Searchable abstracts of presentations at key conferences in endocrinology

ea0049ep182 | Endocrine tumours and neoplasia | ECE2017

Effects of ketoconazole on ACTH-producing and non ACTH-producing neuroendocrine tumor cells

Herrera-Martinez Aura D , Feelders Richard , Castano Justo , Dogan Fadime , Koetsveld Peter van , Hofland Leo

Prolonged spontaneous remission of hypercortisolemia in ectopic ACTH syndrome after long-term treatment with steroidogenesis inhibitors has been described. Direct drug effect on the adrenal glands, effects on tumoral ACTH secretion and/or POMC gene expression have been suggested. Medical treatment could be used for symptoms, but also for disease control.Materials and methods: In human BON-1 and DMS-79 cells, we have evaluated the effects of keto...

ea0049ep933 | Pituitary - Basic | ECE2017

Acquired temozolomide resistance in ACTH-secreting pituitary tumour cells

Silva Ticiana , Van Koetsveld Peter , Dogan Fadime , Feelders Richard , Hofland Leo

Introduction: Temozolomide (TMZ) treatment has been used for aggressive pituitary tumours with positive results, but has proven ineffective in controlling tumour regrowth in cases of disease recurrence. TMZ resistance has been linked to the expression of O6-methyl-guanine-DNA-methyltransferase (MGMT) protein and mismatch repair components (MMR). In the present study, we describe the development of an in vitro model of acquired resistance to TMZ and the mechanisms invo...

ea0099ep702 | Pituitary and Neuroendocrinology | ECE2024

Long-term exposure of corticotroph pituitary tumor cells to glucocorticoid results in resistance to its anti-proliferative effect

Silva Ticiana , Dogan Fadime , Iyer Anand , van Koetsveld Peter , Feelders Richard , Hofland Leo

Background: Cortisol has a suppressive effect on corticotroph proliferation. In Cushing’s disease (CD), the relative resistance to glucocorticoid (GC) action may favor corticotroph tumor formation and autonomous ACTH secretion.Objective: To analyze the consequences of long-term GC exposure on corticotroph tumor cell proliferation and to evaluate the modification of gene expression attributable to prolonged GC treatment.Methods...

ea0035p62 | Adrenal Medulla | ECE2014

Expression of IGF/mTOR pathway components in human pheochromocytomas and in vitro inhibition of PC12 rat pheochromocytoma cell growth by mTOR inhibitors alone and in combination with the dual IGFI-R/INS-R antagonist OSI-906

Martino Maria Cristina De , Feelders Richard A. , Dogan Fadime , Koetsveld Peter M. van , Krijger Ronald R. De , Janssen Joseph A M J L , Sprij-Mooij Diana , Lamberts Steven W. J. , Herder Wouter W de , Colao Annamaria , Pivonello Rosario , Hofland Leo J

The mTOR and IGF pathways have been suggested to play a role in the pathogenesis of pheochromocytomas (PCC). mTOR inhibitors, as sirolimus (S) and everolimus (E), as well as IGF1R antagonists could be a potential novel treatment for malignant PPC.The aim of this study was to evaluate the expression of the main components of the IGF/mTOR pathway in human PCC and to investigate the effects of the mTOR inhibitors S and E and of the IGF1R/insulin receptor (I...