Morphologic changes and molecular regulation of angiogenesis in pituitary adenomas.
Angiogenesis, the process of development of a new vasculature, plays a crucial role in tumour growth. In the pituitary, unlike other tissues, vascularization is lower in adenomas compared to the normal gland. Despite this finding, a relationship between increased vascularity and some aspects of tumour behaviour such as size, invasiveness, surgical outcome and malignancy, has been demonstrated. The process of angiogenesis is the result of a balance of stimulating and inhibiting factors. It is likely that an interaction between gene expression (such as pituitary tumour transforming gene), hormonal stimuli including oestrogens, corticosteroids, dopamine, 16-kDa fragments of prolactin and growth hormone, somatostatin analogues, and pro- and anti-angiogenic growth factors (e.g. vascular endothelial growth factor and fibroblast growth factor), determine the final angiogenic phenotype of pituitary tumours, and thus subsequent tumour behaviour.
Endocrinology Department, The Oxford Centre for Diabetes, Endocrinology and Metabolism, Churchill Hospital, Headington, Oxford, UK.
N Garcia
NG
de la Torre
J A H
JA
Wass
H E
HE
Turner
D000236:Adenoma / Q000098:blood supply*; D000818:Animals; D015870:Gene Expression; D006801:Humans; D009389:Neovascularization, Pathologic / Q000209:etiology / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology*; D010911:Pituitary Neoplasms / Q000098:blood supply*