Induction of chromosome aberrations in B14-150 cells following carbon ions irradiation at low doses

Abstract

Dose-dependences of the chromosomal aberrations induction in B14-150 cells were studied for carbon ions (E ∼455 MeV/nucleon) with different values of the linear energy transfer (LET): 10-12 keV/μm (proximal region of the Bragg curve - plateau) and 25-27 keV/μm (tail of the Bragg curve). It is shown that the level of chromosome aberrations was higher for irradiation at tail of carbon beam. The dose relations were described by a modified linear-quadratic model and had a similar character in the studied dose range of 0.05-2.5 Gy. A sharp increase of the chromosome aberrations yield at the dose range up to 0.1 Gy (hyper-radiosensitivity, HRS), slowdown in it at the range of 0.1-0.3 Gy (induced radioresistance, IRR) and a further its’ growth above 0.3 Gy were observed with a transformation to linear and linear-quadratic dependences. The results obtained agree with the known literature data and indicates the likeness of the biological effect of hyper-radiosensitivity and induced radioresistance (HRS/IRR) for different cell lines.

Hypersensitivity and Induced Radioresistance in Chinese Hamster Cells Exposed to Radiations with Different LET Values

“…The above cytogenetic data obtained for radiations with very different LET values, 1 or 100 keV/μm, supplemented the results of our previous studies using the same cell line exposed to 60 Co γ-rays and carbon ions [ 20 , 21 , 24 ] of intermediate LET values. Detailed cytogenetic results of all experiments are presented in Table A1 , Table A2 , Table A3 , Table A4 and Table A5 of Appendix A .…”

“…As for other radiations, cytogenetic data give no indication of a low border of HRS response in mammalian cells and dose curves starting from zero doses, or more accurately, from the least doses. In our investigations with CHO-K1 cells, they were 0.05 Gy (protons, this paper); 0.03, 0.05 Gy (neutrons [ 20 ]); 0.07 and 0.1 Gy ( 12 C, [ 24 ]); and 0.02, 0.03 Gy (protons, fibrosarcoma B14–150 cells [ 21 ]). The first dose points were 0.075 Gy (14 MeV neutrons, human melanoma cells) in [ 14 ]) and 0.1 Gy ( 12 C ions, HPRT mutation frequency) in [ 17 ].…”

“…Standard methods of statistics implemented in Microsoft Excel and OriginLab software were used. The experimental data were fitted to the linear–quadratic model Equation (1), and to its modification by Marples and Joiner in the form of the induced-repair model (IR model, (2)) [ 1 ] that we described in [ 21 ] as follows:…”

“…Results of experiments with carbon ions in which LET levels were 45.2 keV/μm [ 16 ], 70 keV/μm [ 17 , 18 ], and 252 keV/μm [ 19 ] also disagreed with this suggestion. Our cytogenetic studies with CHO-K1 cells exposed to low-dose rate 14.5 MeV neutrons have also shown HRS/IRR response [ 20 ], as well as in B14–150 cells irradiated with carbon ions at the plateau and “tail” of the Bragg curve [ 21 ]. Both cell cultures were in the stationary (plateau) growth phase.…”

Hyper-radiosensitivity affects low-dose acute myeloid leukemia incidence in a mathematical model

“…Cellular HRS has been extensively investigated for the endpoint of cell survival (Lambin et al 1993;Short et al 1999;Joiner et al 2001;Marples and Collis 2008;Olobatuyi et al 2018); however, it remains extraordinarily difficult to relate the possible effects of HRS to the endpoint of cancer risk. Besides the endpoint of cell survival, HRS has also been shown to stimulate the induction of radiation-induced chromosomal aberrations and deletions at very low doses (Seth et al 2014;Troshina et al 2020). The rAML incidence may be affected if HRS stimulates the formation of the Sfpi1 deletion at very low doses.…”