Cellular Response to Exposure with Different Radiation Qualities with a Focus on Nuclear Factor kB

Kurzfassung

Understanding the cellular radiation response is an essential prerequisite for the risk assessment of astronauts’ space radiation exposure during long-term space missions and for effective countermeasure development. The same holds for improving cancer radiotherapy, including carbon ion therapy. Space radiation exposure bears two major risks: large solar particle events (SPE) might cause the acute radiation syndrome, and the chronic exposure to galactic cosmic rays (GCR) increases the cancer and cataract risk. Energetic heavy ions as GCR components are of major importance because of their high relative biological effectiveness (RBE). The cellular radiation response involves a complex network of signaling pathways, which result in cell-protective (DNA repair, cell cycle arrest) or cell-destructive (cell death) reactions. The central role of p53 in the radiation response was recognized early, while in radiobiological research, the Nuclear Factor kB (NF-kB) pathway was less investigated. NF-kB is a central transcription factor in the immune system and in inflammation, and exhibits pro-survival effects. Especially its activation in response to space relevant radiation qualities and carbon ion therapy needs to be known. Furthermore, possible combined effects of radiation and other spaceflight environmental factors such as microgravity on the NF-kB pathway are unknown.