X-ray and UV Radiation Damage of dsDNA/Protein Complexes

Abstract

Radiation and photodynamic therapies are used for cancer treatment by targeting DNA. However, efficiency is limited due to physico-chemical processes and the insensitivity of native nucleobases to damage. Thus, incorporation of radio- and photosensitizers into these therapies should increase both efficacy and the yield of DNA damage. To date, studies of sensitization processes have been performed on simple model systems, e.g., buffered solutions of dsDNA or sensitizers alone. To fully understand the sensitization processes and to be able to develop new efficient sensitizers in the future, well established model systems are necessary. In the cell environment, DNA tightly interacts with proteins and incorporating this interaction is necessary to fully understand the DNA sensitization process. In this work, we used dsDNA/protein complexes labeled with photo- and radiosensitizers and investigated degradation pathways using LC-MS and HPLC after X-ray or UV radiation.

A Global Analysis of Photoreceptor-Mediated Transcriptional Changes Reveals the Intricate Relationship Between Central Metabolism and DNA Repair in the Filamentous Fungus Trichoderma atroviride

“…DNA damage can have serious consequences for the cell, which if not repaired leads to the generation of mutations that can be inherited from generation to generation and even cause cell death. Therefore, all organisms have developed sophisticated DNA damage repair mechanisms throughout evolution ( Berens and Molines, 2020 ). In this regard, UV-A radiation (320-400 nm) and UV-B (280-320 nm) are slightly harmful, while UV-C radiation (<280 nm) can be very harmful.…”

DNA Protection against Damages Induced by Low-Energy Electrons: Absolute Cross Sections for Arginine–DNA Complexes

“…The present work addresses the protection of DNA against HER-induced damage by histone proteins, ,,− around which genomic DNA is wrapped. , Arginine (Arg) is a major component of histone proteins that pack DNA to form chromatin. − Because of recent advances in thin film technology, we can fabricate composite layers of plasmid DNA intercalated with Arg molecules and derive corresponding damage ACSs for electrons of different specific energies within the energy range of SEs created by HER. Hence, it becomes possible to investigate the details of DNA protection from the direct effects of HER, , particularly, from the damage induced by SEs of energies below 20 eV. These low-energy electrons (LEEs) account for most of the initial SE distribution, whose maximum lies around 9–10 eV, irrespective of energy and nature of HER …”

“…37−40 Because of recent advances in thin film technology, 41 we can fabricate composite layers of plasmid DNA intercalated with Arg molecules and derive corresponding damage ACSs for electrons of different specific energies within the energy range of SEs created by HER. Hence, it becomes possible to investigate the details of DNA protection from the direct effects of HER, 35,42 particularly, from the damage induced by SEs of energies below 20 eV. These lowenergy electrons (LEEs) account for most of the initial SE distribution, whose maximum lies around 9−10 eV, irrespective of energy and nature of HER.…”