Comparison of the Effect of High-Energy Ionizing Radiation and Hydrogen Peroxide on the Conformational Dynamics of DNA

Abstract

Nowadays reactive oxygen species and induction of oxidative stress in cells are widely exploited for treatment of numerous types of cancer. Various endogenous and exogenous factors may generate the reactive oxygen species, such as anticancer drugs and high-energy ionizing radiation. In current project, using FTIR spectroscopy as a sensitive method for conformational DNA analysis it was proposed to use hydrogen peroxide for modeling oxidative stress and its effect on cellular components, particularly, on DNA as a main target. Moreover, the effects of different doses of high-energy ionizing radiation and different concentrations of hydrogen peroxide on DNA solutions were compared using FTIR spectroscopy. Their effects have similar characteristics, since both of them lead to generation of free radicals ОН^- that are the most cytotoxic among reactive oxygen species. It was demonstrated that main changes caused by ionizing radiation include breaks of DNA chains and formation of low-weight fragments, in comparison, hydrogen peroxide treatment mainly induces oxidation of nitrogenous bases and their modifications, however, DNA remains its polymeric structure.