Krasavin E* Dotaz Zobrazit nápovědu
- Publikační typ
- abstrakt z konference MeSH
Fundamental research on the harmful effects of ionizing radiation on living cells continues to be of great interest. Recently, priority has been given to the study of high-charge and high-energy (HZE) ions that comprise a substantial part of the galactic cosmic ray (GCR) spectra that would be encountered during long-term space flights. Moreover, predictions of the delayed genetic effects of high linear energy transfer (LET) exposure is becoming more important as heavy ion therapy use is increasing. This work focuses mainly on the basic research on the delayed effects of HZE ions on V79 Chinese hamster cells, with emphasis on the induction of HPRT mutations after prolonged expression times (ET). The research was conducted under various irradiation conditions with accelerated ions 18O (E=35.2MeV/n), 20Ne (E=47.7MeV/n and 51.8MeV/n), and 11B (E=32.4MeV/n), with LET in the range from 49 to 149 keV/μm and with 60Co γ-rays. The HPRT mutant fractions (MF) were detected in irradiated cells in regular intervals during every cell culture recultivation (every 3days) up to approximately 40days (70-80 generations) after irradiation. The MF maximum was reached at different ET depending on ionizing radiation characteristics. The position of the maximum was shifting towards longer ET with increasing LET. We speculate that the delayed mutations are created de novo and that they are the manifestation of genomic instability. Although the exact mechanisms involved in genomic instability initiation are yet to be identified, we hypothesize that differences in induction of delayed mutations by radiations with various LET values are related to variations in energy deposition along the particle track. A dose dependence of mutation yield is discussed as well.
- MeSH
- buněčné linie MeSH
- Cricetulus MeSH
- fibroblasty účinky záření MeSH
- hypoxanthinfosforibosyltransferasa genetika MeSH
- křečci praví MeSH
- lineární přenos energie MeSH
- mutace * MeSH
- nestabilita genomu účinky záření MeSH
- těžké ionty škodlivé účinky MeSH
- vztah dávky záření a odpovědi MeSH
- záření gama * MeSH
- zvířata MeSH
- Check Tag
- křečci praví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Biological effects of high-LET (linear energy transfer) radiation have received increasing attention, particularly in the context of more efficient radiotherapy and space exploration. Efficient cell killing by high-LET radiation depends on the physical ability of accelerated particles to generate complex DNA damage, which is largely mediated by LET. However, the characteristics of DNA damage and repair upon exposure to different particles with similar LET parameters remain unexplored. We employed high-resolution confocal microscopy to examine phosphorylated histone H2AX (gammaH2AX)/p53-binding protein 1 (53BP1) focus streaks at the microscale level, focusing on the complexity, spatiotemporal behaviour and repair of DNA double-strand breaks generated by boron and neon ions accelerated at similar LET values (~135 keV mum
- MeSH
- 53BP1 * chemie MeSH
- apoptóza MeSH
- dvouřetězcové zlomy DNA * MeSH
- fibroblasty účinky záření MeSH
- fluorescenční protilátková technika MeSH
- fosforylace MeSH
- histony * chemie MeSH
- ionizující záření MeSH
- konfokální mikroskopie * MeSH
- kultivované buňky MeSH
- lidé MeSH
- lineární přenos energie * MeSH
- oprava DNA MeSH
- Check Tag
- lidé MeSH
According to their physical characteristics, protons and ion beams promise a revolution in cancer radiotherapy. Curing protocols however reflect rather the empirical knowledge than experimental data on DNA repair. This especially holds for the spatio-temporal organization of repair processes in the context of higher-order chromatin structure-the problematics addressed in this work. The consequences for the mechanism of chromosomal translocations are compared for gamma rays and proton beams.
