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17β-hydroxysteroid dehydrogenases (17β-HSDs) are enzymes responsible for reversible interconversions of biologically active 17-hydroxy and inactive 17-keto steroids. We have performed a survey of 17β-HSD activity in yeast. Constitutive 17β-HSD activity was found in three mesophilic yeast species: Candida tropicalis, Cryptococcus tsukubaensis, and Saccharomyces cerevisiae as well as in three extremophilic...
The role of estrogens in regulating cellular metabolism in many tissues is well documented. Estrogens regulate cellular activity by interacting with specific intracellular receptor proteins. Two estrogen receptor (ER) isoforms have been isolated, cloned and characterized. Estrogen receptor alpha (ERα) and beta (ERβ) are ligand dependent transcriptional activators, which regulate gene expression via...
The effects of the synthetic glucocorticoid dexamethasone on the cAMP content of murine T lymphocyte cell lines has been investigated. Incubation of the 3B4.15 T cell hybrids with dexamethasone results in an average 5-fold increase in intracellular cyclic AMP levels after 6 h of treatment. This phenomenon is abolished in the presence of RU486 and of cycloheximide, indicating that it requires binding...
Two-hydroxyestrone (2OHE-1) and 16α-hydroxyestrone (16OHE-1) are two estrogen metabolites that may play important roles in the development or promotion of breast cancer. Our study assessed the reliability of a newly developed kit procedure for measuring 2OHE-1. Although under certain conditions the assay would not distinguish 2OHE-1 from estriol, or possibly 2-methoxyestrone, steroids such as 17β-estradiol,...
The risk of breast cancer is 2 to 5 times higher in patients suffering from gross cystic disease. Breast cysts are categorized into two groups (type I and type II) according to the concentration of electrolytes in the cyst fluid. The two types also differ with respect to accumulation of steroids and steroidogenic enzyme activity. In type I cysts a higher risk of breast carcinoma could be expected...
Three new chlorinated marine steroids, yonarasterols G, H and I, were isolated from the Okinawan soft coral, Clavularia viridis. Their structures including the absolute configuration were determined based on the results of spectroscopic analysis and chemical conversion.
Starting from stigmasterol (2), 24-methylenecholest-4-en-3β,6β-diol (1), a cytotoxic natural dihydroxylated sterol, was synthesized via 10 steps in 20% overall yield. The introduction of a side-chain of sterol was achieved by solid-liquid phase-transfer Wittig reaction using (3-methyl-2-oxo)butyltriphenylarsonium bromide (12) and K 2 CO 3 . Construction of the steroidal nucleus was...
Estrogen receptor (ER) mRNA undergoes alternative splicing generating transcripts that have deletions in various combination of exons. Although several reports have shown that the spliced variant mRNAs are expressed in both normal and malignant tissues, the exact functional role(s) of these molecules have not been established in estrogen induced signal transduction processes mainly due to practical...
3α-Hydroxy-20-oxo-5α-pregnan-21-yl hemisuccinate (8) was produced by partial acylation of 3α,21-dihydroxy-5α-pregnan-20-one (14). 3α-Fluoro-5α-pregnan-20-one (9) was prepared by treatment of 3β-hydroxy-5α-pregnan-20-one (11) with DAST and by solvolysis of tosylate 12 with tetrabutylammonium fluoride. A behavioral test on mice was performed using 3α-hydroxy-5α-pregnan-20-one (1) and compounds 8 and...
Localization of steroid sulfatase, a membrane-bound microsomal enzyme, in human fallopian tubes was immunohistochemically investigated, and expression of RNA was confirmed by competitive RT-PCR. Human fallopian tubes were obtained from 10 patients in follicular and early luteal phases during gynecological laparotomy. An anti-human rabbit polyclonal antibody was prepared against sulfatase protein purified...
The syntheses of the 7β-hydroxy metabolite of ORG OD14 (Livial ( R)), (3α,7β,17α)-7-methyl-19-norpregn-5(10)-en-20-yne-3,7,17-triol (35), and its 7-epimer, (3α,7α,17α)-7-methyl-19-norpregn-5(10)-en-20-yne-3,7,17-triol (11), are described.
In this article we described, for the first time to our knowledge, the development of a new non isotopic immunoassay (time resolved-fluoroimmunoassay) for determining 17α-hydroxypregnenolone levels in plasma or serum. This steroid is indeed the most relevant steroid for the diagnosis of 3β-hydroxysteroid dehydrogenase deficiency. For the hapten tracer, we synthesized a biotin-oxyacetyl 17-hydroxypregnenolone...
The dimorphic pattern of growth hormone (GH) secretion and somatic growth in male and female mammals is attributable to the gonadal steroids. Whether these hormones mediate their effects solely on hypothalamic neurons, on somatotropes or on both to evoke the gender-specific GH secretory patterns has not been fully elucidated. The purpose of this study was to determine the effects of 17β-estradiol,...
The conjugation reactions of hydration and dehydrogenation catalyzed by the dehydratase and dehydrogenase activities of D-3-hydroxyacyl-CoA dehydratase/D-3-hydroxyacyl-CoA dehydrogenase bifunctional protein (DBP) and enoyl-CoA hydratase/3-hydroxyacyl-CoA dehydrogenase bifunctional protein (LBP) in the side chain degradation step of bile acid biosynthesis were investigated using chemically synthesized...
Regioselectivity in the anodic electrochemical oxidation of cholic acid with different anodes is described. The oxidation with PbO 2 anode affords the dehydrocholic acid in quantitative yield after 22 h. 3α,12α-Dihydroxy-7-oxo-5β-cholan-24-oic acid (59%) and 3α-hydroxy-7,12-dioxo-5β-cholan-24-oic acid (51%) are obtained stopping the reaction at lower time. The rate of the OH-oxidation is C...
Three major metabolites of 1α,25-dihydroxyvitamin D 4 were isolated from the bile of rat and the structures were elucidated on the basis of spectral data and the periodate oxidative cleavage of the diol structures of the metabolites. One of the metabolites was the known calcitroic acid. Another two metabolites were isomers and identified as 9,10-secoergosta-5,7,10(19)-triene-1α,3β,24,25-tetrahydroxy-26-oic...
This review examines the role of 1α,25(OH) 2 D 3 (1,25D) and the vitamin D 3 receptor in growth regulation of normal and transformed mammary epithelial cells. 1,25D exerts both anti-proliferative and pro-apoptotic functions in transformed mammary cells such as MCF-7. The anti-proliferative effects of 1,25D have been linked to suppression of growth stimulatory signals and potentiation...
Human keratinocytes convert 25(OH)D 3 to hormonally active 1α,25(OH) 2 D 3 and respond to its antiproliferative/prodifferentiating action in vitro and in vivo. Levels and activity of 1α,25(OH) 2 D 3 are short-lived. 1α,25(OH) 2 D 3 induces 24-hydroxylase (CYP24) that rapidly metabolizes the hormone, yielding a cascade of side-chain oxidized products...
Induction of growth arrest and differentiation of some cancer cells by 1α,25-dihydroxyvitamin D 3 [1α,25(OH) 2 D 3 ], and its potent analogs, is well characterized. However, aggressive cancer cell lines are often either insensitive to the antiproliferative effects of 1α,25(OH) 2 D 3 or require toxic concentrations to recapitulate them which has, to-date, precluded...
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