Ary Hydrocarbon receptor interacting protein (AIP) on somatotroph adenomas : a molecular target for somatostatin analogues ?

in Endocrine abstracts - May 2012, volume 29 (2012, May)

Factors associated with AIP expression in somatotropinomas and the possible influence of somatostatin analogues

in European Neuroendocrine Association - Liège, 22-25 septembre 2010 (2010, September)

Somatotropinomas in patients with germline AIP mutations: absence of somatic mutations in the GNAS1 gene

in European Neuroendocrine Association - Liège, 22-25 septembre 2010 (2010, September)

Expression of aryl hydrocarbon receptor (AHR) and AHR-interacting protein in pituitary adenomas: pathological and clinical implications.

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 ▲]

Aryl Hydrocarbon Receptor (AHR) and AHR Interacting Protein (AIP) expression in human GH/PRL-secreting pituitary adenomas

in Italian Congress of Endocrinology - Giornate Endocrinologiche Pisane GEP 2008 : Pisa 2008 (2008)