Possible prospects for cancer therapy: DNA damage mechanism detected in water

This detection was made possible by a combination of various electron spectroscopy methods and high-energy X-rays from a synchrotron. Using the so-called electron coincidence technique, the team was able to detect the underlying process, a complex molecular mechanism in which harmful electrons are generated (RA-ICD). In combination with high-resolution electron spectroscopy, the released electrons could be identified and their formation in the immediate molecular environment could be proven. This showed that electrons with an energy of 15 to 25 electron volts are specifically generated in the calcium ions examined in water - in the range that is particularly effective in causing DNA damage.

The RA-ICD mechanism was already theoretically predicted in 2014, and a potential medical application was also discussed. The underlying idea is to activate certain marker elements that are specifically introduced into malignant tissue, for example, by means of resonant excitation by X-rays. The X-rays interact almost exclusively with the marker atoms, releasing specific electrons in their immediate vicinity in a targeted and efficient manner, which can damage DNA. In contrast, the surrounding atoms and molecules of the healthy tissue remain largely transparent to the radiation, so that damage in these areas is minimized.

In contrast to conventional X-ray therapy, in which the radiation is widely distributed in the tissue, this approach therefore enables localized, minimally invasive treatment. "Even though our study is still basic research, we were still able to show that harmful electrons in water can be generated specifically at defined points," explains Bloß, who conducts research in the field of experimental physics with synchrotron radiation. "This is an important step towards a possible application of the process in more precise and tissue-sparing therapy concepts."

However, there is still a very long way to go before such an application is possible.

The study was carried out in collaboration with Research Groups from France and Sweden and was published in the Journal of the American Chemical Society (JACS). In addition to Bloß, the Kassel Research Group also includes Prof. Dr. Arno Ehresmann and Dr. Andreas Hans (both from the Department of Experimental Physics IV).

Link to the paper: https://pubs.acs.org/doi/full/10.1021/jacs.5c06436

Contact for queries:
Dr. Dana Bloß
University of Kassel - Institute of Physics
dana.bloss@uni-kassel.de
Further information on the Research Group