea Califano. Quantitative assessment of drug combination effects in NSCLC cell lines through network-based analysis of functional protein activity [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4384.

Essential role of STAT5a in DCIS formation and invasion following estrogen treatment.

Ductal carcinoma in situ (DCIS) is one of the earliest stages of breast cancer (BCa). The mechanisms by which DCIS lesions progress to an invasive state while others remain indolent are yet to be fully characterized and both diagnosis and treatment of this pre-invasive disease could benefit from better understanding the pathways involved. While a decreased expression of Caveolin-1 (Cav-1) in the tumor microenvironment of patients with DCIS breast cancer was linked to progression to invasive breast cancer (IBC), the downstream effector(s) contributing to this process remain elusive. The current report shows elevated expression of Signal Transducer and Activator of Transcription 5a (STAT5a) within the DCIS-like lesions in Cav-1 KO mice following estrogen treatment and inhibition of STAT5a expression prevented the formation of these mammary lesions. In addition, STAT5a overexpression in a human DCIS cell line (MCF10DCIS.com) promoted their invasion, a process accelerated by estrogen treatment and associated with increased levels of the matrix metalloproteinase-9 (MMP-9) precursor. In sum, our results demonstrate a novel regulatory axis (Cav-1♦STAT5a♦MMP-9) in DCIS that is fully activated by the presence of estrogen. Our sudies suggest to further study phosphorylated STAT5a (Y694) as a potential biomarker to guide and predict outcome of DCIS patient population.

Single-nucleotide polymorphism biomarkers of adjuvant anastrozole-induced estrogen suppression in early breast cancer.

Based on our previous findings that postmenopausal women with estrone (E1) and estradiol (E2) concentrations at or above 1.3 pg/ml and 0.5 pg/ml, respectively, after 6 months of adjuvant anastrozole therapy had a three-fold risk of recurrence, we aimed to identify a single-nucleotide polymorphism (SNP)-based model that would predict elevated E1 and E2 and then validate it in an independent dataset. The test set consisted of 322 women from the M3 study and the validation set consisted of 152 patients from MA.27. All patients were treated with adjuvant anastrozole, had on-anastrozole E1 and E2 concentrations and genome-wide genotyping. SNPs were identified from the M3 genome-wide association study. The best model to predict the E1-E2 phenotype with high balanced accuracy was a support vector machine model using clinical factors plus 46 SNPs. We did not have an independent cohort that is similar to the M3 study with clinical, E1-E2 phenotypes and genotype data to test our model. Hence, we chose a nested matched case-control cohort (MA.27 study) for testing. Our E1-E2 model was not validated but we found the MA.27 validation cohort was both clinically and genomically different. We identified a SNP-based model that had excellent performance characteristics for predicting the phenotype of elevated E1 and E2 in women treated with anastrozole. This model was not validated in an independent dataset but that dataset was clinically and genomically substantially different. The model will need validation in a prospective study.

Anastrozole has an Association between Degree of Estrogen Suppression and Outcomes in Early Breast Cancer and is a Ligand for Estrogen Receptor α.

To determine if the degree of estrogen suppression with aromatase inhibitors (AI: anastrozole, exemestane, letrozole) is associated with efficacy in early-stage breast cancer, and to examine for differences in the mechanism of action between the three AIs. Matched case-control studies [247 matched sets from MA.27 (anastrozole vs. exemestane) and PreFace (letrozole) trials] were undertaken to assess whether estrone (E1) or estradiol (E2) concentrations after 6 months of adjuvant therapy were associated with risk of an early breast cancer event (EBCE). Preclinical laboratory studies included luciferase activity, cell proliferation, radio-labeled ligand estrogen receptor binding, surface plasmon resonance ligand receptor binding, and nuclear magnetic resonance assays. Women with E1 ≥1.3 pg/mL and E2 ≥0.5 pg/mL after 6 months of AI treatment had a 2.2-fold increase in risk (P = 0.0005) of an EBCE, and in the anastrozole subgroup, the increase in risk of an EBCE was 3.0-fold (P = 0.001). Preclinical laboratory studies examined mechanisms of action in addition to aromatase inhibition and showed that only anastrozole could directly bind to estrogen receptor α (ERα), activate estrogen response element-dependent transcription, and stimulate growth of an aromatase-deficient CYP19A1-/- T47D breast cancer cell line. This matched case-control clinical study revealed that levels of estrone and estradiol above identified thresholds after 6 months of adjuvant anastrozole treatment were associated with increased risk of an EBCE. Preclinical laboratory studies revealed that anastrozole, but not exemestane or letrozole, is a ligand for ERα. These findings represent potential steps towards individualized anastrozole therapy.

The relationship between estrogen-induced phenotypic transformation and proliferation of vascular smooth muscle and hypertensive intracerebral hemorrhage.

BackgroundTo explore the effect of estrogen on human cerebral vascular smooth muscle cells (VSMCs) and to clarify the molecular mechanism of estrogen inhibition of VSMC proliferation, which could provide an important reference basis for the clinical treatment of hypertensive intracerebral hemorrhage.MethodFirstly, the effects of different concentrations of estradiol and estrogen receptor (ESR) blocker (tamoxifen) on the proliferation of human VSMCs and the expression of estrogen-related receptor gene (ESR: ESR1, ESR2, GPER), myocardin (MYOCD), serum reaction factor (SRF), and apoptosis gene caspase-3 were measured to discover the effect and mechanism of tamoxifen on the proliferation and apoptosis of VSMCs. Secondly, the effects of estradiol on human VSMCs treated with angiotensin II (Ang II) were observed by measuring the expression of vascular smooth muscle markers, α-smooth muscle actin (α-SMA), SM22α, FLN, MCP-1, and TLR4.ResultsEstradiol inhibited the proliferation of VSMCs by upregulating the expression of ESR1, ESR2, and GPER and downregulating the expression of caspase-3, MYOCD, and SRF, thereby inhibiting the apoptosis of vascular smooth muscle. At the same time, tamoxifen had opposite effects. Angiotensin II decreased the expression of α-SMA and SM22α and promoted the expression of FLN, MCP-1, and TLR4 protein, while estrogen had the opposite effects.ConclusionsEstrogen suppresses apoptosis by inhibiting the proliferation of human VSMCs and preventing it from changing from contractile to synthetic. Estrogen can further prevents vascular damage and regulate peripheral inflammatory reaction, thereby producing a protective effect on cardiovascular and cerebrovascular.

An Ultrasensitive Routine LC-MS/MS Method for Estradiol and Estrone in the Clinically Relevant Sub-Picomolar Range.

BackgroundCurrent analytical routine methods lack the sensitivity to monitor plasma estrogen levels in breast cancer patients treated with aromatase inhibitors. Such monitoring is warranted for premenopausal patients treated with an aromatase inhibitor and an LH-releasing hormone analogue in particular. Therefore, we aimed to develop a routine tandem mass spectroscopy combined with liquid chromatography (LC-MS/MS) method for estradiol (E2) and estrone (E1) for use in the sub-picomolar range.MethodCalibrators, quality controls (QC), or serum samples were spiked with isotope-labeled internal standard and purified by liquid-liquid extraction. The reconstituted extracts were analyzed by LC-MS/MS in negative electrospray ionization mode. QCs at 6 levels made from pooled patient sera were used to validate the accuracy, sensitivity, and precision of the method.ResultsWe achieved limits of quantification of 0.6 pmol/L (0.16 pg/mL) for E2 and 0.3 pmol/L (0.07 pg/mL) for E1. The coefficient of variation was below 9.0% at all QC levels for E2 (range, 1.7-153 pmol/L), and below 7.8% for E1 (range, 1.7-143 pmol/L). The method is traceable to the E2 reference standard BCR576. Reference ranges for E2 and E1 in healthy, postmenopausal women were obtained, for E2: 3.8 to 36 pmol/L, for E1: 22 to 122 pmol/L. We measured and confirmed ultra-low E2 and E1 concentrations in sera from patients on the aromatase inhibitors letrozole or exemestane.ConclusionThis ultrasensitive LC-MS/MS method is suitable for routine assessment of serum E1 and E2 levels in breast cancer patients during estrogen suppression therapy. The method satisfies all requirements for measurement of E2 in the clinical setting as stated by the Endocrine Society in 2013.PrecisWe report an ultrasensitive LCMS/MS routine assay that measures pretreatment and suppressed levels of estradiol/estrone during aromatase inhibitor treatment of postmenopausal breast cancer patients.

Autonomic Dysfunction in Women with Androgen Excess PCOS

Polycystic ovary syndrome (PCOS) is the most common reproductive endocrinopathy, affecting approximately 10% of reproductive age women. Further, 75% of women with PCOS have the more severe phenotype, Androgen Excess‐PCOS (AE‐PCOS), that is dominated by clinical and biochemical manifestations of hyperandrogenism. AE‐PCOS is also associated with elevated blood pressure (BP), which we hypothesized is the result of androgen‐associated impairments in autonomic function. Thus, we tested the hypothesis that androgen excess is associated with impaired baroreflex sensitivity (BRS) in women with AE‐PCOS. We tested four obese women with AE‐PCOS (age 30±3 y; BMI 39±11 kg/m2) at 0, HDT, ‐20, ‐30 lower body negative pressure (LBNP) under three conditions: Baseline (BL), during hormone suppression with a GnRH antagonist (GnRH ant, 7 days, 250 μg/day), and with GnRH ant+testosterone (T, 4 days, 5 mg/day). Women were mildly hypertensive at rest at BL, but BP increased following hormone suppression with the GnRH ant and remained elevated with T (93±7, 105±5, 105±9 mm Hg for BL, GnRH ant, and T, respectively, P=0.02). Blood pressure was well maintained during LBNP under the three hormone conditions. Forearm vascular resistance (FVR) increased during LBNP under each condition, but the increase was greatest during GnRH ant and T (Δ54±19, Δ235±145, Δ104±64 units for BL, GnRH ant, and T, respectively, P=0.04). The resulting BRS slopes were greater in GnRH ant (−5.2 units/mm Hg) compared to BL (−1.6 units/mm Hg), demonstrating concomitant testosterone and estrogen suppression improved BRS in women with AE‐PCOS. When we restored androgens, the BRS slope was again attenuated (T= −1.7 units/mm Hg), suggesting an important role for androgens in autonomic function in AE‐PCOS. GnRH ant increased resting BP independent of T in AE‐PCOS, which is likely a function of the continued estrogen suppression. Thus, hypertension associated with AE‐PCOS appears closely associated with estrogen suppression and independent of testosterone‐induced changes in BRS. In summary, both estrogens and androgens contribute to BP regulation in women with AE‐PCOS. Women with AE‐PCOS frequently present with mild hypertension that is driven by altered estrogen and testosterone exposures. Treating hypertension is crucial for preventing cardiovascular disease in this vulnerable population.Support or Funding InformationR01 HL135089

Physiological and genomic insight into neuroendocrine regulation of puberty in gilts

The timing of pubertal attainment in gilts is a critical factor for pork production and is an early indicator of future reproductive potential. Puberty, defined as age at first standing estrus in the presence of a boar, is brought about by an escape from estrogen inhibition of the GnRH pulse generator, which allows for increasing LH pulses leading to the onset of cyclicity. The biological mechanisms that control the timing of these events is related to decreasing inhibitory signals with a concomitant increase in stimulatory signals within the hypothalamus. The roles of gamma-aminobutyric acid, endogenous opioid peptides, and gonadotropin-inhibitory hormone in negatively regulating gonadotropin secretion in gilts is explored. Developmental changes in stimulatory mechanisms of glutamatergic and kisspeptin neurons are important for increased LH pulsatility required for the occurrence of puberty in pigs. Age at first estrus of gilts is metabolically gated, and numerous metabolites, metabolic hormones, and appetite-regulating neurotransmitters have been implicated in the nutritional regulation of gonadotropin secretion. Leptin is an important metabolic signal linking body energy reserves with age at puberty in gilts. Leptin acting through neuropeptide Y and proopiomelanocortin neurons in the hypothalamus has important impacts on the function of the reproductive neurosecretory axis of gilts. Age at puberty in swine is heritable, and genomic analyses reveal it to be a polygenic trait. Genome-wide association studies for pubertal age in gilts have revealed several genomic regions in common with those identified for age at menarche in humans. Candidate genes have been identified that have important functions in growth and adiposity. Numerous genes regulating hypothalamic neuronal function, gonadotropes in the adenohypophysis, and ovarian follicular development have been identified and illustrate the complex maturational changes occurring in the hypothalamic–pituitary–ovarian axis during puberty in gilts.

Endocrine Therapy-related Endocrinopathies-Biology, Prevalence and Implications for the Management of Breast Cancer.

Nearly 270,000 new breast cancer cases are predicted to be diagnosed in the USA in 2019 with more than 70% being estrogen receptor positive and treated using endocrine therapy. The suppression of estrogen biosynthesis or action via the use of ovarian suppression, aromatase inhibitors and selective estrogen receptor modulators/degraders, respectively, is effective in approximately 70% of women. The systemic inhibition of estrogen during breast cancer treatment is also associated with side effects due to the important endocrine functions of this steroid hormone, including its role in the maintenance of energy homeostasis and bone health. The current work will present perspectives of the impact of endocrine therapy from the point of view of breast medical oncology, endocrinology, and basic science.