Buglewicz Dylan J, Su Cathy, Banks Austin B, Stenger-Smith Jazmine, Elmegerhi Suad, Hirakawa Hirokazu, Fujimori Akira, Kato Takamitsu A
National Institute of Radiological Sciences, National Institutes of Quantum Science and Technology, Chiba 263-8555, Japan.
Department of Environmental & Radiological Health Sciences, Colorado State University, Fort Collins, CO 80523, USA.
Toxics. 2023 Sep 12;11(9):773. doi: 10.3390/toxics11090773.
Cu and Co are metals known to increase DNA damage in the presence of hydrogen peroxide through a Fenton-type reaction. We hypothesized that these metals could increase DNA damage following irradiations of increasing LET values as hydrogen peroxide is a product of the radiolysis of water. The reaction mixtures contain either double- or single-stranded DNA in solution with Cu or Co and were irradiated either with X-ray, carbon-ion or iron-ion beams, or they were treated with hydrogen peroxide or bleomycin at increasing radiation dosages or chemical concentrations. DNA damage was then assessed via gel electrophoresis followed with a band intensity analysis. DNA damage was the greatest when DNA in the solution with either metal was treated with only hydrogen peroxide followed by the DNA damage of DNA in the solution with either metal post irradiation of low-LET (X-Ray) or high-LET (carbon-ion and iron-ion), respectively, and demonstrated the least damage after treatment with bleomycin. Cu portrayed greater DNA damage than Co following all experimental conditions. The metals' effect caused more DNA damage and was observed to be LET-dependent for single-strand break formation but inversely dependent for double-strand break formation. These results suggest that Cu is more efficient than Co at inducing both DNA single-strand and double-strand breaks following all irradiations and chemical treatments.
铜和钴是已知的在过氧化氢存在下通过类芬顿反应增加DNA损伤的金属。我们推测，由于过氧化氢是水辐射分解的产物，随着传能线密度（LET）值增加的辐射后，这些金属可能会增加DNA损伤。反应混合物含有溶解在溶液中的双链或单链DNA以及铜或钴，并用X射线、碳离子或铁离子束进行辐照，或者用逐渐增加的辐射剂量或化学浓度的过氧化氢或博来霉素进行处理。然后通过凝胶电泳并进行条带强度分析来评估DNA损伤。当仅用过氧化氢处理含有任一种金属的溶液中的DNA时，DNA损伤最大，其次分别是在低LET（X射线）或高LET（碳离子和铁离子）辐照后含有任一种金属的溶液中的DNA损伤，而在用博来霉素处理后显示出最小的损伤。在所有实验条件下，铜造成的DNA损伤都比钴大。金属的作用导致更多的DNA损伤，并且观察到对于单链断裂形成是LET依赖性的，而对于双链断裂形成是反向依赖性的。这些结果表明，在所有辐照和化学处理后，铜在诱导DNA单链和双链断裂方面比钴更有效。
