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Open AccessJournal ArticleDOI

17β-Hydroxysteroid Dehydrogenase Type 1, 2, 3, and 4 Expression and Enzyme Activity in Human Anterior Pituitary Adenomas

TLDR
All 4 17BetaHSD isoforms are variably expressed in human anterior pituitary adenomas, which also show 17betaHSD enzyme activity, suggesting that 17 betaHSD may play an important role in regulating the local cellular levels of estradiol.
Abstract
17Beta-hydroxysteroid dehydrogenase (17betaHSD) isoforms reversibly catalyze the final step in the formation of estradiol (E2) from estrone (E1) and the formation of testosterone from androstenedione. We have investigated 17betaHSD type 1, 2, 3, and 4 gene expression and 17betaHSD estrogenic activity in human anterior pituitary adenomas. 17BetaHSD messenger ribonucleic acid (mRNA) expression was studied by RT-PCR in 42 pituitary tumors and 3 normal pituitaries, 17betaHSD activity was studied in 11 tumors and 17betaHSD type 1 was immunolocalized in vitro in 6 tumors. 17BetaHSD type 1 gene expression was detected in 34 of 42 adenomas in all tumor subtypes; 17betaHSD type 2 mRNA was detected in 18 of 42 adenomas, but not in prolactinomas; 17betaHSD type 3 mRNA was detected in 12 of 42 adenomas, but not in corticotropinomas; 17betaHSD type 4 was expressed in 20 of 42 adenomas by all adenoma subtypes. Reversible 17betaHSD activity was found in 9 of 11 adenomas, and 17betaHSD type 1 immunopositivity was cytoplasmically distributed in all 6 adenomas in vitro. All 4 17betaHSD isoforms are variably expressed in human anterior pituitary adenomas, which also show 17betaHSD enzyme activity, suggesting that 17betaHSD may play an important role in regulating the local cellular levels of estradiol.

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Citations
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Journal ArticleDOI

The role of 17 beta-hydroxysteroid dehydrogenases.

TL;DR: 17 beta-hydroxysteroid dehydrogenases reveal a remarkable multifunctionality being able to modulate concentrations not only of steroids but as well of fatty and bile acids.
Journal ArticleDOI

Immunohistochemical localization and biological activity of the steroidogenic enzyme cytochrome P450 17α‐hydroxylase/C17, 20‐lyase (P450C17) in the frog brain and pituitary

TL;DR: This is the first detailed immunohistochemical mapping of P450C17 in the brain and pituitary of any vertebrate and provides evidence that CNS neurons and pituitsary cells can synthesize androgens.
Book ChapterDOI

Environmental Pollutants and Hydroxysteroid Dehydrogenases

TL;DR: Many environmental pollutants directly inhibit one or more enzymes of these HSDs, thus interfering with endogenous active steroid hormone levels, and this chapter reviews these inhibitors targeting on H SDs.
Journal ArticleDOI

In vivo and in vitro expression of steroid-converting enzymes in human breast tumours: associations with interleukin-6.

TL;DR: It is proposed that these enzymes work in tandem with cytokines thereby providing sufficient quantities of bioactive oestrogen from less active precursors which stimulates tumour growth.
Journal ArticleDOI

Tissue-specific transcription profiles of sex steroid biosynthesis enzymes and the androgen receptor

TL;DR: It is concluded that sex steroid enzymes are expressed not only in genital primary target tissues but also in peripheral blood and the expression in different target tissues may contribute to both the individual sexual and tissue-specific phenotype in humans.
References
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Journal ArticleDOI

Use of avidin-biotin-peroxidase complex (ABC) in immunoperoxidase techniques: a comparison between ABC and unlabeled antibody (PAP) procedures.

TL;DR: The use of avidin-biotin interaction in immunoenzymatic techniques provides a simple and sensitive method to localize antigens in formalin-fixed tissues.
Journal ArticleDOI

Male pseudohermaphroditism caused by mutations of testicular 17β-hydroxysteroid dehydrogenase 3

TL;DR: Four substitution and two splice junction mutations were identified in the 17βHSD3 genes of five unrelated male pseudohermaphrodites that severely compromised the activity of the 17 β–HSD type 3 isozyme.
Journal ArticleDOI

Expression cloning and characterization of human 17 beta-hydroxysteroid dehydrogenase type 2, a microsomal enzyme possessing 20 alpha-hydroxysteroid dehydrogenase activity

TL;DR: The data suggest that the 17 beta-HSD type 2 cDNA encodes the microsomal 17 beta -HSD of human placenta, described by several laboratories.
Journal ArticleDOI

Complete amino acid sequence of human placental 17β-hydroxysteroid dehydrogenase deduced from cDNA

TL;DR: The amino acid sequence of 23 N‐terminal amino acids determined from purified 17‐HSD agreed with the sequence deduced from cDNA, and contained two peptides previously characterized from the proposed catalytic area of placental 17‐ HSD.
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