The glucocorticoid receptor is overexpressed in malignant adrenocortical tumors

Prediction and prognostic potential of NR3C1 gene expression level in DLBCL patients

Objective: Diffuse Large B-Cell Lymphoma (DLBCL) is a common and frequently occurring subtype of Non-Hodgkin Lymphoma (NHL). The effective treatment and prognosis of DLBCL are still urgently needed to be explored. This article aims to shed light on the connection between DLBCL survival and NR3C1 expression levels. Methods: First, we divided the 952 DLBCL patients into an NR3C1 high-expression group and an NR3C1 low-expression group and compared the baseline characteristics of the two groups. Second, we used multivariate analysis to predict the dependent variable for age, pathology, ECOG score, lactate dehydrogenase (LDH) ratio, and NR3C1 expression level. Finally, we analyzed the progression-free survival (PFS) and overall survival rate (OS) of DLBCL patients with high or low NR3C1 expression. Results: DLBCL patients with high NR3C1 expression had a better prognosis than those with low NR3C1 expression (OS, P < 0.0001). In DLBCL patients of CHOP therapy, high NR3C1 expression was associated with a good survival prognosis in OS (OS, P = 0.028). Conclusion: In multivariate analysis, NR3C1 high expression was an independent prognostic factor that predicted a longer OS of DLBCL (OS, P = 0.0003). NR3C1 is considered an independent predictor of DLBCL patients and can be used as a biomarker for the prognosis of DLBCL.

PPARG dysregulation as a potential molecular target in adrenal Cushing's syndrome

Background

We performed a transcriptomic analysis of adrenal signaling pathways in various forms of endogenous Cushing's syndrome (CS) to define areas of dysregulated and druggable targets.

Methodology

Next-generation sequencing was performed on adrenal samples of patients with primary bilateral macronodular adrenal hyperplasia (PBMAH, n=10) and control adrenal samples (n=8). The validation groups included cortisol-producing adenoma (CPA, n=9) and samples from patients undergoing bilateral adrenalectomy for Cushing's disease (BADX-CD, n=8). In vivo findings were further characterized using three adrenocortical cell-lines (NCI-H295R, CU-ACC2, MUC1).

Results

Pathway mapping based on significant expression patterns identified PPARG (peroxisome proliferator-activated receptor gamma) pathway as the top hit. Quantitative PCR (QPCR) confirmed that PPARG (l2fc<-1.5) and related genes - FABP4 (l2fc<-5.5), PLIN1 (l2fc<-4.1) and ADIPOQ (l2fc<-3.3) - were significantly downregulated (p<0.005) in PBMAH. Significant downregulation of PPARG was also found in BADX-CD (l2fc<-1.9, p<0.0001) and CPA (l2fc<-1.4, p<0.0001). In vitro studies demonstrated that the PPARG activator rosiglitazone resulted in decreased cell viability in MUC1 and NCI-H295R (p<0.0001). There was also a significant reduction in the production of aldosterone, cortisol, and cortisone in NCI-H295R and in Dihydrotestosterone (DHT) in MUC1 (p<0.05), respectively.

Outcome

This therapeutic effect was independent of the actions of ACTH, postulating a promising application of PPARG activation in endogenous hypercortisolism.

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.

Comprehensive bioinformatics analysis combined with experimental validation to screen biomarkers for malignant transformation of oral leukoplakia

Oral leukoplakia (OLK) is the most common potentially malignant disorders in the oral cavity. This study aimed to screen the key genes of OLK malignant transformation using the Gene Expression Omnibus (GEO) database and experiments. In this study, the GEO database was employed to screen OLK malignant transformation-related genes, which were subsequently identified with a series of bioinformatic analyses. External validation showed that the model based on LAPTM4B, NR3C1, and COX6A1 had high accuracy in diagnosing OLK malignant transformation. Furthermore, the DMBA-induced potentially malignant disorders and OSCC models in vivo and real-time PCR experiment in vitro further verified the database analysis results. In conclusion, three key genes (LAPTM4B, NR3C1, and COX6A1) were screened as potential biomarkers for the diagnosis and treatment of OLK malignant transformation.

Early transcriptomic response of mouse adrenal gland and Y-1 cells to dexamethasone

Glucocorticoids have short- and long-term effects on adrenal gland function and development. RNA sequencing (RNA-seq) was performed to identify early transcriptomic responses to the synthetic glucocorticoid, dexamethasone (Dex), in vitro and in vivo. In total, 1711 genes were differentially expressed in the adrenal glands of the 1-h Dex-treated mice. Among them, only 113 were also considered differentially expressed genes (DEGs) in murine adrenocortical Y-1 cells treated with Dex for 1 h. Gene ontology analysis showed that the upregulated DEGs in the adrenal gland of the 1-h Dex-treated mice were highly associated with the development of neuronal cells, suggesting the adrenal medulla had a rapid response to Dex. Interestingly, only 4.3% of Dex-responsive genes in the Y-1 cell line under Dex treatment for 1 h were differentially expressed under Dex treatment for 24 h. The heatmaps revealed that most early responsive DEGs in Y-1 cells during 1 h of treatment exhibited a transient response. The expression of these genes under treatment for 24 h returned to basal levels similar to that during control treatment. In summary, this research compared the rapid transcriptomic effects of Dex stimulation in vivo and in vitro. Notably, adrenocortical Y-1 cells had a transient early response to Dex treatment. Furthermore, the DEGs had a minimal overlap in the 1-h Dex-treated group in vivo and in vitro.

Expression of glucocorticoid receptor (GR) and clinical significance in adrenocortical carcinoma

Adrenocortical carcinoma (ACC) is a rare endocrine tumor, and most cases present with hormone excess with poor prognosis. Our research aims to determine the clinical and biological significance of glucocorticoid receptor (GR) expression using large cohorts of ACC patients. Immunohistochemistry was used to assess the expression of GR in 78 ACC cases from the West China Hospital (WCH) cohort. RNA-seq data were retrieved from The Cancer Genome Atlas database (TCGA, n=79). Clinicopathological and follow-up data were obtained from two cohorts. The correlation between the GR gene and tumor immune status was estimated using TIMER and GEPIA2. Kaplan-Meier analysis was performed to identify the prognostic value of GR in ACC. In the WCH cohort, positive nuclear GR staining was identified in 90% of the primary ACC cases. Cortisol-secreting ACCs demonstrated significantly lower GR protein expression than did nonfunctioning tumors (P<0.001). This finding was validated by the mRNA data analysis of the TCGA cohort (P = 0.030). GR expression was found to be positively correlated with the immune cell infiltration level and immune-checkpoint-related gene expression in ACC. Survival comparison and multivariate analysis showed that GR expression is an independent prognostic predictor of disease-free survival and overall survival in ACC patients in both cohorts. Our findings suggest that low GR expression is significantly correlated with excess cortisol, immune signatures and poor survival in ACC patients. We propose that GR signaling may play an important role in ACC behavior and thus may be a therapeutic target, which deserves further research.

Significant prevalence of NR3C1 mutations in incidentally discovered bilateral adrenal hyperplasia: results of the French MUTA-GR Study

BACKGROUND

Recently discovered mutations of NR3C1 gene, encoding for the GR, in patients with glucocorticoid resistance and bilateral adrenal incidentalomas prompted us to investigate whether GR mutations might be associated with adrenal hyperplasia.

OBJECTIVE

The multicenter French Clinical Research Program (Muta-GR) was set up to determine the prevalence of GR mutations and polymorphisms in patients harboring bilateral adrenal incidentalomas associated with hypertension and/or biological hypercortisolism without clinical Cushing's signs.

RESULTS

One hundred patients were included in whom NR3C1 sequencing revealed five original heterozygous GR mutations that impaired GR signaling in vitro. Mutated patients presented with mild glucocorticoid resistance defined as elevated urinary free cortisol (1.7 ± 0.7 vs 0.9 ± 0.8 upper limit of normal range, P = 0.006), incomplete 1 mg dexamethasone suppression test without suppressed 8-AM adrenocorticotrophin levels (30.9 ± 31.2 vs 16.2 ± 17.5 pg/mL) compared to the non-mutated patients. Potassium and aldosterone levels were lower in mutated patients (3.6 ± 0.2 vs 4.1 ± 0.5 mmol/L, P = 0.01, and 17.3 ± 9.9 vs 98.6 ± 115.4 pg/mL, P = 0.0011, respectively) without elevated renin levels, consistent with pseudohypermineralocorticism. Ex vivo characterization of mutated patients' fibroblasts demonstrated GR haploinsufficiency as revealed by below-normal glucocorticoid induction of FKBP5 gene expression. There was no association between GR polymorphisms and adrenal hyperplasia in this cohort, except an over-representation of BclI polymorphism.

CONCLUSION

The 5% prevalence of heterozygous NR3C1 mutations discovered in our series is higher than initially thought and encourages GR mutation screening in patients with adrenal incidentalomas to unambiguously differentiate from Cushing's states and to optimize personalized follow-up.

Functional polymorphisms in NR3C1 are associated with gastric cancer risk in Chinese population

Recently promoter of NR3C1 has been found to be high methylated in gastric cancer tissues which might be involved in the initiation of gastric carcinoma development. To test whether the variants in NR3C1 could modify the risk of gastric cancer, we evaluated the association between four SNPs (rs6194, rs12521436, rs33388 and rs4912913) in NR3C1 and gastric cancer risk in a case-control study with 1,113 gastric cancer cases and 1,848 cancer-free controls in a Chinese population. We found a significant association between rs4912913 and gastric cancer risk (OR=1.18, 95%CI=1.05-1.33, P=5.49×10-3). We also observed that the A-allele of rs12521436 and rs33388 were significantly associated with a decreased risk of gastric cancer (OR=0.84, 95%CI=0.76-0.94, P=2.78×10-3; OR=0.85, 95%CI=0.75-0.97; P=0.018). Finally, we made a joint effect analysis of rs12521436, rs33388 and rs4912913 on risk of gastric cancer (PTrend =2.83×10-5). These findings indicate that the variants rs4912913, rs33388 and rs12521436 of NR3C1 may contribute to gastric cancer susceptibility.

Long noncoding RNA profiles of adrenocortical cancer can be used to predict recurrence

Adrenocortical carcinoma (ACC) is an aggressive malignancy with high rates of recurrence following surgical resection. Long noncoding RNAs (lncRNAs) play an important role in cancer development. Pathogenesis of adrenal tumours have been characterised by mRNA, microRNA and methylation expression signatures, but it is unknown if this extends to lncRNAs. This study describes lncRNA expression signatures in ACC, adrenal cortical adenoma (ACA) and normal adrenal cortex (NAC) and presents lncRNAs associated with ACC recurrence to identify novel prognostic and therapeutic targets. RNA was extracted from freshly frozen tissue with confirmation of diagnosis by histopathology. Focused lncRNA and mRNA transcriptome analysis was performed using the ArrayStar Human LncRNA V3.0 microarray. Differentially expressed lncRNAs were validated using quantitative reverse transcriptase-PCR and correlated with clinical outcomes. Microarray of 21 samples (ten ACCs, five ACAs and six NACs) showed distinct patterns of lncRNA expression between each group. A total of 956 lncRNAs were differentially expressed between ACC and NAC, including known carcinogenesis-related lncRNAs such as H19, GAS5, MALAT1 and PRINS (P≤0.05); 85 lncRNAs were differentially expressed between ACC and ACA (P≤0.05). Hierarchical clustering and heat mapping showed ACC samples correctly grouped compared with NAC and ACA. Sixty-six differentially expressed lncRNAs were found to be associated with ACC recurrence (P≤0.05), one of which, PRINS, was validated in a group of 20 ACCs and also found to be associated with metastatic disease on presentation. The pathogenesis of adrenal tumours extends to lncRNA dysregulation and low expression of the lncRNA PRINS is associated with ACC recurrence.

Intrafollicular cortisol levels inversely correlate with cumulus cell lipid content as a possible energy source during oocyte meiotic resumption in women undergoing ovarian stimulation for in vitro fertilization

OBJECTIVE

To determine whether follicular fluid (FF) cortisol levels affect cumulus cell (CC) lipid content during oocyte meiotic resumption, and whether CCs express genes for glucocorticoid action.

DESIGN

Prospective cohort study.

SETTING

Academic medical center.

PATIENT(S)

Thirty-seven nonobese women underwent ovarian stimulation for in vitro fertilization (IVF).

INTERVENTION(S)

At oocyte retrieval, FF was aspirated from the first follicle (>16 mm in size) of each ovary and pooled CCs were collected.

MAIN OUTCOME MEASURE(S)

Follicular fluid cortisol and cortisone analysis was performed with the use of liquid chromatography-tandem mass spectrometry. CCs were stained with lipid fluorescent dye Bodipy FL C16 to determine lipid content with the use of confocal microscopy. Quantitative real-time polymerase chain reaction was used to detect CC gene expression of 11β-hydroxysteroid dehydrogenase (11β-HSD) types 1 and 2, glucocorticoid receptor (NR3C1), lipoprotein lipase (LPL), and hormone-sensitive lipase (HSL).

RESULT(S)

Adjusting for maternal age, FF cortisol levels negatively correlated with CC lipid content and positively correlated with numbers of total and mature oocytes. CCs expressed genes for 11β-HSD type 1 as the predominant 11β-HSD isoform, NR3C1, LPL, and HSL.

CONCLUSION(S)

FF cortisol levels may regulate CC lipolysis during oocyte meiotic resumption and affect oocyte quality during IVF.

Changes in plasma ACTH levels and corticotroph tumor size in patients with Cushing's disease during long-term treatment with the glucocorticoid receptor antagonist mifepristone

CONTEXT

Pituitary effects of long-term therapy with mifepristone, a glucocorticoid receptor antagonist, in Cushing's disease (CD) patients are not well understood.

OBJECTIVE

Our objective was to report changes in ACTH and pituitary magnetic resonance imaging (MRI) findings during long-term use of mifepristone in CD patients.

DESIGN AND SETTING

The Study of the Efficacy and Safety of Mifepristone in the Treatment of Endogenous Cushing's Syndrome (SEISMIC) was a 24-week, open-label study of mifepristone, and its long-term extension (LTE) is a multicenter U.S. study.

PATIENTS

Forty-three CD patients (mean age 45.3 years) were enrolled in SEISMIC with 27 continuing into the LTE study.

INTERVENTIONS

Mifepristone (300-1200 mg) was administered once daily.

MAIN OUTCOME MEASURES

ACTH and pituitary MRI were assessed at baseline and at regular intervals during treatment.

RESULTS

A ≥2-fold increase in ACTH was observed in 72% of patients treated for a median duration of 11.3 months. The mean peak increase in ACTH was 2.76 ± 1.65-fold during SEISMIC, and mean ACTH concentrations remained stable during the LTE. ACTH was directly correlated with mifepristone dose and declined to near baseline levels after mifepristone discontinuation. Tumor regressed in 2 patients and progressed in 3 patients with macroadenomas. An additional microadenoma was identified after 25 months of treatment after a baseline tumor-negative MRI.

CONCLUSIONS

In the largest prospective study to date, long-term mifepristone treatment increased ACTH in approximately two-thirds of patients with CD. ACTH elevations were observed within the first few weeks of treatment, were dose-dependent, and generally remained stable over time. Corticotroph tumor progression and regression may occur over time, but patients may have significant increases in ACTH levels without evidence of tumor growth.

Autocrine positive regulatory feedback of glucocorticoid secretion: glucocorticoid receptor directly impacts H295R human adrenocortical cell function

Glucocorticoid receptor (GR), a ubiquitous transcriptional factor, regulates target gene expression upon activation by glucocorticoids, notably cortisol, a corticosteroid hormone synthesized in the adrenal cortex. We thus hypothesized that both GR and cortisol might be involved in the regulation of adrenal physiology and steroidogenesis in an autocrine manner. In a cortisol-secreting human adrenocortical cell line (H295R), the GR-dependent signaling pathway was pharmacologically modulated either by dexamethasone (DEX), a GR agonist or by RU486, a GR antagonist, or was knocked-down by small interfering RNA strategy (SiRNA). We showed that GR activation, elicited by 48 h exposure to DEX, exerts a global positive regulatory effect on adrenal steroidogenesis as revealed by a 1.5- to 2-fold increase in cortisol, 11-deoxycortisol and 17-hydroxyprogesterone secretion associated with a significant enhanced expression of steroidogenesis factors such as StAR, CYP11A1, CYP21A2 and CYP11B1. In sharp contrast, RU486 treatment exerted opposite effects by decreasing both steroid production and expression of these steroidogenic factors. Likewise, GR repression by SiRNA also significantly reduced StAR, CYP11A1, and CYP11B1 mRNA levels. Interestingly, RU486 resulted in a significant CYP21A2 enzymatic blockade as demonstrated by a massive increase in 17-hydroxyprogesterone concentrations in RU486-treated H295R cell supernatants, while cortisol and 11-deoxycortisol secretions were reduced by more than 60%. Consistently, we also demonstrated that metabolic conversion of 17-hydroxyprogesterone into 11-deoxycortisol onto H295R cells was drastically blunted in the presence of RU 486. Finally, steady state levels of MC2R transcripts encoding for the ACTH receptor were significantly induced by DEX, unlikely through a direct GR-mediated transcriptional activation as opposed to CYP11A1 and FKBP5 target genes. These results could account for a higher glucocorticoid-elicited ACTH sensitivity of adrenocortical cells. Our study identifies a positive ultra-short regulatory loop exerted by GR on steroidogenesis in H295R cells, thus supporting a complex intra-adrenal GR-mediated feedback, likely relevant for human adrenocortical pathologies.

Expression of angiogenesis-related genes in canine cortisol-secreting adrenocortical tumors

The aim of this study was to evaluate the expression of angiogenesis-related genes in canine cortisol-secreting adrenocortical tumors (ATs). Quantitative RT-PCR analysis revealed mRNA encoding for vascular endothelial growth factor, vascular endothelial growth factor receptors 1 and 2, angiopoietin 1 and 2 (ANGPT1 and ANGPT2), the splice variant ANGPT2443, the ANGPT-receptor Tie2, and basic fibroblast growth factor in 38 canine cortisol-secreting ATs (26 carcinomas and 12 adenomas) and 15 normal adrenals. The relative expression of both ANGPT2 and ANGPT2443 was higher in adenomas (P = 0.020 for ANGPT2 and P = 0.002 for ANGPT2443) and carcinomas (P = 0.003 for ANGPT2 and P < 0.001 for ANGPT2443) compared with normal adrenals, and this enhanced expression was also detected with Western blot analysis. Immunohistochemistry indicated expression of ANGPT2 protein in AT cells and in vascular endothelial cells of carcinomas, whereas Tie2 was mainly present in the tumor vascular endothelial cells. The ANGPT2-to-ANGTPT1 ratio, a marker for a proangiogenic state, was higher in both adenomas (P = 0.020) and carcinomas (P = 0.043). With the use of the human H295R cortisol-producing adrenocortical carcinoma cell line, we were able to demonstrate that the ANGPT2 expression was stimulated by cyclic adenosine monophosphate and progesterone but not by cortisol. In conclusion, canine cortisol-secreting ATs have enhanced ANGPT2 expression with a concomitant shift toward a proangiogenic state. On the basis of this information, treatment modalities may be developed that interfere with ANGPT2 expression, including inhibition of the cyclic adenosine monophosphate/protein kinase A pathway, or of the effect of ANGPT2, by using specific ANGPT2 inhibitors.

Autocrine/paracrine regulatory mechanisms in adrenocortical neoplasms responsible for primary adrenal hypercorticism

A wide variety of autocrine/paracrine bioactive signals are able to modulate corticosteroid secretion in the human adrenal gland. These regulatory factors, released in the vicinity of adrenocortical cells by diverse cell types comprising chromaffin cells, nerve terminals, cells of the immune system, endothelial cells, and adipocytes, include neuropeptides, biogenic amines, and cytokines. A growing body of evidence now suggests that paracrine mechanisms may also play an important role in the physiopathology of adrenocortical hyperplasias and tumors responsible for primary adrenal steroid excess. These intra-adrenal regulatory systems, although globally involving the same actors as those observed in the normal gland, display alterations at different levels, which reinforce the capacity of paracrine factors to stimulate the activity of adrenocortical cells. The main modifications in the adrenal local control systems reported by now include hyperplasia of cells producing the paracrine factors and abnormal expression of the latter and their receptors. Because steroid-secreting adrenal neoplasms are independent of the classical endocrine regulatory factors angiotensin II and ACTH, which are respectively suppressed by hyperaldosteronism and hypercortisolism, these lesions have long been considered as autonomous tissues. However, the presence of stimulatory substances within the neoplastic tissues suggests that steroid hypersecretion is driven by autocrine/paracrine loops that should be regarded as promising targets for pharmacological treatments of primary adrenal disorders. This new potential therapeutic approach may constitute an alternative to surgical removal of the lesions that is classically recommended in order to cure steroid excess.

Glucocorticoid receptor and molecular chaperones in the pathogenesis of adrenal incidentalomas: potential role of reduced sensitivity to glucocorticoids

Glucocorticoid (GC) sensitivity depends on glucocorticoid receptor (GR) and heat shock proteins (Hsps). We investigated whether common GR genes (ER22/23EK, N363S, Bcl I, and 9β) and adrenocorticotropin receptor promoter polymorphisms influence susceptibility for unilateral adrenal incidentaloma (AI), plus GR and Hsp expression in tumorous (n = 19), peritumorous (n = 13) and normal adrenocortical (n = 11) tissues. Patients (n = 112), population-matched controls (n = 100) and tumor tissues (n = 32) were genotyped for these polymorphisms. Postdexamethasone serum cortisol was higher in patients (p < 0.001). GR gene variants, larger allele of Bcl I (odds ratio [OR] 2.9; 95% confidence interval [CI] 1.7-5.1; p < 0.001] and minor allele of 9β (OR 3.0; 95% CI 1.6-5.7; p < 0.001) were independent predictors of AI. In patients, the first allele is linked with larger tumors (p = 0.002) and the latter with higher postdexamethasone cortisol levels (p = 0.025). Both allele carriers had lesser waist circumference (p = 0.02), similar adrenocorticotropin and higher basal (p = 0.024) and postdexamethasone cortisol concentrations (p < 0.001). Tumorous and constitutional genotypes were similar. GR-D is the major receptor isoform in normal adrenal cortex by Western blotting. Loss of other receptor isoforms, decrease in immunostaining for GR (p < 0.0001), underexpression of chaperones (p ≤ 0.01) and the presence of inducible Hsp70 were found in adenomas. In conclusion, GR gene variants, C allele of Bcl I and minor allele of 9β, are associated with AIs. Their concurrent presence in patients reduces GC sensitivity. Normal adrenal cortex preferentially expresses GR-D. In adenomas, the lack of other GR isoforms and underexpression of heat shock proteins perhaps permanently impair GC signaling, which could promote dysregulated cortisol production and tumor growth. The innate GC sensitivity probably modifies these effects.

The glucocorticoid receptor and its expression in the anterior pituitary and the adrenal cortex: a source of variation in hypothalamic-pituitary-adrenal axis function; implications for pituitary and adrenal tumors

OBJECTIVE

To review the expression of the glucocorticoid receptor (GR) in anterior pituitary and adrenocortical cells and tumors derived from these tissues as well as factors that may influence its expression.

METHODS

We present an overview of the relevant literature, with a focus on data generated from our studies.

RESULTS

The expression of the GR is an essential element of the negative feedback that closes the loop formed by corticotropin-releasing hormone, adrenocorticotropic hormone, and cortisol in the context of the hypothalamic-pituitary-adrenal (HPA) axis. Although the GR expression in anterior pituitary cells-and in particular the corticotrophs-was first demonstrated several years ago, it was not known until relatively recently where, by what cells, and in what form the GR is expressed in the adrenal cortex. The variability in the expression of the GR in pituitary and adrenocortical cells may underlie the substantial differences in HPA axis function across individuals, especially when testing for tumors associated with hypercortisolemia. This expression is influenced by a multitude of tissue-specific factors, which may explain why it is so difficult to interpret (or reproduce) studies that are based on GR functional polymorphisms on different cohorts of patients or even different sets of laboratory animals.

CONCLUSION

This review highlights the variability in expression and function of the GR in pituitary and adrenocortical cells as one of the reasons for the appreciable differences in HPA axis function across individuals. Particular attention was paid to interactions that may affect the interpretation of diagnostic testing of the HPA axis in patients with pituitary adenomas (Cushing disease) or adrenocortical tumors (Cushing syndrome).

Molecular markers of adrenocortical tumors

Adrenocortical tumors are common and incidentally discovered in up to 14% of axial imaging studies performed for other indications. Most of these tumors are nonfunctioning but may require removal because of the risk of adrenocortical carcinoma. Unfortunately, most clinical and imaging features are still not accurate enough to allow definitive diagnosis and an increasing number of patients undergo adrenalectomy to exclude a cancer diagnosis. Adrenocortical carcinoma is an aggressive malignancy with no effective therapy for patients with locally advanced and metastatic disease. Studies using new genomic approaches including mRNA, miRNA, methylation, and CGH profiling have identified dysregulated genes and pathways that may have clinical implications in improved molecular diagnosis and prognostication of adrenocortical cancer (ACC). In this review, we highlight recent advances in the molecular diagnosis of adrenocortical tumors.

Toward a pathway-centered approach for the treatment of adrenocortical carcinoma

PURPOSE OF REVIEW

Adrenocortical carcinoma is an aggressive, lethal malignancy of the adrenal cortex. The rarity of the disease has stymied therapeutic development. Recent work toward understanding the molecular pathogenesis of the disease has identified several potential new diagnostic and therapeutic targets.

RECENT FINDINGS

The molecular characterization of adrenocortical carcinoma has identified dysregulation of the Gap 2/mitosis transition and the insulin-like growth factor 1 receptor signaling cascade as two major pathways for therapeutic development. These studies have also highlighted an unappreciated heterogeneity of the disease at the gene level that nevertheless seems to converge onto common cellular pathways. Additionally, the characterization of Wnt signaling through β-catenin in adrenal development, the demonstration of the involvement of BMP signaling in adrenocortical carcinoma growth regulation, and the discovery that ERCC1 expression levels can predict therapeutic response to platinum are just a few of the recent advances that promise to shed light on adrenocortical carcinoma biology.

SUMMARY

Short-term, therapeutic development should target the Gap 2/mitosis transition and the downstream signaling of the insulin-like growth factor 1 receptor receptor. Long-term, additional characterization of patient samples, particularly at the sequence level, is required to fully understand adrenocortical carcinoma biology and apply that knowledge to clinical practice.

Expression of the glucocorticoid receptor in renal cell neoplasms: an immunohistochemical and quantitative reverse transcriptase polymerase chain reaction study

Glucocorticoid receptors mediate the action of steroid hormones in a variety of tissues, including the kidney. Our goal was to determine the expression pattern and prognostic significance of glucocorticoid receptor in renal cell neoplasms. Paraffin-embedded microarrays from 200 patients with RCNs including 147 clear cell renal cell carcinomas, 23 papillary, 16 chromophobe renal cell carcinoma, and 14 oncocytomas were analyzed for glucocorticoid receptor expression by immunohistochemistry. Glucocorticoid receptor expression was also quantitated by real-time reverse transcriptase polymerase chain reaction in 45 cases (33 clear cell renal cell carcinomas, 5 chromophobe renal cell carcinomas, and 3 oncocytomas). Strong nuclear glucocorticoid receptor expression was present in normal glomeruli and in the proximal convoluted tubules. Nuclear glucocorticoid receptor expression was found in most clear cell renal cell carcinomas (66%), in 26% of papillary renal cell carcinomas, and in only 6% of chromophobe renal cell carcinomas and 14% of oncocytoma (P < .005). Within the clear cell renal cell carcinoma group, most positive cases (87%) demonstrated strong immunoreactivity (2+ and 3+), whereas only 1 papillary renal cell carcinoma, 1 chromophobe renal cell carcinoma, and none of the oncocytomas showed strong expression. Glucocorticoid receptor α messenger RNA expression was significantly higher in clear cell renal cell carcinoma than in chromophobe renal cell carcinoma, oncocytoma, or in the normal kidney. Significantly more frequent glucocorticoid receptor expression was associated with tumors of low nuclear grade (Fuhrman grade 1 and 2) and low stage (stages 1 and 2; P = .0068 and P = .0002). Survival analysis revealed a significant direct correlation between glucocorticoid receptor expression and overall survival in clear cell renal cell carcinoma (P = .01). In summary, strong glucocorticoid receptor expression was most commonly seen in clear cell renal cell carcinoma and only rarely seen in other subtypes. The glucocorticoid receptor expression pattern in RCNs seems to reflect the histogenetic origin of clear cell renal cell carcinoma from the proximal nephron. Finally, glucocorticoid receptor expression proved to be a marker of less aggressive behavior in clear cell renal cell carcinoma.

Gene expression profiles in aldosterone-producing adenomas and adjacent adrenal glands

BACKGROUND

Primary aldosteronism (PA) is the most common form of endocrine hypertension affecting ∼8-10% of hypertensive subjects. Aldosterone production in PA occurs under low-renin conditions, and the mechanisms that maintain the production of aldosterone in PA remain unknown. Objective This study was designed to compare the transcript profiles between aldosterone-producing adenoma (APA) and their adjacent adrenal gland (AAG) from the same adrenal.

METHODS

Total RNA was extracted from ten APA and ten AAG; and subsequently analyzed by microarray and real-time quantitative RT-PCR (qPCR). The microarray data were paired for each APA-AAG, and analyzed by GeneSpring GX 11 with paired t-test and fold change calculations for each transcript. Changes identified by microarray analysis were confirmed by qPCR.

RESULTS

Microarray analysis indicated that 14 genes had significantly up-regulated expression in APA compared to AAG. Among the elevated genes were aldosterone synthase (CYP11B2) as well as novel transcription factors, calmodulin-binding proteins, and other genes that have not been previously studied in APA. Selective analysis of 11 steroidogenic enzymes using microarray demonstrated that only CYP11B2 showed a significantly higher transcript level in APA compared to AAG (P<0.001). In contrast, AKR1C3 (17β-hydroxysteroid dehydrogenase type 5), CYP17 (17α-hydroxylase/17,20 lyase), and CYB5 (cytochrome b5) showed significantly lower transcript level in APA (P<0.05).

CONCLUSION

The transcriptome analysis of APA compared with AAG showed several novel genes that are associated with APA phenotype. This gene list provides new candidates for the elucidation of the molecular mechanisms leading to PA.