PURPOSE: To study the induction and the time-course of rejoining of DNA double strand breaks (DSB) in V79 cells irradiated with light ions with different linear energy transfer (LET). MATERIALS AND METHODS: V79 cells were irradiated in monolayer with monoenergetic proton, deuteron, helium-3 or helium-4 ion beams, each at two different energy values. Gamma rays were used as reference radiation. DSB have been measured by constant field gel electrophoresis (CFGE). RESULTS: The initial yield depended little on the particle type and LET. The amount of DSB left unrejoined for up to 2 h incubation time could be roughly described by a decreasing exponential function with a final plateau, although more complex functions cannot be excluded. Radiation quality had little effect on the rejoining rate but affected the plateau. The amount of residual DSB after 2 h was higher for densely than for sparsely ionizing radiation, and for the same particle was dependent on LET. The corresponding RBE ranged from 1.8 to 6.0. CONCLUSIONS: The results support the hypothesis that complex, less reparable DSB are induced in higher proportion by light ions with respect to gamma-rays and that, for the same ion, increasing LET leads to an increase in this proportion.
PURPOSE: To study the induction and the time-course of rejoining of DNA double strand breaks (DSB) in V79 cells irradiated with light ions with different linear energy transfer (LET). MATERIALS AND METHODS: V79 cells were irradiated in monolayer with monoenergetic proton, deuteron, helium-3 or helium-4 ion beams, each at two different energy values. Gamma rays were used as reference radiation. DSB have been measured by constant field gel electrophoresis (CFGE). RESULTS: The initial yield depended little on the particle type and LET. The amount of DSB left unrejoined for up to 2 h incubation time could be roughly described by a decreasing exponential function with a final plateau, although more complex functions cannot be excluded. Radiation quality had little effect on the rejoining rate but affected the plateau. The amount of residual DSB after 2 h was higher for densely than for sparsely ionizing radiation, and for the same particle was dependent on LET. The corresponding RBE ranged from 1.8 to 6.0. CONCLUSIONS: The results support the hypothesis that complex, less reparable DSB are induced in higher proportion by light ions with respect to gamma-rays and that, for the same ion, increasing LET leads to an increase in this proportion.
Authors: Hongyu Zhu; Aimee L McNamara; Stephen J McMahon; Jose Ramos-Mendez; Nicholas T Henthorn; Bruce Faddegon; Kathryn D Held; Joseph Perl; Junli Li; Harald Paganetti; Jan Schuemann Journal: Radiat Res Date: 2020-07-08 Impact factor: 2.841
Authors: Artem L Ponomarev; Mauro Belli; Philip J Hahnfeldt; Lynn Hlatky; Rainer K Sachs; Francis A Cucinotta Journal: Radiat Environ Biophys Date: 2007-04-04 Impact factor: 2.017
Authors: Luca G Mariotti; Giacomo Pirovano; Kienan I Savage; Mihaela Ghita; Andrea Ottolenghi; Kevin M Prise; Giuseppe Schettino Journal: PLoS One Date: 2013-11-29 Impact factor: 3.240