Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.1.1.3 (HSD)
 3,464 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The expression of 17 beta-hydroxysteroid dehydrogenase (17-HSD) enzyme protein was studied in benign and malignant human breast tissue using the time-resolved immunofluorometric assay (IFMA), immunoblotting and immunohistochemistry. The presence and distribution of estrogen and progestin receptors was also analyzed immunohistochemically. Cytosolic 17-HSD concentrations in malignant breast specimens were highly variable (less than or equal to 0.2-311 ng/mg protein). As was previously found for the placental enzyme, the molecular weight of the 17-HSD expressed in malignant breast tissue was 35 kDa, estimated following polyacrylamide gel electrophoresis and immunoblotting. The cellular distribution of 17-HSD was further studied by immunohistochemistry. Immunostaining for 17-HSD was observed in 71% of the benign breast lesions (fibroadenomas and cases of mastopathia chronica) and in 47% of the cancer specimens (intra-ductal carcinomas, invasive ductal carcinomas). In benign lesions, the staining was exclusively localized in the cytoplasm of epithelial cells, with no immunoreactivity in the stromal cells. The staining in the cancer specimens was also detected only in the cytoplasm of malignant epithelial cells. A strong or moderate expression of 17-HSD was related to the presence of PR in the specimen (chi 2 = 4.657, p = 0.031). However, the expression of PR was not a prerequisite for expression of 17-HSD in all the cancer specimens. Our data suggest that, in addition to the reported regulation of 17-HSD by progestins, other factors are also involved in this process in breast tissue.
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PMID:Immunological analysis of 17 beta-hydroxysteroid dehydrogenase in benign and malignant human breast tissue. 173 7

17 Beta-Hydroxysteroid dehydrogenase (17 beta-HSD) is present in multiple forms in human breast tissue. One soluble form, with a molecular weight of approximately 35 kDa, was purified to near homogeneity from whole normal breast tissue. This form catalysed the oxidation of oestradiol and the reduction of oestrone, with NADP+ and NADPH as the preferred coenzymes. Three other soluble forms with higher molecular weights (in the range 50-80 kDa) were isolated. They catalysed the oxidation of oestradiol but not the reduction of oestrone, and all of them had properties very different from those of the low molecular weight enzyme. Activities of 17 beta-HSD were measured in particulate and soluble fractions from normal breast adipose and non-adipose tissues, and from breast tumours obtained from post-menopausal women, in the oxidative direction with NAD+ and NADP+ as coenzymes and in the reductive direction with NADH and NADPH as coenzymes. Particulate fractions from tumours had much higher oxidative and reductive activities than those from normal tissues. Soluble fractions from tumours had higher oxidative activities than those from the normal tissues but similar reductive activities. The major soluble form of 17 beta-HSD in adipose tissue was the 35 kDa enzyme which had both oxidative and reductive activities. In contrast, the majority of the soluble activity in non-adipose tissue was due to enzymes, with molecular weights in the range 50-80 kDa, which had oxidative activity only. The soluble fractions of tumours, like those of non-adipose tissue, contained enzymes with molecular weights in the range 50-80 kDa. In addition, they contained a 35 kDa enzyme with properties different from those of the enzyme with the same molecular weight present in adipose tissue.
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PMID:17 Beta-hydroxysteroid dehydrogenases in human breast tissues: purification and characterization of soluble enzymes and the distribution of particulate and soluble forms in adipose, non-adipose and tumour tissues. 189 41

Estrogenic 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) plays a pivotal role in the synthesis of estrogens. We overproduced human placental estrogenic 17 beta-HSD using a baculovirus expression system for the study of the enzyme mechanism. A cDNA encoding the entire open reading frame of human 17 beta-HSD was inserted into the genome of Autographa californica nuclear polyhedrosis virus and expressed in Spodoptera frugiperda (Sf9) insect cells. Metabolic labeling and Western blot analysis using polyclonal antibodies raised against native human 17 beta-HSD indicated that a molecule with an apparent mass of 35 kDa was maximally expressed 60 h after infection. At that time interval, intracellular 17 beta-HSD activity reached 0.26 U/mg of protein in crude homogenate, about 70 times the level measured in human placenta. Purification of recombinant 17 beta-HSD was achieved by a single affinity fast liquid protein chromatography step yielding 24 mg of purified 17 beta-HSD protein per liter of suspension culture, with a specific activity of about 8 mumol/min/mg of protein for conversion of estradiol into estrone, at pH 9.2. In addition, the recombinant protein purified from infected Sf9 cells was assembled as a dimer with molecular mass and specific activity identical to those of the enzyme purified directly from placenta. The present data show that the baculovirus expression system can provide active 17 beta-HSD that is functionally identical to its natural counter-part and easy to purify in quantities suitable for its physico-chemical studies.
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PMID:Human 17 beta-hydroxysteroid dehydrogenase: overproduction using a baculovirus expression system and characterization. 791 13

Meiotic maturation of fish oocytes is induced by the action of maturation-inducing hormone (MIH). 17 alpha,20 beta-Dihydroxy-4-pregnen-3-one (17 alpha,20 beta-DP) was identified as the MIH of several fish species, including salmonid fishes. The interaction of two ovarian follicle cell layers, the thecal and granulosa cell layers, is required for the synthesis of 17 alpha,20 beta-DP; the thecal layer produces 17 alpha-hydroxyprogesterone that is converted to 17 alpha,20 beta-DP in granulosa cells by the action of 20 beta-hydroxysteroid dehydrogenase (20 beta-HSD). The preovulatory surge of LH-like gonadotropin (GTH II) is responsible for rapid expression of 20 beta-HSD mRNA transcripts in granulosa cells. 17 alpha,20 beta-DP acts via a receptor on the plasma membrane of oocytes. A specific 17 alpha,20 beta-DP receptor has been identified and characterized from defolliculated oocytes of several fish species. The concentrations of 17 alpha,20 beta-DP membrane receptor increase immediately prior to oocyte maturation. The pertussis toxin-sensitive inhibitory G protein is involved in the signal transduction pathway of 17 alpha,20 beta-DP. The early steps following 17 alpha,20 beta-DP action involve the formation of the major mediator of this steroid, maturation-promoting factor, which consists of cdc2 kinase (34 kDa) and cyclin B (46-48 kDa). Immature oocytes contain only monomeric 35 kDa cdc2 and do not stockpile cyclin B, although immature oocytes contain mRNA for cyclin B. 17 alpha,20 beta-DP induces oocytes to synthesize cyclin B, which in turn activates preexisting 35 kDa cdc2 through its threonine 161 phosphorylation by a threonine kinase (M015), producing the 34-kDa active cdc2. 17 alpha,20 beta-DP-induced oocyte maturation is blocked by cordycepin, a polyadenylation inhibitor. Furthermore, cyclin B mRNA was polyadenylated during 17 alpha,20 beta-DP-induced oocyte maturation. These findings suggest that 17 alpha,20 beta-DP initiates translation of cyclin B mRNA through cytoplasmic 3' poly(A) elongation.
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PMID:17 alpha,20 beta-dihydroxy-4-pregnen-3-one, a maturation-inducing hormone in fish oocytes: mechanisms of synthesis and action. 902 36

Estrogenic 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) plays a crucial role in the synthesis of estrogens, but it also produces negative action of estrogens in promoting the growth of hormone-sensitive cancers, especially in breast and prostate. The high specific activity can be taken as an important signal for the diagnosis of cancers. Recombinant rAcBm-NPV/17 beta-HSD virus which contains the human 17 beta-HSD cDNA under the control of polyhedron gene promoter is generated by cotransfection of the BmN cells with the transfer plasmid pVL/17 beta-HSD and wild BmNPV genomic DNA. 17 beta-HSD is maximally expressed 72 h and 120 h post infection in BmN cells and the 5th instar silkworm larvae respectively. At those time interval, intracellular and hemolymphic enzymatic activity reach 0.12 U/mg and 0.15 U/mg of protein which produced total activity of 0.97 U/1.5 x 10(6) cells and 4.7 U/larva. The expressed quantities in female larvae are a little higher than that in male larvae. The present data shows that Silkworm/BmNPV expression system can express 3-5 times higher than that of the richest human placenta. It also indicates that there is an apparent band with a molecular mass of 35 kDa using SDS-PAGE method, the size of which is similar to that of the crude enzyme from placenta.
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PMID:[Expression of human 17 beta-hydroxysteroid dehydrogenase gene in BmNPV expression system]. 1103 17