Endocrine Abstracts

Background: True cyclical Cushing's syndrome is rare and usually due to an ACTH-secreting corticotrophinoma. We describe a man with cyclical Cushing's syndrome of 15 years duration who had unexpected pituitary immunohistopathology.Clinical details: A 22-year-old man presented in 1986 with clinical features of Cushing's syndrome & urinary free cortisols up to 1800 nmol/24h, but normal low-dose DXM suppression, & normal pituitary and adrenals on CT. He was then lost ...

Tyrosine kinase inhibitors have previously been shown to inhibit DNA synthesis in human pituitary adenomas (Jones et al JCEM 1997; 82: 2143-7). ZD1839 ('Iressa'), a selective inhibitor of the epidermal growth factor receptor (EGFR) tyrosine kinase, is currently undergoing clinical trials in human cancers. We have investigated the effects of ZD1839 and EGF in the human pituitary cell line HP75 (derived by SV40 transfection of a human pituitary silent gonadotrophinoma) and in s...

The cytokine IL-6 is synthesed and released by over half of surgically removed human pituitary adenomas and by the HP75 human pituitary tumour cell line. We have previously shown that IL6 is associated with tumour invasiveness but not with Ki67, a marker of cell proliferation. Membrane IL6R (mIL6R) has been demonstrated in some pituitary adenomas, however, we have shown that sIL6R is not shed by the majority (92%) of human pituitary adenomas in culture nor by HP75 cells(super)...