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: 13 (5 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: 35 (4 ULg)
Somatostatin analogues increase AIP expression in somatotropinomas, irrespective of Gsp mutations
; ; et al
in Endocrine-Related Cancer (2013), 20Detailed reference viewed: 33 (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: 32 (6 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: 37 (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)