Clustered DNA damages induced in human hematopoietic cells by low doses of ionizing radiation.
Ionizing radiation induces clusters of DNA damages--oxidized bases, abasic sites and strand breaks--on opposing strands within a few helical turns. Such damages have been postulated to be difficult to repair, as are double strand breaks (one type of cluster). We have shown that low doses of low and high linear energy transfer (LET) radiation induce such damage clusters in human cells. In human cells, DSB are about 30% of the total of complex damages, and the levels of DSBs and oxidized pyrimidine clusters are similar. The dose responses for cluster induction in cells can be described by a linear relationship, implying that even low doses of ionizing radiation can produce clustered damages. Studies are in progress to determine whether clusters can be produced by mechanisms other than ionizing radiation, as well as the levels of various cluster types formed by low and high LET radiation.
Sutherland
Betsy M
BM
Biology Department, Brookhaven National Laboratory, Upton, NY 11973-5000, USA. bms@bnl.gov
Bennett
Paula V
PV
Cintron-Torres
Nela
N
Hada
Megumi
M
Trunk
John
J
Monteleone
Denise
D
Sutherland
John C
JC
Laval
Jacques
J
Stanislaus
Marisha
M
Gewirtz
Alan
A
D002460:Cell Line; D004247:DNA / Q000528:radiation effects; D004249:DNA Damage; D004307:Dose-Response Relationship, Radiation; D006410:Hematopoiesis; D006801:Humans; D018499:Linear Energy Transfer; D009000:Monocytes / Q000502:physiology* / Q000528:radiation effects*; D005810:Multigene Family / Q000528:radiation effects*
D004247:DNA