title: LET and ion-species dependence for mutation induction and mutation spectrum on hprt locus in normal human fibroblasts.
abstract: We have been studying LET and ion species dependence of RBE in mutation frequency and mutation spectrum of deletion pattern of exons in hprt locus. Normal human skin fibroblasts were irradiated with heavy-ion beams, such as carbon- (290 MeV/u and 135 MeV/u), neon- (230 MeV/u and 400 MeV/u), silicon- (490 MeV/u) and iron- (500 MeV/u) ion beams, generated by Heavy Ion Medical Accelerator in Chiba (HIMAC) at national Institute of Radiological Sciences (NIRS). Mutation induction in hprt locus was detected to measure 6-thioguanine resistant colonies and deletion spectrum of exons was analyzed by multiplex PCR. The LET-RBE curves of mutation induction for carbon- and neon-ion beams showed a peak around 75 keV/micrometers and 155 keV/micrometers, respectively. On the other hand, there observed no clear peak for silicon-ion beams. The deletion spectrum of exons was different in induced mutants among different ion species. These results suggested that quantitative and qualitative difference in mutation occurred when using different ion species even if similar LET values.
authors.affiliation: International Space Radiation Laboratory, National Institute Radiological Sciences.
authors.forename: Chizuru
authors.initials: C
authors.lastname: Tsuruoka
authors.forename: Masao
authors.initials: M
authors.lastname: Suzuki
authors.forename: Kazunobu
authors.initials: K
authors.lastname: Fujitaka
mesh_terms: D002244:Carbon; D005091:Exons / Q000528:radiation effects; D005347:Fibroblasts / Q000528:radiation effects; D020450:Heavy Ions; D006801:Humans; D007041:Hypoxanthine Phosphoribosyltransferase / Q000528:radiation effects*; D007501:Iron; D018499:Linear Energy Transfer; D016296:Mutagenesis; D009154:Mutation; D009356:Neon; D010315:Particle Accelerators; D012062:Relative Biological Effectiveness; D012825:Silicon; D012867:Skin
chemical_list: D009356:Neon; D002244:Carbon; D007501:Iron; D007041:Hypoxanthine Phosphoribosyltransferase; D012825:Silicon