2013 Fiscal Year Final Research Report

Radiosensitivity test during low dose rate irradiation in normal and repair deficient cells

Research Project

Project/Area Number	24791338
Research Category	Grant-in-Aid for Young Scientists (B)
Allocation Type	Multi-year Fund
Research Field	Radiation science
Research Institution	Keio University
Principal Investigator	TANAKA Tomoki 慶應義塾大学, 医学部, 助教 (80594598)
Project Period (FY)	2012-04-01 – 2014-03-31
Keywords	低線量被曝 / 放射線感受性 / 染色体解析
Research Abstract	We exposed normal and ataxia telangiectasia cells to 0.5 Gy per day to gamma ray. Cells were maintained under Go during irradiation. The dose was 1 to 3 Gy and chromosomal aberrations using fusion premature chromosomal condensation technique were analyzed. Giemsa staining showed that 1 Gy induces around 0.36 fragments in normal cells and around 1.35 in AT cells, indicating that AT cells rejoin breaks less effectively than normal cells. We also analyzed chromosomal exchange after exposure to 3 Gy using FISH techniques. AT cells have more misrejoined breaks. When cells irradiated with 3 Gy were subcultured and G2 chromosomal aberrations were analyzed using calyculin-A induced PCC technique, unrejoined breaks decreased and misrejoined breaks increased in both cell lines, suggesting that AT cells begin to rejoin breaks when a certain number of beaks are accumulated and an increased number of exchanges were observed in G0 AT cells, which is similar situation after high-dose-rate irradiation