Mitochondrial reactive oxygen species-mediated fibroblast activation has a role in tumor microenvironment formation in radiation carcinogenesis.

Cancer risks attributable to low-dose and low-dose-rate radiation are a serious concern for public health. Radiation risk assessment is based on lifespan studies among Hiroshima-Nagasaki A-bomb survivors; however, there are statistical limitations due to a small sample size for low-dose radiation. Therefore, basic biological studies are helpful in understanding the mechanism of radiation carcinogenesis. The detrimental effects of ionising radiation (IR) are caused by reactive oxygen species (ROS)-mediated oxidative DNA damage. IR-induced delayed ROS are produced in the electron transport chain reaction of the mitochondrial complex. Thus, mitochondria are a source of ROS and a primary target for ROS attacks. Consequently, mitochondrial dysfunction is thought to be a key event in the metabolic changes of cancer cells and is important in radiation-induced carcinogenesis. In this paper, we present recent findings on radiation carcinogenesis effect assessment, focusing on mitochondrial function as stress sensors.