Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2002-4-18
pubmed:abstractText
Aristolochic acid (AA), a naturally occurring nephrotoxin and rodent carcinogen, has recently been associated with the development of urothelial cancer in humans. Understanding which enzymes are involved in AA activation and/or detoxication is important in the assessment of an individual susceptibility to this natural carcinogen. We examined the ability of enzymes of rat renal and hepatic cytosolic fractions to activate AA to metabolites forming DNA adducts by the nuclease P1-enhanced version of the (32)P-postlabeling assay. Cytosolic fractions of both these organs generated AA-DNA adduct patterns reproducing those found in renal tissues from humans exposed to AA. 7-(Deoxyadenosin-N(6)-yl)aristolactam I, 7-(deoxyguanosin-N(2)-yl)aristolactam I and 7-(deoxyadenosin-N(6)-yl)aristolactam II were identified as AA-DNA adducts formed from AAI and 7-(deoxyguanosin-N(2)-yl)aristolactam II and 7-(deoxyadenosin-N(6)-yl)aristolactam II were generated from AAII by hepatic cytosol. Qualitatively the same AA-DNA adduct patterns were observed, although at lower levels, upon incubation of AAs with renal cytosol. To define the role of cytosolic reductases in the reductive activation of AA, we investigated the modulation of AA-DNA adduct formation by cofactors, specific inducers or selective inhibitors of the cytosolic reductases, DT-diaphorase, xanthine oxidase (XO) and aldehyde oxidase. The role of the enzymes in AA activation was also investigated by correlating the DT-diaphorase- and XO-dependent catalytic activities in cytosolic sample with the levels of AA-DNA adducts formed by the same cytosolic sample. On the basis of these studies, we attribute most of the cytosolic activation of AA to DT-diaphorase, although a role of cytosolic XO cannot be ruled out. With purified DT-diaphorase, the participation of this enzyme in the formation of AA-DNA adducts was confirmed. The binding orientation of AAI in the active site of DT-diaphorase was predicted by computer modeling based on published X-ray structures. The results presented here are the first report demonstrating a reductive activation of carcinogenic AAs by DT-diaphorase.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Aldehyde Oxidase, http://linkedlifedata.com/resource/pubmed/chemical/Aldehyde Oxidoreductases, http://linkedlifedata.com/resource/pubmed/chemical/Antineoplastic Agents, http://linkedlifedata.com/resource/pubmed/chemical/Aristolochic Acids, http://linkedlifedata.com/resource/pubmed/chemical/Carcinogens, http://linkedlifedata.com/resource/pubmed/chemical/DNA, http://linkedlifedata.com/resource/pubmed/chemical/DNA, Complementary, http://linkedlifedata.com/resource/pubmed/chemical/DNA Adducts, http://linkedlifedata.com/resource/pubmed/chemical/Drugs, Chinese Herbal, http://linkedlifedata.com/resource/pubmed/chemical/NAD(P)H Dehydrogenase (Quinone), http://linkedlifedata.com/resource/pubmed/chemical/Phenanthrenes, http://linkedlifedata.com/resource/pubmed/chemical/Xanthine Oxidase, http://linkedlifedata.com/resource/pubmed/chemical/aristolochic acid I
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0143-3334
pubmed:author
pubmed:issnType
Print
pubmed:volume
23
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
617-25
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed-meshheading:11960915-Aldehyde Oxidase, pubmed-meshheading:11960915-Aldehyde Oxidoreductases, pubmed-meshheading:11960915-Animals, pubmed-meshheading:11960915-Antineoplastic Agents, pubmed-meshheading:11960915-Aristolochic Acids, pubmed-meshheading:11960915-Carcinogens, pubmed-meshheading:11960915-Cell Nucleus, pubmed-meshheading:11960915-Chromatography, High Pressure Liquid, pubmed-meshheading:11960915-Cytosol, pubmed-meshheading:11960915-DNA, pubmed-meshheading:11960915-DNA, Complementary, pubmed-meshheading:11960915-DNA Adducts, pubmed-meshheading:11960915-Dose-Response Relationship, Drug, pubmed-meshheading:11960915-Drugs, Chinese Herbal, pubmed-meshheading:11960915-Enzyme Activation, pubmed-meshheading:11960915-Liver, pubmed-meshheading:11960915-Models, Chemical, pubmed-meshheading:11960915-Models, Molecular, pubmed-meshheading:11960915-NAD(P)H Dehydrogenase (Quinone), pubmed-meshheading:11960915-Nephritis, pubmed-meshheading:11960915-Phenanthrenes, pubmed-meshheading:11960915-Rats, pubmed-meshheading:11960915-Rats, Wistar, pubmed-meshheading:11960915-Thymus Gland, pubmed-meshheading:11960915-Time Factors, pubmed-meshheading:11960915-Xanthine Oxidase
pubmed:year
2002
pubmed:articleTitle
Carcinogenic aristolochic acids upon activation by DT-diaphorase form adducts found in DNA of patients with Chinese herbs nephropathy.
pubmed:affiliation
Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030,128 40 Prague 2, The Czech Republic. stiborov@natur.cuni.cz
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't