Oxidative stress-mediated DNA damage

TOXI 123

Ian A Blair, ian@spirit.gcrc.upenn.edu1, Seon Hwa Lee2, Dipti Mangal, dipti@mail.med.upenn.edu3, Jong Heum Park, hmpark@mail.med.upenn.edu4, and Trevor M Penning4. (1) Centers for Cancer Pharmacology and Excellence in Environmental Toxicology, University of Pennsylvania School of Medicine, 854 BRB II/III, 421 Curie Blvd, Philadelphia, PA 19104, (2) Department of Pharmacology, Center for Cancer Pharmacology, University of Pennsylvania, 846 BRB II/III, 421 Curie Boulevard, Philadelphia, PA 19104, (3) Department of Pharmacology, Center for Cancer Pharmacology, University of Pennsylvania, 421, Curie Blvd, 846, Biomedical Research Building, Philadelphia, PA 19104, (4) Center of Excellence in Environmental Toxicology, Department of Pharmacology, University of Pennsylvania School of Medicine, 135 John Morgan building, 3620 Hamilton Walk, Philadelphia, PA 19104-6084
Oxidative stress represents a cellular response to toxic insults, to carcinogenic chemicals, and to environmental agents such as viruses and mycotoxins. During oxidative stress there is a decrease in the amount of intracellular glutathione with a concomitant increase in reactive oxygen species (ROS). When antioxidant defense systems are overwhelmed, oxidative DNA damage can occur to form 8-oxo-2'-deoxyguanosine (8-oxo-dGuo). Artifactual formation of 8-oxo-dGuo has made it difficult to quantify 8-oxo-dGuo as a reliable index of DNA damage. These problems have now been overcome by the use of urea during DNA isolation, Chelex-treatment of buffers, iron chelation, and immunoaffinity purification of 8-oxo-dGuo from the DNA hydrolysate before analysis by stable isotope dilution liquid chromatography-tandem mass spectrometry (LC-MS/MS). It is now possible to use immunoaffinity stable isotope dilution LC-MS/MS to reliably quantify 8-oxo-dGuo in order to monitor oxidative DNA damage during cellular oxidative stress. Supported by NIH grants P01CA092537, R01CA039504 and P30ES013508.
 

Mass Spectrometry of DNA and Protein Damages
8:10 AM-11:55 AM, Wednesday, August 22, 2007 BCEC -- 258C, Oral

Division of Chemical Toxicology

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007