Original scientific paper
Evaluation of DNA Damage in Radiotherapy-Treated Cancer Patients Using the Alkaline Comet Assay
Marija Gamulin
Vera Garaj-Vrhovac
Nevenka Kopjar
Abstract
The aim of this study was to evaluate primary DNA damage and the dynamics of the repair of radiotherapy-induced
DNA lesions in non-target cells of cancer patients. This study included patients diagnosed with different solid tumors
who received radiotherapy. The levels of DNA damage were evaluated using the alkaline comet assay on peripheral blood
leukocytes. Altogether four blood samples per patient were collected: before and after receiving the first dose of radiotherapy,
in the middle of radiotherapy cycle, and after the last dose of radiotherapy. The results indicate that after the first radiation
dose significantly increased levels of DNA damage were recorded in almost all cancer patients compared to their
baseline values. Specific patterns of DNA damage were recorded in samples analyzed in the middle of radiotherapy and
after receiving the last dose, indicating the possibility of adaptive response in some patients. Our results indicate that
persistence of post-irradiation damage in peripheral blood leukocytes (and possibly in other non-target cells) of cancer
patients that are strong determinants for the secondary cancer risk. Moreover, the alkaline comet assay was confirmed as
a rapid and sensitive assay for the assessment of genome damage after in vivo irradiation.
Keywords
cancer; comet assay; leukocytes; DNA damage and repair
Hrčak ID:
26898
URI
Publication date:
3.9.2007.
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