[Structural chromosome organisation and radiation-induced interchromosomal aberrations]

Abstract

The quantitative prediction of the biological effects of radiation is one of the actual tasks of radiobiology. The experimental study may be impossible under certain conditions (low doses, complex radiation fields, etc). The development of theoretical tools is required to predict biological and medical consequence of the irradiation of cell and organism. The effect under the consideration in the present paper is chromosome aberrations (CA) induced by low and high LET radiation. One of the most uncertain factors in CA prediction is the impact of chromosomal and nuclear architecture. In the present study the quantitative evaluation of the mechanisms of CA induction are discussed in the framework of the biophysical modelling technique taking into account interphase chromosomes structure in the nucleus of living (human) cell. We show that the surface contacts mechanism of interchromosomal aberrations (interchange) formation does not explain the observed ratio of simple/complex interchanges induced by both low and high LET radiation. The chromatin structure repositioning following irradiation is proposed as a possible mechanism involved in the formation of the complex aberrations.