Back to Search
Start Over
Small field radiotherapy of head and neck cancer patients is responsible for oxidatively damaged DNA/oxidative stress on the level of a whole organism.
- Source :
-
International journal of cancer [Int J Cancer] 2008 Oct 15; Vol. 123 (8), pp. 1964-7. - Publication Year :
- 2008
-
Abstract
- It is possible that oxidatively damaged DNA which arises as a result of radiotherapy may be involved in the therapeutic effect of the ionizing radiation and in the side effects. Therefore, for the first time, the broad spectrum of oxidatively damaged DNA biomarkers: urinary excretion of 8-oxodG (8-oxo-7,8-dihydro-2'-deoxyguanosine), 8-oxoGua (8-oxo-7,8-dihydroguanine) as well as the level of oxidatively damaged DNA in leukocytes, was analyzed in head and neck cancer patients (n = 27) undergoing fractionated radiotherapy using methodologies which involve HPLC (high-performance liquid chromatography) prepurification followed by gas chromatography with isotope dilution mass spectrometry detection and HPLC/EC. Of all the analyzed parameters in the majority of patients, only urinary excretion of the modified nucleoside significantly increased over the initial level in the samples collected 24 hr after the last fraction. However, for the distinct subpopulation of 10 patients, a significant increase in the level of 8-oxodG in cellular DNA and a simultaneous drop in urinary 8-oxoGua (the repair product of oxidative DNA damage) were detected after completion of the therapy. Because 8-oxoGua is a repair product of the DNA damage, there is a possibility that, at least in the case of some patients with the lowest activity of OGG1 (8-oxo-7,8-dihydroguanine glycosylase), the combination of lower OGG1 repair efficacy and irradiation was associated with increased background level of 8-oxoGua in cellular DNA. Apparently reduced DNA repair is unable to cope with the radiation-induced, and the extra amount of 8-oxoGua leading to an increase of potentially mutagenic/carcinogenic lesions.
- Subjects :
- 8-Hydroxy-2'-Deoxyguanosine
Chromatography, High Pressure Liquid
DNA, Neoplasm metabolism
Deoxyguanosine analogs & derivatives
Deoxyguanosine blood
Deoxyguanosine urine
Dose Fractionation, Radiation
Gas Chromatography-Mass Spectrometry
Guanine analogs & derivatives
Guanine blood
Guanine urine
Head and Neck Neoplasms genetics
Head and Neck Neoplasms urine
Humans
Leukocytes metabolism
Leukocytes radiation effects
Oxidative Stress genetics
Radiation Injuries blood
Radiation Injuries metabolism
Radiation Injuries urine
Uric Acid blood
Uric Acid urine
DNA Damage
DNA, Neoplasm radiation effects
Head and Neck Neoplasms radiotherapy
Radiation Injuries genetics
Subjects
Details
- Language :
- English
- ISSN :
- 1097-0215
- Volume :
- 123
- Issue :
- 8
- Database :
- MEDLINE
- Journal :
- International journal of cancer
- Publication Type :
- Academic Journal
- Accession number :
- 18688851
- Full Text :
- https://doi.org/10.1002/ijc.23700