Abstract
Irradiation with heavy ion particles is one of promising procedure for cancer therapy. Heavy ion particles efficiently kill cancer cells with the high LET and the typical Bragg peak, two major characters. However, we have less knowledge about the character of DNA damage induced by heavy ion particles. Therefore, we estimated the number of DNA damage including strand breaks and oxidative base lesions, and compared the localization on pDEL19 and lambda DNA irradiated by gamma-rays, carbon and iron ions, whose LET were 0.2, 13, and 200 keV/um, respectively. Our result showed that total damage per dose were decreased with increase in LET. Even clustered damage per dose also were decrease, LET-dependently. Thus, the increase of LET did not lead increase of number of clustered damage, that is thought to be major driving force of radio-induced cell killing. It suggests that another factor such as quantity of clustered damage is important.
