The Role of microRNA in the Regulation of Cortisol Metabolism in the Adipose Tissue in the Course of Obesity.

The similarity of the clinical picture of metabolic syndrome and hypercortisolemia supports the hypothesis that obesity may be associated with impaired expression of genes related to cortisol action and metabolism in adipose tissue. The expression of genes encoding the glucocorticoid receptor alpha (GR), cortisol metabolizing enzymes (HSD11B1, HSD11B2, H6PDH), and adipokines, as well as selected microRNAs, was measured by real-time PCR in adipose tissue from 75 patients with obesity, 19 patients following metabolic surgery, and 25 normal-weight subjects. Cortisol levels were analyzed by LC-MS/MS in 30 pairs of tissues. The mRNA levels of all genes studied were significantly (p < 0.05) decreased in the visceral adipose tissue (VAT) of patients with obesity and normalized by weight loss. In the subcutaneous adipose tissue (SAT), GR and HSD11B2 were affected by this phenomenon. Negative correlations were observed between the mRNA levels of the investigated genes and selected miRNAs (hsa-miR-142-3p, hsa-miR-561, and hsa-miR-579). However, the observed changes did not translate into differences in tissue cortisol concentrations, although levels of this hormone in the SAT of patients with obesity correlated negatively with mRNA levels for adiponectin. In conclusion, although the expression of genes related to cortisol action and metabolism in adipose tissue is altered in obesity and miRNAs may be involved in this process, these changes do not affect tissue cortisol concentrations.

A novel mutation in the NR3C1 gene associated with reversible glucocorticoid resistance.

OBJECTIVE: Glucocorticoid resistance is a rare endocrine disease caused by variants of the NR3C1 gene encoding the glucocorticoid receptor (GR). We identified a novel heterozygous variant (GRR569Q) in a patient with uncommon reversible glucocorticoid resistance syndrome. METHODS: We performed ex vivo functional characterization of the variant in patient fibroblasts and in vitro through transient transfection in undifferentiated HEK 293T cells to assess transcriptional activity, affinity, and nuclear translocation. We studied the impact of the variant on the tertiary structure of the ligand-binding domain through 3D modeling. RESULTS: The patient presented initially with an adrenal adenoma with mild autonomous cortisol secretion and undetectable adrenocorticotropin hormone (ACTH) levels. Six months after surgery, biological investigations showed elevated cortisol and ACTH (urinary free cortisol 114 µg/24 h, ACTH 10.9 pmol/L) without clinical symptoms, evoking glucocorticoid resistance syndrome. Functional characterization of the GRR569Q showed decreased expression of target genes (in response to 100 nM cortisol: SGK1 control +97% vs patient +20%, P < .0001) and impaired nuclear translocation in patient fibroblasts compared to control. Similar observations were made in transiently transfected cells, but higher cortisol concentrations overcame glucocorticoid resistance. GRR569Q showed lower ligand affinity (Kd GRWT: 1.73 nM vs GRR569Q: 4.61 nM). Tertiary structure modeling suggested a loss of hydrogen bonds between H3 and the H1-H3 loop. CONCLUSION: This is the first description of a reversible glucocorticoid resistance syndrome with effective negative feedback on corticotroph cells regarding increased plasma cortisol concentrations due to the development of mild autonomous cortisol secretion.

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.

Effects of the Glucocorticoid-Mediated Mitochondrial Translocation of Glucocorticoid Receptors on Oxidative Stress and Pyroptosis in BV-2 Microglia.

Microglia are resident macrophages within the central nervous system, serving as the first responders to neuroinflammation. Glucocorticoids (GCs) may cause damage to brain tissue, but the specific mechanism remains unclear. This study was divided into two parts: a glucocorticoid receptor (GR) mitochondrial translocation intervention experiment and a mitochondrial oxidative stress inhibition experiment. BV-2 microglia were stimulated with dexamethasone (DEX) and treated with either tubastatin-A or mitoquinone (MitoQ) for 24 h. Our results showed that DEX increased the translocation of GRs to mitochondria, and this effect was accompanied by decreases in the expression of mitochondrially encoded cytochrome c oxidase 1 (MT-CO1) and mitochondrially encoded cytochrome c oxidase 3 (MT-CO3) and increases in the expression of NOD-like receptor thermal protein domain-associated protein 3 (NLRP3), caspase-1, and Gasdermin D (GSDMD). The level of mitochondrial respiratory chain complex IV (MRCC IV) and adenosine triphosphate (ATP) was decreased. An elevation in the level of mitochondrial oxidative stress and the opening of the mitochondrial permeability transition pore (mPTP) was also observed. Mechanistically, tubastatin-A significantly suppressed the mitochondrial translocation of GRs, improved the expression of mitochondrial genes, promoted the restoration of mitochondrial function, and inhibited pyroptosis. MitoQ significantly prevented mitochondrial oxidative stress, improved mitochondrial function, and reduced apoptosis and pyroptosis. Both tubastatin-A and MitoQ suppressed DEX-induced pyroptosis. This study substantiates that the increase in the mitochondrial translocation of GRs mediated by GCs exacerbates oxidative stress and pyroptosis in microglia, which indicates that the regulation of mitochondrial pathways by GCs is pathogenic to microglia.

Selective Modulation of the Human Glucocorticoid Receptor Compromises GR Chromatin Occupancy and Recruitment of p300/CBP and the Mediator Complex.

Exogenous glucocorticoids are frequently used to treat inflammatory disorders and as adjuncts for the treatment of solid cancers. However, their use is associated with severe side effects and therapy resistance. Novel glucocorticoid receptor (GR) ligands with a patient-validated reduced side effect profile have not yet reached the clinic. GR is a member of the nuclear receptor family of transcription factors and heavily relies on interactions with coregulator proteins for its transcriptional activity. To elucidate the role of the GR interactome in the differential transcriptional activity of GR following treatment with the selective GR agonist and modulator dagrocorat compared to classic (ant)agonists, we generated comprehensive interactome maps by high-confidence proximity proteomics in lung epithelial carcinoma cells. We found that dagrocorat and the antagonist RU486 both reduced GR interaction with CREB-binding protein/p300 and the mediator complex compared to the full GR agonist dexamethasone. Chromatin immunoprecipitation assays revealed that these changes in GR interactome were accompanied by reduced GR chromatin occupancy with dagrocorat and RU486. Our data offer new insights into the role of differential coregulator recruitment in shaping ligand-specific GR-mediated transcriptional responses.

Exploring androgen receptor signaling pathway in prostate cancer: A path to new discoveries.

Androgen deprivation therapy has achieved significant success in treating prostate cancer through strategies centered on the androgen receptor. However, the emergence of castration-resistant prostate cancer highlights this therapy limitation, underscoring the need to elucidate the mechanisms of treatment resistance. This review aimed to focus on multifaceted resistance mechanisms, including androgen receptor overexpression, splice variants, missense mutations, the involvement of the glucocorticoid receptor, and alterations in coregulators and transcription factors, revealing their roles in castration-resistant prostate cancer progression. These mechanisms promote cell survival and proliferation, depending on the androgen receptor signaling pathway, leading to resistance to conventional therapies. Amplification and mutations in the androgen receptor gene facilitate selective adaptation in treatment-resistant cells, consequently diminishing therapeutic efficacy. Furthermore, the activation of glucocorticoid receptors and aberrant regulation of specific coregulators and transcription factors contribute to the activation of androgen receptor-independent signaling pathways, promoting cell survival and proliferation. These findings hold promise for identifying new targets for treating castration-resistant prostate cancer and developing personalized treatment strategies. The development of future therapies will hinge on precisely targeting the androgen receptor signaling pathway, necessitating a deeper understanding of the molecular targets unique to castration-resistant prostate cancer.

Two Adverse Early Life Events Induce Differential Changes in Brain CRH and Serotonin Systems in Rats along with Hyperphagia and Depression.

BACKGROUND: Different types of stress inflicted in early stages of life elevate the risk, among adult animals and humans, to develop disturbed emotional-associated behaviors, such as hyperphagia or depression. Early-life stressed (ELS) adults present hyperactivity of the hypothalamus-pituitary-adrenal (HPA) axis, which is a risk factor associated with mood disorders. However, the prevalence of hyperphagia (17%) and depression (50%) is variable among adults that experienced ELS, suggesting that the nature, intensity, and chronicity of the stress determines the specific behavioral alteration that those individuals develop. METHODS: We analyzed corticosterone serum levels, Crh, GR, Crhr1 genes expression in the hypothalamic paraventricular nucleus, amygdala, and hippocampus due to their regulatory role on HPA axis in adult rats that experienced maternal separation (MS) or limited nesting material (LNM) stress; as well as the serotonergic system activity in the same regions given its association with the corticotropin-releasing hormone (CRH) pathway functioning and with the hyperphagia and depression development. RESULTS: Alterations in dams' maternal care provoked an unresponsive or hyper-responsive HPA axis function to an acute stress in MS and LNM adults, respectively. The differential changes in amygdala and hippocampal CRH system seemed compensating alterations to the hypothalamic desensitized glucocorticoids receptor (GR) in MS or hypersensitive in LNM. However, both adult animals developed hyperphagia and depression-like behavior when subjected to the forced-swimming test, which helps to understand that both hypo and hypercortisolemic patients present those disorders. CONCLUSION: Different ELS types induce neuroendocrine, brain CRH and 5-hydroxytriptamine (5-HT) systems' alterations that may interact converging to develop similar maladaptive behaviors.

Association between glucocorticoid receptor beta and steroid resistance: A systematic review.

BACKGROUND: Glucocorticoids are the most commonly used anti-inflammatory drugs for a variety of diseases, despite the fact that resistance to them is growing in a number of conditions. There is currently no biomarker that can be used to identify steroid resistance. According to a number of studies, an overexpression of the glucocorticoid receptor beta (GR-ß) isoform is associated with steroid-resistant illness. Our goal is to find out whether or not steroid-resistant disorders are associated with an increased level of GR-ß expression. METHODS: We conducted searches in the databases of Web of Science and PubMed until January 17, 2023. This systematic review was done according to the preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The Joanna Briggs Institute Appraisal scale was used to assess the quality of the included studies. RESULTS: After the initial search, we identified 556 papers and finally included 20 studies. Twelve of these studies found an elevated level of GR-ß in the steroid resistant group. All five studies on asthma, two out of three on nasal polyps, both studies on ulcerative colitis found an up regulation of GR-ß in steroid resistant group as compared to steroid-sensitive groups. GR-ß was also shown to be elevated in patients with allergic rhinitis, Crohn's disease and rheumatoid arthritis. In the majority of the investigations, higher levels of GR-ß were identified in peripheral blood mononuclear cells through the use of reverse transcription polymerase chain reaction. CONCLUSION: GR-ß was associated with steroid-resistant diseases. It was overexpressed in steroid-resistant diseases and has the potential to be used as a biomarker for disorders involving steroid resistance.

The Prenatal Hypoxic Pathology Associated with Maternal Stress Predisposes to Dysregulated Expression of the chrna7 Gene and the Subsequent Development of Nicotine Addiction in Adult Offspring.

INTRODUCTION: Previous studies have shown that fetal hypoxia predisposes individuals to develop addictive disorders in adulthood. However, the specific impact of maternal stress, mediated through glucocorticoids and often coexisting with fetal hypoxia, is not yet fully comprehended. METHODS: To delineate the potential effects of these pathological factors, we designed models of prenatal severe hypoxia (PSH) in conjunction with maternal stress and prenatal intrauterine ischemia (PII). We assessed the suitability of these models for our research objectives by measuring HIF1α levels and evaluating the glucocorticoid neuroendocrine system. To ascertain nicotine dependence, we employed the conditioned place aversion test and the startle response test. To identify the key factor implicated in nicotine addiction associated with PSH, we employed techniques such as Western blot, immunohistochemistry, and correlational analysis between chrna7 and nr3c1 genes across different brain structures. RESULTS: In adult rats exposed to PSH and PII, we observed increased levels of HIF1α in the hippocampus (HPC). However, the PSH group alone exhibited reduced glucocorticoid receptor levels and disturbed circadian glucocorticoid rhythms. Additionally, they displayed signs of nicotine addiction in the conditioned place aversion and startle response tests. We also observed elevated levels of phosphorylated DARPP-32 protein in the nucleus accumbens (NAc) indicated compromised glutamatergic efferent signaling. Furthermore, there was reduced expression of α7 nAChR, which modulates glutamate release, in the medial prefrontal cortex (PFC) and HPC. Correlation analysis revealed strong associations between chrna7 and nr3c1 expression in both brain structures. CONCLUSION: Perturbations in the glucocorticoid neuroendocrine system and glucocorticoid-dependent gene expression of chrna7 associated with maternal stress response to hypoxia in prenatal period favor the development of nicotine addiction in adulthood.

The glucocorticoid receptor gene (NR3C1) is linked to and associated with polycystic ovarian syndrome in Italian families.

OBJECTIVES: Components of the hypothalamic-pituitary axis (HPA) pathway are potential mediators of the genetic risk of polycystic ovarian syndrome (PCOS). Impaired glucocorticoid receptor (NR3C1) expression and function may underlie impaired HPA-axis cortisol activity, thereby also contributing to the increased adrenal cortisol and androgen production present in women with PCOS. In this study, we aimed to identify whether NR3C1 is linked or in linkage disequilibrium (LD), that is, linkage joint to association, with PCOS in Italian peninsular families. METHOD: In 212 Italian families with type 2 diabetes (T2D) from the Italian peninsula, previously recruited for a T2D study and phenotyped for PCOS, we used microarray to genotype 25 variants in the NR3C1 gene. We analyzed the 25 NR3C1 variants by Pseudomarker parametric linkage and LD analysis. RESULTS: We found the novel implication in PCOS risk of two intronic variants located within the NR3C1 gene (rs10482672 and rs11749561), thereby extending the phenotypic implication related to impaired glucocorticoid receptor. CONCLUSIONS: To the best of our knowledge, this is the first study to report NR3C1 as a risk gene in PCOS.

Chromatin accessibility and pioneer factor FOXA1 restrict glucocorticoid receptor action in prostate cancer.

Treatment of prostate cancer relies predominantly on the inhibition of androgen receptor (AR) signaling. Despite the initial effectiveness of the antiandrogen therapies, the cancer often develops resistance to the AR blockade. One mechanism of the resistance is glucocorticoid receptor (GR)-mediated replacement of AR function. Nevertheless, the mechanistic ways and means how the GR-mediated antiandrogen resistance occurs have remained elusive. Here, we have discovered several crucial features of GR action in prostate cancer cells through genome-wide techniques. We detected that the replacement of AR by GR in enzalutamide-exposed prostate cancer cells occurs almost exclusively at pre-accessible chromatin sites displaying FOXA1 occupancy. Counterintuitively to the classical pioneer factor model, silencing of FOXA1 potentiated the chromatin binding and transcriptional activity of GR. This was attributed to FOXA1-mediated repression of the NR3C1 (gene encoding GR) expression via the corepressor TLE3. Moreover, the small-molecule inhibition of coactivator p300's enzymatic activity efficiently restricted GR-mediated gene regulation and cell proliferation. Overall, we identified chromatin pre-accessibility and FOXA1-mediated repression as important regulators of GR action in prostate cancer, pointing out new avenues to oppose steroid receptor-mediated antiandrogen resistance.

Adipocyte Glucocorticoid Receptor Activation With High Glucocorticoid Doses Impairs Healthy Adipose Tissue Expansion by Repressing Angiogenesis.

In humans, glucocorticoids (GCs) are commonly prescribed because of their anti-inflammatory and immunosuppressive properties. However, high doses of GCs often lead to side effects, including diabetes and lipodystrophy. We recently reported that adipocyte glucocorticoid receptor (GR)-deficient (AdipoGR-KO) mice under corticosterone (CORT) treatment exhibited a massive adipose tissue (AT) expansion associated with a paradoxical improvement of metabolic health compared with control mice. However, whether GR may control adipose development remains unclear. Here, we show a specific induction of hypoxia-inducible factor 1α (HIF-1α) and proangiogenic vascular endothelial growth factor A (VEGFA) expression in GR-deficient adipocytes of AdipoGR-KO mice compared with control mice, together with an increased adipose vascular network, as assessed by three-dimensional imaging. GR activation reduced HIF-1α recruitment to the Vegfa promoter resulting from Hif-1α downregulation at the transcriptional and posttranslational levels. Importantly, in CORT-treated AdipoGR-KO mice, the blockade of VEGFA by a soluble decoy receptor prevented AT expansion and the healthy metabolic phenotype. Finally, in subcutaneous AT from patients with Cushing syndrome, higher VEGFA expression was associated with a better metabolic profile. Collectively, these results highlight that adipocyte GR negatively controls AT expansion and metabolic health through the downregulation of the major angiogenic effector VEGFA and inhibition of vascular network development.

Glucocorticoid treatment influences prostate cancer cell growth and the tumor microenvironment via altered glucocorticoid receptor signaling in prostate fibroblasts.

Despite significant therapeutic advances in recent years, treatment of metastatic prostate cancer (PCa) remains palliative, owing to the inevitable occurrence of drug resistance. There is increasing evidence that epithelial glucocorticoid receptor (GR) signaling and changes in the tumor-microenvironment (TME) play important roles in this process. Since glucocorticoids (GCs) are used as concomitant medications in the course of PCa treatment, it is essential to investigate the impact of GCs on stromal GR signaling in the TME. Therefore, general GR mRNA and protein expression was assessed in radical prostatectomy specimens and metastatic lesions. Elevated stromal GR signaling after GC treatment resulted in altered GR-target gene, soluble protein expression, and in a morphology change of immortalized and primary isolated cancer-associated fibroblasts (CAFs). Subsequently, these changes affected proliferation, colony formation, and 3D-spheroid growth of multiple epithelial PCa cell models. Altered expression of extra-cellular matrix (ECM) and adhesion-related proteins led to an ECM remodeling. Notably, androgen receptor pathway inhibitor treatments did not affect CAF viability. Our findings demonstrate that GC-mediated elevated GR signaling has a major impact on the CAF secretome and the ECM architecture. GC-treated fibroblasts significantly influence epithelial tumor cell growth and must be considered in future therapeutic strategies.

DNMT1-mediated NR3C1 DNA methylation enables transcription activation of connexin40 and augments angiogenesis during colorectal cancer progression.

Colorectal cancer (CRC) continues to be a major contributor to cancer-related mortality. Connexin 40 (CX40) is one of the major gap junction proteins with the capacity in regulating cell-to-cell communication and angiogenesis. This study investigates its role in angiogenesis in CRC and explores the regulatory mechanism. Aberrant high CX40 expression was detected in tumor tissues, which was associated with a poor prognosis in CRC patients. Elevated CX40 expression was detected in CRC cell lines as well. Conditioned medium of SW620 and HT29 cell lines was used to induce angiogenesis of human umbilical vein endothelial cells (HUVECs). CX40 knockdown in CRC cells reduced angiogenesis and mobility of HUVECs and blocked CRC cell proliferation, mobility, and survival. Following bioinformatics predictions, we validated by chromatin immunoprecipitation and luciferase assays that nuclear receptor subfamily 3 group C member 1 (NR3C1), which was poorly expressed in CRC samples, suppressed CX40 transcription. The poor NR3C1 expression was attributive to DNA hypermethylation induced by DNA methyltransferase 1 (DNMT1). Restoration of NR3C1 suppressed the pro-angiogenic effect, proliferation and survival, and tumorigenic activity of CRC cells, which were, however, rescued by CX40 upregulation. Collectively, this study demonstrates that transcription activation of CX40 upon DNMT1-mediated NR3C1 DNA methylation potentiates angiogenesis in CRC.

Monitoring Glucocorticoid Receptor in Plasma-derived Extracellular Vesicles as a Marker of Resistance to Androgen Receptor Signaling Inhibition in Prostate Cancer.

Disease progression following androgen ablation was shown to be associated with upregulation of the glucocorticoid receptor (GR). Longitudinal monitoring of GR expression in circulating extracellular vesicles (EV) may reflect changes in the tumor cell and facilitates detection of acquired resistance. We utilized LNCaP, LREX cells and a patient-derived xenograft, MDA PDX 322-2-6a, for in vitro and in vivo experiments. Plasma-derived EVs were isolated from patients with localized high-risk prostate cancer undergoing androgen ablation. The mRNA levels of GR in EVs and their responsive genes were detected by transcriptome analysis, qRT-PCR and the protein levels by Western blot analysis. We detected changes in GR expression at mRNA and protein levels in EVs derived from LNCaP and LREX cells in in vitro studies. In in vivo experiments, LNCaP and the PDX MDA 322-2-6a-bearing mice were treated with enzalutamide. GR levels in plasma-derived EVs were increased only in those tumors that did not respond to enzalutamide. Treatment of mice bearing enzalutamide-resistant tumors with a GR inhibitor in combination with enzalutamide led to a transient pause in tumor growth in a subset of tumors and decreased GR levels intracellular and in plasma-derived EVs. In a subgroup of patients with high-risk localized prostate cancer treated with androgen signaling inhibition, GR was found upregulated in matching tissue and plasma EVs. These analyses showed that GR levels in plasma-derived EVs may be used for monitoring the transition of GR expression allowing for early detection of resistance to androgen ablation treatment. SIGNIFICANCE: Longitudinal monitoring of GR expression in plasma-derived EVs from patients with prostate cancer treated with androgen signaling inhibitors facilitates early detection of acquisition of resistance to androgen receptor signaling inhibition in individual patients.

Ginsenoside compound K exerts anti-inflammatory effects through transcriptional activation and transcriptional inhibition of glucocorticoid receptor in rheumatoid arthritis fibroblast-like synoviocytes.

Ginsenoside compound K (GCK) has anti-inflammatory and immunoregulatory effects, and glucocorticoid receptor (GR) has been considered as its potential target. But the mechanism by which GCK exerts its anti-inflammatory effects after GR activation remains unclear. In this study, molecular docking, isothermal titration calorimetry, siRNA of GR and GRA458T mutation were used to confirm the anti-inflammatory mechanism of GCK targeting GR in fibroblast-like synoviocytes (FLS). The results showed that the key binding sites of GR and GCK were identified as ASN564, MET560 and ASN638, with binding levels at the µm level. In addition, the inhibitory effect of GCK on the proliferation of FLS and the secretion of inflammatory cytokines (IL-6, IL-8, and IL-1ß) were mediated by transcriptional activation of GR, but on the migration, invasion, and TNF-α secretion of FLS were mediated by transcriptional inhibition of GR. These actions exert anti-inflammatory effects through indirect and direct inhibition of NF-κB transcriptional activity, respectively. In conclusion, this study elucidates that GCK can directly bind to and activate GR. Furthermore, after activation, GR mediates the anti-inflammatory effects of GCK through two mechanisms: transcriptional activation and transcriptional inhibition.

Luminal breast cancer identity is determined by loss of glucocorticoid receptor activity.

Glucocorticoid receptor (GR) is a transcription factor that plays a crucial role in cancer biology. In this study, we utilized an in silico-designed GR activity signature to demonstrate that GR relates to the proliferative capacity of numerous primary cancer types. In breast cancer, the GR activity status determines luminal subtype identity and has implications for patient outcomes. We reveal that GR engages with estrogen receptor (ER), leading to redistribution of ER on the chromatin. Notably, GR activation leads to upregulation of the ZBTB16 gene, encoding for a transcriptional repressor, which controls growth in ER-positive breast cancer and associates with prognosis in luminal A patients. In relation to ZBTB16's repressive nature, GR activation leads to epigenetic remodeling and loss of histone acetylation at sites proximal to cancer-driving genes. Based on these findings, epigenetic inhibitors reduce viability of ER-positive breast cancer cells that display absence of GR activity. Our findings provide insights into how GR controls ER-positive breast cancer growth and may have implications for patients' prognostication and provide novel therapeutic candidates for breast cancer treatment.

Discovery of a glucocorticoid receptor (GR) activity signature correlates with immune cell infiltration in adrenocortical carcinoma.

BACKGROUND: Adrenocortical carcinoma (ACC) is a rare and highly aggressive endocrine malignancy, of which >40% present with glucocorticoid excess. Glucocorticoids and glucocorticoid receptor (GR) signaling have long been thought to suppress immunity and promote tumor progression by acting on immune cells. Here, we provide new insights into the interaction between GR signaling activity and the immune signature of ACC as a potential explanation for immune escape and resistance to immunotherapy. METHODS: First, GR immunohistochemical staining and immunofluorescence analysis of tumor-infiltrating lymphocyte (CD4 T, CD8 T cells, natural killer (NK) cells, dendritic cells and macrophages) were performed in 78 primary ACC tissue specimens. Quantitative data of immune cell infiltration in ACC were correlated with clinical characteristics. Second, we discovered a GR activity signature (GRsig) using GR-targeted gene networks derived from global gene expression data of primary ACC. Finally, we identified two GRsig-related subtypes based on the GRsig and assessed the differences in immune characteristics and prognostic stratification between the two subtypes. RESULTS: GR was expressed in 90% of the ACC tumors, and CD8+ cytotoxic T lymphocytes were the most common infiltrating cell type in ACC specimens (88%, 8.6 cells/high power field). GR expression positively correlated with CD8+ T cell (Phi=0.342, p<0.001), CD4+ T cell (Phi=0.280, p<0.001), NK cell (Phi=0.280, p<0.001), macrophage (Phi=0.285, p<0.001), and dendritic cell (Phi=0.397, p<0.001) infiltration. Clustering heatmap analysis also displayed high immune cell infiltration in GR high-expressing tumors and low immune cell infiltration in GR-low tumors. High GR expression and high immune cell infiltration were significantly associated with better survival. Glucocorticoid excess is associated with low immune cell abundance and unfavorable prognosis. A GRsig comprizing n=34 GR-associated genes was derived from Gene Expression Omnibus/The Cancer Genome Atlas (TCGA) data sets and used to define two GRsig-related subtypes in the TCGA cohort. We demonstrated distinct differences in the immune landscape and clinical outcomes between the two subtypes. CONCLUSION: GR expression positively correlates with tumor-infiltrating immune cells in ACC. The GRsig could serve as a prognostic biomarker and may be helpful for prognosis prediction and response to immunotherapy. Consequently, targeting the GR signaling pathway might be pivotal and should be investigated in clinical studies.

Mapping the Direction of Nucleocytoplasmic Transport of Glucocorticoid Receptor (GR) in Live Cells Using Two-Foci Cross-Correlation in Massively Parallel Fluorescence Correlation Spectroscopy (mpFCS).

Nucleocytoplasmic transport of transcription factors is vital for normal cellular function, and its breakdown is a major contributing factor in many diseases. The glucocorticoid receptor (GR) is an evolutionarily conserved, ligand-dependent transcription factor that regulates homeostasis and response to stress and is an important target for therapeutics in inflammation and cancer. In unstimulated cells, the GR resides in the cytoplasm bound to other molecules in a large multiprotein complex. Upon stimulation with endogenous or synthetic ligands, GR translocation to the cell nucleus occurs, where the GR regulates the transcription of numerous genes by direct binding to glucocorticoid response elements or by physically associating with other transcription factors. While much is known about molecular mechanisms underlying GR function, the spatial organization of directionality of GR nucleocytoplasmic transport remains less well characterized, and it is not well understood how the bidirectional nucleocytoplasmic flow of GR is coordinated in stimulated cells. Here, we use two-foci cross-correlation in a massively parallel fluorescence correlation spectroscopy (mpFCS) system to map in live cells the directionality of GR translocation at different positions along the nuclear envelope. We show theoretically and experimentally that cross-correlation of signals from two nearby observation volume elements (OVEs) in an mpFCS setup presents a sharp peak when the OVEs are positioned along the trajectory of molecular motion and that the time position of the peak corresponds to the average time of flight of the molecule between the two OVEs. Hence, the direction and velocity of nucleocytoplasmic transport can be determined simultaneously at several locations along the nuclear envelope. We reveal that under ligand-induced GR translocation, nucleocytoplasmic import/export of GR proceeds simultaneously but at different locations in the cell nucleus. Our data show that mpFCS can characterize in detail the heterogeneity of directional nucleocytoplasmic transport in a live cell and may be invaluable for studies aiming to understand how the bidirectional flow of macromolecules through the nuclear pore complex (NPC) is coordinated to avoid intranuclear transcription factor accretion/abatement.

Knockdown of NR3C1 inhibits the proliferation and migration of clear cell renal cell carcinoma through activating endoplasmic reticulum stress-mitophagy.

BACKGROUND: Clear cell renal cell carcinoma (ccRCC) is closely associated with steroid hormones and their receptors affected by lipid metabolism. Recently, there has been growing interest in the carcinogenic role of NR3C1, the sole gene responsible for encoding glucocorticoid receptor. However, the specific role of NR3C1 in ccRCC remains unclear. The present study was thus developed to explore the underlying mechanism of NR3C1's carcinogenic effects in ccRCC. METHODS: Expression of NR3C1 was verified by various tumor databases and assessed using RT-qPCR and western blot. Stable transfected cell lines of ccRCC with NR3C1 knockdown were constructed, and a range of in vitro and in vivo experiments were performed to examine the effects of NR3C1 on ccRCC proliferation and migration. Transcriptomics and lipidomics sequencing were then conducted on ACHN cells, which were divided into control and sh-NR3C1 group. Finally, the sequencing results were validated using transmission electron microscopy, mitochondrial membrane potential assay, immunofluorescence co-localization, cell immunofluorescent staining, and Western blot. The rescue experiments were designed to investigate the relationship between endoplasmic reticulum stress (ER stress) and mitophagy in ccRCC cells after NR3C1 knockdown, as well as the regulation of their intrinsic signaling pathways. RESULTS: The expression of NR3C1 in ccRCC cells and tissues was significantly elevated. The sh-NR3C1 group, which had lower levels of NR3C1, exhibited a lower proliferation and migration capacity of ccRCC than that of the control group (P < 0.05). Then, lipidomic and transcriptomic sequencing showed that lipid metabolism disorders, ER stress, and mitophagy genes were enriched in the sh-NR3C1 group. Finally, compared to the control group, ER stress and mitophagy were observed in the sh-NR3C1 group, while the expression of ATF6, CHOP, PINK1, and BNIP3 was also up-regulated (P < 0.05). Furthermore, Ceapin-A7, an inhibitor of ATF6, significantly down-regulated the expression of PINK1 and BNIP3 (P < 0.05), and significantly increased the proliferation and migration of ccRCC cells (P < 0.05). CONCLUSIONS: This study confirms that knockdown of NR3C1 activates ER stress and induces mitophagy through the ATF6-PINK1/BNIP3 pathway, resulting in reduced proliferation and migration of ccRCC. These findings indicate potential novel targets for clinical treatment of ccRCC.