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

PDE9A polymorphism and association analysis with growth performance and gastrointestinal weight of Hu sheep

Phosphodiesterase 9A (PDE9A) plays a crucial role in activating the cGMP-dependent signaling pathway and may have important effects on the growth and development of the gastrointestinal tract in Hu sheep. In this study, we analyzed the single nucleotide polymorphisms of PDE9A in 988 Hu sheep and their correlation with growth performance, feed efficiency, and gastrointestinal development. Additionally, we examined the expression level of different PDE9A genotypes in the gastrointestinal tract of Hu sheep by using fluorescence quantitative PCR. The results revealed a moderate level of polymorphism (0.25 < PIC < 0.50) at the g.286248617 T > C mutation site located in the first intron of PDE9A in Hu sheep, with three genotypes: CC, CT, and TT. The weights of the omasum, colon, and cecum were significantly greater in the CC genotype than in the TT genotype (P < 0.05), and the expression level of PDE9A in the tissues of the rumen, ileum, cecum, and colon was notably lower in the CC genotype individuals (P < 0.05). These findings suggest that the polymorphism of PDE9A affects the weight of the stomach, colon, and cecum in Hu sheep through expression regulation. Overall, the results of this study suggest that the g.286248617 T > C mutation site in the first intron of PDE9A can serve as a potential molecular marker for breeding practices related to the gastrointestinal weight of Hu sheep.

Once upon a Testis: The Tale of Cyclic Nucleotide Phosphodiesterase in Testicular Cancers

Phosphodiesterases are key regulators that fine tune the intracellular levels of cyclic nucleotides, given their ability to hydrolyze cAMP and cGMP. They are critical regulators of cAMP/cGMP-mediated signaling pathways, modulating their downstream biological effects such as gene expression, cell proliferation, cell-cycle regulation but also inflammation and metabolic function. Recently, mutations in PDE genes have been identified and linked to human genetic diseases and PDEs have been demonstrated to play a potential role in predisposition to several tumors, especially in cAMP-sensitive tissues. This review summarizes the current knowledge and most relevant findings regarding the expression and regulation of PDE families in the testis focusing on PDEs role in testicular cancer development.

Retrospective Analysis of Prognostic Factors in Pediatric Patients with Adrenocortical Tumor from Unique Tertiary Center with Long-Term Follow-Up

Pediatric adrenocortical tumors (PACTs) represent rare causes of malignancies. However, the south/southeast regions of Brazil are known to have a high incidence of PACTs because of the founder effect associated with a germline pathogenic variant of tumor suppressor gene TP53. We aimed to retrospectively analyze the types of variables among hormone production, radiological imaging, tumor staging, histological and genetic features that were associated with the occurrence of malignancy in 95 patients (71% females) with PACTs from a unique center. The worst prognosis was associated with those aged > 3 years (p < 0.05), high serum levels of 11-desoxicortisol (p < 0.001), tumor weight ≥ 200 g (p < 0.001), tumor size ≥ 5 cm (p < 0.05), Weiss score ≥ 5 (p < 0.05), Wieneke index ≥ 3 (p < 0.001) and Ki67 ≥ 15% (p < 0.05). Furthermore, patients with MacFarlane stage IV had an overall survival rate almost two times shorter than patients with other stages (p < 0.001). Additionally, the subtractions of BUB1B-PINK1 (<6.95) expression (p < 0.05) and IGF-IR overexpression (p = 0.0001) were associated with malignant behavior. These results helped identify patients who are likely to have an aggressive course; further multicenter prospective studies are required to confirm our results. In conclusion, PACTs with these patterns of prognostic factors could be treated using an adjuvant approach that may improve the overall survival in such patients.

Functional characteristics and research trends of PDE11A in human diseases (Review)

cAMP and cGMP are important secondary messengers involved in cell regulation and metabolism driven by the G protein-coupled receptor. cAMP is converted via adenylyl cyclase (AC) and activates protein kinase A to phosphorylate intracellular proteins that mediate specific responses. cAMP signaling serves a role at multiple steps in tumorigenesis. The level of cAMP is increased in association with cancer cell formation through activation of AC-stimulatory G protein by mutation. Phosphodiesterases (PDEs) hydrolyze cAMP and cGMP to AMP and GMP. PDEs are composed of 11 families, and each can hydrolyze cAMP and cGMP or both cAMP and cGMP. PDEs perform various roles depending on their location and expression site, and are involved in several diseases, including male erectile dysfunction, pulmonary hypertension, Alzheimer's disease and schizophrenia. PDE11A is the 11th member of the PDE family and is characterized by four splice variants with varying tissue expression and N-terminal regulatory regions. Among tissues, the expression of PDE11A was highest in the prostate, and it was also expressed in hepatic skeletal muscle, pituitary, pancreas and kidney. PDE11A is the first PDE associated with an adrenocortical tumor associated genetic condition. In several studies, three PDE11A mutations have been reported in patients with Cushing syndrome with primary pigmented nodular adrenocortical disease or isolated micronodular adrenocortical disease without other genetic defects. It has been reported that an increase in PDE11A expression affects the proliferation of glioblastoma and worsens patient prognosis. The present mini-review summarizes the location of PDE11A expression, the impact of structural differences and disease relevance.

Molecular genotyping of adrenocortical carcinoma: a systematic analysis of published literature 2019-2021

PURPOSE OF REVIEW

comprehensive molecular characterization of adrenocortical carcinoma (ACC) through next-generation sequencing and bioinformatics analyses is expanding the number of targets with potential prognostic and therapeutic value. We performed a critical review of recent published literature on genotyping of ACC.

RECENT FINDINGS

423 studies were published between 2019 and 2021. After manual curation we summarized selected evidence in two thematic areas: germline deoxyribonucleic acid (DNA) variations, genomic alterations and prognosis.

SUMMARY

the evolving genomic landscape of ACC requires target validation in terms of prognostic and predictive value within scientific consortia. Although the existing multiple driver genes are difficult targets in the perspective of precision oncology, alterations in DNA damage repair genes or in promoter hypermethylation could open new venues for repurposing of existing drugs in ACC.

The cAMP-signaling cancers: Clinically-divergent disorders with a common central pathway

The cAMP-signaling cancers, which are defined by functionally-significant somatic mutations in one or more elements of the cAMP signaling pathway, have an unexpectedly wide range of cell origins, clinical manifestations, and potential therapeutic options. Mutations in at least 9 cAMP signaling pathway genes (TSHR, GPR101, GNAS, PDE8B, PDE11A, PRKARA1, PRKACA, PRKACB, and CREB) have been identified as driver mutations in human cancer. Although all cAMP-signaling pathway cancers are driven by mutation(s) that impinge on a single signaling pathway, the ultimate tumor phenotype reflects interactions between five critical variables: (1) the precise gene(s) that undergo mutation in each specific tumor type; (2) the effects of specific allele(s) in any given gene; (3) mutations in modifier genes (mutational "context"); (4) the tissue-specific expression of various cAMP signaling pathway elements in the tumor stem cell; and (5) and the precise biochemical regulation of the pathway components in tumor cells. These varying oncogenic mechanisms reveal novel and important targets for drug discovery. There is considerable diversity in the "druggability" of cAMP-signaling components, with some elements (GPCRs, cAMP-specific phosphodiesterases and kinases) appearing to be prime drug candidates, while other elements (transcription factors, protein-protein interactions) are currently refractory to robust drug-development efforts. Further refinement of the precise driver mutations in individual tumors will be essential for directing priorities in drug discovery efforts that target these mutations.

Prognostic and clinicopathological insights of phosphodiesterase 9A gene as novel biomarker in human colorectal cancer

BACKGROUND

PDE9A (Phosphodiesterase 9A) plays an important role in proliferation of cells, their differentiation and apoptosis via intracellular cGMP (cyclic guanosine monophosphate) signaling. The expression pattern of PDE9A is associated with diverse tumors and carcinomas. Therefore, PDE9A could be a prospective candidate as a therapeutic target in different types of carcinoma. The study presented here was designed to carry out the prognostic value as a biomarker of PDE9A in Colorectal cancer (CRC). The present study integrated several cancer databases with in-silico techniques to evaluate the cancer prognosis of CRC.

RESULTS

The analyses suggested that the expression of PDE9A was significantly down-regulated in CRC tissues than in normal tissues. Moreover, methylation in the DNA promoter region might also manipulate PDE9A gene expression. The Kaplan-Meier curves indicated that high level of expression of PDE9A gene was associated to higher survival in OS, RFS, and DSS in CRC patients. PDE9A demonstrated the highest positive correlation for rectal cancer recurrence with a marker gene CEACAM7. Furtheremore, PDE9A shared consolidated pathways with MAPK14 to induce survival autophagy in CRC cells and showed interaction with GUCY1A2 to drive CRPC.

CONCLUSIONS

Overall, the prognostic value of PDE9A gene could be used as a potential tumor biomarker for CRC.

Adrenocortical Carcinoma

Adrenocortical carcinoma (ACC) is an extremely rare disease, the incidence of which is 0 [...].

Clinical prognostic factors in pediatric adrenocortical tumors: A meta-analysis

Pediatric adrenocortical tumors (ACT) are rare and sometimes aggressive malignancies, but there is no consensus on the outcome predictors in children. A systematic search of MEDLINE, SCOPUS, Web of Science, and the Cochrane Library for studies from 1994 to 2020 about pediatric ACT was performed. In 42 studies, 1006 patients, aged 0-18 years, were included. The meta-analyses resulted in the following predictors of better outcome: age <4 years (P < .00001), nonsecreting tumors (P = .004), complete surgical resection (P < .00001), tumor volume (P < .0001), tumor weight (P < .00001), tumor maximum diameter (P = .0009), and Stage I disease (P < .00001). Moreover, patients affected by Cushing syndrome showed a worse outcome (P < .0001). International prospective studies should be implemented to standardize clinical prognostic factors evaluation, together with pathological scores, in the stratification of pediatric ACT.

Pde8b haploinsufficiency in mice is associated with modest adrenal defects, impaired steroidogenesis, and male infertility, unaltered by concurrent PKA or Wnt activation

PDE8B, PRKAR1A and the Wnt/β-catenin signaling are involved in endocrine disorders. However, how PDEB8B interacts with both Wnt and protein kinase A (PKA) signaling in vivo remains unknown. We created a novel Pde8b knockout mouse line (Pde8b-/-); Pde8b haploinsufficient (Pde8b+/-) mice were then crossed with mice harboring: (1) constitutive beta-catenin activation (Pde8b+/-;ΔCat) and (2) Prkar1a haploinsufficieny (Pde8b+/-;Prkar1a+/-). Adrenals and testes from mice (3-12-mo) were evaluated in addition to plasma corticosterone, aldosterone and Dkk3 concentrations, and the examination of expression of steroidogenesis-, Wnt- and cAMP/PKA-related genes. Pde8b-/- male mice were infertile with down-regulation of the Wnt/β-catenin pathway which did not change significantly in the Pde8b+/-;ΔCat mice. Prkar1a haploinsufficiency also did not change the phenotype significantly. In vitro studies showed that PDE8B knockdown upregulated the Wnt pathway and increased proliferation in CTNNB1-mutant cells, whereas it downregulated the Wnt pathway in PRKAR1A-mutant cells. These data support an overall weak, if any, role for PDE8B in adrenocortical tumorigenesis, even when co-altered with Wnt signaling or PKA upregulation; on the other hand, PDE8B appears to play a significant role in male fertility.

A phosphodiesterase 11 (Pde11a) knockout mouse expressed functional but reduced Pde11a: Phenotype and impact on adrenocortical function

Phosphodiesterases catalyze the hydrolysis of cyclic nucleotides and maintain physiologic levels of intracellular concentrations of cyclic adenosine and guanosine mono-phosphate (cAMP and cGMP, respectively). Increased cAMP signaling has been associated with adrenocortical tumors and Cushing syndrome. Genetic defects in phosphodiesterase 11A (PDE11A) may lead to increased cAMP signaling and have been found to predispose to the development of adrenocortical, prostate, and testicular tumors. A previously reported Pde11a knockout (Pde11a-/-) mouse line was studied and found to express PDE11A mRNA and protein still, albeit at reduced levels; functional studies in various tissues showed increased cAMP levels and reduced PDE11A activity. Since patients with PDE11A defects and Cushing syndrome have PDE11A haploinsufficiency, it was particularly pertinent to study this hypomorphic mouse line. Indeed, Pde11a-/- mice failed to suppress corticosterone secretion in response to low dose dexamethasone, and in addition exhibited adrenal subcapsular hyperplasia with predominant fetal-like features in the inner adrenal cortex, mimicking other mouse models of increased cAMP signaling in the adrenal cortex. We conclude that a previously reported Pde11a-/- mouse showed continuing expression and function of PDE11A in most tissues. Nevertheless, Pde11a partial inactivation in mice led to an adrenocortical phenotype that was consistent with what we see in patients with PDE11A haploinsufficiency.

Adrenocortical Tumors in Children With Constitutive Chromosome 11p15 Paternal Uniparental Disomy: Implications for Diagnosis and Treatment

Pediatric adrenocortical tumors (ACTs) are rare and heterogeneous. Approximately 50% of children with ACT carry a germline TP53 variant; however, the genetic underpinning of remaining cases has not been elucidated. In patients having germline TP53 variants, loss of maternal chromosome 11 and duplication of the paternal copy [paternal uniparental disomy, (UPD)] occurs early in tumorigenesis and explains the overexpression of IGF2, the hallmark of pediatric ACT. Beckwith-Wiedemann syndrome (BWS) is also associated with overexpression of IGF2 due to disruption of the 11p15 loci, including segmental UPD. Here, we report six children with ACT with wild type TP53 and germline paternal 11p15 UPD. Median age of five girls and one boy was 3.2 years (range 0.5-11 years). Two patients met the criteria for BWS before diagnosis of ACT. However, ACT was the first and only manifestation of paternal 11p15 UPD in four children. Tumor weight ranged from 21.5 g to 550 g. Despite poor prognostic features at presentation, such as pulmonary metastasis, bilateral adrenal involvement, and large tumors, all patients are alive 8-21 years after cancer diagnosis. Our observations suggest that children with ACT and wild type TP53, irrespective of their age, should be screened for germline abnormalities in chromosome 11p15.

Phosphodiesterase 2A and 3B variants are associated with primary aldosteronism

Familial primary aldosteronism (PA) is rare and mostly diagnosed in early-onset hypertension (HT). However, 'sporadic' bilateral adrenal hyperplasia (BAH) is the most frequent cause of PA and remains without genetic etiology in most cases. Our aim was to investigate new genetic defects associated with BAH and PA. We performed whole-exome sequencing (paired blood and adrenal tissue) in six patients with PA caused by BAH that underwent unilateral adrenalectomy. Additionally, we conducted functional studies in adrenal hyperplastic tissue and transfected cells to confirm the pathogenicity of the identified genetic variants. Rare germline variants in phosphodiesterase 2A (PDE2A) and 3B (PDE3B) genes were identified in three patients. The PDE2A heterozygous variant (p.Ile629Val) was identified in a patient with BAH and early-onset HT at 13 years of age. Two PDE3B heterozygous variants (p.Arg217Gln and p.Gly392Val) were identified in patients with BAH and HT diagnosed at 18 and 33 years of age, respectively. A strong PDE2A staining was found in all cases of BAH in zona glomerulosa and/or micronodules (that were also positive for CYP11B2). PKA activity in frozen tissue was significantly higher in BAH from patients harboring PDE2A and PDE3B variants. PDE2A and PDE3B variants significantly reduced protein expression in mutant transfected cells compared to WT. Interestingly, PDE2A and PDE3B variants increased SGK1 and SCNN1G/ENaCg at mRNA or protein levels. In conclusion, PDE2A and PDE3B variants were associated with PA caused by BAH. These novel genetic findings expand the spectrum of genetic etiologies of PA.

Role of Phosphodiesterase in the Biology and Pathology of Diabetes

Glucose metabolism is the initiator of a large number of molecular secretory processes in β cells. Cyclic nucleotides as a second messenger are the main physiological regulators of these processes and are functionally divided into compartments in pancreatic cells. Their intracellular concentration is limited by hydrolysis led by one or more phosphodiesterase (PDE) isoenzymes. Literature data confirmed multiple expressions of PDEs subtypes, but the specific roles of each in pancreatic β-cell function, particularly in humans, are still unclear. Isoforms present in the pancreas are also found in various tissues of the body. Normoglycemia and its strict control are supported by the appropriate release of insulin from the pancreas and the action of insulin in peripheral tissues, including processes related to homeostasis, the regulation of which is based on the PDE- cyclic AMP (cAMP) signaling pathway. The challenge in developing a therapeutic solution based on GSIS (glucose-stimulated insulin secretion) enhancers targeted at PDEs is the selective inhibition of their activity only within β cells. Undeniably, PDEs inhibitors have therapeutic potential, but some of them are burdened with certain adverse effects. Therefore, the chance to use knowledge in this field for diabetes treatment has been postulated for a long time.

Frequency of the TP53 p.R337H mutation in a Brazilian cohort of pediatric patients with solid tumors

TP53 p.R337H germline mutation is highly prevalent in the Southern region of Brazil. We sought to investigate TP53 p.R337H mutation in pediatric tumor samples from a population settled in a geographic area of high prevalence for this variant. Mutation assessment and genetic counseling for carriers/relatives were provided. 6/57 tumor samples were heterozygous for TP53 p.R337H. As expected, a high frequency was observed within adrenocortical tumors (3/3) and choroid plexus carcinomas (2/2). Interestingly, the TP53 R337H mutation was found in one case of pediatric rhabdomyosarcoma with Li-Fraumeni pedigree. Our finding expands the spectrum of childhood cancer associated with this germline mutation.

Adrenocortical tumorigenesis: Lessons from genetics

Advances in genomics over the past two decades have allowed for elucidation of the genetic alterations leading to the development of adrenocortical tumors and/or hyperplasias. These molecular changes were initially discovered through the study of rare familial tumor syndromes such as McCune-Albright Syndrome, Carney complex, Li-Fraumeni syndrome, and Beckwith-Wiedemann syndrome, with the identification of alterations in genes and molecular pathways that subsequently led to the discovery of aberrations in these or related genes and pathways in sporadic tumors. Genetic alterations in GNAS, PRKAR1A, PRKACA, PRKACB, PDE11A, and PDE8B, that lead to aberrant cyclic adenosine monophosphate-protein (cAMP) kinase A signaling, were found to play a major role in the development of benign cortisol-producing adrenocortical tumors and/or hyperplasias, whereas genetic defects in KCNJ5, ATP1A1, ATP2B3, CACNA1D, CACNA1H, and CLCN2 were implicated in the development of benign aldosterone-producing tumors and/or hyperplasias through modification of intracellular calcium signaling. Germline ARMC5 defects were found to cause the development of primary bilateral macronodular adrenocortical hyperplasia with glucocorticoid and/or mineralocorticoid oversecretion. Adrenocortical carcinoma was linked primarily to aberrant p53 signaling and/or Wnt-β-catenin signaling, as well as IGF2 overexpression, with frequent genetic alterations in TP53, ZNRF3, CTNNB1, and 11p15. This review focuses on the genetic underpinnings of benign cortisol- and aldosterone-producing adrenocortical tumors/hyperplasias and adrenocortical carcinoma.