Maria Candida Barisson Villares Fragoso

The desmopressin stimulation test in the differential diagnosis of Cushing's syndrome

objective We assessed the ability of desmopressin to stimulate the pituitary‐adrenal axis in patients with Cushings syndrome.

Expression of Insulin-Like Growth Factor-II and Its Receptor in Pediatric and Adult Adrenocortical Tumors

BACKGROUND Adrenocortical tumors are heterogeneous neoplasms with incompletely understood pathogenesis. IGF-II overexpression has been consistently demonstrated in adult adrenocortical carcinomas. OBJECTIVES The objective of the study was to analyze expression of IGF-II and its receptor (IGF-IR) in pediatric and adult adrenocortical tumors and the effects of a selective IGF-IR kinase inhibitor (NVP-AEW541) on adrenocortical tumor cells. PATIENTS Fifty-seven adrenocortical tumors (37 adenomas and 20 carcinomas) from 23 children and 34 adults were studied. METHODS Gene expression was determined by quantitative real-time PCR. Cell proliferation and apoptosis were analyzed in NCI H295 cells and a new cell line established from a pediatric adrenocortical adenoma. RESULTS IGF-II transcripts were overexpressed in both pediatric adrenocortical carcinomas and adenomas. Otherwise, IGF-II was mainly overexpressed in adult adrenocortical carcinomas (270.5 +/- 130.2 vs. 16.1 +/- 13.3; P = 0.0001). IGF-IR expression was significantly higher in pediatric adrenocortical carcinomas than adenomas (9.1 +/- 3.1 vs. 2.6 +/- 0.3; P = 0.0001), whereas its expression was similar in adult adrenocortical carcinomas and adenomas. IGF-IR expression was a predictor of metastases in pediatric adrenocortical tumors in univariate analysis (hazard ratio 1.84; 95% confidence interval 1.28-2.66; P = 0.01). Furthermore, NVP-AEW541 blocked cell proliferation in a dose- and time-dependent manner in both cell lines through a significant increase of apoptosis. CONCLUSION IGF-IR overexpression was a biomarker of pediatric adrenocortical carcinomas. Additionally, a selective IGF-IR kinase inhibitor had antitumor effects in adult and pediatric adrenocortical tumor cell lines, suggesting that IGF-IR inhibitors represent a promising therapy for human adrenocortical carcinoma.

Comprehensive Pan-Genomic Characterization of Adrenocortical Carcinoma

We describe a comprehensive genomic characterization of adrenocortical carcinoma (ACC). Using this dataset, we expand the catalogue of known ACC driver genes to include PRKAR1A, RPL22, TERF2, CCNE1, and NF1. Genome wide DNA copy-number analysis revealed frequent occurrence of massive DNA loss followed by whole-genome doubling (WGD), which was associated with aggressive clinical course, suggesting WGD is a hallmark of disease progression. Corroborating this hypothesis were increased TERT expression, decreased telomere length, and activation of cell-cycle programs. Integrated subtype analysis identified three ACC subtypes with distinct clinical outcome and molecular alterations which could be captured by a 68-CpG probe DNA-methylation signature, proposing a strategy for clinical stratification of patients based on molecular markers.

Progression to Adrenocortical Tumorigenesis in Mice and Humans through Insulin-Like Growth Factor 2 and β-Catenin

Dysregulation of the WNT and insulin-like growth factor 2 (IGF2) signaling pathways has been implicated in sporadic and syndromic forms of adrenocortical carcinoma (ACC). Abnormal β-catenin staining and CTNNB1 mutations are reported to be common in both adrenocortical adenoma and ACC, whereas elevated IGF2 expression is associated primarily with ACC. To better understand the contribution of these pathways in the tumorigenesis of ACC, we examined clinicopathological and molecular data and used mouse models. Evaluation of adrenal tumors from 118 adult patients demonstrated an increase in CTNNB1 mutations and abnormal β-catenin accumulation in both adrenocortical adenoma and ACC. In ACC, these features were adversely associated with survival. Mice with stabilized β-catenin exhibited a temporal progression of increased adrenocortical hyperplasia, with subsequent microscopic and macroscopic adenoma formation. Elevated Igf2 expression alone did not cause hyperplasia. With the combination of stabilized β-catenin and elevated Igf2 expression, adrenal glands were larger, displayed earlier onset of hyperplasia, and developed more frequent macroscopic adenomas (as well as one carcinoma). Our results are consistent with a model in which dysregulation of one pathway may result in adrenal hyperplasia, but accumulation of a second or multiple alterations is necessary for tumorigenesis.

ARMC5 Mutations Are a Frequent Cause of Primary Macronodular Adrenal Hyperplasia

CONTEXT Primary macronodular adrenal hyperplasia (PMAH) is a rare cause of Cushings syndrome, usually characterized by functioning adrenal macronodules and increased cortisol production. Familial clustering of PMAH has been described, suggesting an inherited genetic cause for this condition. OBJECTIVE The aim of the present study was to identify the gene responsible for familial PMAH. PATIENTS AND METHODS Forty-seven individuals of a Brazilian family with PMAH were evaluated. A single-nucleotide polymorphism-based genome-wide linkage analysis followed by whole-exome sequencing were then performed in selected family members. Additionally, 29 other patients with PMAH and 125 randomly selected healthy individuals were studied to validate the genetic findings. Moreover, PMAH tissue was also analyzed through whole-exome sequencing, conventional sequencing, and microsatellite analysis. RESULTS A heterozygous germline variant in the ARMC5 gene (p.Leu365Pro) was identified by whole-exome sequencing in a candidate genomic region (16p11.2). Subsequently, the same variant was confirmed by conventional sequencing in all 16 affected family members. The variant was predicted to be damaging by in silico methods and was not found in available online databases or in the 125 selected healthy individuals. Seven additional ARMC5 variants were subsequently identified in 5 of 21 patients with apparently sporadic PMAH and in 2 of 3 families with the disease. Further molecular analysis identified a somatic mutational event in 4 patients whose adrenal tissue was available. CONCLUSIONS Inherited autosomal dominant mutations in the ARMC5 gene are a frequent cause of PMAH. Biallelic inactivation of ARMC5 is consistent with its role as a potential tumor suppressor gene.

Steroidogenic Factor 1 Overexpression and Gene Amplification Are More Frequent in Adrenocortical Tumors from Children than from Adults

BACKGROUND Steroidogenic factor 1 (SF-1) is a key determinant of endocrine development and function of adrenal cortex. SF-1 overexpression and gene amplification were previously demonstrated in a small group of pediatric adrenocortical tumors. OBJECTIVE Our objective was to determine the frequency of SF-1 protein expression and gene amplification in a large cohort of pediatric and adult adrenocortical tumors. PATIENTS SF-1 protein expression was assessed in a cohort of 103 adrenocortical tumors from 36 children and 67 adults, whereas gene amplification was studied in 38 adrenocortical tumors (17 from children). METHODS Tissue microarray, multiplex ligation-dependent probe amplification, and quantitative real-time PCR were used. RESULTS A strong nuclear SF-1 expression was detected by tissue microarray in 56% (20 of 36) and 19% (13 of 67) of the pediatric and adult adrenocortical tumors, respectively (P = 0.0004). Increased SF-1 copy number was identified in 47% (eight of 17) and 10% (two of 21) of the pediatric and adult adrenocortical tumors, respectively (P = 0.02). All adrenocortical tumors with SF-1 gene amplification showed a strong SF-1 staining, whereas most of the tumors (61%) without SF-1 amplification displayed a weak or negative staining (P = 0.0008). Interestingly, a strong SF-1 staining was identified in five (29%) pediatric adrenocortical tumors without SF-1 amplification. The frequency of SF-1 overexpression and gene amplification was similar in adrenocortical adenomas and carcinomas. CONCLUSION We demonstrated a higher frequency of SF-1 overexpression and gene amplification in pediatric than in adult adrenocortical tumors, suggesting an important role of SF-1 in pediatric adrenocortical tumorigenesis.

The role of desmopressin in bilateral and simultaneous inferior petrosal sinus sampling for differential diagnosis of ACTH-dependent Cushing's syndrome

Objective   Bilateral inferior petrosal sinus sampling (BIPSS) with corticotrophin‐releasing hormone (CRH) stimulation is currently the gold standard test for the differential diagnosis of ACTH‐dependent Cushings syndrome. Reports on the use of desmopressin in this approach are limited. The aim of this study was to evaluate the use of desmopressin during BIPSS in a cohort of patients with ACTH‐dependent Cushings syndrome.

High Penetrance of Pheochromocytoma Associated with the Novel C634Y/Y791F Double Germline Mutation in the RET Protooncogene

CONTEXT Previous studies have shown that double RET mutations may be associated with unusual multiple endocrine neoplasia type 2 (MEN 2) phenotypes. OBJECTIVE Our objective was to report the clinical features of patients harboring a previously unreported double mutation of the RET gene and to characterize this mutation in vitro. PATIENTS Sixteen patients from four unrelated families and harboring the C634Y/Y791F double RET germline mutation were included in the study. RESULTS Large pheochromocytomas measuring 6.0-14 cm and weighing up to 640 g were identified in the four index cases. Three of the four tumors were bilateral. High penetrance of pheochromocytoma was also seen in the C634Y/Y791F-mutation-positive relatives (seven of nine, 77.7%). Of these, two cases had bilateral tumors, one presented with multifocal tumors, two cases had large tumors (>5 cm), and one case, which was diagnosed with a large (5.5 x 4.5 x 4.0 cm) pheochromocytoma, reported early onset of symptoms of the disease (14 yr old). The overall penetrance of pheochromocytoma was 84.6% (11 of 13). Development of medullary thyroid carcinoma in our patients seemed similar to that observed in patients with codon 634 mutations. Haplotype analysis demonstrated that the mutation did not arise from a common ancestor. In vitro studies showed the double C634Y/Y791F RET receptor was significantly more phosphorylated than either activated wild-type receptor or single C634Y and Y791F RET mutants. CONCLUSIONS Our data suggest that the natural history of the novel C634Y/Y791F double mutation carries a codon 634-like pattern of medullary thyroid carcinoma development, is associated with increased susceptibility to unusually large bilateral pheochromocytomas, and is likely more biologically active than each individual mutation.

Combined expression of BUB1B, DLGAP5, and PINK1 as predictors of poor outcome in adrenocortical tumors: validation in a Brazilian cohort of adult and pediatric patients

BACKGROUND A recent microarray study identified a set of genes whose combined expression patterns were predictive of poor outcome in a cohort of adult adrenocortical tumors (ACTs). The difference between the expression values measured by qRT-PCR of DLGAP5 and PINK1 genes was the best molecular predictor of recurrence and malignancy. Among the adrenocortical carcinomas, the combined expression of BUB1B and PINK1 genes was the most reliable predictor of overall survival. The prognostic and molecular heterogeneity of ACTs raises the need to study the applicability of these molecular markers in other cohorts. OBJECTIVE To validate the combined expression of BUB1B, DLGAP5, and PINK1 as outcome predictor in ACTs from a Brazilian cohort of adult and pediatric patients. PATIENTS AND METHODS BUB1B, DLGAP5, and PINK1 expression was assessed by quantitative PCR in 53 ACTs from 52 patients - 24 pediatric and 28 adults (one pediatric patient presented a bilateral asynchronous ACT). RESULTS DLGAP5-PINK1 and BUB1B-PINK1 were strong predictors of disease-free survival and overall survival, respectively, among adult patients with ACT. In the pediatric cohort, these molecular predictors were only marginally associated with disease-free survival but not with overall survival. CONCLUSION This study confirms the prognostic value of the combined expression of BUB1B, DLGAP5, and PINK1 genes in a Brazilian group of adult ACTs. Among pediatric ACTs, other molecular predictors of outcome are required.

Isolated familial somatotropinoma: 11Q13-LOH and gene/protein expression analysis suggests a possible involvement of aip also in non-pituitary tumorigenesis

OBJECTIVE Non-pituitary tumors have been reported in a subset of patients harboring germline mutations in the aryl hydrocarbon receptor-interacting protein (AIP) gene. However, no detailed investigations of non-pituitary tumors of AIP-mutated patients have been reported so far. PATIENTS We examined a MEN1- and p53-negative mother-daughter pair with acromegaly due to somatotropinoma. Subsequently, the mother developed a large virilizing adrenocortical carcinoma and a grade II B-cell non-Hodgkin’s lymphoma. DESIGN Mutational analysis was performed by automated sequencing. Loss-of-heterozygosity (LOH) analysis was carried out by sequencing and microsatellite analysis. AIP expression was assessed through quantitative PCR (qPCR) and immunohistochemistry. RESULTS The functional inactivating mutation c.241C>T (R81X), which blocks the AIP protein from interacting with phosphodiesterase 4A (PDE4A), was identified in the heterozygous state in the leukocyte DNA of both patients. Analyzing the tumoral DNA revealed that the AIP wild-type allele was lost in the daughter’s somatotropinoma and the mother’s adrenocortical carcinoma. Both tumors displayed low AIP protein expression levels. Low AIP gene expression was confirmed by qPCR in the adrenocortical carcinoma. No evidence of LOH was observed in the DNA sample from the mother’s B-cell lymphoma, and this tumor displayed normal AIP immunostaining. CONCLUSIONS Our study presents the first molecular analysis of non-pituitary tumors in AIP-mutated patients. The finding of AIP inactivation in the adrenocortical tumor suggests that further investigation of the potential role of this recently identified tumor suppressor gene in non-pituitary tumors, mainly in those tumors in which the cAMP and the 11q13 locus are implicated, is likely to be worthwhile.