Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.12.7.2 (hydrogenase)
 3,522 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hepatocyte nodules that persist throughout chemical carcinogenesis are linked to carcinomas both as one site at which hepatomas are seen to arise and as a tissue which shows more than a dozen significant protein changes also found in liver cancers. In view of the differential stimulus to growth of these persistent nodules by progesterone, progesterone metabolism and binding to the microsomes of nodules and hepatomas were studied. Progesterone metabolizing enzyme activities in nodule microsomes showed striking shifts with a 42% decrease in 16 alpha-hydroxylase activity and a 2- to 3-fold increase in 6 beta-hydroxylase activity compared to control levels. Hepatomas had a dramatic 20-fold increase relative to nodules or controls in the reductive pathway for progesterone metabolism as measured by delta 4-5 alpha-hydrogenase activity. The rate and saturation of the specific binding of progesterone to microsomes of nodules and liver cancers were significantly decreased when compared either to the tissue surrounding the nodules or to their respective control microsomes. This change in progesterone binding of nodular microsomes may relate to an altered balance of progesterone content and its metabolites in the nodular cells or to alterations in the microsomal membrane binding site. The functional significance of reduced binding of progesterone for liver carcinogenesis is thus open to further inquiry.
Cancer Res 1986 Jan
PMID:Changes in progesterone binding and metabolism in liver microsomes from persistent hepatocyte nodules and hepatomas in male rats. 394 Feb 12

Forty-one postmenopausal patients with advanced breast cancer have been treated with trilostane, a 3 beta D-hydrogenase delta 5-isomerase inhibitor, for periods of up to 1 year. One patient responded to trilostane and in six patients the disease was stabilized. The remaining patients failed to respond to therapy. Six patients who failed to respond to trilostane subsequently responded to other forms of endocrine therapy. It is concluded that trilostane alone is not a useful agent in the treatment of advanced breast cancer.
Cancer Treat Rep 1985 Apr
PMID:Trilostane therapy for advanced breast cancer. 399 7

The endocrine effects of replacement doses of hydrocortisone in postmenopausal women with advanced breast cancer were compared with the same doses of hydrocortisone plus aminoglutethimide. Fifteen patients received aminoglutethimide (AG) 250 mg three times a day plus hydrocortisone (HC) 20 mg twice a day for 2 weeks, then AG was increased to 250 mg four times a day. Another 13 patients received HC alone for 2 weeks, then AG was added. HC alone significantly suppressed oestrone (75% of baseline) and oestradiol (50% of baseline). Addition of AG to these patients produced further oestrone suppression (50% of baseline) significantly greater than HC alone. HC alone suppressed dehydroepiandrosterone sulphate as much as AG + HC. delta 4-androstenedione (delta 4A) and dehydroepiandrosterone (DHA) were suppressed by HC alone. Addition of AG produced a rise of delta 4A to basal levels. These results show that 3-beta-ol de hydrogenase is not induced by AG. AG plus HC together from day 1 produced significantly greater oestrone suppression (50% of baseline) than HC alone. Because high-dose steroids may induce aromatase and replacement doses produced marked peripheral endocrine effects, the use of replacement hydrocortisone should be reassessed in advanced breast cancer.
Eur J Cancer Clin Oncol 1984 Apr
PMID:Hydrocortisone alone vs hydrocortisone plus aminoglutethimide: a comparison of the endocrine effects in postmenopausal breast cancer. 623 50

The biosynthesis of the active metal-bound form of the nickel-dependent enzyme urease involves the formation of a lysine-carbamate functional group concomitantly with the delivery of two Ni(2+) ions into the precast active site of the apoenzyme and with GTP hydrolysis. In the urease system, this role is performed by UreG, an accessory protein belonging to the group of homologous P-loop GTPases, often required to complete the biosynthesis of nickel-enzymes. This study is focused on UreG from Helicobacter pylori (HpUreG), a bacterium responsible for gastric ulcers and cancer, infecting large part of the human population, and for which urease is a fundamental virulence factor. The soluble HpUreG was expressed in E. coli and purified to homogeneity. On-line size exclusion chromatography and light scattering indicated that apo-HpUreG exists as a monomer in solution. Circular dichroism, which demonstrated the presence of a well-defined secondary structure, and NMR spectroscopy, which revealed a large number of residues that appear structured on the basis of their backbone amide proton chemical shift dispersion, indicated that, at variance with other UreG proteins so far characterized, this protein is significantly folded in solution. The amino acid sequence of HpUreG is 29% identical to that of HypB from Methanocaldococcus jannaschii, a dimeric zinc-binding GTPase involved in the in vivo assembly of [Ni,Fe]-hydrogenase. A homology-based molecular model of HpUreG was calculated, which allowed us to identify structural and functional features of the protein. Isothermal titration microcalorimetry demonstrated that HpUreG specifically binds 0.5 equivalents of Zn(2+) per monomer (K(d) = 0.33 +/- 0.03 microM), whereas it has 20-fold lower affinity for Ni(2+) (K(d) = 10 +/- 1 microM). Zinc ion binding (but not Ni(2+) binding) causes protein dimerization, as confirmed using light scattering measurements. The structural rearrangement occurring upon Zn(2+)-binding and consequent dimerization was evaluated using circular dichroism and fluorescence spectroscopy. Fully conserved histidine and cysteine residues were identified and their role in zinc binding was verified by site-directed mutagenesis and microcalorimetry. The results are analyzed and discussed with respect to analogous examples of GTPases in nickel metabolism.
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PMID:Zn2+-linked dimerization of UreG from Helicobacter pylori, a chaperone involved in nickel trafficking and urease activation. 1876 50

5-Fluorouracil (5-FU) and its prodrugs are used to treat various cancers. Response to 5-FU-based chemotherapy and expression of 5-FU-related enzymes differ among cancers. The objective of the present study was to investigate the relationship between the expression of 5-FU-related enzymes and clinicopathologic factors in bladder cancer. Formalin-fixed, paraffin-embedded sections of 44 bladder cancers and 27 normal bladders were included in this study. After laser capture microdissection, "Danenberg tumor profile," was performed for the measurement of 5-FU-related enzymes. There was no significant difference between dihydropyrimidine hydrogenase (DPD) mRNA expression in bladder cancer and in normal bladder. On the contrary, mRNA expressions of orotate phosphoribosyltransferase (OPRT), thymidylate synthase (TS), and thymidine phosphorylase (TP) in bladder cancer were higher than those in normal bladder. Compared with previously reported DPD mRNA expressions in other types of cancer, DPD mRNA expression in bladder cancer was relatively low. The 5-FU-related enzymatic condition of bladder cancer is favorable for 5-FU.
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PMID:Expression of the fluoropyrimidine-metabolizing enzymes in bladder cancers as measured by the Danenberg tumor profile. 2011 1

Helicobacter pylori is one of the most common pathogens affecting humankind, infecting approximately 50% of the world's population. Of those infected, many will develop asymptomatic gastritis, but 10% develop gastric or duodenal ulcers. The clinical outcome of the infection may involve a combination of bacterial factors, host factors and environmental factors. In the process of development of gastritis, ulceration and cancer, several cellular and molecular steps follow each other. Infection, acid survival, adhesion, cytotoxicity, epithelial cell turnover changes, inflammation, regeneration or pathological alteration towards erosions, ulceration, and cancer can be observed on the cellular level. Bacterial factors like urease, AmiE, AmiF, hydrogenase and arginase are needed for survival in the acidic gastric environment. The bacterial flagellae are essential to move the bacteria towards the epithelial surface. Adhesive factors like BabA, SabA and ureaseA are necessary for adhesion against MHC-II complexes and Le antigens. The bacteria VacA and CagA are cytotoxic factors. The Cag type IV secretion system delivers these proteins inside the epithelial cells. After disruption of epithelial cell junctions, the bacteria can pass through the gastric wall facing direct immune response from neutrophils, lymphocytes, mast cells and dendritic cells. This review describes and summarizes our present molecular biological information and knowledge about the Helicobacter infective component, cell functions and processes. The possible role of host counter responses and interactions with gastric epithelia and immune cells are also detailed.
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PMID:Molecular pathogenesis of Helicobacter pylori infection: the role of bacterial virulence factors. 2108 10

Copper nanoparticles (CuNPs) and palladium nanoparticles (PdNPs) have attracted wide attention owing to their multifaceted utility in catalysis, sensors, and biomedical applications. Their therapeutic spectrum includes anticancer, antiviral, antibacterial, antifungal, antidiabetic, antioxidant potential which rationalizes the exploration of diverse physical, chemical, and biological routes for fabrication. In this article, we focused on bacterium-assisted design of nanostructured copper and palladium for applications in therapy against multidrug-resistant pathogens, dehalogenation of diatrizoate, Heck coupling of iodobenzene, polymer electric membrane fuel cell, metal recovery, and electronic waste management. Further, hypothesis behind microbial synthesis of PdNPs in E. coli containing [NiFe] hydrogenase Hyd-1 is discussed. Similarly, detailed mechanism of synthesis and stabilization in Cyanobacteria is also documented. Both CuNPs and PdNPs act as potent chemotherapeutic agents that can further be enhanced by conjugation with drugs and/or fluorophores and ligands for simultaneous diagnosis and targeted drug delivery to the cancer site or infection. These bacteriogenic nanoparticles can be used in sensors and pollution control.
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PMID:Copper and palladium nanostructures: a bacteriogenic approach. 2999 11