(April 2022) Radiotherapy is a proven approach to destroy tumours. But it can do more in the future: stimulate the immune system and fight cancer more intensively. Researchers led by TU Darmstadt laid the foundations for this. They found out that X-rays trigger a calcium signalling cascade in cells of the immune system.
Ionising radiation is successfully used in cancer therapy to kill tumour cells. In the past two decades, it has been shown that the success of the therapy can be increased even more if the radiation treatment is combined with measures that stimulate the immune system. In this context, a new study involving biologists from the TU Darmstadt and the GSI Helmholtz Centre for Heavy Ion Research as well as researchers from the hospitals of the Universities of Frankfurt and Homburg is currently attracting attention. The researchers report in the Journal of General Physiology that the desired stimulating effect on the immune system is already directly triggered when T cells are co-irradiated by X-rays. Dominque Tandl, a researcher at the Department of Biology at TU Darmstadt, and her co-authors show in the now published study that clinically relevant doses of X-rays trigger an immune response-typical signalling cascade in T-lymphocytes, which begins with a release of the messenger substance calcium (Ca2+) from internal stores.
Mediated by the so-called store operated Ca2+ entry (SOCE) pathway, the concentration of Ca2+ in the cells begins to oscillate at a critical frequency, which in turn leads to the translocation of a transcription factor from the cytoplasm into the nucleus. Once there, this transcription factor initiates gene expression and the cell begins to produce molecules that are important for the immune response, such as cytokines. Since the irradiation of tumours inevitably always hits the blood cells in the target tissue, medicine could make use of the stimulating effect of X-rays on T-lymphocytes. The researchers hope that their studies will contribute to improving cancer therapy in the long term, according to Professor Gerhard Thiel, head of the Membrane Biophysics research area at the Department of Biology at TU Darmstadt and co-author of the study. “It might be possible to enhance the killing effect of ionising radiation on tumour cells and at the same time stimulate the immune system with the help of this radiation.”
