Abstract
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.
Highlights
The molecular and cellular basis of radiosensitivity is very complex but it would be very important to have a predictive assay for individual estimation of the radiation dose, which would lead to better treatment results
Mn superoxide dismutase (MnSOD) is clearly involved in radioresistance, there is an obvious need for further investigation of the role of mitochondria oxidative stress in radiation injury [4]
After dose of 2 Gy of gamma irradiation the activity of superoxide dismutase (SOD) in blood samples was decreased (51.9±9.8 U/mg protein)
Summary
The molecular and cellular basis of radiosensitivity is very complex but it would be very important to have a predictive assay for individual estimation of the radiation dose, which would lead to better treatment results. The enzymes of the antioxidant (AO) defense system represent the key component of the cell defense mechanism and tissue protection system from the harmful effects of free reactive radicals, which influence the genome and other biomolecules in cells [1] As it is known, the exposure of cells to ionizing radiation leads to formation of the reactive oxygen species (ROS), which are associated with radiation induced cytotoxicity [2]. 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. 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
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
