Background: The goal of this study was to introduce a new predictive biomarker assay that might improve a clinical irradiation treatment of malignant diseases. Methods: Thirty-two peripheral blood samples obtained from breast cancer patients were analyzed for superoxide dismutase (SOD) after irradiation with gamma rays (60 Co). SOD was measured in subcellular fractions prepared from unirradiated and irradiated blood samples (McCord and Fridovich). The activity of SOD was measured by the method of Misra and Fridovich and protein concentration by the method of Lowry et al. Results Antioxidant radiation response of patients' blood cells was very variable and specific for each individual. The results indicated that the radiation response during radiotherapy directly depends on the initial state of antioxidant activity in the blood of cancer patients. In the blood samples with high level of SOD activity the irradiation decreased enzymatic activity while in the samples with medium or low level of SOD, the SOD activity was preserved or increased by irradiation with 2 Gy of gamma rays. Conclusion We showed that the modulation of SOD activity in blood cells after irradiation in vitro might be used as predictive biomarker in individualization of therapy protocols
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.