A review of studies of ionizing radiation-induced double-strand break clustering

Citation
Km. Prise et al., A review of studies of ionizing radiation-induced double-strand break clustering, RADIAT RES, 156(5), 2001, pp. 572-576
Citations number
32
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Experimental Biology
Journal title
RADIATION RESEARCH
ISSN journal
0033-7587 → ACNP
Volume
156
Issue
5
Year of publication
2001
Part
2
Pages
572 - 576
Database
ISI
SICI code
0033-7587(200111)156:5<572:AROSOI>2.0.ZU;2-V
Abstract
Underpinning current models of the mechanisms of the action of radiation is a central role for DNA damage and in particular double-strand breaks (DSBs ). For radiations of different LET, there is a need to know the exact yield s and distributions of DSBs in human cells. Most measurements of DSB yields within cells now rely on pulsed-field gel electrophoresis as the technique of choice. Previous measurements of DSB yields have suggested that the yie lds are remarkably similar for different types of radiation with RBE values less than or equal to1.0. More recent studies in mammalian cells, however, have suggested that both the yield and the spatial distribution of DSBs ar e influenced by radiation quality. RBE values for DSBs induced by high-LET radiations are greater than 1.0, and the distributions are nonrandom. Under lying this is the interaction of particle tracks with the higher-order chro mosomal structures within cell nuclei. Further studies are needed to relate nonrandom distributions of DSBs to their rejoining kinetics. At the molecu lar level, we need to determine the involvement of clustering of damaged ba ses with strand breakage, and the relationship between higher-order cluster ing over sizes of kilobase pairs and above to localized clustering at the D NA level. Overall, these studies will allow us to elucidate whether the non random distributions of breaks produced by high-LET particle tracks have an y consequences for their repair and biological effectiveness. (C) 2001 by R adiation Research Society.