Linear Energy Transfer Modulates Radiation-Induced NF-kappa B Activation and Expression of its Downstream Target Genes

Nuclear factor kappaB ( NF-κB) is a central transcription factor in the immune system and modulates cell survival in response to radiotherapy. Activation of NF-κBwas shown to be an early step in the cellular response to ultraviolet A (UVA) and ionizing radiation exposure in human cells. NF-κBactivation by the genotoxicstress-dependent sub-pathway after exposure to different radiation qualities had been evaluated to a very limited extent. In addition, the resulting gene expression profile, which shapes the cellular and tissue response, is unknown. Therefore, in this study the activation of NF-κBafter exposure to low- and high- linear energy transfer(LET) radiation and the expression of its target genes were analyzed in human embryonic kidney (HEK) cells. The activation of NF-κBvia canonical and genotoxicstress-induced pathways was visualized by the cell line HEK-pNF-κB-d2EGFP/Neo L2 carrying the destabilized enhanced green fluorescent protein(d2EGFP) as reporter. The NF-κB-dependent d2EGFP expression...