Linked Life Data

2060851

Source:http://linkedlifedata.com/resource/pubmed/id/2060851

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
1991-8-7
pubmed:abstractText
To determine whether oxidants capable of DNA modification are produced by cells treated with tumor promoters, we adapted a fluorometric method to our needs. HeLa cells were preincubated with 2',7'-dichlorofluorescin diacetate (DCFdAc), treated with various agents, sonicated, centrifuged and fluorescence of the oxidized product (DCF) was determined in supernatants. When cells were exposed to H2O2 in the presence of azide (catalase inhibitor) or o-phenanthroline (a lipophilic Fe chelator), an increase in fluorescence was observed. These results show that some Fe ions were interacting with the H2O2 which entered the cells, thus decreasing its levels available for oxidation of the substrate and potentially increasing formation of .OH, known DNA-damaging species. Glutathione (GSH), which is present in cells in substantial amounts, was found to reduce DCF whereas azide counteracted GSH-mediated reduction. Treatment of HeLa cells with 12-0-tetradecanoyl-phorbol-13-acetate (TPA) in the presence of DCFdAc and azide resulted in dose- and time-dependent formation of DCF. Even when cells were sonicated prior to incubation with TPA, DCF was formed at levels proportional to the number of cells as well as dose of TPA. Flow cytometry of TPA-treated cells confirmed these findings. These results demonstrate that tumor promoters can cause oxidative activation of HeLa cells, which produce active oxygen species, most likely H2O2, that ultimately contribute to the formation of oxidized bases such as 5-hydroxymethyl uracil in cellular DNA. They also show that this fluorometric method can be utilized for determination of cellular H2O2 formation at nM concentrations.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
8755-0199
pubmed:author
pubmed:issnType
Print
pubmed:volume
12-13 Pt 2
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
783-94
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Hydrogen peroxide formation by cells treated with a tumor promoter.
pubmed:affiliation
Department of Environmental Medicine, New York University Medical Center, NY 10016.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.