Radiation Effects on Regulation of Gene Expression

Mitsuru Nenoi

Authors: Mitsuru Nenoi, Bing Wang, Tetsuo Nakajima
Radiation Effect Mechanisms Research Group, Natl. Inst. Radiol. Sci., Chiba, Japan

Risk estimation of ionizing radiation in the middle to high dose range has been mainly based on the epidemiological studies on Hiroshima and Nagasaki A-Bomb survivors. However, the importance of molecular and cellular studies on mechanisms for the biological effects should be emphasized due to the inherent limitation of the epidemiological studies at low levels of radiation exposure and risk. An increasing number of low-dose ionizing radiation-responsive genes are being reported in mouse and human cells. Analyses of these genes are considered to provide clues to the mechanisms for low-dose radiation effects, because the major ionizing radiation-protection mechanisms, including cell cycle checkpoint regulation and apoptosis, involve the regulation of gene expression in response to ionizing radiation.

Radioadaptive response is a biological response, by which individuals/cells acquire radiation-resistance after exposure to low-dose radiation. This is observed only after exposure to low-dose radiation, and is therefore considered to be an important determinant of low-dose radiation risk. In this paper, authors describe the regulation of gene expression in low-dose range. Especially, transcriptional regulation involved in the radioadaptive response will be discussed.

Keywords: low-dose ionizing radiation, gene regulation, radioadaptive response