Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0476089 (endometrial cancer)
 11,379 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Different subcellular fractions (purity checked by electron microscopy and respective marker enzymes) were incubated with 0.1 muCi 14C-progesterone (10 muM) in 0.15 M phosphate buffer at pH 7.4 and 37 C under air for varying periods of time in the presence of NAD(P)H (500 muM). By the preparation of chromic acid oxidation products and acetates, thin-layer chromatography, and crystallisation to constant specific activity, the following metabolites were identified: 20alpha-hydroxypregn-4-en-3-one, 20alpha-hydroxy-5alpha-pregnan-3-one, 20alpha-hydroxy-5beta-pregnan-3-one, 5alpha-pregnane-3,20-dione, and 5beta-pregnane-3,20-dione, indicating the presence of a 20alpha-hydroxysteroid dehydrogenase (20alpha-HSD) and 5alpha- and 5beta-reductases. Most of the 20alpha-HSD activity was located in mitochondria (associated mainly with outer membranes) and microsomes. Purified nuclei and cytosol contained 1/6 to 1/18 of the activity of mitochondria and microsomes, respectively. SUBFRACTIONS OF ENDOMETRIAL CELLS ONLY CONTAINED EITHER 5ALPHA- OR 5BETA-REDUCTASE ACTIVITY. 5alpha-reductase activity was mainly associated with microsomes, 5beta-reductase activity was found only in the cytosol. While in normal endometrium specific enzyme activities in subcellular fractions depended on the phase of the cycle, in endometrial carcinoma it depended on the degree of tumour differentiation. The highest values of 5alpha-reductase activity were found in the early proliferative phase. 20alpha-HSD activity was highest in the middle of the secretory phase. The specific activity of the 5alpha-reductase increased with decreasing differentiation of the tumour while the specific activity of the 20alpha-HSD decreased. Kinetic parameters (Km-values, coenzyme requirements and maximum velocities) were determined. The Km-value for progesterone of the 20alpha-HSD in proliferative endometrium was significantly higher than in secretory endometrium, while the Km-values of the 5alpha- and 5beta-reductases were considerably lower during the proliferative than secretory phase.
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PMID:Progesterone metabolism in normal human endometrium during the menstrual cycle and in endometrial carcinoma. 24 Aug 67

Endometrial cancer is the most common malignancy of the female genital tract. Its incidence correlates with prolonged estrogen stimulation unopposed by progesterone or synthetic progestins. Estrogen and progestin action is regulated at the pre-receptor level, by interconversion of active hormones (estradiol (E2), progesterone (P)) with their inactive counterparts (estrone (E1), 20alpha-hydroxyprogesterone (20alpha-OHP)) in target tissues. Expression of enzymes that control the ratio of E2 and P may thus play role in the disease process. We first confirmed that AKR1C1 (human 20alpha-hydroxysteroid dehydrogenase) in a cellular context inactivates P by forming 20alpha-OHP but does not catalyze the reverse reaction. We next examined the expression of AKR1C1 and AKR1C3 (type 5 17beta-hydroxysteroid dehydrogenase) in 16 paired specimens of endometrial cancer and adjacent normal endometrium. Quantification by isoform specific real-time PCR revealed higher expression of AKR1C1 in nine specimens and higher expression of AKR1C3 in four specimens of endometrial cancer. Importantly, upregulation of both enzymes in the same specimen was observed. Since AKR1C1 inactivates P its elevated expression in diseased endometrium may contribute to diminished protection by P, while elevated expression of AKR1C3 which forms E2 in vivo, may contribute to the enhanced estrogen action. It is suggested that the expression of AKR1C1 and AKR1C3 in endometrial cancer will govern the ratio of P:E2.
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PMID:AKR1C1 and AKR1C3 may determine progesterone and estrogen ratios in endometrial cancer. 1633 60

20alpha-hydroxysteroid dehydrogenase (AKR1C1) plays a key role in the metabolism of progesterone and other steroid hormones, thereby regulating their action at the pre-receptor level. AKR1C1 is implicated in neurological and psychiatric conditions such as catamenial epilepsy and depressive disorders. Increased activity of AKR1C1 is associated with termination of pregnancy and the development of breast cancer, endometriosis and endometrial cancer. Inhibition of the undesired activity of AKR1C1 will help reduce risks of premature birth, neurological disorders and the development of cancer. In order to identify potential leads for new inhibitors of AKR1C1 we adopted a virtual screening-based approach using the automated DOCK program. Approximately 250,000 compounds from the NCI database were screened for potential ligands based on their chemical complementarity and steric fit within the active site of AKR1C1. Kinetic analysis revealed 3,5-diiodosalicylic acid, an analogue of salicylic acid, as a potent competitive inhibitor with respect to the substrate 5beta-pregnane-3alpha,20alpha-diol with a K(i) of 9 nM. Aspirin, which is a well known salicylic acid-based drug, was also found to inhibit AKR1C1 activity. This is the first report to show aspirin (IC(50)=21 microM) and its metabolite salicylic acid (IC(50)=7.8 microM) as inhibitors of AKR1C1.
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PMID:A salicylic acid-based analogue discovered from virtual screening as a potent inhibitor of human 20alpha-hydroxysteroid dehydrogenase. 1804 4

Endometrial cancer is related to estrogen stimulation not opposed by progesterone. We have examined expression of the pre-receptor regulatory enzymes aromatase, 17beta-hydroxysteroid dehydrogenases (17beta-HSDs), 20alpha-hydroxysteroid dehydrogenases (20alpha-HSDs), sulfatase and sulfotransferase, and estrogen (ERs) and progesterone (PRs) receptors in samples of endometrial cancer and adjacent normal endometrium. No significant gene up-regulation was seen, although aromatase, AKR1C3, a 17beta-HSD and 20alpha-HSD, and AKR1C1, the major 20alpha-HSD, were up-regulated in 50% of samples. Significant down-regulation was seen for 17beta-HSD types 1 and 7, sulfotransferase, ERalpha, ERbeta, PR-AB. Western blotting revealed higher levels of AKR1C3 and PR-B and lower levels of ERalpha in cancerous endometrium, and immunohistochemistry confirmed expression of AKR1C3, PR-B and ERalpha at the cellular level. Up-regulation of aromatase in concert with AKR1C3 can lead to increased levels of estradiol, which acts via ERalpha. Up-regulation of AKR1C1 and AKR1C3 can result in lower levels of the protective progesterone, which acts mainly via PR-B.
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PMID:Aberrant pre-receptor regulation of estrogen and progesterone action in endometrial cancer. 1893 Jul 84

Human hydroxysteroid dehydrogenase (HSD) AKR1C1 is a member of the aldo-keto reductase superfamily, and it functions mainly as a 20alpha-HSD. It catalyzes the reduction of the potent progesterone to the weak 20alpha-hydroxyprogesterone, and of 3alpha,5alpha-tetrahydroprogesterone (5alpha-THP; allopregnanolone) to 5alpha-pregnane-3alpha,20alpha-diol. AKR1C1 thus decreases the levels of progesterone and 5alpha-THP in peripheral tissue. Progesterone inhibits cell proliferation, stimulates differentiation of endometrial cells, and is also important for maintenance of pregnancy, while 5alpha-THP allosterically modulates the activity of the gamma-aminobutyric acid receptor. Inhibitors of AKR1C1 are thus potential agents for treatment of endometrial cancer and endometriosis, as well as other diseases like premenstrual syndrome, catamenial epilepsy and depressive disorders.We have synthesized a series of pyrimidine, phthalimido and athranilic acid derivatives, and have here examined their inhibitory properties towards AKR1C1. A common aldo-keto reductase substrate, 1-acenaphthenol, was used to monitor the NAD(+)-dependent oxidation catalyzed by AKR1C1. The most potent inhibitors of AKR1C1 were the pyrimidine derivative N-benzyl-2-(2-(4-methoxybenzyl)-6-oxo-1,6-dihydropyrimidin-4-yl)acetamide (K(i)=17 microM) and the anthranilic acid derivative 2-(((2',3-dichlorobiphenyl-4-yl)carbonyl)(methyl)amino)benzoic acid (K(i)=33 microM), both of which are non-competitive inhibitors.
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PMID:Derivatives of pyrimidine, phthalimide and anthranilic acid as inhibitors of human hydroxysteroid dehydrogenase AKR1C1. 1900 63