Inducible response required for repair of low-dose radiation damage in human fibroblasts.

ABSTRACT: Ionizing radiation (IR) induces a variety of DNA lesions among which DNA double-strand breaks (DSBs) are the biologically most significant. It is currently unclear if DSB repair is equally efficient after low and high doses. Here, we use gamma-H2AX, phospho-ATM (pATM), and 53BP1 foci analysis to monitor DSB repair. We show, consistent with a previous study, that the kinetics of gamma-H2AX and pATM foci loss in confluent primary human fibroblasts are substantially compromised after doses of 10 mGy and lower. Following 2.5 mGy, cells fail to show any foci loss. Strikingly, cells pretreated with 10 microM H(2)O(2) efficiently remove all gamma-H2AX foci induced by 10 mGy. At the concentration used, H(2)O(2) produces single-strand breaks and base damages via the generation of oxygen radicals bu

SUBMITTER: Grudzenski S 

PROVIDER: S-EPMC2922519 | biostudies-literature | 2010 Aug

REPOSITORIES: biostudies-literature