title: Expression of hypoxia-inducible factor-1alpha (HIF-1alpha) in pituitary tumours.
abstract: The present study was performed to investigate HIF-1alpha (hypoxia-inducible factor-1alpha) expression in a large number of immunohistochemically and ultrastructurally characterized surgically removed pituitary tumours. The potential relation of HIF-1alpha with outcome variables as well as the presence of HIF-1alpha expression in the tumours treated with dopamine agonists and octreotide, a long-acting somatostatin analogue was also investigated. HIF-1alpha immunoreactivity was confined to the nucleoplasm whereas the nucleoli were unconspicuous. The distribution of HIF-1alpha was evident in the tumours whereas normal adenohypophysial cells showed no HIF-1alpha staining. HIF-1alpha expression was detected not only in the tumour cells but also in endothelial cells lining the blood vessels within the tumour. ACTH producing adenomas showed the lowest level of HIF-1alpha expression whereas pituitary carcinomas and GH producing adenomas had the highest counts. The statistical study demonstrated no significant correlation between HIF-1alpha expression, patient age, gender, tumour, size, invasiveness, cell proliferation rate and vascularity. These results suggest that the behaviour of pituitary tumours does not primarily depend of HIF-1alpha expression. Our study demonstrated an increase HIF-1alpha expression in bromocriptine treated PRL producing pituitary adenomas compared with untreated tumours but no increase in octreotide treated tumours.
authors.affiliation: Department of Anatomy, Laboratory of Histology, University of Santiago de Compostela, Lugo, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Vidal
authors.forename: E
authors.initials: E
authors.lastname: Horvath
authors.forename: K
authors.initials: K
authors.lastname: Kovacs
authors.forename: T
authors.initials: T
authors.lastname: Kuroki
authors.forename: R V
authors.initials: RV
authors.lastname: Lloyd
authors.forename: B W
authors.initials: BW
authors.lastname: Scheithauer
mesh_terms: D000236:Adenoma / Q000378:metabolism; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D018931:Antineoplastic Agents, Hormonal / Q000494:pharmacology; D001971:Bromocriptine / Q000494:pharmacology; D002277:Carcinoma / Q000378:metabolism / Q000473:pathology; D002455:Cell Division; D002466:Cell Nucleolus / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D002648:Child; D003593:Cytoplasm / Q000378:metabolism; D018491:Dopamine Agonists / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000378:metabolism; D005260:Female; D006727:Hormone Antagonists / Q000494:pharmacology; D006728:Hormones / Q000494:pharmacology; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D007150:Immunohistochemistry; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D009389:Neovascularization, Pathologic; D015282:Octreotide / Q000494:pharmacology; D010911:Pituitary Neoplasms / Q000098:blood supply / Q000378:metabolism* / Q000473:pathology; D013004:Somatostatin / Q000031:analogs & derivatives; D014157:Transcription Factors / Q000096:biosynthesis*
chemical_list: D018931:Antineoplastic Agents, Hormonal; D018491:Dopamine Agonists; C497442:HIF1A protein, human; D006727:Hormone Antagonists; D006728:Hormones; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D014157:Transcription Factors; D001971:Bromocriptine; D013004:Somatostatin; D015282:Octreotide