Defects in AMPAR trafficking and microglia activation underlie socio-cognitive deficits associated to decreased expression of phosphodiesterase 2 a.

Phosphodiesterase 2 A (PDE2A) is an enzyme involved in the homeostasis of cAMP and cGMP and is the most highly expressed PDE in human brain regions critical for socio-cognitive behavior. In cerebral cortex and hippocampus, PDE2A expression level is upregulated in Fmr1-KO mice, a model of the Fragile X Syndrome (FXS), the most common form of inherited intellectual disability (ID) and autism spectrum disorder (ASD). Indeed, PDE2A translation is negatively modulated by FMRP, whose functional absence causes FXS. While the pharmacological inhibition of PDE2A has been associated to its pro-cognitive role in normal animals and in models of ID and ASD, homozygous PDE2A mutations have been identified in patients affected by ID, ASD and epilepsy. To clarify this apparent paradox about the role of PDE2A in brain development, we characterized here Pde2a+/- mice (homozygote animals being not viable) at the behavioral, cellular, molecular and electrophysiological levels. Pde2a+/- females display a milder form of the disorder with reduced cognitive performance in adulthood, conversely males show severe socio-cognitive deficits throughout their life. In males, these phenotypes are associated with microglia activation, elevated glutathione levels and increased externalization of Glutamate receptor (GluR1) in CA1, producing reduced mGluR-dependent Long-term Depression. Overall, our results reveal molecular targets of the PDE2A-dependent pathway underlying socio-cognitive performance. These results clarify the mechanism of action of pro-cognitive drugs based on PDE2A inactivation, which have been shown to be promising therapeutic approaches for Alzheimer's disease, schizophrenia, FXS as well as other forms of ASD.

A reappraisal of transcriptional regulation by NR5A1 and beta-catenin in adrenocortical carcinoma.

Background: Overexpression of the transcription factor NR5A1 and constitutive activation of canonical Wnt signalling leading to nuclear translocation of beta-catenin are hallmarks of malignancy in adrenocortical carcinoma (ACC). Based on the analysis of genomic profiles in H295R ACC cells, Mohan et al. (Cancer Res. 2023; 83: 2123-2141) recently suggested that a major determinant driving proliferation and differentiation in malignant ACC is the interaction of NR5A1 and beta-catenin on chromatin to regulate gene expression. Methods: I reanalyzed the same set of data generated by Mohan et al. and other published data of knockdown-validated NR5A1 and beta-catenin target genes. Results: Beta-catenin is mainly found in association to canonical T cell factor/lymphoid enhancer factor (TCF/LEF) motifs in genomic DNA. NR5A1 and beta-catenin regulate distinct target gene sets in ACC cells. Conclusion: Overall, my analysis suggests a model where NR5A1 overexpression and beta-catenin activation principally act independently, rather than functionally interacting, to drive ACC malignancy.

ACTH and prolactin synergistically and selectively regulate CYP17 expression and adrenal androgen production in human foetal adrenal organ cultures.

OBJECTIVE: The essential role of ACTH on the growth and function of the human foetal adrenal (HFA) has long been recognized. In addition, many studies have suggested a role of the pituitary hormone prolactin (PRL) in the regulation of the HFA, but the effects of this hormone on steroidogenesis and gene expression are still unknown. Our objective was to investigate the effect of ACTH and PRL on the steroidogenic capacities of the HFA. DESIGN: In vitro/ex vivo experimental study. METHODS: We used a hanging drop in vitro organ culture system. First trimester HFA samples were cultured for 14 days in basal conditions or treated with ACTH, PRL, or a combination of the 2 (3 to 11 replicates depending on the experiment). Steroids were measured by liquid chromatography/tandem mass spectrometry or immunoassay, gene expression by RT-qPCR, and protein expression by immunoblot. RESULTS: ACTH significantly increased corticosterone, cortisol, and cortisone production, both by itself and when used together with PRL. PRL stimulation by itself had no effect. Combined stimulation with ACTH + PRL synergistically and selectively increased adrenal androgen (DHEAS and Δ4-androstenedione) production and CYP17A1 expression in the HFA, while treatment with each single hormone had no significant effect on those steroids. CONCLUSIONS: These results have important implications for our understanding of the hormonal cues regulating adrenal steroidogenesis in the HFA during the first trimester in physiological and pathological conditions and warrant further studies to characterize the molecular mechanisms of converging ACTH and PRL signalling to regulate CYP17A1 expression.

Complex and pleiotropic signaling pathways regulated by the secreted protein augurin.

The secreted protein augurin, the product of the tumor suppressor gene Ecrg4, has been identified as a peptide hormone in the human proteome in 2007. Since then, a number of studies have been carried out to highlight its structure and processing and its potential roles in physiopathology. Although augurin has been shown to be implicated in a variety of processes, ranging from tumorigenesis, inflammation and infection to neural stem cell proliferation, hypothalamo-pituitary adrenal axis regulation and osteoblast differentiation, the molecular mechanisms of its biological effects and the signaling pathways it regulates are still poorly characterized. Here we provide a comprehensive overview of augurin-dependent signal transduction pathways. Because of their secreted nature and the potential to be manipulated pharmacologically, augurin and its derived peptides represent attractive targets for diagnostic development and discovery of new therapeutic agents for the human diseases resulting from the deregulation of the signaling cascades they modulate. From this perspective, the characterization of the precise nature of augurin derived peptides and the identification of the receptor(s) on the cell surface conveying augurin signaling to downstream effectors are crucial to develop agonists and antagonists for this protein. Video abstract.

FSCN1 as a new druggable target in adrenocortical carcinoma.

Adrenocortical carcinoma (ACC) is a rare endocrine malignancy with a high risk of relapse and metastatic spread. The actin-bundling protein fascin (FSCN1) is overexpressed in aggressive ACC and represents a reliable prognostic indicator. FSCN1 has been shown to synergize with VAV2, a guanine nucleotide exchange factor for the Rho/Rac GTPase family, to enhance the invasion properties of ACC cancer cells. Based on those results, we investigated the effects of FSCN1 inactivation by CRISPR/Cas9 or pharmacological blockade on the invasive properties of ACC cells, both in vitro and in an in vivo metastatic ACC zebrafish model. Here, we showed that FSCN1 is a transcriptional target for ß-catenin in H295R ACC cells and that its inactivation resulted in defects in cell attachment and proliferation. FSCN1 knock-out modulated the expression of genes involved in cytoskeleton dynamics and cell adhesion. When Steroidogenic Factor-1 (SF-1) dosage was upregulated in H295R cells, activating their invasive capacities, FSCN1 knock-out reduced the number of filopodia, lamellipodia/ruffles and focal adhesions, while decreasing cell invasion in Matrigel. Similar effects were produced by the FSCN1 inhibitor G2-044, which also diminished the invasion of other ACC cell lines expressing lower levels of FSCN1 than H295R. In the zebrafish model, metastases formation was significantly reduced in FSCN1 knock-out cells and G2-044 significantly reduced the number of metastases formed by ACC cells. Our results indicate that FSCN1 is a new druggable target for ACC and provide the rationale for future clinical trials with FSCN1 inhibitors in patients with ACC.

Steroidogenic Factor 1, a Goldilocks Transcription Factor from Adrenocortical Organogenesis to Malignancy.

Steroidogenic factor-1 (SF-1, also termed Ad4BP; NR5A1 in the official nomenclature) is a nuclear receptor transcription factor that plays a crucial role in the regulation of adrenal and gonadal development, function and maintenance. In addition to its classical role in regulating the expression of P450 steroid hydroxylases and other steroidogenic genes, involvement in other key processes such as cell survival/proliferation and cytoskeleton dynamics have also been highlighted for SF-1. SF-1 has a restricted pattern of expression, being expressed along the hypothalamic-pituitary axis and in steroidogenic organs since the time of their establishment. Reduced SF-1 expression affects proper gonadal and adrenal organogenesis and function. On the other hand, SF-1 overexpression is found in adrenocortical carcinoma and represents a prognostic marker for patients' survival. This review is focused on the current knowledge about SF-1 and the crucial importance of its dosage for adrenal gland development and function, from its involvement in adrenal cortex formation to tumorigenesis. Overall, data converge towards SF-1 being a key player in the complex network of transcriptional regulation within the adrenal gland in a dosage-dependent manner.

Prolactin as an adrenocorticotropic hormone: Prolactin signalling is a conserved key regulator of sexually dimorphic adrenal gland function in health and disease.

A large number of previous reports described an effect of the pituitary hormone prolactin (PRL) on steroid hormone production by the adrenal cortex. However, those studies remained anecdotal and were never converted into a conceptual and mechanistic framework, let alone being translated into clinical care. In the light of our recently published landmark study where we described PRL signalling as a pivotal regulator of the sexually dimorphic adrenal phenotype in mouse and of adrenal androgen production in humans, we present here the overarching hypothesis that PRL signalling increases the activity of Steroidogenic Factor-1 (SF-1/NR5A1), a transcription factor that has an essential role in adrenal gland development and function, to regulate adrenal cortex growth and hormonal production in physiological and pathological conditions. PRL can then be considered as a bona fide adrenocorticotropic hormone synergizing with ACTH in the endocrine control of adrenal cortex function.

Environmental Contaminants Modulate Breast Cancer Development and Outcome in TP53 p.R337H Carriers and Noncarriers.

Two major concerns associated with cancer development in Paraná state, South Brazil, are environmental pollution and the germline TP53 p.R337H variant found in 0.27−0.30% of the population. We assessed breast cancer (BC) risk in rural (C1 and C2) and industrialized (C3) subregions, previously classified by geochemistry, agricultural productivity, and population density. C2 presents lower organochloride levels in rivers and lower agricultural outputs than C1, and lower levels of chlorine anions in rivers and lower industrial activities than C3. TP53 p.R337H status was assessed in 4658 women aged >30 years from C1, C2, and C3, subsequent to a genetic screening (Group 1, longitudinal study). BC risk in this group was 4.58 times higher among TP53 p.R337H carriers. BC prevalence and risk were significantly lower in C2 compared to that in C3. Mortality rate and risk associated with BC in women aged >30 years (n = 8181 deceased women; Group 2) were also lower in C2 than those in C3 and C1. These results suggest that environmental factors modulate BC risk and outcome in carriers and noncarriers.

Mitotane treatment in adrenocortical carcinoma: mechanisms of action and predictive markers of response to therapy.

Adrenocortical carcinoma (ACC) is a rare malignancy with a high risk of recurrence even in cases with complete surgical tumor resection. Mitotane represents the cornerstone of the adjuvant therapy as well as the first line of medical treatment in advanced cases. However, evidence on mitotane efficacy is mostly based on retrospective studies and the use of mitotane continues to represent a clinical challenge. Mitotane causes selective damage to adrenocortical cells, causing an increase of cell apoptosis through a disruption of mitochondria and the induction of the endoplasmic reticulum stress. Different clinical and molecular markers predicting response to mitotane have been proposed with uncertain results. Attainment of mitotane plasma levels within the target range of 14 to 20 mg/L represent the strongest predictor of mitotane effectiveness both in adjuvant and advanced tumor setting. The occurrence of late recurrence after primary ACC diagnosis and changes in metabolic activity on FDG-PET are only weakly associated with mitotane response. Among the proposed molecular markers associated with mitotane efficacy, the investigation of the CYP2W1*6 and CYP2B6*6 single nucleotide polymorphisms appears to be currently the most promising predictive molecular markers of mitotane therapy. However, none of the evaluated markers has been validated for clinical use. In the era of precision medicine, a better insight into mitotane molecular mechanisms as well as the potential use in the daily clinical practice of clinical parameters and molecular markers predicting the individual response to mitotane are urgently needed.

'You cannot expect miracles to happen overnight': patience pays off when you wish to establish a new adrenocortical carcinoma cell line.

Growing attention is being paid to the association of adrenocortical carcinoma (ACC), a rare endocrine malignancy, to cancer predisposition syndromes caused by germline mutations in genes involved in the control of genome stability. Tumour cells with a defective DNA mismatch repair pathway have a high mutation burden, which results in the production of tumour-associated specific neoantigens and in an increase of the sensitivity to therapies that loosen the constraints of tumour attack by the immune system. The study by Landwehr et al. published in a recent issue of the European Journal of Endocrinology describes a patient with an aggressive ACC bearing a germline MUTYH mutation with loss of heterozygosity in the tumour and accumulation of 8-hydroxyguanine in its genomic DNA. The authors managed to establish a novel differentiated cell line from that tumour which bears the stigma of the defective DNA repair mechanism in its genome. The availability of this new cell model inside the expanding toolbox of the ACC cell lines will allow for novel experimental possibilities, in particular for the study of the tumour microenvironment and the response to immunotherapy.

The Common Germline TP53-R337H Mutation Is Hypomorphic and Confers Incomplete Penetrance and Late Tumor Onset in a Mouse Model.

The TP53-R337H founder mutation exists at a high frequency throughout southern Brazil and represents one of the most common germline TP53 mutations reported to date. It was identified in pediatric adrenocortical tumors in families with a low incidence of cancer. The R337H mutation has since been found in association with early-onset breast cancers and Li-Fraumeni syndrome (LFS). To study this variability in tumor susceptibility, we generated a knockin mutant p53 mouse model (R334H). Endogenous murine p53-R334H protein was naturally expressed at high levels in multiple tissues and was functionally compromised in a tissue- and stress-specific manner. Mutant p53-R334H mice developed tumors with long latency and incomplete penetrance, consistent with many human carriers being at a low but elevated risk for cancer. These findings suggest the involvement of additional cooperating genetic alterations when TP53-R337H occurs in the context of LFS, which has important implications for genetic counseling and long-term clinical follow-up. SIGNIFICANCE: A p53-R334H knockin mouse serves as an important model for studying the most common inherited germline TP53 mutation (R337H) that is associated with variable tumor susceptibility.

Targeting the cytoskeleton against metastatic dissemination.

Cancer is a pathology characterized by a loss or a perturbation of a number of typical features of normal cell behaviour. Indeed, the acquisition of an inappropriate migratory and invasive phenotype has been reported to be one of the hallmarks of cancer. The cytoskeleton is a complex dynamic network of highly ordered interlinking filaments playing a key role in the control of fundamental cellular processes, like cell shape maintenance, motility, division and intracellular transport. Moreover, deregulation of this complex machinery contributes to cancer progression and malignancy, enabling cells to acquire an invasive and metastatic phenotype. Metastasis accounts for 90% of death from patients affected by solid tumours, while an efficient prevention and suppression of metastatic disease still remains elusive. This results in the lack of effective therapeutic options currently available for patients with advanced disease. In this context, the cytoskeleton with its regulatory and structural proteins emerges as a novel and highly effective target to be exploited for a substantial therapeutic effort toward the development of specific anti-metastatic drugs. Here we provide an overview of the role of cytoskeleton components and interacting proteins in cancer metastasis with a special focus on small molecule compounds interfering with the actin cytoskeleton organization and function. The emerging involvement of microtubules and intermediate filaments in cancer metastasis is also reviewed.

From adrenarche to aging of adrenal zona reticularis: precocious female adrenopause onset.

OBJECTIVE: Adaptive changes in DHEA and sulfated-DHEA (DHEAS) production from adrenal zona reticularis (ZR) have been observed in normal and pathological conditions. Here we used three different cohorts to assess timing differences in DHEAS blood level changes and characterize the relationship between early blood DHEAS reduction and cell number changes in women ZR. MATERIALS AND METHODS: DHEAS plasma samples (n = 463) were analyzed in 166 healthy prepubertal girls before pubarche (<9 years) and 324 serum samples from 268 adult females (31.9-83.8 years) without conditions affecting steroidogenesis. Guided by DHEAS blood levels reduction rate, we selected the age range for ZR cell counting using DHEA/DHEAS and phosphatase and tensin homolog (PTEN), tumor suppressor and cell stress marker, immunostaining, and hematoxylin stained nuclei of 14 post-mortem adrenal glands. RESULTS: We confirmed that overweight girls exhibited higher and earlier DHEAS levels and no difference was found compared with the average European and South American girls with a similar body mass index (BMI). Adrenopause onset threshold (AOT) defined as DHEAS blood levels <2040 nmol/L was identified in >35% of the females >40 years old and associated with significantly reduced ZR cell number (based on PTEN and hematoxylin signals). ZR cell loss may in part account for lower DHEA/DHEAS expression, but most cells remain alive with lower DHEA/DHEAS biosynthesis. CONCLUSION: The timely relation between significant reduction of blood DHEAS levels and decreased ZR cell number at the beginning of the 40s suggests that adrenopause is an additional burden for a significant number of middle-aged women, and may become an emergent problem associated with further sex steroids reduction during the menopausal transition.

Astemizole Sensitizes Adrenocortical Carcinoma Cells to Doxorubicin by Inhibiting Patched Drug Efflux Activity.

Adrenocortical carcinoma (ACC) presents a high risk of relapse and metastases with outcomes not improving despite extensive research and new targeted therapies. We recently showed that the Hedgehog receptor Patched is expressed in ACC, where it strongly contributes to doxorubicin efflux and treatment resistance. Here, we report the identification of a new inhibitor of Patched drug efflux, the anti-histaminergic drug astemizole. We show that astemizole enhances the cytotoxic, proapoptotic, antiproliferative and anticlonogenic effects of doxorubicin on ACC cells at concentrations of astemizole or doxorubicin that are not effective by themselves. Our results suggest that a low concentration of astemizole sensitizes ACC cells to doxorubicin, which is a component of the standard treatment for ACC composed of etoposide, doxorubicin, cisplatin and mitotane (EDPM). Patched uses the proton motive force to efflux drugs. This makes its function specific to cancer cells, thereby avoiding toxicity issues that are commonly observed with inhibitors of ABC multidrug transporters. Our data provide strong evidence that the use of astemizole or a derivative in combination with EDPM could be a promising therapeutic option for ACC by increasing the treatment effectiveness at lower doses of EDPM, which would reduce the severe side effects of this regimen.

Cancer-testis Antigen FATE1 Expression in Adrenocortical Tumors Is Associated with A Pervasive Autoimmune Response and Is A Marker of Malignancy in Adult, but Not Children, ACC.

The SF-1 transcription factor target gene FATE1 encodes a cancer-testis antigen that has an important role in regulating apoptosis and response to chemotherapy in adrenocortical carcinoma (ACC) cells. Autoantibodies directed against FATE1 were previously detected in patients with hepatocellular carcinoma. In this study, we investigated the prevalence of circulating anti-FATE1 antibodies in pediatric and adult patients with adrenocortical tumors using three different methods (immunofluorescence, ELISA and Western blot). Our results show that a pervasive anti-FATE1 immune response is present in those patients. Furthermore, FATE1 expression is a robust prognostic indicator in adult patients with ACC and is associated with increased steroidogenic and decreased immune response gene expression. These data can open perspectives for novel strategies in ACC immunotherapy.

A common polymorphism in the retinoic acid pathway modifies adrenocortical carcinoma age-dependent incidence.

BACKGROUND: Genome-wide association studies (GWASs) have enriched the fields of genomics and drug development. Adrenocortical carcinoma (ACC) is a rare cancer with a bimodal age distribution and inadequate treatment options. Paediatric ACC is frequently associated with TP53 mutations, with particularly high incidence in Southern Brazil due to the TP53 p.R337H (R337H) germline mutation. The heterogeneous risk among carriers suggests other genetic modifiers could exist. METHODS: We analysed clinical, genotype and gene expression data derived from paediatric ACC, R337H carriers, and adult ACC patients. We restricted our analyses to single nucleotide polymorphisms (SNPs) previously identified in GWASs to associate with disease or human traits. RESULTS: A SNP, rs971074, in the alcohol dehydrogenase 7 gene significantly and reproducibly associated with allelic differences in ACC age-of-onset in both cohorts. Patients homozygous for the minor allele were diagnosed up to 16 years earlier. This SNP resides in a gene involved in the retinoic acid (RA) pathway and patients with differing levels of RA pathway gene expression in their tumours associate with differential ACC progression. CONCLUSIONS: These results identify a novel genetic component to ACC development that resides in the retinoic acid pathway, thereby informing strategies to develop management, preventive and therapeutic treatments for ACC.

Germline Variants in Phosphodiesterase Genes and Genetic Predisposition to Pediatric Adrenocortical Tumors.

Phosphodiesterases (PDEs) form a superfamily of enzymes that catalyze the hydrolysis of cyclic nucleotides adenosine 3'5'-cyclic monophosphate (cAMP) and guanosine 3'5'-cyclic monophosphate (cGMP) to their inactive 5' monophosphates. cAMP plays a critical role as a second messenger in endocrine tissues, and activation of cAMP signaling has been reported in endocrine tumors. Germline variants in PDEs have been associated with benign cortisol-secreting adrenocortical adenomas and testicular germ cell cancer but not adrenocortical carcinoma. We performed whole genome sequencing (WGS) and whole exome sequencing (WES) of paired blood and tumor samples from 37 pediatric adrenocortical tumors (ACTs). Germline inactivating variants in PDEs were observed in 9 of 37 (24%) patients. Tumor DNA analysis revealed loss of heterozygosity, with maintenance of the mutated allele in all cases. Our results suggest that germline variants in PDEs and other regulators of the cAMP-signaling pathway may contribute to pediatric adrenocortical tumorigenesis, perhaps by cooperating with germline hypomorphic mutant TP53 alleles and uniparental disomy of chromosome 11p15 (Beckwith-Wiedemann syndrome).