[Show abstract][Hide abstract] ABSTRACT: Low DICER1 expression was associated with poor outcome in several cancers. Recently, hot-spot DICER1 mutations were found in ovarian tumors, and TARBP2 truncating mutations in tumor cell lines with microsatellite instability. In this study, we assessed DICER1 e TRBP protein expression in 154 adult adrenocortical tumors (75 adenomas and 79 carcinomas). Expression of DICER1 and TARBP2 gene was assessed in a subgroup of 61 tumors. Additionally, we investigated mutations in metal biding sites located at the RNase IIIb domain of DICER1 and in the exon 5 of TARBP2 in 61 tumors. A strong DICER1 expression was demonstrated in 32% of adenomas and in 51% of carcinomas (p = 0.028). Similarly, DICER1 gene overexpression was more frequent in carcinomas (60%) than in adenomas (23%, p = 0.006). But, among adrenocortical carcinomas, a weak DICER1 expression was significantly more frequent in metastatic than in non-metastatic adrenocortical carcinomas (66% vs. 31%; p = 0.002). Additionally, a weak DICER1 expression was significantly correlated with a reduced overall (p = 0.004) and disease-free (p = 0.005) survival. In the multivariate analysis, a weak DICER1 expression (p = 0.048) remained as independent predictor of recurrence. Regarding TARBP2 gene, its protein and gene expression did not correlate with histopathological and clinical parameters. No variant was identified in hot spot areas of DICER1 and TARBP2. In conclusion, a weak DICER1 protein expression was associated with reduced disease-free and overall survival and was a predictor of recurrence in adrenocortical carcinomas.
[Show abstract][Hide abstract] ABSTRACT: RFamide-related peptide-3 (RFRP-3), the ortholog of avian gonadotropin-inhibitory hormone, and its receptor GPR147 have been recently identified in the human hypothalamus, and their roles on the regulation of reproductive axis has been interrogated. Our aim was to investigate if the presence of variants in the genes encoding human RFRP-3 (NPVF gene) and its receptor, GPR147 (NPFFR1 gene), is associated with the occurrence of GnRH-dependent pubertal disorders. Seventy-eight patients with idiopathic central precocious puberty (CPP) and 51 with normosmic isolated hypogonadotropic hypogonadism (nIHH) were investigated. Fifty healthy subjects comprised the control group. The coding sequences of the NPVF and NPFFR1 genes were amplified and sequenced. The frequencies of polymorphisms were compared among the groups and the odds ratio for the occurrence of CPP or nIHH was determined. All polymorphisms have been already described in the NCBI database. A 3-nucleotide in frame deletion was identified in the NPVF gene (p.I71_K72), with a slightly smaller proportion in the CPP (5%) as compared to the nIHH (15%) group (p=0.06). It results in the deletion of the isoleucine at position 71, adjacent to lysine at an endoproteolytic cleavage site of the precursor peptide. This polymorphism was associated with a reduced risk for the occurrence of CPP (OR 0.33; 95%CI: 0.08-0.88); interestingly, only 2 men with nIHH were homozygotes for this variant. A total of 5 missense polymorphisms were found in the NPFFR1 gene, which encodes GPR147, with similar frequencies among groups and no association with pubertal timing. Our data suggest that RFRP-3/GPR147 may play secondary, modulatory roles on the regulation of pubertal development; a restraining modulatory effect of the NPVF p.I71_K72 variant on the activation of the gonadotropic axis cannot be ruled out and deserves further investigation.This article is protected by copyright. All rights reserved.
Journal of Neuroendocrinology 11/2014; in press(11). DOI:10.1111/jne.12207 · 3.14 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: ObjectiveLIN28 control cells reprogramming and pluripotency mainly through miRNA regulation and has been overexpressed in many advanced cancers. In this study, we evaluated the prognostic role of LIN28 and its regulatory miRNAs in a large cohort of adrenocortical tumors (ACTs).Patients and methodsLIN28 protein expression was assessed in 266 adults ACTs (78 adenomas and 188 carcinomas) from Brazil and Germany. LIN28A and LIN28B gene expression was analyzed in 59 ACTs (31 adenomas and 28 carcinomas) and copy number variation in 39 ACTs. In addition, we determined the expression of let-7 family, mir-9, mir-30 and mir-125 in 28 carcinomas.ResultsLIN28A gene was overexpressed in aggressive ACCs when compared with adenomas and non-aggressive ACCs, but no LIN28A copy number variation was found in ACTs. Unexpectedly, weak LIN28 protein expression was significantly associated with reduced disease-free survival in ACC patients (p= 0.01), but for overall survival only a trend was detectable (p= 0.117). In the multivariate analysis, only Ki67 index ≥ 10% (HR 4.6, p= 0.000) and weak LIN28 protein expression (HR 2.0, p= 0.03) were independent predictors of recurrence in ACC patients. Interestingly, mir-9 expression, a negative LIN28A/B regulator, was significantly higher in aggressive than in non-aggressive ACCs [2076 (from 36 to 9307) vs. 133.4 (from 2.4 to 5193); p= 0.011] and was highly associated with reduced overall (p= 0.01) and disease-free survival (p= 0.01). However, mir-9 prognostic role should be further evaluated in a larger cohort.Conclusion
Weak LIN28 protein expression was associated with recurrence in ACCs. Additionally, overexpression of mir-9, a negative LIN28A regulator, was associated with poor outcome.This article is protected by copyright. All rights reserved.
[Show abstract][Hide abstract] ABSTRACT: Context:
IGF1R overexpression appears to be a prognostic biomarker of metastatic pediatric adrenocortical tumors. However, the molecular mechanisms that are implicated in its upregulation remain unknown. Aim. To investigate the potential mechanisms involved in IGF1R overexpression.
Patients and methods:
We studied 64 adrenocortical tumors. IGF1R copy number variation was determined in all patients using MLPA and confirmed using real time PCR. In a subgroup of 32 patients, automatic sequencing was used to identify IGF1R allelic variants and the expression of microRNAs involved in IGF1R regulation by real time PCR.
IGF1R amplification was detected in an adrenocortical carcinoma that was diagnosed in a 46-year-old woman with Cushing's syndrome and virilization. IGF1R overexpression was demonstrated in this case. In addition, gene amplification of other loci was identified in this adrenocortical malignant tumor, but no IGF1R copy number variation was evidenced in the remaining cases. Automatic sequencing revealed three known polymorphisms but they did not correlate with its expression. Expression of miR-100, miR-145, miR-375, and miR-126 did not correlate with IGF1R expression.
We demonstrated amplification and overexpression of IGF1R gene in only one adrenocortical carcinoma, suggesting that these combined events are uncommon. In addition, IGF1R polymorphisms and abnormal microRNA expression did not correlate with IGF1R upregulation in adrenocortical tumors.
BioMed Research International 07/2014; 2014:936031. DOI:10.1155/2014/936031 · 2.71 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: MicroRNAs play an essential role in posttranscriptional regulation of gene expression. They are evolutionary conserved, small, noncoding, 19-22-nucleotide RNAs, whose abnormalities, such as up- or downregulated expression, have been associated with several neoplasms, including adrenocortical tumors. Expression levels of distinct microRNAs can distinguish benign from malignant adrenal tumors. This current review provides recent data on the miRNAs profile in benign and malignant adrenocortical tumors diagnosed in adult and pediatric patients.
BioMed Research International 06/2014; 2014:381917. DOI:10.1155/2014/381917 · 3.17 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background: The sonic hedgehog (SHH) pathway plays a key role in rodent adrenal cortex development and is involved in tumorigenesis in several human tissues, but data in human adrenal glands are limited. Objectives: To analyze the involvement of the SHH pathway in human adrenal development and tumorigenesis and the effects of SHH inhibition on an adrenocortical tumor (ACT) cell line. Patients & Methods: Expression of SHH pathway components was evaluated by immunohistochemistry (IHC) in 51 normal adrenals (33 fetal) and 34 ACTs (23 pediatric), and by qPCR in 81 ACTs (61 pediatric) and 19 controls (10 pediatric). The effects of SHH pathway inhibition on gene expression and cell viability in the NCI-H295A adrenocortical tumor cell line after cyclopamine treatment were analyzed. Results: SHH pathway proteins were present in fetal and postnatal normal adrenals and showed distinct patterns of spatiotemporal expression throughout development. Adult ACCs presented with higher expression of PTCH1, SMO, GLI3 and SUFU compared with normal adult adrenal cortices. Conversely, pediatric ACTs showed lower mRNA expression of SHH, PTCH1, SMO, GLI1 and GLI3 compared with normal pediatric adrenal cortices. In vitro treatment with cyclopamine resulted in decreased GLI3, SFRP1, CTNNB1 mRNA expression and beta-catenin staining, as well as decreased cell viability. Conclusions: The SHH pathway is active in human fetal and postnatal adrenals, up regulated in adult ACCs and down regulated in pediatric ACTs. SHH pathway antagonism impaired cell viability. The SHH pathway is deregulated in ACTs and might provide a new target therapy to be explored.
The Journal of Clinical Endocrinology and Metabolism 04/2014; 99(7):jc20134098. DOI:10.1210/jc.2013-4098 · 6.21 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: ContextThe role of planar cell polarity (Wnt/PCP) and calcium-dependent (Wnt/Ca) noncanonical Wnt pathways in adrenocortical tumours (ACTs) is unknown.Objectives
To investigate gene expression of Wnt/PCP and Wnt/Ca pathways and its association with TP53 p.R337H and CTNNB1 mutations in paediatric and adult ACTs and to correlate these findings with clinical outcome.PatientsExpression of noncanonical Wnt-related genes was evaluated in 91 ACTs (66 children, 25 adults) by qPCR and beta-catenin, P53, and protein effectors of Wnt/Ca (NFAT) and Wnt/PCP (JNK) by immunohistochemistry. TP53 and CTNNB1 genes were sequenced.ResultsTP53 p.R337H mutation frequency was higher in children (86% vs 28%) while CTNNB1 mutation was higher in adults (32% vs 6%). Mortality was higher in adults harbouring TP53 p.R337H and in children with CTNNB1 mutations. Overexpression of WNT5A, Wnt/Ca ligand, was observed in children and adults. Overexpression of MAPK8 and underexpression of PRICKLE, Wnt/PCP mediators, were observed in paediatric, but not in adult cases. Cytoplasmic/nuclear beta-catenin and P53 accumulation were observed in the majority of pediatric and adult ACTs as well as NFAT and JNK. Overexpression of MAPK8 and underexpression of PRICKLE were associated with mortality in children while overexpression of WNT5A and underexpression of PRICKLE were associated with mortality in adults.Conclusions
In our study, TP53 p.R337H and CTNNB1 mutations correlated with poor prognosis in adults and children, respectively. We demonstrate, for the first time, the activation of Wnt/PCP and Wnt/Ca noncanonical pathway genes, and their association with poor outcome in children and adults, suggesting their putative involvement in ACTs aggressiveness.This article is protected by copyright. All rights reserved.
[Show abstract][Hide abstract] ABSTRACT: The onset of puberty is first detected as an increase in the amplitude and frequency of pulses of gonadotropin-releasing hormone (GnRH) after a quiescent period during childhood. The reemergence of pulsatile GnRH secretion leads to increases in the secretion of the gonadotropins, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) by the pituitary gland, and the consequent activation of gonadal function. Early activation of the hypothalamic-pituitary-gonadal axis results in gonadotropin-dependent precocious puberty, also known as central precocious puberty (CPP), which is clinically defined by the development of secondary sexual characteristics before the age of 8 years in girls and 9 years in boys. Pubertal timing is influenced by complex interactions among genetic, nutritional, environmental, and socioeconomic factors. CPP is diagnosed on the basis of clinical signs of progressive pubertal development before the age of 8 years in girls and 9 years in boys, pubertal basal and/or GnRH-stimulated LH levels, and advanced bone age. Magnetic resonance imaging of the central nervous system is essential for establishing the CPP form as organic or idiopathic. Depot GnRH-analogues represent the first-line of therapy in CPP. Very recently, the genetic component of CPP was demonstrated by the evidence that the deficiency of the MKRN3 gene, located on long arm of chromosome 15, causes familial CPP in humans. In this current review, clinical and therapeutic aspects of the CPP will be discussed, contributing to adequate diagnosis and criterious approach of this relevant condition of pediatric endocrinology.
Arquivos brasileiros de endocrinologia e metabologia 03/2014; 58(2):108-17. DOI:10.1590/0004-2730000002931 · 0.84 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Neurokinin B (NKB) and its G-protein-coupled receptor, NK3R, have been implicated in the neuroendocrine control of GnRH release; however, little is known about the structure-function relationship of this ligand-receptor pair. Moreover, loss-of-function NK3R mutations cause GnRH deficiency in humans. Using missense mutations in NK3R we previously identified in patients with GnRH deficiency, we demonstrate that Y256H and Y315C NK3R mutations in the fifth and sixth transmembrane domains (TM5 and TM6), resulted in reduced whole-cell (79.3±7.2%) or plasma membrane (67.3±7.3%) levels, respectively, compared with wild-type (WT) NK3R, with near complete loss of inositol phosphate (IP) signaling, implicating these domains in receptor trafficking, processing, and/or stability. We further demonstrate in a FRET-based assay that R295S NK3R, in the third intracellular loop (IL3), bound NKB but impaired dissociation of Gq-protein subunits from the receptor compared with WT NK3R, which showed a 10.0 ± 1.3% reduction in FRET ratios following ligand binding, indicating activation of Gq-protein signaling. Interestingly, R295S NK3R, identified in the heterozygous state in a GnRH-deficient patient, also interfered with dissociation of G proteins and IP signaling from wild-type NK3R, indicative of dominant-negative effects. Collectively, our data illustrate roles for TM5 and TM6 in NK3R trafficking and ligand binding and for IL3 in NK3R signaling.-Noel, S. D., Abreu, A. P., Xu, S., Muyide, T., Gianetti, E., Tusset, C., Carroll, J., Latronico, A. C., Seminara, S. B., Carroll, R. S., Kaiser, U. B. TACR3 mutations disrupt NK3R function through distinct mechanisms in GnRH-deficient patients.
The FASEB Journal 12/2013; 28(4). DOI:10.1096/fj.13-240630 · 5.04 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background:
The onset of puberty is first detected as an increase in pulsatile secretion of gonadotropin-releasing hormone (GnRH). Early activation of the hypothalamic-pituitary-gonadal axis results in central precocious puberty. The timing of pubertal development is driven in part by genetic factors, but only a few, rare molecular defects associated with central precocious puberty have been identified.
We performed whole-exome sequencing in 40 members of 15 families with central precocious puberty. Candidate variants were confirmed with Sanger sequencing. We also performed quantitative real-time polymerase-chain-reaction assays to determine levels of messenger RNA (mRNA) in the hypothalami of mice at different ages.
We identified four novel heterozygous mutations in MKRN3, the gene encoding makorin RING-finger protein 3, in 5 of the 15 families; both sexes were affected. The mutations included three frameshift mutations, predicted to encode truncated proteins, and one missense mutation, predicted to disrupt protein function. MKRN3 is a paternally expressed, imprinted gene located in the Prader-Willi syndrome critical region (chromosome 15q11-q13). All affected persons inherited the mutations from their fathers, a finding that indicates perfect segregation with the mode of inheritance expected for an imprinted gene. Levels of Mkrn3 mRNA were high in the arcuate nucleus of prepubertal mice, decreased immediately before puberty, and remained low after puberty.
Deficiency of MKRN3 causes central precocious puberty in humans. (Funded by the National Institutes of Health and others.).
New England Journal of Medicine 06/2013; 368(26). DOI:10.1056/NEJMoa1302160 · 55.87 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Hypogonadotropic hypogonadism (HH) or secondary hypogonadism is defined as a clinical syndrome that results from gonadal failure due to abnormal pituitary gonadotropin levels. HH may result from either absent or inadequate hypothalamic GnRH secretion or failure of pituitary gonadotropin secretion. Several congenital and acquired causes, including functional and organic forms, have been associated with this condition. One important aspect of the HH diagnosis is that it may reflect the presence of a tumor of the hypothalamic pituitary region or even a systemic disease. On the other hand, functional forms of HH, characterized by a transient defect in GnRH secretion, are relatively common in women, in response to significant weight loss, exercise, or stress leading to hypothalamic amenorrhea. HH is typically characterized by low circulating sexual steroids associated with low or inappropriately normal gonadotropin levels. The precise and early diagnosis of HH can prevent negative physical and psychological sequelae, preserve normal peak bone mass, and restore the fertility in affected patients.
The Journal of Clinical Endocrinology and Metabolism 05/2013; 98(5):1781-8. DOI:10.1210/jc.2012-3550 · 6.21 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The hypothalamic hormone GnRH has traditionally been viewed as a central driver of the hypothalamic-pituitary-gonadal axis. Pulsatile GnRH release is required for pulsatile gonadotropin secretion, which then modulates gonadal steroid feedback and brings about full fertility in the adult. Pathways governing GnRH ontogeny and physiology have been discovered by studying humans with disorders of GnRH secretion. In this chapter, the human genetics of the kisspeptin signaling pathway in patients with diverse reproductive phenotypes will be explored. The discovery of defects in the kisspeptin system in several reproductive disorders has shed light on the mechanisms involved in regulating GnRH secretion, revealing the critical role played by the kisspeptin signaling pathway in pubertal initiation and reproductive function.
Advances in Experimental Medicine and Biology 04/2013; 784:187-99. DOI:10.1007/978-1-4614-6199-9_9 · 1.96 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Pituitary gonadotropins are essential for normal reproductive function. LH and FSH exert their effects by acting on G protein-coupled receptors. Pituitary LH and placental hCG share the same receptor (LHCGR). Homozygous or compound heterozygous inactivating mutations of LHCGR are associated with a phenotypic spectrum from female or ambiguous external genitalia due to Leydig cell hypoplasia to micropenis, hypergonadotropic hypogonadism and delayed puberty in genetic males. Testes size is slightly reduced, and testosterone levels are low in affected males. Interestingly, the clinical phenotypes are closely correlated with the severity of the mutation. In females, the phenotype is also variable and can range from primary amenorrhea to oligoamenorrhea, associated with constant infertility. Estradiol and progesterone levels remain in the early to mid-follicular phase, whereas the ovaries are normal or enlarged with cysts. In both sexes, LH levels are increased, whereas FSH is usually normal. Inactivating mutations of FSH receptor are associated with partial to complete premature ovarian failure in women and variable impairment of spermatogenesis and small testes in men. Mutations of the human gonadotropin receptors provide natural models for elucidating the differential effects of LH and FSH on the gonads.
Endocrine development 02/2013; 24:25-32. DOI:10.1159/000342496
[Show abstract][Hide abstract] ABSTRACT: Pod-1/Tcf21 is expressed at epithelial-mesenchymal interaction sites during development of many organs. Different approaches have demonstrated that Pod-1 transcriptionally inhibits Sf-1/NR5A1 during gonadal development. Disruption of Sf-1 can lead to disorders of adrenal development, while increased dosage of SF-1 has been related to increased adrenal cell proliferation and tumorigenesis. In this study, we analyzed whether POD-1 overexpression inhibits the endogenous Sf-1 expression in human and mouse adrenocortical tumor cells. Cells were transiently transfected with luciferase reporter gene under the control of Sf-1 promoter and with an expression vector encoding Pod-1. Pod-1 construct inhibited the transcription of the Sf1/Luc reporter gene in a dose-dependent manner in mouse Y-1 adrenocortical carcinoma (ACC) cells, and inhibited endogenous SF-1 expression in the human H295R and ACC-T36 adrenocortical carcinoma cells. These results were validated by chromatin immunoprecipitation assay with POD-1-transfected H295R cells using primers specific to E-box sequence in SF-1 promoter region, indicating that POD-1 binds to the SF-1 E-box promoter. Moreover, POD-1 over-expression resulted in a decrease in expression of the SF-1 target gene, StAR (Steroidogenic Acute Regulatory Protein). Lastly, while the induced expression of POD-1 did not affect the cell viability of H295R/POD-1 or ACC-T36/POD-1 cells, the most significantly enriched KEGG pathways for genes negatively correlated to POD-1/TCF21 in 33 human ACCs were those associated with cell cycle genes.