Singlet oxygen-induced DNA damage.
Singlet oxygen, hydrogen peroxide, hydroxyl radical and hydrogen peroxide are the reactive oxygen species (ROS) considered most responsible for producing oxidative stress in cells and organisms. Singlet oxygen interacts preferentially with guanine to produce 8-oxo-7,8-dihydroguanine and spiroiminodihydantoin. DNA damage due to the latter lesion has not been detected directly in the DNA of cells exposed to singlet oxygen. In this study, the singlet oxygen-induced lesion was isolated from a short synthetic oligomer after exposure to UVA radiation in the presence of methylene blue. The lesion could be enzymatically excised from the oligomer in the form of a modified dinucleoside monophosphate. Using liquid chromatography-tandem mass spectrometry (LC-MS/MS), the singlet oxygen lesion was detected in the form of modified dinucleoside monophosphates in double-stranded DNA and in the DNA of HeLa cells exposed to singlet oxygen. Pentamer containing the singlet oxygen-induced lesion and an isotopic label was synthesized as an internal standard for quantifying the lesion and served as well as for correcting for losses of product during sample preparation.
Department of Cellular Stress Biology, Roswell Park Cancer Institute, Buffalo, New York 14263, USA.
Han-Chun
HC
DeFedericis
Helen B
HB
Patrzyc
Michael J
MJ
Rajecki
Edwin E
EE
Budzinski
Herbert
H
Iijima
Jean B
JB
Dawidzik
Marianne S
MS
Evans
Kellee F
KF
Greene
Harold C
HC
Box
D000818:Animals; D002853:Chromatography, Liquid / Q000379:methods; D004247:DNA / Q000737:chemistry* / Q000235:genetics / Q000528:radiation effects*; D004249:DNA Damage; D015226:Dinucleoside Phosphates / Q000737:chemistry / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D006367:HeLa Cells; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods*; D009152:Mutagenicity Tests / Q000379:methods; D011829:Radiation Dosage; D026082:Singlet Oxygen / Q000737:chemistry*; D013941:Thymine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000528:radiation effects
D015226:Dinucleoside Phosphates; D026082:Singlet Oxygen; C029389:thymine glycol; D004247:DNA; C427203:calf thymus DNA; D013941:Thymine