UNDERSTANDING THE EFFECTS OF CANCER RADIATION THERAPY ON ENDOTHELIAL CELL DYSFUNCTION - THE ROLE OF NF[kappa]B/JNK

Cardiovascular disease is the principal cause of mortality in developed societies. Studies have identified a correlation between radiotherapy for cancer and atherosclerosis in later life 1 . Endothelial cell dysfunction is a defining feature of atherosclerosis initiation. This study aims to investigate the effect of radiation on endothelial cell intracellular signalling networks, including the Nuclear Factor-kappaB (NFκB) and c-Jun N-terminal kinase (JNK) pathways. Human umbilical vein endothelial cells (HUVECs) were exposed to 10 Gy X-rays using an X-RAD 225 biological irradiator. Western blotting was used to detect NFκB and JNK pathway activation in whole cell lysates using anti-phospho-p65, anti-IκBα, anti-tp100/p52 and anti-phospho-JNK antibodies and in nuclear extracts using anti-NFκB-p65 antibodies. An in vitro kinase assay utilising 32P enabled detection of JNK-mediated phosphorylation of c-Jun. X-irradiation induced p65 phosphorylation (fold increase at 2hrs; 2.5±0.42, p