Determining How Low Energy Electrons Damage DNA May Enhance Radiation Protection Strategies

A new study by a group of French and Canadian researchers has produced clues into a little-examined but common radiation threat to DNA: low-energy electrons (LEEs), with energies of 0–15 eV.

The scientists have devised the preliminary model of a close DNA cellular environment under threat from LEEs, revealing for the first time their effects on DNA in natural, biologic conditions. Their study was published online August 8, 2013, in the Journal of Chemical Physics.

The investigators’ project is a significant move toward determining how LEEs injure DNA because it provides a realistic research platform for analysis of results. The goal is to use this knowledge to improve current uses of radiation, such as in cancer treatments.

“The way by which these electrons can damage DNA, and how much damage they inflict, quantitatively, is of major importance not only for general radiation protection purposes, but also for improving the efficiency and safety of therapeutic and diagnostic radiation therapy,” said Dr. Michel Fromm, the lead researcher from the Université de Franche-Comté (Besançon, France), whose expertise is in creating nanometer-scaled DNA layers. His co-author of the study is Dr. Leon Sanche, of Sherbrooke University (Sherbrooke, QC, Canada), who is one of the world’s leading authorities on LEE research.

The investigators studied specific features of a small DNA molecule called a plasmid on a specialized thin film they created, which was irradiated by an electron gun. The impact generated transient particles called anions, which dissociate into snippets of DNA. When analyzed, these molecular fragments provide clues into the processes of DNA strand breaks and other DNA injuries that health researchers seek to understand, repair, and prevent.

“The fascinating point is that each time the close environment of DNA changes, new mechanisms of interaction of LEEs appear,” Dr. Fromm said.

Related Links:
Université de Franche-Comté
Sherbrooke University