Somatic mosaicism underlies X-linked acrogigantism (XLAG) syndrome in sporadic male subjects
Daly, Adrian Francis ; ; et al
in Endocrine-Related Cancer (2016)
Somatic mosaicism has been implicated as a causative mechanism in a number of genetic and genomic disorders. X-linked acrogigantism (XLAG) syndrome is a recently characterized genomic form of pediatric ... [more ▼]
Somatic mosaicism has been implicated as a causative mechanism in a number of genetic and genomic disorders. X-linked acrogigantism (XLAG) syndrome is a recently characterized genomic form of pediatric gigantism due to aggressive pituitary tumors that is caused by submicroscopic chromosome Xq26.3 duplications that include GPR101. We studied XLAG syndrome patients (N=18) to determine if somatic mosaicism contributed to the genomic pathophysiology. Eighteen subjects with XLAG syndrome were identified with Xq26.3 duplications using high definition array comparative genome hybridization (HD-aCGH). We noted males with XLAG had a decreased log2 ratio compared with expected values, suggesting potential mosaicism, while females showed no such decrease. As compared with familial male XLAG cases, sporadic males had more marked evidence for mosaicism, with levels of Xq26.3 duplication between 16.1-53.8%. These characteristics were replicated using a novel, personalized breakpoint-junction specific quantification droplet digital PCR (ddPCR) technique. Using a separate ddPCR technique we studied the feasibility of identifying XLAG syndrome cases in a distinct patient population of 64 unrelated subjects with acromegaly/gigantism and identified one female gigantism patient that had increased copy number variation (CNV) threshold for GPR101 that was subsequently diagnosed as having XLAG syndrome on HD-aCGH. Employing a combination of HD-aCGH and novel ddPCR approaches, we have demonstrated that XLAG syndrome can be caused by variable degrees of somatic mosaicism for duplications at chromosome Xq26.3. Somatic mosaicism was shown to occur in sporadic males but not in females with XLAG syndrome, although the clinical characteristics of the disease were similarly severe in both sexes. [less ▲]Detailed reference viewed: 17 (7 ULg)
Breast cancer in a male to female transsexual patient with a BRCA2 mutation
CORMAN, Vinciane ; Potorac, Iulia ; Manto, Florence et al
in Endocrine-Related Cancer (2016)Detailed reference viewed: 24 (6 ULg)
Screening for GPR101 defects in pediatric pituitary corticotropinomas.
; ; et al
in Endocrine-related cancer (2016)
Cushing disease (CD) in children is caused by adrenocorticotropic hormone (ACTH)-secreting pituitary adenomas. Germline or somatic mutations in genes such as MEN1, CDKIs, AIP, and USP8 have been ... [more ▼]
Cushing disease (CD) in children is caused by adrenocorticotropic hormone (ACTH)-secreting pituitary adenomas. Germline or somatic mutations in genes such as MEN1, CDKIs, AIP, and USP8 have been identified in pediatric CD, but the genetic defects in a significant percentage of cases are still unknown. We investigated the orphan G protein-coupled receptor GPR101, a gene known to be involved in somatotropinomas, for its possible involvement in corticotropinomas. We performed GPR101 sequencing, expression analyses by RT-qPCR and immunostaining, and functional studies (cell proliferation, pituitary hormones secretion, and cAMP measurement) in a series of patients with sporadic CD secondary to ACTH-secreting adenomas in whom we had peripheral and tumor DNA (N=36). No increased GPR101 expression was observed in tumors compared to normal pituitary (NP) tissues, nor did we find a correlation between GPR101 and ACTH expression levels. Sequence analysis revealed a very rare germline heterozygous GPR101 variant (p.G31S) in one patient with CD. Overexpression of the p.G31S variant did not lead to increased growth and proliferation, although modest effects on cAMP signaling were seen. GPR101 is not overexpressed in ACTH-secreting tumors compared to NPs. A rare germline GPR101 variant was found in one patient with CD but in vitro studies did not support a consistent pathogenic effect. GPR101 is unlikely to be involved in the pathogenesis of CD. [less ▲]Detailed reference viewed: 12 (2 ULg)
X-linked acrogigantism (X-LAG) syndrome : Clinical Profile and Therapeutic responses
Beckers, Albert ; ; et al
in Endocrine-Related Cancer (2015), 22Detailed reference viewed: 22 (11 ULg)
Pituitary MRI characteristics in 297 acromegaly patients based on T2-weighted sequences.
Potorac, Iulia ; PETROSSIANS, Patrick ; Daly, Adrian et al
in Endocrine-related cancer (2015)
Context: Responses of GH-secreting adenomas to multimodal management of acromegaly varies widely between patients. Understanding the behavioral patterns of GH-secreting adenomas by identifying predictive ... [more ▼]
Context: Responses of GH-secreting adenomas to multimodal management of acromegaly varies widely between patients. Understanding the behavioral patterns of GH-secreting adenomas by identifying predictive factors of their evolution is a research priority. Objective: To clarify the relationship between adenoma T2-weighted signal on diagnostic MRI in acromegaly and clinical and biological features at diagnosis. Design: International, multicenter, retrospective analysis. Setting: 10 endocrine tertiary referral centers. Patients: 297 acromegalic recently diagnosed patients with available diagnostic MRI evaluations were included in the study. Main outcome measure: Clinical, biochemical characteristics and MRI signal findings. Results: T2-hypointense adenomas represented 52.9% of the series, were smaller than their T2-hyper- and isointense counterparts (p<0.0001), were associated with higher IGF1 levels (p=0.0001), invaded the cavernous sinus less frequently (p=0.0002) and rarely caused optic chiasm compression (p<0.0001). Acromegalic men tended to be younger at diagnosis than women (p=0.067) and presented higher IGF1 values (p=0.01). Although in total, adenomas had a predominantly inferior extension in 45.8% of cases, in men this was more frequent (p<0.0001), whereas in women optic chiasm compression of macroadenomas occurred more often (p=0.0067). Most adenomas (45.1%) measured between 11-20mm in maximal diameter and bigger adenomas were diagnosed at younger ages (p=0.0001). Conclusions: T2-weighted signal differentiates GH-secreting adenomas into subgroups with particular behaviors. This raises the question of whether T2-weighted signal could represent a factor in the classification of acromegalic patients in future studies. [less ▲]Detailed reference viewed: 39 (8 ULg)
Clinical and genetic characterization of pituitary gigantism: an international collaborative study in 208 patients.
Rostomyan, Liliya ; Daly, Adrian ; PETROSSIANS, Patrick et al
in Endocrine-related cancer (2015)
Despite being a classical growth disorder, pituitary gigantism has not been studied previously in a standardized way. We performed a retrospective, multicenter, international study to characterize a large ... [more ▼]
Despite being a classical growth disorder, pituitary gigantism has not been studied previously in a standardized way. We performed a retrospective, multicenter, international study to characterize a large series of pituitary gigantism patients. We included 208 patients (163 males; 78.4%) with growth hormone excess and current/previous abnormal growth velocity for age or final height >2SD above country normal means. The median onset of rapid growth was 13.0 years and occurred significantly earlier in females than in males; pituitary adenomas were diagnosed earlier in females than males (15.8 vs. 21.5 years, respectively). Adenomas were >/=10 mm (i.e. macroadenomas) in 84%, of which extrasellar extension occurred in 77% and invasion in 54%. GH/IGF-1 control was achieved in 39% during long-term follow-up. Final height was greater in those with younger age of onset, with larger tumors and higher GH levels. Later disease control was associated with a greater difference from mid-parental height (r=0.23, P=0.02). AIP mutations occurred in 29%; microduplication at Xq26.3 -X-linked acro-gigantism (X-LAG)- occurred in two familial isolated pituitary adenoma (FIPA) kindreds and in ten sporadic patients. Tumor size was not different in X-LAG, AIP mutated and genetically-negative patient groups. AIP-mutated and X-LAG patients had significantly younger age at onset and diagnosis, but disease control was worse in genetically-negative cases. Pituitary gigantism patients are characterized by male predominance and large tumors that are difficult to control. Treatment delay increases final height and symptom burden. AIP mutations and X-LAG explain many cases, but no genetic etiology is seen in >50% of cases. [less ▲]Detailed reference viewed: 48 (13 ULg)
Growth hormone releasing hormone excess and blockade in X-LAG syndrome.
Daly, Adrian Francis ; ; et al
in Endocrine-related cancer (2015)
X-linked acrogigantism (X-LAG) syndrome is a newly-described form of inheritable pituitary gigantism that begins in early childhood and is usually associated with markedly elevated growth hormone (GH) and ... [more ▼]
X-linked acrogigantism (X-LAG) syndrome is a newly-described form of inheritable pituitary gigantism that begins in early childhood and is usually associated with markedly elevated growth hormone (GH) and prolactin secretion by mixed pituitary adenomas/hyperplasia. Microduplications on chromosome Xq26.3 including the GPR101 gene cause X-LAG syndrome. In individual cases random GH-releasing hormone (GHRH) levels have been elevated. We performed a series of hormonal profiles in a young female sporadic X-LAG syndrome patient and subsequently undertook in vitro studies of primary pituitary tumor culture following neurosurgical resection. The patient demonstrated consistently elevated circulating GHRH levels throughout preoperative testing, which was accompanied by marked GH and prolactin hypersecretion; GH demonstrated a paradoxical increase following TRH administration. In vitro, the pituitary cells showed baseline GH and prolactin release that was further stimulated by GHRH administration. Co-incubation with GHRH and the GHRH receptor antagonist, acetyl-(D-Arg(2))-GHRH (1-29) amide, blocked the GHRH-induced GH stimulation; the GHRH receptor antagonist alone significantly reduced GH release. Pasireotide, but not octreotide, inhibited GH secretion. A ghrelin receptor agonist and an inverse agonist led to modest, statistically significant increases and decreases in GH secretion, respectively. GHRH hypersecretion can accompany the pituitary abnormalities seen in X-LAG syndrome. These data suggest that the pathology of X-LAG syndrome may include hypothalamic dysregulation of GHRH secretion, which is in keeping with localization of GPR101 in the hypothalamus. Therapeutic blockade of GHRH secretion could represent a way to target the marked hormonal hypersecretion and overgrowth that characterizes X-LAG syndrome. [less ▲]Detailed reference viewed: 27 (8 ULg)
A bittersweet symphony.
Daly, Adrian ; Beckers, Albert
in Endocrine-related cancer (2014)
This issue sees the publication of work expanding the range of how genetic dysregulation of SDHx genes can cause cancer syndromes with a prominent endocrine component, in this case Carney triad, which is ... [more ▼]
This issue sees the publication of work expanding the range of how genetic dysregulation of SDHx genes can cause cancer syndromes with a prominent endocrine component, in this case Carney triad, which is characterized by gastrointestinal stromal tumors (GIST), paraganglioma and pulmonary chondromas. [less ▲]Detailed reference viewed: 39 (4 ULg)
Somatostatin analogues increase AIP expression in somatotropinomas, irrespective of Gsp mutations
; ; et al
in Endocrine-Related Cancer (2013), 20Detailed reference viewed: 34 (10 ULg)
Cyclin dependent kinase inhibitor (CDKN1B) gene variants in AIP mutation-negative familial isolated pituitary adenomas (FIPA) kindreds
; ; et al
in Endocrine-Related Cancer (2012), 19Detailed reference viewed: 14 (6 ULg)
Hyperplasia-adenoma sequence in pituitary tumorigenesis related to aryl hydrocarbon receptor interacting protein gene mutation.
; ; et al
in Endocrine-Related Cancer (2011)
Mutations of the aryl hydrocarbon receptor interacting protein (AIP) gene are associated with pituitary adenomas that usually occur as familial isolated pituitary adenomas (FIPA). Detailed pathological ... [more ▼]
Mutations of the aryl hydrocarbon receptor interacting protein (AIP) gene are associated with pituitary adenomas that usually occur as familial isolated pituitary adenomas (FIPA). Detailed pathological and tumor genetic data on AIP mutation-related pituitary adenomas are scarce. Non-identical twin females presented as adolescents to the emergency department with severe progressive headaches caused by large pituitary macroadenomas requiring emergency neurosurgery; one patient had incipient pituitary apoplexy. Post-surgically the patients were found to have silent somatotrope adenomas on pathological examination. Furthermore, the light microscopic, immunohistochemical and electron microscopic studies demonstrated tumors of virtually identical characteristics. The adenomas were accompanied by multiple areas of pituitary hyperplasia, which stained positively for growth hormone, indicating somatotrope hyperplasia. Genetic analyses of the FIPA kindred revealed a novel E216X mutation of the AIP gene, which was present in both affected patients and the unaffected father. Molecular analysis of surgical specimens revealed loss of heterozygosity (LOH) in the adenoma, but showed that LOH was not present in the hyperplasic pituitary tissue from either patient. AIP immunostaining confirmed normal staining in the hyperplastic tissue and decreased staining in the adenoma in the tumors from both patients. These results demonstrate that patients with AIP germline mutation can present with clinically silent somatotroph pituitary adenomas. The finding of somatotrope hyperplasia unaccompanied by AIP LOH, suggests that LOH at the AIP locus may be a late event in the progression from hyperplastic to adenomatous tissue. [less ▲]Detailed reference viewed: 34 (7 ULg)
Expression of aryl hydrocarbon receptor (AHR) and AHR-interacting protein in pituitary adenomas: pathological and clinical implications.
; ; et al
in Endocrine-Related Cancer (2009), 16(3), 1029-1043
Germline mutations of the aryl hydrocarbon receptor (AHR)-interacting protein (AIP) gene confer a predisposition to pituitary adenomas (PA), usually in the setting of familial isolated PA. To provide ... [more ▼]
Germline mutations of the aryl hydrocarbon receptor (AHR)-interacting protein (AIP) gene confer a predisposition to pituitary adenomas (PA), usually in the setting of familial isolated PA. To provide further insights into the possible role of AIP in pituitary tumour pathogenesis, the expression of AIP and AHR was determined by real-time RT-PCR and/or immunohistochemistry (IHC) in a large series of PA (n=103), including 17 with AIP mutations (AIP(mut)). Variable levels of AIP and AHR transcripts were detected in all PA, with a low AHR expression (P<0.0001 versus AIP). Cytoplasmic AIP and AHR were detected by IHC in 84.0 and 38.6% of PA respectively, and significantly correlated with each other (P=0.006). Nuclear AHR was detected in a minority of PA (19.7%). The highest AIP expression was observed in somatotrophinomas and non-secreting (NS) PA, and multivariate analysis in somatotrophinomas showed a significantly lower AIP immunostaining in invasive versus non-invasive cases (P=0.019). AIP expression was commonly low in other secreting PA. AIP immunostaining was abolished in a minority of AIP(mut) PA, with a frequent loss of cytoplasmic AHR and no evidence of nuclear AHR. In contrast, AIP overexpression in a subset of NS PA could be accompanied by nuclear AHR immunopositivity. We conclude that down-regulation of AIP and AHR may be involved in the aggressiveness of somatotrophinomas. Overall, IHC is a poorly sensitive tool for the screening of AIP mutations. Data obtained on AHR expression suggest that AHR signalling may be differentially affected according to PA phenotype. [less ▲]Detailed reference viewed: 38 (10 ULg)
Oxytocin- and vasopressin-induced growth of human small-cell lung cancer is mediated by the mitogen-activated protein kinase pathway
Pequeux, Christel ; ; et al
in Endocrine-Related Cancer (2004), 11(4), 871-885
Malignant growth of small-cell lung carcinoma is promoted by various neuroendocrine autocrine/paracrine loops. Therefore, to interfere with this mitogenic process, it is crucial to elucidate the ... [more ▼]
Malignant growth of small-cell lung carcinoma is promoted by various neuroendocrine autocrine/paracrine loops. Therefore, to interfere with this mitogenic process, it is crucial to elucidate the mechanisms involved. It is known that the oxytocin (OT) and vasopressin (VP) genes, normally transcriptionally restricted in their expression, are activated in small-cell lung cancer (SCLC), concomitantly with expression of their receptors (OTR, V1aR, V1bR/V3R and V2R). The aim of the present study was to characterize, in concentrations close to physiological and pharmacological conditions, intracellular signalling events triggered by OT and VP binding to their specific receptors in SCLC cells and to identify factors mediating OT- and VP-induced mitogenic effects on SCLC. Known agonists for OTR ([Thr(4),GlY(7)]OT) and V1aR (F180), in addition to OT and VP, were able to elicit increases in cytosolic Ca2+ levels and this effect could be blocked using an OTR antagonist (OVTA) or a V1aR antagonist (SR49059) respectively. There was no activation of the cAMP pathway detected after VP, dDAVP (a V2R agonist), or OT treatment. Stimulation of SCLC cells with OT and VP led to an increase of extracellular signal-regulated kinase (ERK) 1/2 phosphorylation, maximal at 5 min, and the subsequent phosphorylation of its downstream target p90 ribosomal S6 kinase (p90(RSK)). Pre-incubation with OVTA and SR49059, and with inhibitors of phospholipase C (PLC), protein kinase C (PKC), mitogen-activated protein kinase/ERK kinase (MEK) 1/2 and a Ca2+ chelator significantly reduced OT- and VP-induced ERK1/2 phosphorylations. OVTA, SR49059 as well as MEK1/2 and PKC inhibitors also downregulated OT- and VP-induced p90RSK phosphorylation. In [H-3]thymidine-uptake 2, experiments, we subsequently observed that PLC, Ca2+, PKC and ERK1/2 are absolutely required for the OT- and VP-stimulated SCLC cellular growth process. In conclusion, the results presented here indicate that OT- and VP-induced mitogenic effects on SCLC are respectively mediated by OTR and V1aR signalling and that this mitogenic signalling passes through the phosphorylation of ERK1/2 and p90(RSK) in a PLC-, Ca2+-, PKC- and MEK1/2-dependent pathway. [less ▲]Detailed reference viewed: 28 (2 ULg)