FIAS Scientific Report 2011 - Frankfurt Institute for Advanced Studies ...

Assessment of complex DNA damage
Collaborators: E. Surdutovich 1 , A.V. Solov’yov 2 , A.V. Yakubovich 2 , W. Greiner 2
1 Oakland University, Michigan, USA, 2 Frankfurt Institute for Advanced Studies
In 2011, we have further explored approaches to the assessment of clustered or complex DNA damage[1]. The
damage complexity is one of the most significant specific features of irradiation with ions. It arises from a
high concentration of agents causing the damage. It is much more difficult to the repair mechanisms, present
in the cell, to fix the complex damage and, as a result, such damage is more lethal than isolated DNA damage.
We suggested ways to quantify the complex damage in ref. [1]. The fluence of secondary electrons through
the DNA segment (two adjacent twists of DNA are the host of complex damage of DNA) is shown in Fig. 1.
This fluence as well as the calculated radial dose, shown in Fig. 2, lead to the calculation of the distribution of
clustered damage around the ion’s path.
N A
5
4
3
2
1
0
5 6 7 8 9 10 11
Ρ�nm�
The dependence of number of secondary electrons hitting
a two-twist-segment of DNA on the surface of a nucleosome
on the distance of the nucleosome from the ion’s
path.
Dose�Gy�
10 5
10 4
10 3
10 2
10 1
2 5 10 20 50
Ρ�nm�
Comparison of the calculated (line) with the simulated
(dots) radial dose for 25 MeV/u carbon ions.
Examples of radial distribution of complexity and cell survival on the radial dose based on damage complexity
are shown in the figures below.
P C
0.30
0.25
0.20
0.15
0.10
0.05
0
0 2 4 6 8
Ρ�nm�
An example of radial distribution of clusters of two (solid
line) and clusters of three lesions (dashed line).
1�P d
1
10 �1
10 �2
10 �3
1 2 3 4 5 6 7
Radial Dose�MGy�
The dependence of cell survival probability on the local
radial dose per ion.
Related publications in 2011:
1. E. Surdutovich, D.C. Gallagher, and A.V. Solov’yov, Calculation of complex DNA damage induced by
ions, Phys. Rev. E 84, 051918 (2011).
101