Works in concert with the 5-alpha/5-beta-steroid reductases to convert steroid hormones into the 3-alpha/5-alpha and 3-alpha/5-beta-tetrahydrosteroids. Catalyzes the inactivation of the most potent androgen 5-alpha-dihydrotestosterone (5-alpha-DHT) to 5-alpha-androstane-3-alpha,17-beta-diol (3-alpha-diol). Has a high bile-binding ability.
Biochem. J. 313 ( Pt 2), 373-376 (1996)[PubMed:8573067]
We previously isolated three monomeric dihydrodiol dehydrogenases, DD1, DD2 and DD4, from human liver, and cloned a cDNA (C9) thought to encode DD2, which is identical with those for human bile-acid-binding protein and an oxidoreductase of human colon carcinoma HT29 cells. In the present study we have provided evidence that the C9 cDNA clone encodes DD1, not DD2. A recombinant enzyme expressed from the cDNA in a bacterial system was purified, and its catalytic properties, bile-acid-binding ability and primary sequence were compared with those of the hepatic dihydrodiol dehydrogenases. The results show that DD1 encoded by C9 possesses prostaglandin F synthase activity but low affinity for lithocholic acid, whereas DD2, showing differences of six amino acid residues from the DD1 sequence, exhibited high-affinity binding for the bile acid. Refined relationship between dihydrodiol dehydrogenases and their related proteins of human tissues is proposed.
Endometriosis is a very common disease that is characterized by increased formation of estradiol and disturbed progesterone action. This latter is usually explained by a lack of progesterone receptor B (PR-B) expression, while the role of pre-receptor metabolism of progesterone is not yet fully understood. In normal endometrium, progesterone is metabolized by reductive 20α-hydroxysteroid dehydrogenases (20α-HSDs), 3α/β-HSDs and 5α/β-reductases. The aldo-keto reductases 1C1 and 1C3 (AKR1C1 and AKR1C3) are the major reductive 20α-HSDs, while the oxidative reaction is catalyzed by 17β-HSD type 2 (HSD17B2). Also, 3α-HSD and 3β-HSD activities have been associated with the AKR1C isozymes. Additionally, 5α-reductase types 1 and 2 (SRD5A1, SRD5A2) and 5β-reductase (AKR1D1) are responsible for the formation of 5α- and 5β-reduced pregnanes. In this study, we examined the expression of PR-AB and the progesterone metabolizing enzymes in 31 specimens of ovarian endometriosis and 28 specimens of normal endometrium. Real-time PCR analysis revealed significantly decreased mRNA levels of PR-AB, HSD17B2 and SRD5A2, significantly increased mRNA levels of AKR1C1, AKR1C2, AKR1C3 and SRD5A1, and negligible mRNA levels of AKR1D1. Immunohistochemistry staining of endometriotic tissue compared to control endometrium showed significantly lower PR-B levels in epithelial cells and no significant differences in stromal cells, there were no significant differences in the expression of AKR1C3 and significantly higher AKR1C2 levels were seen only in stromal cells. Our expression analysis data at the mRNA level and partially at the cellular level thus suggest enhanced metabolism of progesterone by SRD5A1 and the 20α-HSD and 3α/β-HSD activities of AKR1C1, AKR1C2 and AKR1C3.
Catalysis of the reaction: NAD(P)+ + androsterone = NAD(P)H + H+ + 5-alpha-androstane-3,17-dione. The reaction is A-specific (i.e. the pro-R hydrogen is transferred from the 4-position of reduced nicotinamide cofactor) with respect to NAD(P)+.
Biochem. J. 313 ( Pt 2), 373-376 (1996)[PubMed:8573067]
We previously isolated three monomeric dihydrodiol dehydrogenases, DD1, DD2 and DD4, from human liver, and cloned a cDNA (C9) thought to encode DD2, which is identical with those for human bile-acid-binding protein and an oxidoreductase of human colon carcinoma HT29 cells. In the present study we have provided evidence that the C9 cDNA clone encodes DD1, not DD2. A recombinant enzyme expressed from the cDNA in a bacterial system was purified, and its catalytic properties, bile-acid-binding ability and primary sequence were compared with those of the hepatic dihydrodiol dehydrogenases. The results show that DD1 encoded by C9 possesses prostaglandin F synthase activity but low affinity for lithocholic acid, whereas DD2, showing differences of six amino acid residues from the DD1 sequence, exhibited high-affinity binding for the bile acid. Refined relationship between dihydrodiol dehydrogenases and their related proteins of human tissues is proposed.
Biochem. J. 313 ( Pt 2), 373-376 (1996)[PubMed:8573067]
We previously isolated three monomeric dihydrodiol dehydrogenases, DD1, DD2 and DD4, from human liver, and cloned a cDNA (C9) thought to encode DD2, which is identical with those for human bile-acid-binding protein and an oxidoreductase of human colon carcinoma HT29 cells. In the present study we have provided evidence that the C9 cDNA clone encodes DD1, not DD2. A recombinant enzyme expressed from the cDNA in a bacterial system was purified, and its catalytic properties, bile-acid-binding ability and primary sequence were compared with those of the hepatic dihydrodiol dehydrogenases. The results show that DD1 encoded by C9 possesses prostaglandin F synthase activity but low affinity for lithocholic acid, whereas DD2, showing differences of six amino acid residues from the DD1 sequence, exhibited high-affinity binding for the bile acid. Refined relationship between dihydrodiol dehydrogenases and their related proteins of human tissues is proposed.
Endometriosis is a very common disease that is characterized by increased formation of estradiol and disturbed progesterone action. This latter is usually explained by a lack of progesterone receptor B (PR-B) expression, while the role of pre-receptor metabolism of progesterone is not yet fully understood. In normal endometrium, progesterone is metabolized by reductive 20α-hydroxysteroid dehydrogenases (20α-HSDs), 3α/β-HSDs and 5α/β-reductases. The aldo-keto reductases 1C1 and 1C3 (AKR1C1 and AKR1C3) are the major reductive 20α-HSDs, while the oxidative reaction is catalyzed by 17β-HSD type 2 (HSD17B2). Also, 3α-HSD and 3β-HSD activities have been associated with the AKR1C isozymes. Additionally, 5α-reductase types 1 and 2 (SRD5A1, SRD5A2) and 5β-reductase (AKR1D1) are responsible for the formation of 5α- and 5β-reduced pregnanes. In this study, we examined the expression of PR-AB and the progesterone metabolizing enzymes in 31 specimens of ovarian endometriosis and 28 specimens of normal endometrium. Real-time PCR analysis revealed significantly decreased mRNA levels of PR-AB, HSD17B2 and SRD5A2, significantly increased mRNA levels of AKR1C1, AKR1C2, AKR1C3 and SRD5A1, and negligible mRNA levels of AKR1D1. Immunohistochemistry staining of endometriotic tissue compared to control endometrium showed significantly lower PR-B levels in epithelial cells and no significant differences in stromal cells, there were no significant differences in the expression of AKR1C3 and significantly higher AKR1C2 levels were seen only in stromal cells. Our expression analysis data at the mRNA level and partially at the cellular level thus suggest enhanced metabolism of progesterone by SRD5A1 and the 20α-HSD and 3α/β-HSD activities of AKR1C1, AKR1C2 and AKR1C3.
Oxidoreductase activity, acting on NAD(P)H, quinone or similar compound as acceptordefinition[GO:0016655]
Catalysis of an oxidation-reduction (redox) reaction in which NADH or NADPH acts as a hydrogen or electron donor and reduces a quinone or a similar acceptor molecule.
Doxorubicin (DOX) and daunorubicin (DAUN) are effective anticancer drugs; however, considerable interpatient variability exists in their pharmacokinetics. This may be caused by altered metabolism by nonsynonymous single-nucleotide polymorphisms (ns-SNPs) in genes encoding aldo-keto reductases (AKRs) and carbonyl reductases. This study examined the effect of 27 ns-SNPs, in eight human genes, on the in vitro metabolism of both drugs to their major metabolites, doxorubicinol and daunorubicinol. Kinetic assays measured metabolite levels by high-performance liquid chromatography separation with fluorescence detection using purified, histidine-tagged, human wild-type, and variant enzymes. Maximal rate of activity (V(max)), substrate affinity (K(m)), turnover rate (k(cat)), and catalytic efficiency (k(cat)/K(m)) were determined. With DAUN as substrate, variants for three genes exhibited significant differences in these parameters compared with their wild-type counterparts: the A106T, R170C, and P180S variants significantly reduced metabolism compared with the AKR1C3 wild-type (V(max), 23-47% decrease; k(cat), 22-47%; k(cat)/K(m), 38-44%); the L311V variant of AKR1C4 significantly decreased V(max) (47% lower) and k(cat) and k(cat)/K(m) (both 43% lower); and the A142T variant of AKR7A2 significantly affected all kinetic parameters (V(max) and k(cat), 61% decrease; K(m), 156% increase; k(cat)/K(m), 85% decrease). With DOX, the R170C and P180S variants of AKR1C3 showed significantly reduced V(max) (41-44% decrease), k(cat) (39-45%), and k(cat)/K(m) (52-69%), whereas the A142T variant significantly altered all kinetic parameters for AKR7A2 (V(max), 41% decrease; k(cat), 44% decrease; K(m), 47% increase; k(cat)/K(m), 60% decrease). These findings suggest that ns-SNPs in human AKR1C3, AKR1C4, and AKR7A2 significantly decrease the in vitro metabolism of DOX and DAUN.
Human AKR (aldo-keto reductase) 1C proteins (AKR1C1-AKR1C4) exhibit relevant activity with steroids, regulating hormone signalling at the pre-receptor level. In the present study, investigate the activity of the four human AKR1C enzymes with retinol and retinaldehyde. All of the enzymes except AKR1C2 showed retinaldehyde reductase activity with low Km values (~1 μM). The kcat values were also low (0.18-0.6 min-1), except for AKR1C3 reduction of 9-cis-retinaldehyde whose kcat was remarkably higher (13 min-1). Structural modelling of the AKR1C complexes with 9-cis-retinaldehyde indicated a distinct conformation of Trp227, caused by changes in residue 226 that may contribute to the activity differences observed. This was partially supported by the kinetics of the AKR1C3 R226P mutant. Retinol/retinaldehyde conversion, combined with the use of the inhibitor flufenamic acid, indicated a relevant role for endogenous AKR1Cs in retinaldehyde reduction in MCF-7 breast cancer cells. Overexpression of AKR1C proteins depleted RA (retinoic acid) transactivation in HeLa cells treated with retinol. Thus AKR1Cs may decrease RA levels in vivo. Finally, by using lithocholic acid as an AKR1C3 inhibitor and UVI2024 as an RA receptor antagonist, we provide evidence that the pro-proliferative action of AKR1C3 in HL-60 cells involves the RA signalling pathway and that this is in part due to the retinaldehyde reductase activity of AKR1C3.
Members of the aldo-keto reductase (AKR) superfamily have been implicated in prostaglandin (PG) metabolism and prostate cancer. AKR1C3 possesses 11-ketoprostaglandin reductase activity and is capable of converting PGD2 to 9alpha, 11beta-PGF2alpha, whereas AKR1C2-mediated PG metabolism remains unclear. The accumulation of PGF2alpha may generate proliferative signals to promote prostate cell growth. Levels of AKR1C2 and AKR1C3 expression are elevated in localized and advanced prostate cancer. To study the significance of AKR1C2- and AKR1C3-mediated PGD2 conversion in human prostate cell proliferation, we stably transfected androgen insensitive human prostate cancer PC-3 cells with AKR1C2 or AKR1C3 cDNA. PC-3 cells overexpressing AKR1C2 and AKR1C3 had elevated cell proliferation in response to PGD2 stimulation as compared to mock transfectants. Overexpression of AKR1C2 or AKR1C3 did not alter levels of PGF receptor (FP) expression. Inclusion of an FP antagonist (AL8810) significantly suppressed PGD2-stimulated PC-3 cell proliferation in these stable transfectants. In addition, PGD2 significantly elevated levels of total Akt protein expression and Akt Ser473 phosphorylation in AKR1C2 and AKR1C3 stable transfectants; and inclusion of a phosphatidylinositol 3-kinase (PI3K) chemical inhibitor (LY294002) attenuated PGD2-stimulated cell proliferation in these transfectants. Our results suggested that both AKR1C2 and AKR1C3 mediate similar PGD2 conversion toward the accumulation of proliferative signals through FP and PI3K/Akt signaling pathways to promote prostate cell proliferation.
Biochem. J. 313 ( Pt 2), 373-376 (1996)[PubMed:8573067]
We previously isolated three monomeric dihydrodiol dehydrogenases, DD1, DD2 and DD4, from human liver, and cloned a cDNA (C9) thought to encode DD2, which is identical with those for human bile-acid-binding protein and an oxidoreductase of human colon carcinoma HT29 cells. In the present study we have provided evidence that the C9 cDNA clone encodes DD1, not DD2. A recombinant enzyme expressed from the cDNA in a bacterial system was purified, and its catalytic properties, bile-acid-binding ability and primary sequence were compared with those of the hepatic dihydrodiol dehydrogenases. The results show that DD1 encoded by C9 possesses prostaglandin F synthase activity but low affinity for lithocholic acid, whereas DD2, showing differences of six amino acid residues from the DD1 sequence, exhibited high-affinity binding for the bile acid. Refined relationship between dihydrodiol dehydrogenases and their related proteins of human tissues is proposed.
Any process that results in a change in state or activity of a cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a jasmonic acid stimulus.
Members of the aldo-keto reductase (AKR) superfamily, particularly the AKR1C subfamily, are emerging as important mediators of the pathology of cancer. Agents that inhibit these enzymes may provide novel agents for either the chemoprevention or treatment of diverse malignancies. Recently, jasmonates, a family of plant stress hormones that bear a structural resemblance to prostaglandins, have been shown to elicit anticancer activities both in vitro and in vivo. In this study, we show that jasmonic acid (JA) and methyl jasmonate (MeJ) are capable of inhibiting all four human AKR1C isoforms. Although JA is the more potent inhibitor of recombinant AKR1C proteins, including the in vitro prostaglandin F synthase activity of AKR1C3, MeJ displayed greater potency in cellular systems that was, at least in part, due to increased cellular uptake of MeJ. Moreover, using the acute myelogenous leukemia cell lines HL-60 and KG1a, we found that although both jasmonates were able to induce high levels of reactive oxygen species in a dose-dependent fashion, only MeJ was able to induce high levels of mitochondrial superoxide (MSO), possibly as an epiphenomenon of mitochondrial damage. There was a strong correlation observed between MSO formation at 24 hours and reduced cellularity at day 5. In conclusion, we have identified AKR1C isoforms as a novel target of jasmonates in cancer cells and provide further evidence of the promise of these compounds, or derivatives thereof, as adjunctive therapies in the treatment of cancer.
The chemical reactions and pathways involving daunorubicin, a chemotherapeutic of the anthracycline family that is given as a treatment for some types of cancer.
Evidence
1:
Inferred from Mutant PhenotypeUniProtKB
Doxorubicin (DOX) and daunorubicin (DAUN) are effective anticancer drugs; however, considerable interpatient variability exists in their pharmacokinetics. This may be caused by altered metabolism by nonsynonymous single-nucleotide polymorphisms (ns-SNPs) in genes encoding aldo-keto reductases (AKRs) and carbonyl reductases. This study examined the effect of 27 ns-SNPs, in eight human genes, on the in vitro metabolism of both drugs to their major metabolites, doxorubicinol and daunorubicinol. Kinetic assays measured metabolite levels by high-performance liquid chromatography separation with fluorescence detection using purified, histidine-tagged, human wild-type, and variant enzymes. Maximal rate of activity (V(max)), substrate affinity (K(m)), turnover rate (k(cat)), and catalytic efficiency (k(cat)/K(m)) were determined. With DAUN as substrate, variants for three genes exhibited significant differences in these parameters compared with their wild-type counterparts: the A106T, R170C, and P180S variants significantly reduced metabolism compared with the AKR1C3 wild-type (V(max), 23-47% decrease; k(cat), 22-47%; k(cat)/K(m), 38-44%); the L311V variant of AKR1C4 significantly decreased V(max) (47% lower) and k(cat) and k(cat)/K(m) (both 43% lower); and the A142T variant of AKR7A2 significantly affected all kinetic parameters (V(max) and k(cat), 61% decrease; K(m), 156% increase; k(cat)/K(m), 85% decrease). With DOX, the R170C and P180S variants of AKR1C3 showed significantly reduced V(max) (41-44% decrease), k(cat) (39-45%), and k(cat)/K(m) (52-69%), whereas the A142T variant significantly altered all kinetic parameters for AKR7A2 (V(max), 41% decrease; k(cat), 44% decrease; K(m), 47% increase; k(cat)/K(m), 60% decrease). These findings suggest that ns-SNPs in human AKR1C3, AKR1C4, and AKR7A2 significantly decrease the in vitro metabolism of DOX and DAUN.
The whole of the physical, chemical, and biochemical processes carried out by multicellular organisms to break down ingested nutrients into components that may be easily absorbed and directed into metabolism.
Biochem. J. 313 ( Pt 2), 373-376 (1996)[PubMed:8573067]
We previously isolated three monomeric dihydrodiol dehydrogenases, DD1, DD2 and DD4, from human liver, and cloned a cDNA (C9) thought to encode DD2, which is identical with those for human bile-acid-binding protein and an oxidoreductase of human colon carcinoma HT29 cells. In the present study we have provided evidence that the C9 cDNA clone encodes DD1, not DD2. A recombinant enzyme expressed from the cDNA in a bacterial system was purified, and its catalytic properties, bile-acid-binding ability and primary sequence were compared with those of the hepatic dihydrodiol dehydrogenases. The results show that DD1 encoded by C9 possesses prostaglandin F synthase activity but low affinity for lithocholic acid, whereas DD2, showing differences of six amino acid residues from the DD1 sequence, exhibited high-affinity binding for the bile acid. Refined relationship between dihydrodiol dehydrogenases and their related proteins of human tissues is proposed.
Doxorubicin (DOX) and daunorubicin (DAUN) are effective anticancer drugs; however, considerable interpatient variability exists in their pharmacokinetics. This may be caused by altered metabolism by nonsynonymous single-nucleotide polymorphisms (ns-SNPs) in genes encoding aldo-keto reductases (AKRs) and carbonyl reductases. This study examined the effect of 27 ns-SNPs, in eight human genes, on the in vitro metabolism of both drugs to their major metabolites, doxorubicinol and daunorubicinol. Kinetic assays measured metabolite levels by high-performance liquid chromatography separation with fluorescence detection using purified, histidine-tagged, human wild-type, and variant enzymes. Maximal rate of activity (V(max)), substrate affinity (K(m)), turnover rate (k(cat)), and catalytic efficiency (k(cat)/K(m)) were determined. With DAUN as substrate, variants for three genes exhibited significant differences in these parameters compared with their wild-type counterparts: the A106T, R170C, and P180S variants significantly reduced metabolism compared with the AKR1C3 wild-type (V(max), 23-47% decrease; k(cat), 22-47%; k(cat)/K(m), 38-44%); the L311V variant of AKR1C4 significantly decreased V(max) (47% lower) and k(cat) and k(cat)/K(m) (both 43% lower); and the A142T variant of AKR7A2 significantly affected all kinetic parameters (V(max) and k(cat), 61% decrease; K(m), 156% increase; k(cat)/K(m), 85% decrease). With DOX, the R170C and P180S variants of AKR1C3 showed significantly reduced V(max) (41-44% decrease), k(cat) (39-45%), and k(cat)/K(m) (52-69%), whereas the A142T variant significantly altered all kinetic parameters for AKR7A2 (V(max), 41% decrease; k(cat), 44% decrease; K(m), 47% increase; k(cat)/K(m), 60% decrease). These findings suggest that ns-SNPs in human AKR1C3, AKR1C4, and AKR7A2 significantly decrease the in vitro metabolism of DOX and DAUN.
A series of molecular signals that proceeds with an activated receptor promoting the exchange of GDP for GTP on the alpha-subunit of an associated heterotrimeric G-protein complex. The GTP-bound activated alpha-G-protein then dissociates from the beta- and gamma-subunits to further transmit the signal within the cell. The pathway begins with receptor-ligand interaction, or for basal GPCR signaling the pathway begins with the receptor activating its G protein in the absence of an agonist, and ends with regulation of a downstream cellular process, e.g. transcription.
Members of the aldo-keto reductase (AKR) superfamily have been implicated in prostaglandin (PG) metabolism and prostate cancer. AKR1C3 possesses 11-ketoprostaglandin reductase activity and is capable of converting PGD2 to 9alpha, 11beta-PGF2alpha, whereas AKR1C2-mediated PG metabolism remains unclear. The accumulation of PGF2alpha may generate proliferative signals to promote prostate cell growth. Levels of AKR1C2 and AKR1C3 expression are elevated in localized and advanced prostate cancer. To study the significance of AKR1C2- and AKR1C3-mediated PGD2 conversion in human prostate cell proliferation, we stably transfected androgen insensitive human prostate cancer PC-3 cells with AKR1C2 or AKR1C3 cDNA. PC-3 cells overexpressing AKR1C2 and AKR1C3 had elevated cell proliferation in response to PGD2 stimulation as compared to mock transfectants. Overexpression of AKR1C2 or AKR1C3 did not alter levels of PGF receptor (FP) expression. Inclusion of an FP antagonist (AL8810) significantly suppressed PGD2-stimulated PC-3 cell proliferation in these stable transfectants. In addition, PGD2 significantly elevated levels of total Akt protein expression and Akt Ser473 phosphorylation in AKR1C2 and AKR1C3 stable transfectants; and inclusion of a phosphatidylinositol 3-kinase (PI3K) chemical inhibitor (LY294002) attenuated PGD2-stimulated cell proliferation in these transfectants. Our results suggested that both AKR1C2 and AKR1C3 mediate similar PGD2 conversion toward the accumulation of proliferative signals through FP and PI3K/Akt signaling pathways to promote prostate cell proliferation.
A metabolic process that results in the removal or addition of one or more electrons to or from a substance, with or without the concomitant removal or addition of a proton or protons.
Endometriosis is a very common disease that is characterized by increased formation of estradiol and disturbed progesterone action. This latter is usually explained by a lack of progesterone receptor B (PR-B) expression, while the role of pre-receptor metabolism of progesterone is not yet fully understood. In normal endometrium, progesterone is metabolized by reductive 20α-hydroxysteroid dehydrogenases (20α-HSDs), 3α/β-HSDs and 5α/β-reductases. The aldo-keto reductases 1C1 and 1C3 (AKR1C1 and AKR1C3) are the major reductive 20α-HSDs, while the oxidative reaction is catalyzed by 17β-HSD type 2 (HSD17B2). Also, 3α-HSD and 3β-HSD activities have been associated with the AKR1C isozymes. Additionally, 5α-reductase types 1 and 2 (SRD5A1, SRD5A2) and 5β-reductase (AKR1D1) are responsible for the formation of 5α- and 5β-reduced pregnanes. In this study, we examined the expression of PR-AB and the progesterone metabolizing enzymes in 31 specimens of ovarian endometriosis and 28 specimens of normal endometrium. Real-time PCR analysis revealed significantly decreased mRNA levels of PR-AB, HSD17B2 and SRD5A2, significantly increased mRNA levels of AKR1C1, AKR1C2, AKR1C3 and SRD5A1, and negligible mRNA levels of AKR1D1. Immunohistochemistry staining of endometriotic tissue compared to control endometrium showed significantly lower PR-B levels in epithelial cells and no significant differences in stromal cells, there were no significant differences in the expression of AKR1C3 and significantly higher AKR1C2 levels were seen only in stromal cells. Our expression analysis data at the mRNA level and partially at the cellular level thus suggest enhanced metabolism of progesterone by SRD5A1 and the 20α-HSD and 3α/β-HSD activities of AKR1C1, AKR1C2 and AKR1C3.
Members of the aldo-keto reductase (AKR) superfamily have been implicated in prostaglandin (PG) metabolism and prostate cancer. AKR1C3 possesses 11-ketoprostaglandin reductase activity and is capable of converting PGD2 to 9alpha, 11beta-PGF2alpha, whereas AKR1C2-mediated PG metabolism remains unclear. The accumulation of PGF2alpha may generate proliferative signals to promote prostate cell growth. Levels of AKR1C2 and AKR1C3 expression are elevated in localized and advanced prostate cancer. To study the significance of AKR1C2- and AKR1C3-mediated PGD2 conversion in human prostate cell proliferation, we stably transfected androgen insensitive human prostate cancer PC-3 cells with AKR1C2 or AKR1C3 cDNA. PC-3 cells overexpressing AKR1C2 and AKR1C3 had elevated cell proliferation in response to PGD2 stimulation as compared to mock transfectants. Overexpression of AKR1C2 or AKR1C3 did not alter levels of PGF receptor (FP) expression. Inclusion of an FP antagonist (AL8810) significantly suppressed PGD2-stimulated PC-3 cell proliferation in these stable transfectants. In addition, PGD2 significantly elevated levels of total Akt protein expression and Akt Ser473 phosphorylation in AKR1C2 and AKR1C3 stable transfectants; and inclusion of a phosphatidylinositol 3-kinase (PI3K) chemical inhibitor (LY294002) attenuated PGD2-stimulated cell proliferation in these transfectants. Our results suggested that both AKR1C2 and AKR1C3 mediate similar PGD2 conversion toward the accumulation of proliferative signals through FP and PI3K/Akt signaling pathways to promote prostate cell proliferation.
Any process that activates or increases the frequency, rate or extent of the protein kinase B signaling cascade, a series of reactions mediated by the intracellular serine/threonine kinase protein kinase B.
Members of the aldo-keto reductase (AKR) superfamily have been implicated in prostaglandin (PG) metabolism and prostate cancer. AKR1C3 possesses 11-ketoprostaglandin reductase activity and is capable of converting PGD2 to 9alpha, 11beta-PGF2alpha, whereas AKR1C2-mediated PG metabolism remains unclear. The accumulation of PGF2alpha may generate proliferative signals to promote prostate cell growth. Levels of AKR1C2 and AKR1C3 expression are elevated in localized and advanced prostate cancer. To study the significance of AKR1C2- and AKR1C3-mediated PGD2 conversion in human prostate cell proliferation, we stably transfected androgen insensitive human prostate cancer PC-3 cells with AKR1C2 or AKR1C3 cDNA. PC-3 cells overexpressing AKR1C2 and AKR1C3 had elevated cell proliferation in response to PGD2 stimulation as compared to mock transfectants. Overexpression of AKR1C2 or AKR1C3 did not alter levels of PGF receptor (FP) expression. Inclusion of an FP antagonist (AL8810) significantly suppressed PGD2-stimulated PC-3 cell proliferation in these stable transfectants. In addition, PGD2 significantly elevated levels of total Akt protein expression and Akt Ser473 phosphorylation in AKR1C2 and AKR1C3 stable transfectants; and inclusion of a phosphatidylinositol 3-kinase (PI3K) chemical inhibitor (LY294002) attenuated PGD2-stimulated cell proliferation in these transfectants. Our results suggested that both AKR1C2 and AKR1C3 mediate similar PGD2 conversion toward the accumulation of proliferative signals through FP and PI3K/Akt signaling pathways to promote prostate cell proliferation.
The chemical reactions and pathways involving progesterone, a steroid hormone produced in the ovary which prepares and maintains the uterus for pregnancy. Also found in plants.
Endometriosis is a very common disease that is characterized by increased formation of estradiol and disturbed progesterone action. This latter is usually explained by a lack of progesterone receptor B (PR-B) expression, while the role of pre-receptor metabolism of progesterone is not yet fully understood. In normal endometrium, progesterone is metabolized by reductive 20α-hydroxysteroid dehydrogenases (20α-HSDs), 3α/β-HSDs and 5α/β-reductases. The aldo-keto reductases 1C1 and 1C3 (AKR1C1 and AKR1C3) are the major reductive 20α-HSDs, while the oxidative reaction is catalyzed by 17β-HSD type 2 (HSD17B2). Also, 3α-HSD and 3β-HSD activities have been associated with the AKR1C isozymes. Additionally, 5α-reductase types 1 and 2 (SRD5A1, SRD5A2) and 5β-reductase (AKR1D1) are responsible for the formation of 5α- and 5β-reduced pregnanes. In this study, we examined the expression of PR-AB and the progesterone metabolizing enzymes in 31 specimens of ovarian endometriosis and 28 specimens of normal endometrium. Real-time PCR analysis revealed significantly decreased mRNA levels of PR-AB, HSD17B2 and SRD5A2, significantly increased mRNA levels of AKR1C1, AKR1C2, AKR1C3 and SRD5A1, and negligible mRNA levels of AKR1D1. Immunohistochemistry staining of endometriotic tissue compared to control endometrium showed significantly lower PR-B levels in epithelial cells and no significant differences in stromal cells, there were no significant differences in the expression of AKR1C3 and significantly higher AKR1C2 levels were seen only in stromal cells. Our expression analysis data at the mRNA level and partially at the cellular level thus suggest enhanced metabolism of progesterone by SRD5A1 and the 20α-HSD and 3α/β-HSD activities of AKR1C1, AKR1C2 and AKR1C3.
The chemical reactions and pathways involving prostaglandins, any of a group of biologically active metabolites which contain a cyclopentane ring due to the formation of a bond between two carbons of a fatty acid. They have a wide range of biological activities.
Biochem. J. 313 ( Pt 2), 373-376 (1996)[PubMed:8573067]
We previously isolated three monomeric dihydrodiol dehydrogenases, DD1, DD2 and DD4, from human liver, and cloned a cDNA (C9) thought to encode DD2, which is identical with those for human bile-acid-binding protein and an oxidoreductase of human colon carcinoma HT29 cells. In the present study we have provided evidence that the C9 cDNA clone encodes DD1, not DD2. A recombinant enzyme expressed from the cDNA in a bacterial system was purified, and its catalytic properties, bile-acid-binding ability and primary sequence were compared with those of the hepatic dihydrodiol dehydrogenases. The results show that DD1 encoded by C9 possesses prostaglandin F synthase activity but low affinity for lithocholic acid, whereas DD2, showing differences of six amino acid residues from the DD1 sequence, exhibited high-affinity binding for the bile acid. Refined relationship between dihydrodiol dehydrogenases and their related proteins of human tissues is proposed.
Any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a prostagladin stimulus.
Members of the aldo-keto reductase (AKR) superfamily have been implicated in prostaglandin (PG) metabolism and prostate cancer. AKR1C3 possesses 11-ketoprostaglandin reductase activity and is capable of converting PGD2 to 9alpha, 11beta-PGF2alpha, whereas AKR1C2-mediated PG metabolism remains unclear. The accumulation of PGF2alpha may generate proliferative signals to promote prostate cell growth. Levels of AKR1C2 and AKR1C3 expression are elevated in localized and advanced prostate cancer. To study the significance of AKR1C2- and AKR1C3-mediated PGD2 conversion in human prostate cell proliferation, we stably transfected androgen insensitive human prostate cancer PC-3 cells with AKR1C2 or AKR1C3 cDNA. PC-3 cells overexpressing AKR1C2 and AKR1C3 had elevated cell proliferation in response to PGD2 stimulation as compared to mock transfectants. Overexpression of AKR1C2 or AKR1C3 did not alter levels of PGF receptor (FP) expression. Inclusion of an FP antagonist (AL8810) significantly suppressed PGD2-stimulated PC-3 cell proliferation in these stable transfectants. In addition, PGD2 significantly elevated levels of total Akt protein expression and Akt Ser473 phosphorylation in AKR1C2 and AKR1C3 stable transfectants; and inclusion of a phosphatidylinositol 3-kinase (PI3K) chemical inhibitor (LY294002) attenuated PGD2-stimulated cell proliferation in these transfectants. Our results suggested that both AKR1C2 and AKR1C3 mediate similar PGD2 conversion toward the accumulation of proliferative signals through FP and PI3K/Akt signaling pathways to promote prostate cell proliferation.
Biochem. J. 313 ( Pt 2), 373-376 (1996)[PubMed:8573067]
We previously isolated three monomeric dihydrodiol dehydrogenases, DD1, DD2 and DD4, from human liver, and cloned a cDNA (C9) thought to encode DD2, which is identical with those for human bile-acid-binding protein and an oxidoreductase of human colon carcinoma HT29 cells. In the present study we have provided evidence that the C9 cDNA clone encodes DD1, not DD2. A recombinant enzyme expressed from the cDNA in a bacterial system was purified, and its catalytic properties, bile-acid-binding ability and primary sequence were compared with those of the hepatic dihydrodiol dehydrogenases. The results show that DD1 encoded by C9 possesses prostaglandin F synthase activity but low affinity for lithocholic acid, whereas DD2, showing differences of six amino acid residues from the DD1 sequence, exhibited high-affinity binding for the bile acid. Refined relationship between dihydrodiol dehydrogenases and their related proteins of human tissues is proposed.
Biochem. J. 313 ( Pt 2), 373-376 (1996)[PubMed:8573067]
We previously isolated three monomeric dihydrodiol dehydrogenases, DD1, DD2 and DD4, from human liver, and cloned a cDNA (C9) thought to encode DD2, which is identical with those for human bile-acid-binding protein and an oxidoreductase of human colon carcinoma HT29 cells. In the present study we have provided evidence that the C9 cDNA clone encodes DD1, not DD2. A recombinant enzyme expressed from the cDNA in a bacterial system was purified, and its catalytic properties, bile-acid-binding ability and primary sequence were compared with those of the hepatic dihydrodiol dehydrogenases. The results show that DD1 encoded by C9 possesses prostaglandin F synthase activity but low affinity for lithocholic acid, whereas DD2, showing differences of six amino acid residues from the DD1 sequence, exhibited high-affinity binding for the bile acid. Refined relationship between dihydrodiol dehydrogenases and their related proteins of human tissues is proposed.
Biochem. J. 313 ( Pt 2), 373-376 (1996)[PubMed:8573067]
We previously isolated three monomeric dihydrodiol dehydrogenases, DD1, DD2 and DD4, from human liver, and cloned a cDNA (C9) thought to encode DD2, which is identical with those for human bile-acid-binding protein and an oxidoreductase of human colon carcinoma HT29 cells. In the present study we have provided evidence that the C9 cDNA clone encodes DD1, not DD2. A recombinant enzyme expressed from the cDNA in a bacterial system was purified, and its catalytic properties, bile-acid-binding ability and primary sequence were compared with those of the hepatic dihydrodiol dehydrogenases. The results show that DD1 encoded by C9 possesses prostaglandin F synthase activity but low affinity for lithocholic acid, whereas DD2, showing differences of six amino acid residues from the DD1 sequence, exhibited high-affinity binding for the bile acid. Refined relationship between dihydrodiol dehydrogenases and their related proteins of human tissues is proposed.
Inhibited by hexestrol with an IC(50) of 2.8 uM, 1,10-phenanthroline with an IC(50) of 2100 uM, 1,7-phenanthroline with an IC(50) of 1500 uM, flufenamic acid with an IC(50) of 0.9 uM, indomethacin with an IC(50) of 75 uM, ibuprofen with an IC(50) of 6.9 uM, lithocholic acid with an IC(50) of 0.07 uM, ursodeoxycholic acid with an IC(50) of 0.08 uM and chenodeoxycholic acid with an IC(50) of 0.13 uM.
Biochem. J. 313 ( Pt 2), 373-376 (1996)[PubMed:8573067]
We previously isolated three monomeric dihydrodiol dehydrogenases, DD1, DD2 and DD4, from human liver, and cloned a cDNA (C9) thought to encode DD2, which is identical with those for human bile-acid-binding protein and an oxidoreductase of human colon carcinoma HT29 cells. In the present study we have provided evidence that the C9 cDNA clone encodes DD1, not DD2. A recombinant enzyme expressed from the cDNA in a bacterial system was purified, and its catalytic properties, bile-acid-binding ability and primary sequence were compared with those of the hepatic dihydrodiol dehydrogenases. The results show that DD1 encoded by C9 possesses prostaglandin F synthase activity but low affinity for lithocholic acid, whereas DD2, showing differences of six amino acid residues from the DD1 sequence, exhibited high-affinity binding for the bile acid. Refined relationship between dihydrodiol dehydrogenases and their related proteins of human tissues is proposed.
Protein involved in the biochemical reactions of lipids. Lipids are a diverse class of compounds which are insoluble in water but soluble in organic solvents. They include fats, oils, triacylglycerols, fatty acids, glycolipids, phospholipids and steroids.
Protein involved in the biochemical reactions of steroids. Steroids are a large group of complex tetracyclic lipids that consist of a 17- carbon-ring system. Examples are bile acids, sterols, various hormones and saponins.
A reference proteome is a set of protein sequences derived from a complete proteome which constitutes a defined standard for a particular user community. Reference proteomes are manually defined according to a number of criteria. They cover the proteomes of well- studied model organisms and other proteomes of interest for biomedical and biotechnological research. Reference proteomes have been selected to provide broad coverage of the tree of life, and constitute a representative cross-section of the taxonomic diversity to be found within UniProtKB.
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