Prognostic Significance of Glucocorticoid Receptor Expression in Cancer: A Systematic Review and Meta-Analysis

A randomized phase II trial of nab-paclitaxel with or without mifepristone for advanced triple-negative breast cancer

PURPOSE

Glucocorticoid receptor (GR) activity may mediate chemoresistance in advanced triple-negative breast cancer (TNBC). Preclinical studies demonstrate that GR antagonism can augment the effect of taxanes in TNBC models. We hypothesized that pretreatment with mifepristone, a potent GR antagonist, would enhance nab-paclitaxel efficacy in advanced TNBC.

METHODS

This trial was terminated early due to poor accrual. 29 of 64 planned patients were enrolled. Patients were randomized to receive nab-paclitaxel with or without mifepristone; oral mifepristone 300 mg was administered the day prior and day of each dose of nab-paclitaxel. The primary endpoint was progression-free survival (PFS); secondary/exploratory endpoints included response rate and correlation of response with GR expression.

RESULTS

The addition of mifepristone to nab-paclitaxel did not improve PFS (3.0 m vs 3.0 m, p = 0.687) or overall response rate (23% vs 31.5%) compared to nab-paclitaxel alone. There was a trend towards improved overall survival in the combination group, primarily driven by one long-term responder. Increased rates of grade 3 neutropenia (46% vs 7%) and febrile neutropenia were observed in the combination arm, while other toxicities were similar in both groups. Increased GR expression was not correlated with clinical response in the combination arm.

CONCLUSIONS

While there were responders to the combination, the study was underpowered to meet the primary endpoint. Higher rates of neutropenia were observed in the combination, but overall it was well tolerated. Preclinical data in TNBC and clinical data in other malignancies support further investigation of GR modulators. Future studies should incorporate biomarkers to select patients who benefit from GR inhibition.

Expression and prognosis of NR3C1 in uterine corpus endometrial carcinoma based on multiple datasets

Uterine corpus endometrial carcinoma (UCEC), a prevalent malignancy in the female reproductive system, has witnessed a 30% increase in recent year. Recognizing the significance of early treatment in reducing patient mortality, the identification of potential biomarkers for UCEC plays a crucial role in early diagnosis. This study was to identify key genes associated with UCEC utilizing the Gene Expression Omnibus database, followed by validating their prognostic value across multiple databases. Analysis of four UCEC databases (GSE17025, GSE36389, GSE63678, GSE115810) yielded 72 co-expressed genes. KEGG and GO enrichment analyses revealed their involvement in physiological processes such as transcriptional misregulation in cancer. Constructing a protein-protein interaction network for these 72 genes, the top 10 genes with significant interactions were identified. Survival regression analysis highlighted NR3C1 as the gene with a substantial impact on UCEC prognostic outcomes. Differential expression analysis indicated lower expression of NR3C1 in UCEC compared to normal endometrial tissue. Cox regression analysis, performed on clinical datasets of UCEC patients, identified clinical stage III, clinical stage IV, age, and NR3C1 as independent prognostic factors influencing UCEC outcomes. The LinkedOmics online database revealed the top 50 positively and negatively correlated genes with NR3C1 in UCEC. Subsequent investigations into the relationship between NR3C1 and tumor-infiltrating immune cells were conducted using R software. Gene set enrichment analysis provided insights into NR3C1-related genes, showing enrichment in processes such as Ribosome, Oxidative phosphorylation in UCEC. Collectively, these comprehensive analyses suggest that NR3C1 may serve as a potential biomarker indicating the prognosis of UCEC.

High tumor glucocorticoid receptor expression in early-stage, triple-negative breast cancer is associated with increased T-regulatory cell infiltration

PURPOSE

In early-stage, triple-negative breast cancer (TNBC), immune cell infiltration contributes to cancer cell survival, tumor invasion, and metastasis. High TNBC glucocorticoid receptor (GR) expression in early-stage TNBC is associated with poor long-term outcomes; it is unknown if high GR expression is associated with an immunosuppressed tumor microenvironment. We hypothesized that high tumor GR expression would be associated with an immune-suppressed tumor microenvironment, which could thus account for the poor prognosis observed in GR-positive TNBC.

METHODS

Formalin fixed-paraffin embedded tissue (n = 47) from patients diagnosed with early-stage TNBC from The University of Chicago (2002-2014) were evaluated for both tumor cell anti-GR immunohistochemistry and for infiltrating immune cells by immunofluorescence. Multiplexed antibodies were used to enumerate CD8+, FOXP3+, and BATF3+ immune cells infiltrating within pan-cytokeratin positive tumor cell regions of interest, and nonparametric tests compared absolute counts of each of these tumor-infiltrating immune cell types.

RESULTS

The average age of patients represented in this study was 52 years, and 63% self-identified as Black. There was no significant association between tumor GR expression and age, race, or clinical stage at diagnosis. Compared to GR-low tumors, high GR expression in early-stage, treatment-naïve TNBC was associated with relatively increased numbers of immunosuppressive FOXP3 + regulatory T cells (p = 0.046) and BATF3+immune cells (p = 0.021). While there was a positive correlation with high GR expression and CD8+ cell infiltration, it was not significant (p = 0.068). The ratio of CD8+/FOXP3+cells was also not significant (p = 0.24).

CONCLUSIONS

These data support the hypothesis that in early-stage TNBC, high GR expression is significantly associated with infiltration of immunosuppressive regulatory T cells, suggesting a tumor-intrinsic role in shaping the immunosuppressive immune cell milieu. Furthermore, suppression of GR activity may regulate the tumor immune microenvironment and improve long-term outcomes in GR-high TNBC.

Investigation of selective glucocorticoid receptor modulation in high-grade serous ovarian cancer PDX models

OBJECTIVE

In ovarian cancer (OvCa), tumor cell high glucocorticoid receptor (GR) has been associated with poor patient prognosis. In vitro, GR activation inhibits chemotherapy-induced OvCa cell death in association with transcriptional upregulation of genes encoding anti-apoptotic proteins. A recent randomized phase II study demonstrated improvement in progression-free survival (PFS) for heavily pre-treated OvCa patients randomized to receive therapy with a selective GR modulator (SGRM) plus chemotherapy compared to chemotherapy alone. We hypothesized that SGRM therapy would improve carboplatin response in OvCa patient-derived xenograft (PDX).

METHODS

Six high-grade serous (HGS) OvCa PDX models expressing GR mRNA (NR3C1) and protein were treated with chemotherapy +/- SGRM. Tumor size was measured longitudinally by peritoneal transcutaneous ultrasonography.

RESULTS

One of the 6 GR-positive PDX models showed a significant improvement in PFS with the addition of a SGRM. Interestingly, the single model with an improved PFS was least carboplatin sensitive. Possible explanations for the modest SGRM activity include the high carboplatin sensitivity of 5 of the PDX tumors and the potential that SGRMs activate the tumor invasive immune cells in patients (absent from immunocompromised mice). The level of tumor GR protein expression alone appears insufficient for predicting SGRM response.

CONCLUSION

The significant improvement in PFS shown in 1 of the 6 models after treatment with a SGRM plus chemotherapy underscores the need to determine predictive biomarkers for SGRM therapy in HGS OvCa and to better identify patient subgroups that are most likely to benefit from adding GR modulation to chemotherapy.

Asoprisnil as a Novel Ligand Interacting with Stress-Associated Glucocorticoid Receptor

Background/objective: The glucocorticoid receptor (GR) is critical in regulating cortisol production during stress. This makes it a key target for treating conditions associated with hypothalamic-pituitary-adrenal (HPA) axis dysregulation, such as mental disorders. This study explores novel ligands beyond mifepristone for their potential to modulate GR with improved efficacy and safety. By investigating these interactions, we seek to identify new pharmacotherapeutic options for stress-related mental illness. Methods: The ligands asoprisnil, campestanol, and stellasterol were selected based on structural similarities to mifepristone (reference ligand) and evaluated for pharmacological and ADME (absorption, distribution, metabolism, and excretion) properties using the SwissADME database. Molecular docking with AutoDock 4.2.6 and molecular dynamics simulations were performed to investigate ligand-protein interactions with the human glucocorticoid receptor, and binding free energies were calculated using MMPBSA. Results: Pharmacokinetic analysis revealed that asoprisnil exhibited high gastrointestinal absorption and obeyed Lipinski's rule, while mifepristone crossed the blood-brain barrier. Toxicological predictions showed that mifepristone was active for neurotoxicity and immunotoxicity, while asoprisnil, campestanol, and stellasterol displayed lower toxicity profiles. Asoprisnil demonstrated the highest stability in molecular dynamics simulations, with the highest negative binding energy of -62.35 kcal/mol, when compared to mifepristone, campestanol, and stellasterol, with binding energies of -57.08 kcal/mol, -49.99 kcal/mol, and -46.69 kcal/mol, respectively. Conclusion: This makes asoprisnil a potentially favourable therapeutic candidate compared to mifepristone. However, further validation of asoprisnil's interaction, efficacy, and safety in stress-related mental disorders through experimental studies and clinical trials is needed.

Relacorilant in recurrent ovarian cancer: clinical evidence and future perspectives

INTRODUCTION

Relacorilant (CORT125134, Corcept Therapeutics) is a selective glucocorticoid receptor modulator, which reverses the glucocorticoid-mediated anti-apoptotic effects and restores the taxane chemosensitivity in epithelial ovarian cancer cells. Given those preclinical findings, relacorilant is currently under investigation in clinical trials in combination with nab-paclitaxel for the platinum-resistant ovarian cancer setting.

AREAS COVERED

Already published preclinical and clinical evidence of relacorilant antitumor activity was analyzed and discussed. Ongoing clinical trials registered on clincaltrials.gov were also reported. The review aimed to summarize the status of relacorilant, the mechanism of action, the published and ongoing trials, and its safety and efficacy.

EXPERT OPINION

Relacorilant combined with nab-paclitaxel, may represent a promising strategy for the treatment of platinum-resistant ovarian cancer patients. After preliminary positive results in terms of clinical efficacy, a randomized phase III trial is ongoing to confirm the findings from the published phase II study.

Is a low dose of dexamethasone sufficient to prevent paclitaxel-related hypersensitivity reactions? A retrospective study in patients with gynecologic malignancy

BACKGROUND

Paclitaxel hypersensitivity reactions (HSRs) are prevalent, especially in females. The common paclitaxel pretreatment, dexamethasone, may inhibit chemotherapy efficacy and accelerate tumor progression. We aimed to balance paclitaxel HSRs and the lowest dexamethasone dose for gynecologic malignancies.

METHODS

We retrospectively examined 1,074 cycles of 3-weekly paclitaxel-containing treatment for 231 gynecologic malignancies at Xiangya Hospital. HSR incidence with different dexamethasone regimens was the primary outcome. Risk factors were examined in all cycles using univariate and multivariate models with generalized estimating equations. A subgroup analysis of initial exposure to paclitaxel was also conducted.

RESULTS

HSR occurred in 33 patients (14.29%) and 49 cycles (4.56%), including 69.39% in cycles 1-2. There were no severe HSRs (grade ≥3). Different premedication regimens, including dexamethasone dosage and route, ranitidine presence or absence, didn't affect HSR incidence in univariate and multivariate analyzes (p > 0.05). Premenopausal women exerted fewer HSRs (ORadj 0.22, 95%CI 0.08-0.58; p = 0.002). At the first exposure to paclitaxel, more than 10 mg of dexamethasone didn't diminish HSRs (OR 0.83, 95%CI 0.27-2.59; p = 0.753).

CONCLUSIONS

In gynecologic malignancies, 10 mg dexamethasone along with 20 mg diphenhydramine may be adequate to prevent paclitaxel HSRs without ranitidine. It is necessary to reevaluate paclitaxel premedication regimens.

The role of serum and glucocorticoid-regulated kinase 1 in cellular signaling: Implications for drug development

Serum and glucocorticoid-regulated kinase 1 (SGK1) is a ubiquitously expressed protein belonging to the Ser/Thr kinase family. It regulates diverse physiological processes, including epithelial sodium channel activity, hypertension, cell proliferation, and insulin sensitivity. Due to its significant role in the pathogenesis of numerous diseases, SGK1 can be exploited as a potential therapeutic target to address challenging health problems. SGK1 is associated with the development of obesity, and its overexpression enhances the sodium-glucose co-transporter 1 activity, which absorbs intestinal glucose. This review highlighted the detailed functional significance of SGK1 signaling and role in different diseases and subsequent therapeutic targeting. We aim to provide deeper mechanistic insights into understanding the pathogenesis and recent advancements in the SGK1 targeted drug development process. Small-molecule inhibitors are being developed with excellent binding affinity and improved SGK1 inhibition with desired selectivity. We have discussed small molecule inhibitors designed explicitly as potent SGK1 inhibitors and their therapeutic implications in various diseases. We further addressed the therapeutic potential and mechanism of action of these SGK1 inhibitors and provided a strong scientific foundation for developing effective therapeutics.

Dexamethasone-Free Antiemetic Prophylaxis for Highly Emetogenic Chemotherapy: A Double-Blind, Phase III Randomized Controlled Trial (CINV POD study)

PURPOSE

The effectiveness of a dexamethasone (DEX)-free regimen for chemotherapy-induced nausea and vomiting (CINV) prophylaxis in patients receiving highly emetogenic chemotherapy (HEC) is not known.

METHODS

This was a double-blind, phase III trial designed to show the noninferiority of a DEX-free regimen (olanzapine, palonosetron, and fosaprepitant [OPF]) compared with the DEX-containing regimen (olanzapine, palonosetron, and DEX [OPD]). Chemotherapy-naïve patients age 18-80 years receiving single-day HEC were randomly assigned 1:1 to receive either the OPD regimen or the OPF regimen. The primary objective was to compare complete response (CR) rates for vomiting during the overall period (start of chemotherapy to 120 hours). Secondary objectives included CR for vomiting during the acute period (0-24 hours) and delayed period (24-120 hours), CR for nausea, and comparison of toxicities and patient-reported outcomes.

RESULTS

Three hundred forty-six patients received the study interventions, 174 in the OPD arm and 172 in the OPF arm. The DEX-free OPF arm had significantly higher CR rates for vomiting compared with the DEX-containing OPD arm in acute (94.7% v 85.6%; P < .004), delayed (81.9% v 50.5%; P < .001), and overall (79.6% v 48.8%; P < .001) periods. For nausea, CR rates in the OPF arm were higher in delayed (53.4% v 39.6%; P = .009) and overall (50.5% v 39.1%; P = .031) periods but not in the acute period (77.9% v 81.6%; P = .39). Fatigue (P = .009) and drowsiness (P = .002) were more in the OPF arm in the acute period and insomnia (P < .001) in the OPD arm in the overall period.

CONCLUSION

This study shows that a DEX-free OPF regimen is efficacious and should be considered a standard option for acute and delayed CINV prophylaxis for HEC.

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.

Intratumoral cortisol associated with aromatase in the endometrial cancer microenvironment

Glucocorticoids bind to glucocorticoid receptors (GR). In the peripheral tissues, active cortisol is produced from inactive cortisone by 11β-hydroxysteroid dehydrogenase (HSD)1. 11β-HSD2 is responsible for this reverse catalysis. Although GR and 11β-HSDs have been reported to be involved in the malignant behavior of various cancer types, the concentration of glucocorticoids in cancer tissues has not been investigated. In this study, we measured glucocorticoids in serum and cancer tissues using liquid chromatography-tandem mass spectrometry and clarified, for the first time, the intratumoral "intracrine" production of cortisol by 11β-HSD1/2 in endometrial cancer. Intratumoral cortisol levels were high in the high-malignancy type and the cancer proliferation marker Ki-67-high group, suggesting that cortisol greatly contributes to the malignant behavior of endometrial cancer. A low expression level of the metabolizing enzyme 11β-HSD2 is more important than a high expression level of the synthase 11β-HSD1 for intratumoral cortisol action. Intratumoral cortisol was positively related to the expression/activity of estrogen synthase aromatase, which involved GR expressed in fibroblastic stromal cells but not in cancer cells. Blockade of GR signaling by hormone therapy is expected to benefit patients with endometrial cancer.

Relacorilant + Nab-Paclitaxel in Patients With Recurrent, Platinum-Resistant Ovarian Cancer: A Three-Arm, Randomized, Controlled, Open-Label Phase II Study

PURPOSE

Despite therapeutic advances, outcomes for patients with platinum-resistant/refractory ovarian cancer remain poor. Selective glucocorticoid receptor modulation with relacorilant may restore chemosensitivity and enhance chemotherapy efficacy.

METHODS

This three-arm, randomized, controlled, open-label phase II study (ClinicalTrials.gov identifier: NCT03776812) enrolled women with recurrent, platinum-resistant/refractory, high-grade serous or endometrioid epithelial ovarian, primary peritoneal, or fallopian tube cancer, or ovarian carcinosarcoma treated with ≤4 prior chemotherapeutic regimens. Patients were randomly assigned 1:1:1 to (1) nab-paclitaxel (80 mg/m2) + intermittent relacorilant (150 mg the day before, of, and after nab-paclitaxel); (2) nab-paclitaxel (80 mg/m2) + continuous relacorilant (100 mg once daily); or (3) nab-paclitaxel monotherapy (100 mg/m2). Nab-paclitaxel was administered on days 1, 8, and 15 of each 28-day cycle. The primary end point was progression-free survival (PFS) by investigator assessment; objective response rate (ORR), duration of response (DOR), overall survival (OS), and safety were secondary end points.

RESULTS

A total of 178 women were randomly assigned. Intermittent relacorilant + nab-paclitaxel improved PFS (hazard ratio [HR], 0.66; log-rank test P = .038; median follow-up, 11.1 months) and DOR (HR, 0.36; P = .006) versus nab-paclitaxel monotherapy, while ORR was similar across arms. At the preplanned OS analysis (median follow-up, 22.5 months), the OS HR was 0.67 (P = .066) for the intermittent arm versus nab-paclitaxel monotherapy. Continuous relacorilant + nab-paclitaxel showed numerically improved median PFS but did not result in significant improvement over nab-paclitaxel monotherapy. Adverse events were comparable across study arms, with neutropenia, anemia, peripheral neuropathy, and fatigue/asthenia being the most common grade ≥3 adverse events.

CONCLUSION

Intermittent relacorilant + nab-paclitaxel improved PFS, DOR, and OS compared with nab-paclitaxel monotherapy. On the basis of protocol-prespecified Hochberg step-up multiplicity adjustment, the primary end point did not reach statistical significance (P < .025). A phase III evaluation of this regimen is underway (ClinicalTrials.gov identifier: NCT05257408).

Dexamethasone induces cancer mitigation and irreversible senescence in lung cancer cells via damaging cortical actin and sustained hyperphosphorylation of pRb

Activation of the glucocorticoid receptors by its cognate ligand, dexamethasone (DEX) is commonly used as an adjuvant treatment in solid tumors. However, its direct effect on cancerous phenotype is not fully understood. We explored the effect and molecular mechanisms of DEX action in lung cancer. In in vitro experiments, DEX treatment causes decrease in migration, invasion and colony formation ability of A549 cells even at lower doses. DEX also decreased adhesion of A549 cells by reducing the formation of cortical actin. Treatment with RU486, a GR antagonist, indicated that these effects are partially mediated through GR. Further; DEX induces G0/G1 arrest of A549 cells. Mechanistically, DEX induces expression of both CDK inhibitors (p21Cip1, p27Kip1) and cyclin-dependent kinases (CDK4, CDK6). Due to this compensatory activation of CDKs and CDKIs, DEX induces the hyper phosphorylation state of Rb protein (pRb) leading to irreversible senescence as confirmed by β-gal staining. Next, in clinical dataset of NSCLC (Non-small cell lung cancer), GR was lowly expressed in cancer patients as compared to the normal group, where higher expression of GR led to higher overall survival of NSCLC indicating for a protective role of GR. Interestingly, when combined with chemotherapeutic agents, DEX can modulate the drug-sensitivity of cells. Taken together, these data indicate that DEX through GR activation may suppress tumor growth by decreasing proliferation and inducing irreversible senescence and combination of standard chemotherapy and DEX can be a potential treatment for NSCLC.

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.

Dexamethasone activates c-Jun NH2-terminal kinase (JNK) which interacts with GR and protects it from ubiquitin-mediated degradation in NSCLC cells

Dexamethasone-mediated pharmacological activation of the glucocorticoid receptor (GR) is widely used in the treatment regimen of hematological malignancies and solid cancers. However, DEX sensitivity towards patients primarily depends on the endogenous protein levels of GR. We observed that DEX treatment leads to an increase in GR protein levels despite inhibition of neo-protein synthesis in non-small cell lung cancer (NSCLC) cells. Mechanistically, DEX-stimulation concomitantly increased the JNK phosphorylation and GR protein levels, however the JNK stimulation preceds GR upregulation. Moreover, we also observed that DEX-mediated phosphorylation is partially mediated by upregulation in MEKK1 phosphorylation. Further, GR protein levels were significantly decreased in JNK inhibitor (JNKi, SP600125) treated cells whereas MG132 treatment restored GR levels indicating that DEX induced JNK activity regulated the GR protein levels through proteasomal-degradation pathway. Next, we showed that DEX led to JNK activation which physically interacts with GR and protects it from ubiquitination-mediated degradation. Furthermore, at basal level GR interacts with JNK in cytoplasm whereas upon DEX stimulation GR and pJNK both localized to nucleus and interact with each other. Next, we show that JNK-mediated GR stabilization affects its nuclear transcriptional functional activity in NSCLC cells. In line with these in vitro data, patient dataset analysis also shows that increased levels of both JNK and GR contributes towards better prognosis of NSCLC patients. Taken together, our data shows that DEX treatment may lead to positive feedback regulation of GR by activating JNK and thus highlights importance of GR-JNK crosstalk in NSCLC.

Prognostic value of β-Arrestins in combination with glucocorticoid receptor in epithelial ovarian cancer

Hormones may be key factors driving cancer development, and epidemiological findings suggest that steroid hormones play a crucial role in ovarian tumorigenesis. We demonstrated that high glucocorticoid receptor (GR) expression is associated with a poor prognosis of epithelial ovarian cancer. Recent studies have shown that the GR affects β-arrestin expression, and vice versa. Hence, we assessed the clinical significance of β-arrestin expression in ovarian cancer and determined whether β-arrestin and the GR synergistically have clinical significance and value as prognostic factors. We evaluated the expression of β-arrestins 1 and 2 and the GR in 169 patients with primary epithelial ovarian cancer using immunohistochemistry. The staining intensity was graded on a scale of 0-4 and multiplied by the percentage of positive cells. We divided the samples into two categories based on the expression levels. β-arrestin 1 and GR expression showed a moderate correlation, whereas β-arrestin 2 and GR expression did not demonstrate any correlation. Patients with high β-arrestin 1 and 2 expression exhibited improved survival rates, whereas patients with low GR expression showed a better survival rate. Patients with high β-arrestin 1 and low GR levels had the best prognosis among all groups. β-arrestin is highly expressed in ovarian cancer, suggesting its potential as a diagnostic and therapeutic biomarker. The combination of β-arrestin and GR demonstrated greater predictive prognostic power than GR expression alone, implicating another possible role in prognostication.

RCAS1 increases cell morphological changes in murine fibroblasts by reducing p38 phosphorylation

Receptor‑binding cancer antigen expressed on SiSo cells (RCAS1) is a tumor‑associated antigen that is expressed in a number of human malignancies. RCAS1 acts as a ligand for a putative RCAS1 receptor that is present on various human cells including T and B lymphocytes and natural killer cells, in which it induces cell growth inhibition and apoptosis. It has been suggested that RCAS1 might serve an important role in tumor cell evasion from the host immune system. In fact, RCAS1 expression is related to malignant characteristics including tumor size, invasion depth, clinical stage and poor overall survival. The authors previously established doxycycline‑induced RCAS1 overexpression murine fibroblast L cells to analyze the biological functions of RCAS1 and reported that its expression inhibited cell cycle progression via the downregulation of cyclin D3, which subsequently induced apoptosis. Additionally, it was found that RCAS1 expression induced cell morphological changes prior to caspase‑mediated apoptosis. Thus, the present study examined signaling pathways associated with changes in cell morphology that were induced by RCAS1 expression. The data showed that increased RCAS1 expression caused a reduction in actin stress fibers and decreased cofilin phosphorylation. Recent studies have shown that p38 signaling regulates actin polymerization. The data the present study showed that increased RCAS1 expression significantly decreased p38 phosphorylation.

Survival Mechanisms of Metastatic Melanoma Cells: The Link between Glucocorticoids and the Nrf2-Dependent Antioxidant Defense System

Circulating glucocorticoids increase during stress. Chronic stress, characterized by a sustained increase in serum levels of cortisol, has been associated in different cases with an increased risk of cancer and a worse prognosis. Glucocorticoids can promote gluconeogenesis, mobilization of amino acids, fat breakdown, and impair the body's immune response. Therefore, conditions that may favor cancer growth and the acquisition of radio- and chemo-resistance. We found that glucocorticoid receptor knockdown diminishes the antioxidant protection of murine B16-F10 (highly metastatic) melanoma cells, thus leading to a drastic decrease in their survival during interaction with the vascular endothelium. The BRAF^V600E mutation is the most commonly observed in melanoma patients. Recent studies revealed that VMF/PLX40-32 (vemurafenib, a selective inhibitor of mutant BRAF^V600E) increases mitochondrial respiration and reactive oxygen species (ROS) production in BRAF^V600E human melanoma cell lines. Early-stage cancer cells lacking Nrf2 generate high ROS levels and exhibit a senescence-like growth arrest. Thus, it is likely that a glucocorticoid receptor antagonist (RU486) could increase the efficacy of BRAF-related therapy in BRAF^V600E-mutated melanoma. In fact, during early progression of skin melanoma metastases, RU486 and VMF induced metastases regression. However, treatment at an advanced stage of growth found resistance to RU486 and VMF. This resistance was mechanistically linked to overexpression of proteins of the Bcl-2 family (Bcl-xL and Mcl-1 in different human models). Moreover, melanoma resistance was decreased if AKT and NF-κB signaling pathways were blocked. These findings highlight mechanisms by which metastatic melanoma cells adapt to survive and could help in the development of most effective therapeutic strategies.

The Role of Glucocorticoids in Breast Cancer Therapy

Glucocorticoids (GCs) are anti-inflammatory and immunosuppressive steroid molecules secreted by the adrenal gland and regulated by the hypothalamic-pituitary-adrenal (HPA) axis. GCs present a circadian release pattern under normal conditions; they increase their release under stress conditions. Their mechanism of action can be via the receptor-independent or receptor-dependent pathway. The receptor-dependent pathway translocates to the nucleus, where the ligand-receptor complex binds to specific sequences in the DNA to modulate the transcription of specific genes. The glucocorticoid receptor (GR) and its endogenous ligand cortisol (CORT) in humans, and corticosterone in rodents or its exogenous ligand, dexamethasone (DEX), have been extensively studied in breast cancer. Its clinical utility in oncology has mainly focused on using DEX as an antiemetic to prevent chemotherapy-induced nausea and vomiting. In this review, we compile the results reported in the literature in recent years, highlighting current trends and unresolved controversies in this field. Specifically, in breast cancer, GR is considered a marker of poor prognosis, and a therapeutic target for the triple-negative breast cancer (TNBC) subtype, and efforts are being made to develop better GR antagonists with fewer side effects. It is necessary to know the type of breast cancer to differentiate the treatment for estrogen receptor (ER)-positive, ER-negative, and TNBC, to implement therapies that include the use of GCs.

Overexpression of glucocorticoid receptor promotes the poor progression and induces cisplatin resistance through p38 MAP kinase in cervical cancer patients

Glucocorticoid receptor (GR) is activated by synthetic glucocorticoid or endogenous cortisol which were released by the physical and psychosocial stress, and recent studies reported that it is involved in tumor initiation and metastasis in various solid cancers. However, role of GR in cervical cancer has not been elucidated yet. Therefore, here we aim to unveil the role of GR in cervical cancer with cervical cancer clinical specimen and cervical cancer cell lines. We found that overexpression of GR was associated with poor prognosis in cervical cancer patients. Also, GR knockdown in cervical cancer cell lines showed diminished proliferation, invasion and EMT properties. Besides, we found that GR was positively associated with FoxP3 expression, and combination of GR and FoxP3 overexpression revealed as more reliable biomarker for poor prognosis and poor response to chemotherapy of cervical cancer patient than GR alone. Moreover, FACS-based Annexin-V/PI double staining and cleavage of poly ADP ribose polymerase (PARP) showed that siGR enhanced cisplatin-induced apoptosis, which was mediated by p38 MAP kinase. Collectively, our findings established that the combination of high GR and FoxP3 was associated with cervical cancer progression and platinum resistance, suggesting a potential predictive biomarker for clinical management in patients with cervical cancer.

Rewiring of the Endocrine Network in Triple-Negative Breast Cancer

The immunohistochemical definition of estrogen/progesterone receptors dictates endocrine feasibility in the treatment course of breast cancer. Characterized by the deficiency of estrogen receptor α, ERα-negative breast cancers are dissociated from any endocrine regimens in the routine clinical setting, triple-negative breast cancer in particular. However, the stereotype was challenged by triple-negative breast cancers’ retained sensitivity and vulnerability to endocrine agents. The interplay of hormone action and the carcinogenic signaling program previously underscored was gradually recognized along with the increasing investigation. In parallel, the overlooked endocrine-responsiveness in ERα-negative breast cancers attracted attention and supplied fresh insight into the therapeutic strategy in an ERα-independent manner. This review elaborates on the genomic and non-genomic steroid hormone actions and endocrine-related signals in triple-negative breast cancers attached to the hormone insensitivity label. We also shed light on the non-canonical mechanism detected in common hormone agents to showcase their pleiotropic effects.

Tumor Suppressive Effects of GAS5 in Cancer Cells

In recent years, long non-coding RNAs (lncRNAs) have been shown to play important regulatory roles in cellular processes. Growth arrests specific transcript 5 (GAS5) is a lncRNA that is highly expressed during the cell cycle arrest phase but is downregulated in actively growing cells. Growth arrests specific transcript 5 was discovered to be downregulated in several cancers, primarily solid tumors, and it is known as a tumor suppressor gene that regulates cell proliferation, invasion, migration, and apoptosis via multiple molecular mechanisms. Furthermore, GAS5 polymorphism was found to affect GAS5 expression and functionality in a cell-specific manner. This review article focuses on GAS5’s tumor-suppressive effects in regulating oncogenic signaling pathways, cell cycle, apoptosis, tumor-associated genes, and treatment-resistant cells. We also discussed genetic polymorphisms of GAS5 and their association with cancer susceptibility.

Mechanisms behind context-dependent role of glucocorticoids in breast cancer progression

Glucocorticoids (GCs), mostly dexamethasone (dex), are routinely administered as adjuvant therapy to manage side effects in breast cancer. However, recently, it has been revealed that dex triggers different effects and correlates with opposite outcomes depending on the breast cancer molecular subtype. This has raised new concerns regarding the generalized use of GC and suggested that the context-dependent effects of GCs can be taken into potential consideration during treatment design. Based on this, attention has recently been drawn to the role of the glucocorticoid receptor (GR) in development and progression of breast cancer. Therefore, in this comprehensive review, we aimed to summarize the different mechanisms behind different context-dependent GC actions in breast cancer by applying a multilevel examination, starting from the association of variants of the GR-encoding gene to expression at the mRNA and protein level of the receptor, and its interactions with other factors influencing GC action in breast cancer. The role of GCs in chemosensitivity and chemoresistance observed during breast cancer therapy is discussed. In addition, experiences using GC targeting therapeutic options (already used and investigated in preclinical and clinical trials), such as classic GC dexamethasone, selective glucocorticoid receptor agonists and modulators, the GC antagonist mifepristone, and GR coregulators, are also summarized. Evidence presented can aid a better understanding of the biology of context-dependent GC action that can lead to further advances in the personalized therapy of breast cancer by the evaluation of GR along with the conventional estrogen receptor (ER) and progesterone receptor (PR) in the routine diagnostic procedure.