Luciana Pinto Brito

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.

PROP1 and CTNNB1 expression in adamantinomatous craniopharyngiomas with or without β-catenin mutations

INTRODUCTION: Activating mutations in exon 3 of the β-catenin gene are involved in the pathogenesis of adamantinomatous craniopharyngiomas. Recently, the interaction between β-catenin and PROP1 has been shown to be responsible for pituitary cell lineage determination. We hypothesized that dysregulated PROP1 expression could also be involved in the pathogenesis of craniopharyngiomas. OBJECTIVES: To determine whether dysregulated gene expression was responsible for tumor pathogenesis in adamantinomatous craniopharyngiomas, the β-catenin gene was screened for mutations, and the expression of the β-catenin gene and PROP1 was evaluated. METHODS: The β-catenin gene was amplified and sequenced from 14 samples of adamantinomatous craniopharyngiomas. PROP1 and β-catenin gene expression was assessed by real-time RT-PCR from 12 samples, and β-catenin immunohistochemistry was performed on 11 samples. RESULTS: Mutations in the β-catenin gene were identified in 64% of the adamantinomatous craniopharyngiomas samples. Evidence of β-catenin gene overexpression was found in 71% of the tumors with β-catenin mutations and in 40% of the tumors without mutations, and β-catenin immunohistochemistry revealed a nuclear staining pattern for each of the analyzed samples. PROP1 expression was undetectable in all of the tumor samples. CONCLUSION: We found evidence of β-catenin gene overexpression in the majority of adamantinomatous craniopharyngiomas, and we also detected a nuclear β-catenin staining pattern regardless of the presence of a β-catenin gene mutation. These results suggest that WNT signaling activation plays an important role in the pathogenesis of adamantinomatous craniopharyngiomas. Additionally, this study was the first to evaluate PROP1 expression in adamantinomatous craniopharyngiomas, and the absence of PROP1 expression indicates that this gene is not involved in the pathogenesis of this tumor, at least in this cohort.

The role of fibroblast growth factor receptor 4 overexpression and gene amplification as prognostic markers in pediatric and adult adrenocortical tumors

In the last decade, relevant progresses in the molecular basis of adrenocortical tumors (ACTs) were achieved and abnormalities involving growth pathway deregulation were frequently associated with malignancy. Remarkably, upregulation of insulin-like growth factor 2 (IGF2) and its receptor (IGF1R) has been demonstrated in a significant proportion of ACTs, and the presence of these abnormalities has both prognostic and therapeutic implications (Almeida et al. 2008). In fact, clinical trials involving pharmacological blockade of IGF1R are currently under process. Besides the IGF system, other growth signaling pathways have been suggested to be important for ACC progression and are possible therapeutic targets. Among these, fibroblast growth factor receptor 4 (FGFR4) overexpression has been observed in both adult and pediatric ACT by genome-wide expression studies in the same extent as the IGF system (de Fraipont et al. 2005, Laurell et al. 2009). However, these data have not been validated in an independent cohort and the molecular mechanisms responsible forFGFR4 upregulation have not been assessed. Therefore, we studied the expression levels of FGFR4 and gene amplification in a cohort of ACT patients from our institution. This study was approved by the Ethics Committee of Hospital das Clinicas, Sao Paulo, Brazil, and an informedwritten consentwas obtained from all patients and/or parents. Our cohort consisted of 57 patients – 32 adults (ageR18 years, 18–66 years) and 25 pediatric (age!18 years, 0.9–17 years) with the diagnosis of ACT, with a mean follow-up period of 77.5G53 months. FGFR4 transcript levels were assessed through quantitative real-time RT-PCR in all 57 samples using TaqMan gene expression assays (Applied Biosystem, Foster City, CA,USA). The endogenous control gene used was ACTB for each sample and the reactions were carried out in triplicate. The relative expression levels of FGFR4 were calculated using the 2t method as described previously (Livak & Schmittgen 2001). A commercial pool of 61 human adrenal glands of autopsy was the reference sample (Clontech). The criteria used for underand overexpression was a twofold change in comparison

Increased expression of ACTH (MC2R) and androgen (AR) receptors in giant bilateral myelolipomas from patients with congenital adrenal hyperplasia

BackgroundAlthough chronic adrenocorticotropic hormone (ACTH) and androgen hyperstimulation are assumed to be involved in the pathogenesis of adrenal myelolipomas associated with poor-compliance patients with congenital adrenal hyperplasia (CAH), the expression of their receptors has not yet been demonstrated in these tumors so far.MethodsWe analyzed Melanocortin 2 receptor (MC2R), Androgen Receptor (AR), Leptin (LEP), and Steroidogenic factor 1 (SF1) expression using real-time qRT-PCR in two giant bilateral adrenal myelolipomas from two untreated simple virilizing CAH cases and in two sporadic adrenal myelolipomas. In addition, the X- chromosome inactivation pattern and CAG repeat numbers in AR exon 1 gene were evaluated in the 4 cases.ResultsThe MC2R gene was overexpressed in myelolipomas from 3 out of 4 patients. AR overexpression was detected in 2 tumors: a giant bilateral myelolipoma in a CAH patient and a sporadic case. Simultaneous overexpression of AR and MC2R genes was found in two of the cases. Interestingly, the bilateral giant myelolipoma associated with CAH that had high androgen and ACTH levels but lacked MC2R and AR overexpression presented a significantly shorter AR allele compared with other tumors. In addition, X-chromosome inactivation pattern analysis showed a polyclonal origin in all tumors, suggesting a stimulatory effect as the trigger for tumor development.ConclusionThese findings are the first evidence for MC2R or AR overexpression in giant bilateral myelolipomas from poor-compliance CAH patients.

Influence of the Fibroblast Growth Factor Receptor 4 Expression and the G388R Functional Polymorphism on Cushing's Disease Outcome

CONTEXT Abnormal FGFR4 expression has been detected in pituitary tumors, especially in larger and invasive adenomas. In addition, the FGFR4 functional polymorphism G388R has been associated with poor outcome in several human malignancies. Then, we hypothesized that FGFR4 expression and genotype could be markers of adverse outcome of Cushings disease after transsphenoidal surgery. OBJECTIVES The objective was to investigate whether there is an association between the postoperative outcome of Cushings disease (remission/recurrence) and the FGFR4 G388R genotype or the FGFR4 expression in corticotrophinomas. DESIGN AND PATIENTS Clinical, hormonal, and pathological data of 76 patients who underwent the first transsphenoidal surgery were retrospectively reviewed. All patients were genotyped for G388R polymorphism. FGFR4 expression was assessed by real-time PCR in 18 corticotrophinomas. MAIN OUTCOME MEASURES The outcome measures included the FGFR4 G388R genotype and FGFR4 expression in postoperative remission and recurrence of Cushings disease. RESULTS Homozygosis for FGFR4 glycine (Gly(388)) allele was associated with reduced disease-free survival, in the univariate analysis (hazard ratio of 6.91; 95% confidence interval of 1.14-11.26; P = 0.028). Male gender (P = 0.036), lack of pathology confirmation (P = 0.009), and cortisol levels more than 2 μg/dl in the early postoperative period (P < 0.001) were also significant predictors of Cushings disease recurrence in the univariate analysis. FGFR4 overexpression was found in 44% of the corticotrophinomas, and it was associated with lower postoperative remission rate (P = 0.009). CONCLUSIONS Our data suggest that homozygosis for FGFR4 Gly(388) allele and FGFR4 overexpression are associated with higher frequency of postoperative recurrence and persistence of Cushings disease, respectively.

Clinical and molecular aspects of a pediatric metachronous adrenocortical tumor

The occurrence of metachronous adrenocortical carcinoma has rarely been described. We report a case of a child with virilizing adrenocortical metachronous tumors that, despite several metastases, presented long-term survival (15 years). We analyzed in this tumor IGF2, IGF1R and FGFR4 gene expression, and evaluated the presence of p.R337H germline p53 mutation and somatic CTNNB1 mutation. IGF2 gene was over-expressed in both left (Weiss score 5) and right (Weiss 7) adrenocortical tumors. IGF1R expression levels were higher in the right adrenocortical tumor. FGFR4 over-expression was also detected in the right adrenocortical tumor. In addition, this patient harbors the germline p.R337H p53 mutation and loss of heterozygosity (LOH) was detected in the tumors. No somatic CTNNB1 mutations were found in both tumors. In conclusion, we demonstrated in this unusual case the over-expression of growth signaling pathways, which are molecular mechanisms previously related to adrenocortical tumorigenesis. Furthermore, the absence of somatic CTNNB1 mutations, which is a molecular marker of poor prognosis in adults, might be related to the long-term survival of this patient.

A missense TCF1 mutation in a patient with mody-3 and liver adenomatosis

This diseaseis caused by heterozygous germline mutations of the TCF1gene. The product encoded by this gene is the hepatocytenuclear factor 1 alpha (HNF-1a – accession number NP_000536) transcription factor, which has important physiolo-gic roles in organs such as the pancreas, liver and kidneys.Hepatocellular adenomas are benign neoplasms thatusually develop as a solitary nodule and are associatedwith oral contraceptive use in 90% of cases. On the otherhand, liver adenomatosis (LA) is characterized by thepresence of multiple nodules (usually more than 5) and isconsidered to be a distinct disease, due to the higherprevalence in male sex and the unclear association withOCs.

Validation of an immunoassay for anti-Müllerian hormone measurements and reference intervals in healthy Brazilian subjects

Background Anti-Müllerian hormone is marker of ovarian and testicular reserve. The clinical use of this hormone requires proper standardization of reference intervals. The aims of this study were to validate the Anti-Müllerian hormone Gen II immunoassay, to establish Anti-Müllerian hormone reference intervals in healthy subjects, and to evaluate the influence of hormonal contraceptives, smoking, and body mass index on Anti-Müllerian hormone. Methods The validation of the Anti-Müllerian hormone Gen II assay (Beckman Coulter Company, TX, USA) was performed using a simplified protocol recommended by Clinical Laboratory Standard Institute. One-hundred and thirty-three healthy females and 120 males were prospectively selected for this study. Results The analytical and functional sensitivities of the Anti-Müllerian hormone Gen II immunoassay were 0.02 and 0.2 ng/mL, respectively. Intra-assay coefficients ranged from 5.2 to 9.0%, whereas inter-assay precision ranged from 4.6 to 7.8% at different concentrations. In females, Anti-Müllerian hormone showed progressive decline with increasing age (r = −0.4, p < 0.001), whereas in males, age showed no influence on Anti-Müllerian hormone concentrations. In females, Anti-Müllerian hormone concentrations did not differ between users and non-users of hormonal contraceptives, smokers, and non-smokers and obese and lean individuals. However, there was a negative and significant correlation between Anti-Müllerian hormone and body mass index in males (r = −0.3, p = 0.008). Conclusions Anti-Müllerian hormone Gen II assay was reliable for determining serum Anti-Müllerian hormone concentrations. Anti-Müllerian hormone concentrations declined with aging and presented a wide inter-individual variability. The lack of influence of hormonal contraceptives, smoking, and obesity on Anti-Müllerian hormone in both sexes allowed us to refine the normative concentrations for the Brazilian population.

Fatal factitious Cushing syndrome (Münchhausen's syndrome) in a patient with macroprolactinoma and silent corticotrophinoma: case report and literature review

Münchhausen’s syndrome (MS) is a chronic factitious disorder characterized by the intentional production of clinical symptoms without external incentive. One type of MS is factitious Cushing syndrome, an extremely rare clinical situation in which the diagnosis is challenging mainly due to interference of the exogenous medication in cortisol immunoassays. We described a 26-year-old woman who was originally diagnosed with a macroprolactinoma and during follow-up developed clinical and laboratorial hypercortisolism. A transsphenoidal surgery was performed and immunohistochemistry revealed positive and diffuse staining for both hormones. Four years later, her hypercortisolism recurred and the confirmation of factitious Cushing syndrome was delayed due to conflicting laboratorial results.There are few cases in the literature of factitious Cushing syndrome, and only one had a fatal outcome. The diagnosis of this condition is complex and includes cyclic Cushing syndrome in the differential diagnosis. These patients have high morbidity and increased mortality risk and are likely to have other psychiatric disorders. Prednisone was identified as the culprit in the majority of the cases.

Absence of PRKAR1A loss of heterozygosity in laser-captured microdissected pigmented nodular adrenocortical tissue from a patient with Carney complex caused by the novel nonsense mutation p.Y21X

OBJECTIVE Primary pigmented nodular adrenocortical disease (PPNAD) is the main endocrine manifestation of Carney complex, a multiple neoplasia syndrome caused by PRKAR1A gene mutations. The presence of PRKAR1A loss of heterozygosity (LOH) in adrenocortical tumorigenesis remains controversial. The aim of the present study is to investigate the presence of PRKAR1A LOH in adrenocortical cells in a patient with Carney complex. METHODS The LOH was investigated using a PRKAR1A informative intragenic marker by GeneScan software analysis in DNA obtained from laser-captured microdissected cells of several adrenal nodules. PATIENTS A young adult male patient with Carney complex and his family were studied. RESULTS A novel heterozygous mutation (p. Y21X) was identified at PRKAR1A in blood DNA of the male proband and his relatives. No PRKAR1A LOH was evidenced in the laser-captured microdissected cells from PPNAD tissue by different methodologies. CONCLUSION We identified a new PRKAR1A nonsense mutation and in addition we did not evidence PRKAR1A LOH in laser-captured nodules cells, suggesting that adrenocortical tumorigenesis in PPNAD may occurs apart from the second hit.