Repair of single-strand breaks in EAOH cells and their sensitivity to low-dose-rate radiation

Abstract

EAOH (Early-onset ataxia with ocular motor apraxia and hypoalbuminemia)/AOA is characterized as a unique disorder. Patients of EOAH have mutations in the APTX gene which encodes Aprataxin. Since Aprataxin has been reported to associate with Xrcc1, PARP-1 and p53, it is supposed to be involved in the repir of DNA single strand breaks.We have established immortal cell line of the cells obtained from a EAOH patient by in introducing the hTERT gene. This EAOH cell was more sensitive to hydrogen peroxide than normal cells. We then analyzed amount of single strand breaks by using the Comet assay and found increased number of single strand breaks in EAOH cells after treatment with hydrogen peroxide. We then analyzed effect of low-dose-rate radiation on this EAOH cells. EAOH cells were more sensitive to low-dose-rate radiation than normal cells and dose dependent amount of single strand breaks were observed after low-dose-rate radiation.