Spectroscopy Department, Physics Research Institute, National Research Centre, Cairo, Egypt. 12622 , a.b.abdelrazzak@gmail.com
Abstract: (529 Views)
Background:Radiotherapy is an important and effective modality in treating cancer patients. Radiation-induced cardiovascular injury is one of the consequences of radiotherapy due to undesired exposure of the heart. The non-targeted effects of radiation add to the risk of cardiovascular injury following radiotherapy. Accordingly, we investigated the abscopal effect of radiation in the myocardium of partially irradiated rats and compared the abscopal effect with the effect induced in the myocardium following either direct or sham irradiation. Materials and Methods: Twenty male rats divided into four groups; sham, 2Gy whole-body, 2Gy cranially- and 2Gy lower-limb irradiated, were used. Myocardium samples were collected and examined for MDA, p53, caspase 3, and glutathione reduced expression. Additionally, TGF-β and NF-κB expression levels were investigated. Results: Our data revealed elevated levels of lipid peroxidation in abscopal myocardium following cranial- /lower-limb irradiation with 2 Gy γ-radiation, as compared with the sham or whole-body irradiated groups. Similar behavior was noticed with p53 and caspase3 expression, suggesting apoptosis induction in the abscopal cardiomyocytes. The rise in lipid peroxidation and apoptosis markers in the abscopal myocardium was associated with an increase in glutathione reduced. The data propose oxidative stress induction in the myocardium following distant irradiation, which was further confirmed by the elevation in TGF-β and nuclear NF-κB expression. Conclusion: Abscopal effect was induced in the myocardium of partially-irradiated rats, suggesting increased risk of myocardial injury following localized radiotherapy.