Searchable abstracts of presentations at key conferences in endocrinology

ea0026p37 | Adrenal cortex | ECE2011

Thoracic and gastroenteropancreatic (GEP) neuroendocrine tumors (NETs) and the ectopic ACTH syndrome (EAS)

Kamp K , Alwani A , Feelders R A , de Herder W W

Introduction: The ectopic ACTH syndrome (EAS) is associated with a variety of malignancies, mostly of (neuro-)endocrine origin. Several series report on the relative contribution of EAS in the spectrum of Cushing’s syndrome. However, information on the incidence/prevalence of EAS in the setting of patients diagnosed with thoracic or gastroenteropancreatic (GEP) neuroendocrine tumours (NETs) is virtually absent.Study design: In our tertiary academic ...

ea0026p33 | Adrenal cortex | ECE2011

Response of human adrenocortical carcinoma cell lines to cytostatic drugs and mitotane and the role of the multidrug resistance pump MDR1

van Koetsveld P M , Dogan F , Misier M B , Feelders R A , de Herder W W , Hofland L J

Introduction: In case of inoperable disease or tumor recurrence, therapy with mitotane (MIT), sometimes in combination with doxorubicin (DOX), etoposide (ETO), cisplatin (CIS) or streptozocin (STREP), is frequently applied in patients with adrenocortical carcinoma (ACC). The multidrug resistance pump MDR1 is responsible for resistance of tumor cells to cytostatic drugs. The activity of MDR1 is inhibited by the calcium-channel blocker verapamil. There are equivocal data in the ...

ea0026oc5.4 | Hormone metabolism and action | ECE2011

Adrenal melanocortin 2 receptor associated protein (MRAP) expression is regulated by ACTH and angiotensin II, whereas MRAP2 levels are associated with ACTH responsiveness

Hofland J , Delhanty P J , Steenbergen J , Hofland L J , van Koetsveld P M , van Nederveen F H , de Herder W W , Feelders R A , de Jong F H

Introduction: ACTH stimulates adrenocortical steroid production through the melanocortin 2 receptor (MC2R). MC2R trafficking and signaling depend on the melanocortin 2 receptor accessory protein (MRAP). The MRAP-homolog MRAP2 also transports the MC2R but prevents effective activation. We investigated expression of these components of the MC2R complex in human adrenal tissues in order to uncover novel regulatory mechanisms and their contribution to ACTH responsiveness.<p cl...

ea0026p291 | Pituitary | ECE2011

GH receptor mRNA expression and the effect of pegvisomant on GH secretion by somatotroph pituitary adenomas

Neggers S J C M M , Bidlingmaier M , van Koetsveld P M , Feelders R A , Sprij-Mooij D M , de Herder W W , van der Lely A J , Hofland L J

Background: Of the currently available treatment regimes for acromegaly, pegvisomant (PEG-V) has the highest efficacy. During PEG-V treatment, GH serum levels increase. The exact mechanism behind this is remains unclear. It could be explained by an ultra-short feedback loop via GH receptors in the anterior pituitary gland.Objective: To assess the level of GH receptor (GHR) mRNA expression in somatotroph adenomas and to evaluate whether GHR blockade by PE...

ea0026p363 | Adrenal medulla | ECE2011

Expression of IGF/mTOR pathway components in human pheochromocytomas and in vitro inhibition of PC12 rat pheochromocytoma cell growth by mTOR inhibitors

De Martino M C , Feelders R A , van Koetsveld P M , De Krijger R R , Janssen J A M J L , Sprij-Mooij D , Lamberts S W J , de Herder W W , Colao Annamaria , Pivonello Rosario , Hofland Leo

The pathogenesis of pheochromocytomas (pheo) is poorly understood and malignant pheo need new treatment options. mTOR inhibitors, as sirolimus (S) and everolimus (E), are new promising antineoplastic drugs.Aim: To evaluate whether the IGF/mTOR pathways have a role in the pathogenesis and whether S and E may have antiproliferative effects in pheo.In 24 human pheo and two normal adrenal medulla (NM), we evaluated the mRNA expression ...