Computer modeling of radiation effects

Noriyuki Bob Ouchi and Kimiaki Saito

Nuclear Science and Engineering Directorate , Japan Atomic Energy Agency, Japan

Biological effects of low-dose radiation are studied by computational methods. Assessing the risks of low-dose radiation, i.e. radiation induced cancer, is getting worth for the study of public health due to many types of exposures, medical exposures, and for the radiation protection view points.

Here we introduc e our on going study of describing low-dose radiation effects. Computer modeling and simulation are quite effective to clarify the mechanism of radiation effects since a phenomenon taking place in a small region in a very short time can be observed which is difficult to examine by experimental approaches. We will show our researches concerning the 3 stages of the radiation effects from atomic level to cellular level, 1) Simulation of DNA strand breaks by ionizing radiation, 2) Molecular dynamical study of the DNA lesion repair, 3) modeling and simulation of the cellular level tumorigenesis. In study 1), the relation of radiation quality to the amount of DNA breaks has been examined. In study 2), the molecular mechanism on the recognition process of DNA damages by repair enzymes has been studied, and we will show in study 3), the simulation of the tumor development process based on the multistage genomic mutation.

In this presentation, some essential results from these studies will be reported.

Keywords: Computer Simulation, model, DNA damage-repair, tumorigenesis