Quantitative modelling of DNA damage using Monte Carlo track structure method

Citation
H. Nikjoo et al., Quantitative modelling of DNA damage using Monte Carlo track structure method, RADIAT ENV, 38(1), 1999, pp. 31-38
Citations number
62
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Multidisciplinary
Journal title
RADIATION AND ENVIRONMENTAL BIOPHYSICS
ISSN journal
0301-634X → ACNP
Volume
38
Issue
1
Year of publication
1999
Pages
31 - 38
Database
ISI
SICI code
0301-634X(199905)38:1<31:QMODDU>2.0.ZU;2-Y
Abstract
This paper presents data on modelling of DNA damage induced by electrons, p rotons and alpha-particles to provide an insight into factors which determi ne the biological effectiveness of radiations of high and low linear energy transfer (LET). These data include the yield of single- and double-strand breaks (ssb, dsb) and base damage in a cellular environment. We obtain a ra tio of 4-15 for ssb:dsb for solid and cellular DNA and a preliminary ratio of about 2 for base damage to strand breakage. Data are also given on speci fic characteristics of damage at the DNA level in the form of clustered dam age of varying complexity, that challenge the repair processes and if not p rocessed adequately could lead to the observed biological effects. It is sh own that nearly 30% of dsb are of complex form for low-LET radiation, solel y by virtue of additional breaks, rising to about 70% for high-LET radiatio n. Inclusion of base damage increases the complex proportion to about 60% a nd 90% for low- and high-LET radiation, respectively. The data show a twofo ld increase in frequencies of complex dsb from low-LET radiation when base damage is taken into account. It is shown that most ssb induced by high-LET radiation have associated base damages, and also a substantial proportion is induced by low-energy electrons.