Steroid Receptor Research Articles

NLRP4E regulates actin cap formation through SRC and CDC42 during oocyte meiosis

BackgroundMembers of the nucleotide-binding oligomerization domain, leucine rich repeat and pyrin domain containing (NLRP) family regulate various physiological and pathological processes. However, none have been shown to regulate actin cap formation or spindle translocation during the asymmetric division of oocyte meiosis I. NLRP4E has been reported as a candidate protein in female fertility, but its function is unknown.MethodsImmunofluorescence, reverse transcription polymerase chain reaction (RT-PCR), and western blotting were employed to examine the localization and expression levels of NLRP4E and related proteins in mouse oocytes. small interfering RNA (siRNA) and antibody transfection were used to knock down NLRP4E and other proteins. Immunoprecipitation (IP)-mass spectrometry was used to identify the potential proteins interacting with NLRP4E. Coimmunoprecipitation (Co-IP) was used to verify the protein interactions. Wild type (WT) or mutant NLRP4E messenger RNA (mRNA) was injected into oocytes for rescue experiments. In vitro phosphorylation was employed to examine the activation of steroid receptor coactivator (SRC) by NLRP4E.ResultsNLRP4E was more predominant within oocytes compared with other NLRP4 members. NLRP4E knockdown significantly inhibited actin cap formation and spindle translocation toward the cap region, resulting in the failure of polar body extrusion at the end of meiosis I. Mechanistically, GRIN1, and GANO1 activated NLRP4E by phosphorylation at Ser429 and Thr430; p-NLRP4E is translocated and is accumulated in the actin cap region during spindle translocation. Next, we found that p-NLRP4E directly phosphorylated SRC at Tyr418, while p-SRC negatively regulated p-CDC42-S71, an inactive form of CDC42 that promotes actin cap formation and spindle translocation in the GTP-bound form.ConclusionsNLRP4E activated by GRIN1 and GANO1 regulates actin cap formation and spindle translocation toward the cap region through upregulation of p-SRC-Tyr418 and downregulation of p-CDC42-S71 during meiosis I.

Mineralocorticoid receptor antagonists and reno-protection: What's the evidence & where do they fit? A guide for non-specialists.

The role of aldosterone has yet to be well appreciated in chronic kidney disease (CKD). Two variables define CKD: an estimated glomerular filtration rate of <60 ml/min/1.73 m2 and a spot urine albumin-creatinine ratio of >30 mg/g. Both are needed for an accurate diagnosis. The presence of CKD at this level is associated with an elevated risk of cardiovascular death and a greater risk of CKD progression to kidney failure and subsequent dialysis. This paper presents an overview of aldosterone's importance in CKD and its contribution to the inflammatory processes involved in CKD development. Data on outcomes, both surrogate and hard, related to outcomes on CKD progression will also be discussed in the context of mineralocorticoid blockade. Based on recent epidemiological data as well as data examining markers of diabetic kidney disease progression, it is clear that use of both renin-angiotensin system inhibitors and aldosterone receptor antagonists have a significant role in altering the natural history of kidney disease progression itself, as well as reducing the risk of cardiovascular events that generally accompany long-standing kidney disease. This paper will discuss these issues and the management of consequent hyperkalaemia when both steroidal and non-steroidal mineralocorticoid receptor antagonists are used in detail.

Vaginal leiomyoma in a goat expressing the nuclear progesterone receptor (PGR): a case report

BackgroundThe risk of developing tumorous diseases in the genital tract also increases with age in animals. One of the classified tumor types is genital leiomyoma. Presently, our understanding of the pathogenesis of this tumor in goats is, however, limited. This accounts also for the information regarding the presence of steroid hormone receptors and, thus, possible responsiveness to circulating steroids.Case presentationThis study describes the case of a vaginal tumor in a seven-year-old Anglo-Nubian goat. The goat was presented due to blood mixed vaginal discharge. Per vaginal examination a singular pedunculated mass in the dorsum of the vagina measuring approximately 3 cm x 4 cm x 4 cm was revealed. After administering epidural anesthesia, the mass was removed electrothermally. There were no postoperative complications. The histopathological examination identified the mass as a leiomyoma. The immunohistochemical examination revealed the presence of the nuclear progesterone receptor (PGR) in the tumor tissue. One year after the surgery, during the follow-up examination, the goat was in good overall health, and the owners had not observed any recurrence of vaginal discharge.ConclusionsWhen observing vaginal discharge in goats, it is important to consider the possibility of genital tract tumors. These tumors may express sex steroid receptors. In the future, it is worth considering the investigation of potential approaches for preventing tumorigenesis or treating the tumor, such as castration or the administration of antiprogestogens.

The multifaceted role of the mineralocorticoid receptor in cancers

The mineralocorticoid receptor (MR/NR3C2) is a member of the family of steroid receptors (SR) which also includes the estrogen receptor (ER), progesterone receptor (PR), androgen receptor (AR) and glucocorticoid receptor (GR). They function primarily as nuclear receptors to regulate gene expression. While the other steroid hormone receptors are known to play important roles in the pathogenesis and progression of many cancers, relatively little is understood about the role of MR in cancer biology. This review focuses on examining new insights into the potential roles and mechanisms of action of MR in cancers.

Abstract PO2-24-04: Exploring the role and therapeutic potential of Ubiquitin Specific Peptidase 11 (USP11) in estrogen receptor positive breast cancer

Abstract Dysregulated estrogen receptor (ER) function is a key feature of 70% of breast cancers. In this setting ER primarily functions as a growth-controlling transcription factor driving pro-tumorigenic properties, thus there is a need to identify novel modulators of ER transcriptional activity as alternative therapeutic options. Previously, we showed a significant association between high ubiquitin specific protease 11 (USP11) expression and poor survival in ER+ breast cancer patients, but not in ER- patients, indicating a role for USP11 in ER+ subtypes. However, the precise role of USP11 in controlling ER function remains undescribed. To interrogate USP11 function in ER+ breast cancer we generated a CRISPR USP11 knockout MCF7 breast cancer cell line. Our results showed for the first time that USP11 knockout significantly reduces proliferation, induces G2 cell cycle arrest and apoptosis, abrogates ERα transcriptional activity, significantly impairs cell migration and invasion, whilst also impairing MCF7 cancer stem-cell like properties and malignant transformation in vitro. In addition, we also observed significant dysregulation of epithelial-mesenchymal transition-related markers including E-cadherin, N-cadherin, Snail and Slug. Using RNA-seq of MCF7 cells +/- estradiol, +/- stable USP11 knockdown we identified dysregulated pathways in protein binding, cell adhesion molecule binding and cell cycle regulation following USP11 modulation. Of note, gene expression analysis indicated NCOA3 as the most differentially expressed coding gene. Further validation confirmed a significant reduction in NCOA3- encoded Steroid receptor coactivator- 3 (SRC-3) protein expression following USP11 modulation with immunocytochemical analysis also indicating co-localisation within the nucleus. Frequently upregulated in breast cancer and associated with poor outcome, SRC-3 promotes ER transcriptional activity and co-activates a wide range of additional pro-tumorigenic transcription factors. Thus, SRC-3 modulation offers an attractive therapeutic target in breast cancer. This finding may present a novel role for USP11 in controlling SRC-3 and therefore associated ER transcriptional activity. We then aimed to explore the therapeutic potential of USP11. Although rare in primary breast cancer, activating mutations in the ER ligand-binding domain have recently been linked to recurrent, anti-endocrine resistant disease and metastasis. As such cancers remain dependent on ER-signalling for proliferation, but are resistant to ER targeted therapies, we identified USP11 as a potential novel therapeutic target. Using CRISPR knock-in ER mutant MCF7 cell lines expressing the four most common ER activating mutations, we demonstrated that USP11 knockdown continues to significantly reduce proliferation and abrogates mutant ERα transcriptional activity. We then explored amphipathic cell penetrating peptide RALA encapsulation as a delivery method for siRNA targeting USP11. Optimisation of nanoparticle delivery in the Y537S ER-mutant MCF7 breast cancer cell line achieved significant knockdown of USP11 and ER- related target genes including TFF1, PgR, GREB1 and PKIB in 2D with minimal associated cellular toxicity. To overcome the siRNA-related issues of rapid clearance upon systemic delivery, we then explored the use of a freeze-dried collagen-based scaffold model as an in vitro 3D RALA-encapsulated siRNA delivery system. Here we observed successful delivery of nanoparticle to MCF7 breast cancer cells, with a significant reduction in USP11 mRNA expression. Bio-compatible scaffold- facilitated delivery may therefore offer a more feasible translation of this siRNA-based therapeutic. Overall, this study highlights a novel role for USP11 in various oncogenic pathways. USP11 may therefore offer a novel therapeutic target to be exploited for the management of ER-positive breast cancer, including ER mutant breast cancer. Citation Format: Rachel Moore, Anna Blümel, Elspeth Ward, Elizabeth Sainsbury, Emer Conroy, Fergal O’Brien, Caroline Curtin, Simak Ali, Helen McCarthy, William Gallagher, Darran O'Connor. Exploring the role and therapeutic potential of Ubiquitin Specific Peptidase 11 (USP11) in estrogen receptor positive breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-24-04.

Exploring the Underlying Mechanisms of Enteritis Impact on Golden Pompano (Trachinotus ovatus) through Multi-Omics Analysis

Enteritis posed a significant health challenge to golden pompano (Trachinotus ovatus) populations. In this research, a comprehensive multi-omics strategy was implemented to elucidate the pathogenesis of enteritis by comparing both healthy and affected golden pompano. Histologically, enteritis was characterized by villi adhesion and increased clustering after inflammation. Analysis of the intestinal microbiota revealed a significant increase (P<0.05) in the abundance of specific bacterial strains, including Photobacterium and Salinivibrio, in diseased fish compared to the healthy group. Metabolomic analysis identified 5479 altered metabolites, with significant impacts on terpenoid and polyketide metabolism, as well as lipid metabolism (P<0.05). Additionally, the concentrations of several compounds such as calcitetrol, vitamin D2, arachidonic acid, and linoleic acid were significantly reduced in the intestines of diseased fish post-enteritis (P<0.05), with the detection of harmful substances such as Efonidipine. In transcriptomic profiling, enteritis induced 68 upregulated and 73 downregulated genes, predominantly affecting steroid hormone receptor activity (P<0.05). KEGG pathway enrichment analysis highlighted upregulation of SQLE and CYP51 in steroidogenesis, while the HSV-1 associated MHC1 gene exhibited significant downregulation. Integration of multi-omics results suggested a potential pathogenic mechanism: enteritis may have resulted from concurrent infection of harmful bacteria, specifically Photobacterium and Salinivibrio, along with HSV-1. Efonidipine production within the intestinal tract may have blocked certain calcium ion channels, leading to downregulation of MHC1 gene expression and reduced extracellular immune recognition. Upregulation of SQLE and CYP51 genes stimulated steroid hormone synthesis within cells, which, upon binding to G protein-coupled receptors, influenced calcium ion transport, inhibited immune activation reactions, and further reduced intracellular synthesis of anti-inflammatory substances like arachidonic acid. Ultimately, this cascade led to inflammation progression, weakened intestinal peristalsis, and villi adhesion. This study utilized multi-level omics detection to investigate the pathological symptoms of enteritis and proposed a plausible pathogenic mechanism, providing innovative insights into enteritis verification and treatment in offshore cage culture of golden pompano.

Chronic Serous Chorioretinopathy: A Case Study

Introduction Chronic central serous chorioretinopathy (CSCR) is characterized by persistent subretinal fluid that disrupts the outer layers of the retina and may lead to complications such as: outer retinal atrophy, increased risk of choroidal neovascularization (CNVM) and the potential for permanent vision loss. This report describes the clinical features of chronic CSCR. Case Presentation A 73-year-old male with a history of systemic steroid and inhaler use presented for a routine eye exam without visual complaints. Examination findings included normal visual acuity in both eyes and multiple areas of retinal hyper and hypopigmentation along the arcades with no macular involvement in the right eye; the left eye was unremarkable. Fundus photography and optical coherence tomography showed localized areas of outer retinal disruption and thinning near the optic nerve head and along the corresponding retinal areas of irregular pigmentation in the right eye; the left eye was unremarkable. Discussion In chronic CSCR, structural changes in the retina can lead to retinal dysfunction and permanent vision loss. Treatment options for chronic CSCR include photodynamic therapy, intravitreal anti-vascular endothelial growth factor therapy, or systemic steroid receptor blockers. Visual prognosis varies depending on the severity of the disease, age of onset, risk of CNVM and the degree of outer retinal degeneration. Conclusion Patients with chronic CSCR are at risk for permanent vision loss. The structural changes in the outer retina also increase the risk for CNVM. Hence, it is important that patients with chronic CSR receive regular eye examinations and are educated on the role of regular Amsler grid testing.

Cell-type specific effects of mineralocorticoid receptor gene expression suggest intercellular communication regulating fibrosis in skeletal muscle disease.

Introduction: Duchenne muscular dystrophy (DMD) is a fatal striated muscle degenerative disease. DMD is caused by loss of dystrophin protein, which results in sarcolemmal instability and cycles of myofiber degeneration and regeneration. Pathology is exacerbated by overactivation of infiltrating immune cells and fibroblasts, which leads to chronic inflammation and fibrosis. Mineralocorticoid receptors (MR), a type of nuclear steroid hormone receptors, are potential therapeutic targets for DMD. MR antagonists show clinical efficacy on DMD cardiomyopathy and preclinical efficacy on skeletal muscle in DMD models. Methods: We have previously generated myofiber and myeloid MR knockout mouse models to dissect cell-specific functions of MR within dystrophic muscles. Here, we compared skeletal muscle gene expression from both knockouts to further define cell-type specific signaling downstream from MR. Results: Myeloid MR knockout increased proinflammatory and profibrotic signaling, including numerous myofibroblast signature genes. Tenascin C was the most highly upregulated fibrotic gene in myeloid MR-knockout skeletal muscle and is a component of fibrosis in dystrophic skeletal muscle. Surprisingly, lysyl oxidase (Lox), canonically a collagen crosslinker, was increased in both MR knockouts, but did not localize to fibrotic regions of skeletal muscle. Lox localized within myofibers, including only a region of quadriceps muscles. Lysyl oxidase like 1 (Loxl1), another Lox family member, was increased only in myeloid MR knockout muscle and localized specifically to fibrotic regions. Discussion: This study suggests that MR signaling in the dystrophic muscle microenvironment involves communication between contributing cell types and modulates inflammatory and fibrotic pathways in muscle disease.

Multiplex analysis platform for evaluation of endocrine disruption of emerging contaminants against human steroid hormone receptors using autobioluminescent yeast bioassay: Application to bisphenols

Emerging synthetic or derivative chemicals have drawn global concern due to their potential endocrine-disrupting effects, either as agonists or antagonists or through indirect effects on enzymes of signal transduction pathways. Currently, in vitro screening models are limited to poor tolerance, robustness, high cost and need for sphisticated equipment or complex procedures that require high levels of expertise. Herein, a multiplex analysis platform based on autobioluminescent yeast strains, including BLYhERαS, BLYhERβS, BLYhPRS, BLYhARS, BLYhMRS, and BLYhGRS, was developed for use in easy, rapid, robust, and sensitive screening for potential modulation of endocrine systems. Methods were applied to assess endocrine-disrupting effects of Bisphenol A (BPA) and its alternatives. Disrupting activities of bisphenols (BPs) varied greatly, and some BPA substitutes exerted more potent activities than those of BPA. Most BPs were primarily agonists of ERα and ERβ, while others were antagonists to AR, PR, GR, and MR. BPP and BPM exhibited non-monotonic dose-response relationships toward ERα and ERβ, and BHPF and BPG displayed converse disrupting activities to ERα and ERβ. Overall, the bioassay system provides an efficient tool for comprehensive evaluation of endocrine-disrupting activities of emerging contaminants.

Correlation between steroid receptor expression and response to progestational therapy in patients with atypical endometrial hyperplasia or cancer

BackgroundConservative management of atypical endometrial hyperplasia (AEH) or endometrial cancer (EMCA) often relies on the treatment of synthetic progestins, which show varied success and response rates. We evaluate the correlation between steroid receptor expression and response to progestin therapy in patients with AEH and EMCA. MethodsRetrospective cohort study collected data for patients with AEH or EMCA who had an endometrial sample after receiving conservative therapy utilizing either Megestrol acetate or Levonorgestrel Intrauterine device (IUD). Immunohistochemistry (IHC) was performed on pre- and post- treatment biopsy samples to assess androgen receptor (AR), estrogen receptor (ER), and progesterone receptor (PR) expression. IHC scores (1–12) were calculated based on staining intensity and percentage of positive cells. Results and analysisWe identified 15 patients with AEH and EMCA between 2015 and 2023 with the majority of African American ethnicity (53 %). Fourteen patients (93 %) received Megestrol acetate, and 1 patient received Levonorgestrel IUD alone. Three patients ultimately underwent hysterectomy. Seven (46.6 %) endometrial samples had strong positivity for AR, PR and ER expression on pre-treatment biopsies, and only 3 (20 %) of them maintained strong positivity for the 3 receptors in the post-treatment. Patients who successfully responded to the treatment demonstrated a significantly greater decrease in IHC scores after the treatment compared to those who did not respond (p = 0.009). ConclusionSteroid receptor expression could be used as a possible biomarker for response to progestin therapy in patients undergoing conservative management for AEH and EMCA.

Mesenchymal stem cell-derived exosomes overexpressing SRC-3 protect mice from cerebral ischemia by inhibiting ferroptosis

BackgroundThe treatment for cerebral ischemia remains limited, and new therapeutic strategies are urgently needed. Exosome has shown great promise for the treatment of cerebral ischemia. Steroid receptor coactivator-3 (SRC-3) was reported to be involved in neurological performances. In this study, we aimed to investigate the protective effects of mesenchymal stem cell (MSC)-derived exosomes overexpressing SRC-3 on cerebral ischemia in mice. MethodsThe mice were treated with an intracerebroventricular injection of GFP-overexpressed exosomes (GFP-exo) and SRC-3-overexpressed exosomes (SRC3-exo) in a middle cerebral artery occlusion (MCAO) model of cerebral ischemia. ResultsThe results showed that SRC3-exo treatment significantly inhibited lipid peroxidation and ferroptosis of the neurons subjected to oxygen-glucose deprivation. It further suppressed the activation of microglia and astrocytes, and decreased the production of pro-inflammatory cytokines in the brains of MCAO mice. Furthermore, SRC3-exo treatment reduced the water content of brain tissue and infarct size, which alleviated the neurological damage and improved neurological performances in the MCAO mice. ConclusionsOur results suggest that MSC-derived exosomes expressing SRC3 can be a therapeutic strategy for cerebral ischemia by inhibiting ferroptosis.

Thyroid Hormone Receptor Agonistic and Antagonistic Activity of Newly Synthesized Dihydroxylated Polybrominated Diphenyl Ethers: An In Vitro and In Silico Coactivator Recruitment Study.

Dihydroxylated polybrominated diphenyl ethers (DiOH-PBDEs) could be the metabolites of PBDEs of some organisms or the natural products of certain marine bacteria and algae. OH-PBDEs may demonstrate binding affinity to thyroid hormone receptors (TRs) and can disrupt the functioning of the systems modulated by TRs. However, the thyroid hormone disruption mechanism of diOH-PBDEs remains elusive due to the absence of diOH-PBDEs standards. This investigation explores the potential disruptive effects of OH/diOH-PBDEs on thyroid hormones via competitive binding and coactivator recruitment with TRα and TRβ. At levels of 5000 nM and 25,000 nM, 6-OH-BDE-47 demonstrated significant recruitment of steroid receptor coactivator (SRC), whereas none of the diOH-PBDEs exhibited SRC recruitment within the range of 0.32-25,000 nM. AutoDock CrankPep (ADCP) simulations suggest that the conformation of SRC and TR-ligand complexes, particularly their interaction with Helix 12, rather than binding affinity, plays a pivotal role in ligand agonistic activity. 6,6'-diOH-BDE-47 displayed antagonistic activity towards both TRα and TRβ, while the antagonism of 3,5-diOH-BDE-100 for TRα and TRβ was concentration-dependent. 3,5-diOH-BDE-17 and 3,5-diOH-BDE-51 exhibited no discernible agonistic or antagonistic activities. Molecular docking analysis revealed that the binding energy of 3,3',5-triiodo-L-thyronine (T3) surpassed that of OH/diOH-PBDEs. 3,5-diOH-BDE-100 exhibited the highest binding energy, whereas 6,6'-diOH-BDE-47 displayed the lowest. These findings suggest that the structural determinants influencing the agonistic and antagonistic activities of halogen phenols may be more intricate than previously proposed, involving factors beyond high-brominated PBDEs or hydroxyl group and bromine substitutions. It is likely that the agonistic or antagonistic propensities of OH/diOH-PBDEs are instigated by protein conformational changes rather than considerations of binding energy.

Enantiopure Corral[4]BINOLs as Ultrastrong Receptors for Recognition and Differential Sensing of Steroids.

The precise recognition and sensing of steroids, a type of vital biomolecules, hold immense practical value across various domains. In this study, we introduced corral[4]BINOLs (C[4]BINOLs), a pair of enantiomeric conjugated deep-cavity hosts, as novel synthetic receptors for binding steroids. Due to the strong hydrophobic effect of their deep nonpolar, chiral cavities, the two enantiomers of C[4]BINOLs demonstrated exceptionally high recognition affinities (up to 1012 M-1) for 16 important steroidal compounds as well as good enantioselectiviy (up to 15.5) in aqueous solutions, establishing them as the most potent known steroid receptors. Harnessing their ultrahigh affinity, remarkable enantioselectivity, and fluorescence emission properties, the two C[4]BINOL enantiomers were employed to compose a fluorescent sensor array which achieved discrimination and sensing of 16 structurally similar steroids at low concentrations.

Enantiopure Corral[4]BINOLs as Ultrastrong Receptors for Recognition and Differential Sensing of Steroids

The precise recognition and sensing of steroids, a type of vital biomolecules, hold immense practical value across various domains. In this study, we introduced corral[4]BINOLs (C[4]BINOLs), a pair of enantiomeric conjugated deep‐cavity hosts, as novel synthetic receptors for binding steroids. Due to the strong hydrophobic effect of their deep nonpolar, chiral cavities, the two enantiomers of C[4]BINOLs demonstrated exceptionally high recognition affinities (up to 1012 M−1) for 16 important steroidal compounds as well as good enantioselectiviy (up to 15.5) in aqueous solutions, establishing them as the most potent known steroid receptors. Harnessing their ultrahigh affinity, remarkable enantioselectivity, and fluorescence emission properties, the two C[4]BINOL enantiomers were employed to compose a fluorescent sensor array which achieved discrimination and sensing of 16 structurally similar steroids at low concentrations.

Abstract LB335: Steroid receptor cross-talk in breast cancer

Abstract Breast cancer is the most frequently diagnosed cancer in women worldwide. Oestrogen Receptor-α (ERα), is expressed in two thirds of human breast cancers, and the majority of patients are sensitive to endocrine therapy, i.e. anti-oestrogens or aromatase inhibitors that aim to block oestrogen signalling. In addition to ERα, the other members of the steroid receptor family (androgen, AR; progesterone, PR; glucocorticoid, GR; mineralocorticoid receptors, MR) also appear to play an important role in tumour development and recurrence, but the role of this signalling in cancer progression has not been fully characterised. Therefore, this study aims to address the role of the steroid receptor family members in breast cancer and to assess the effect of downstream signalling upon prognosis. Investigation of receptor signalling cross-talk using reporter, proliferation and migration assays, demonstrated that ERα and the other steroid receptors inhibit each other’s activity in endocrine responsive breast cancer cell lines, MCF7 and T47D. Furthermore, treatment with antioestrogen reversed the suppressive effects of ER𝛼;;; on the activity of the androgen, glucocorticoid progesterone receptors. To characterize receptor crosstalk on a global scale, RNA-seq and ChIP-seq datasets were analysed. Analysis of the ChIP-seq data demonstrated that the PR, GR and AR reprogramming of ERα results in the loss of ERα canonical binding sites and the gain of novel response elements/binding sites. Motif enrichment analysis of the novel ERα binding sites suggested that the altered binding in response to AR, GR and PR signalling, promotes the recruitment of ERα to androgen, glucocorticoid and progesterone response elements, respectively. Gene ontology analysis also revealed that this change in ERα binding sites is correlated with alterations in genes linked to cell proliferation and growth. Moreover, transcriptome studies showed that cotreatment of cells with estradiol and glucocorticoid or mineralocorticoid resulted in the upregulation of apoptotic signalling pathways. These findings may provide an explanation for the observed downregulation of GR and MR expression in ERα positive breast cancer. Patient datasets were used to investigate the prognostic significance of the steroid receptor target genes of interest, more specifically, those deregulated as a result of cross-talk. Considering overall survival and disease specific survival, univariate and multivariate Cox models with Lasso Regression were used to identify prognostic gene signatures using RNA_seq datasets. Kaplan-Meier (KM) and ROC analyses were applied to evaluate risk models. Established genetic markers associated with MR, AR, GR and PR was used to stratify BC patients into low and high risk groups. Patients survival was found to be positively correlated with these signatures, demonstrates that these gene sets have prognostic value. Further studies are required to validate these preliminary results to understand the role of steroid receptor crosstalk in breast cancer formation, progression, and survival. Citation Format: Aygun Azadova, Greg Brooke, Antonio Marco. Steroid receptor cross-talk in breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB335.

EP300/CREBBP acetyltransferase inhibition limits steroid receptor and FOXA1 signaling in prostate cancer cells

The androgen receptor (AR) is a primary target for treating prostate cancer (PCa), forming the bedrock of its clinical management. Despite their efficacy, resistance often hampers AR-targeted therapies, necessitating new strategies against therapy-resistant PCa. These resistances involve various mechanisms, including AR splice variant overexpression and altered activities of transcription factors like the glucocorticoid receptor (GR) and FOXA1. These factors rely on common coregulators, such as EP300/CREBBP, suggesting a rationale for coregulator-targeted therapies. Our study explores EP300/CREBBP acetyltransferase inhibition’s impact on steroid receptor and FOXA1 signaling in PCa cells using genome-wide techniques. Results reveal that EP300/CREBBP inhibition significantly disrupts the AR-regulated transcriptome and receptor chromatin binding by reducing the AR-gene expression. Similarly, GR’s regulated transcriptome and receptor binding were hindered, not linked to reduced GR expression but to diminished FOXA1 chromatin binding, restricting GR signaling. Overall, our findings highlight how EP300/CREBBP inhibition distinctively curtails oncogenic transcription factors’ signaling, suggesting the potential of coregulatory-targeted therapies in PCa.

Clinical study of steroid receptors in nonmuscle invasive bladder cancer: A domain worth revisiting.

The prognostic significance of steroid receptors in bladder cancer remains controversial. This study was designed to determine the expression status of androgen receptor (AR), estrogen receptors (ERα and Erβ), and its potential role in predicting survival in patients with nonmuscle invasive bladder cancer (NMIBC). Sixty patients of NMIBC were screened and 57 (41 males and 16 females) were included in our study. The tissue microarray slides were evaluated by pathologists blinded to the clinical information. Association of distribution of steroid receptors with stage, grade, progression, and recurrence was seen. The mean age of the population was 60.9 ± 9.3 years. Pathologically, majority of the patients were Ta (Ta: T1 stage 61.4% vs. 38.6%). Nine (15.8%) of the tumors stained positive for AR while one (1.8%) tumor stained positive for ERα and 36 (63.2%) tumors stained for ERβ. A higher proportion of male NMIBC stained positive for AR (19.5% vs. 6.2%, P = 0.420) while ERβ positivity was higher in females (58.5% vs. and 75%,P = 0.247). AR-negative tumors showed higher recurrence (20/48%-42%) as compared to AR-positive tumors (2/9%-22%). ERβ-positive tumors showed higher recurrence (15/36%-42% vs. 7/21%-33%, P = 0.179). Progression-free survival (PFS) was found to be significantly lower for ERβ-negative group (log-rank test P = 0.035). AR and ERβ positivity is found in NMIBC patients while ERα shows minimal staining in NMIBC patients. Although it did not reach a statistical significance, a higher proportion of AR-negative and ERβ-positive tumors recurred as compared to AR-positive and ERβ-negative patients. PFS was significantly lower in ERβ-negative group. Further exploratory studies on larger sample sizes are required to validate these findings in NMIBC patients.

507 Neuroprotective Effects of a Steroid Receptor Coactivator Stimulator in a Murine Model of Acute Ischemic Stroke with Reperfusion

INTRODUCTION: Stroke is the leading cause of adult disability and the fifth leading cause of mortality in the United States. Despite the study of many neuroprotective agents for acute ischemic stroke, none has been shown to be effective in large randomized clinical trials. Steroid receptor coactivator (SRC) is a promising class of agents since they are involved in cellular proliferation and regeneration, immune modulation, angiogenesis, antioxidant protection and are expressed in the brain. METHODS: Twenty c57bl/6 mice were randomly assigned to control or treatment groups (n = 10 mice per group). All mice underwent middle cerebral artery occlusion for 90 minutes followed by reperfusion via the intraluminal filament method. Occlusion was confirmed by laser doppler flowmetry. Intraperitoneal injections of saline (control) or 10-1 (treatment) were given 30 minutes after reperfusion. Each animal was tested using a modified Bederson’s neurological deficit scale (mNDS) and euthanized at the conclusion of the 24-hour survival period. Brain slices were stained with 2,3,5- triphenyltetrazolium chloride (TTC) to identify ischemic brain tissue. RESULTS: When compared with the control group, 10-1 treated mice showed significantly lower mNDS scores (p = 0.000336) and incidence of circling (p = 0.00256). Calculated infarct volumes, based on TTC staining, of the 10-1 treated group were significantly lower (p = 0.0009) when compared to the control group. CONCLUSIONS: We have shown that 10-1 is a promising therapeutic agent and provides substantial neuroprotection through its many multicellular processes in a rodent study. Current studies are being conducted to investigate the mechanism of 10-1 as neuroprotectant.

A novel long non-coding RNA SLNCR1 promotes proliferation, migration, and invasion of melanoma via transcriptionally regulating SOX5

Steroid receptor RNA activator (SRA)-like non-coding RNA (SLNCR1) has been implicated in various tumorigenic processes, but the precise regulatory role in melanoma progression remains uncertain. We performed a comprehensive analysis to investigate the prognostic value of SLNCR1 expression in patients with melanoma by TCGA database and melanoma tissue samples via the Kaplan–Meier method. Subsequently, we conducted qRT-PCR and Fluorescence in Situ Hybridization (FISH) assays to identify SLNCR1 expression levels and localization in tissues and cells, respectively. Loss-of-function assays utilizing shRNAs vectors were used to investigate the potential impact of SLNCR1. Our data showed that SLNCR1 is significantly up-regulated in human malignant melanoma tissues and cell lines and functions as an oncogene. Silencing of SLNCR1 suppressed melanoma cell proliferation, migration, invasion, and inhibited tumorigenesis in a mouse xenograft model. Additionally, we employed bioinformatic predictive analysis, combined with dual-luciferase reporter analysis and functional rescue assays, to elucidate the mechanistic target of the SLNCR1/SOX5 axis in melanoma. Mechanistically, we discovered that SLNCR1 promotes EMT of human melanoma by targeting SOX5, as downregulation of SLNCR1 expression leads to a decrease in SOX5 protein levels and inhibits melanoma tumorigenesis. Our research offers promising insights for more precise diagnosis and treatment of human melanoma.

Lead Compound Development of SRC-3 Inhibitors with Improved Pharmacokinetic Properties and Anticancer Efficacy.

Steroid receptor coactivator 3 (SRC-3) is a critical mediator of many intracellular signaling pathways that are crucial for cancer proliferation and metastasis. In this study, we performed structure-activity relationship exploration and drug-like optimization of the hit compound SI-2, guided by in vitro/in vivo metabolism studies and cytotoxicity assays. Our efforts led to the discovery of two lead compounds, SI-10 and SI-12. Both compounds exhibit potent cytotoxicity against a panel of human cancer cell lines and demonstrate acceptable pharmacokinetic properties. A biotinylated estrogen response element pull-down assay demonstrated that SI-12 could disrupt the recruitment of SRC-3 and p300 in the estrogen receptor complex. Importantly, SI-10 and SI-12 significantly inhibited tumor growth and metastasis in vivo without appreciable acute toxicity. These results demonstrate the potential of SI-10 and SI-12 as drug candidates for cancer therapy, given their potent SRC-3 inhibition and promising pharmacokinetic and toxicity profiles.