title: Cellular and molecular effects for mutation induction in normal human cells irradiated with accelerated neon ions.
abstract: We investigated the linear energy transfer (LET) dependence of mutation induction on the hypoxanthine-guanine phosphoribosyl transferase (HPRT) locus in normal human fibroblast-like cells irradiated with accelerated neon-ion beams. The cells were irradiated with neon-ion beams at various LETs ranging from 63 to 335 keV/microm. Neon-ion beams were accelerated by the Riken Ring Cyclotron at the Institute of Physical and Chemical Research in Japan. Mutation induction at the HPRT locus was detected to measure 6-thioguanine-resistant clones. The mutation spectrum of the deletion pattern of exons of mutants was analyzed using the multiplex polymerase chain reaction (PCR). The dose-response curves increased steeply up to 0.5 Gy and leveled off or decreased between 0.5 and 1.0 Gy, compared to the response to (137)Cs gamma-rays. The mutation frequency increased up to 105 keV/microm and then there was a downward trend with increasing LET values. The deletion pattern of exons was non-specific. About 75-100% of the mutants produced using LETs ranging from 63 to 335 keV/mum showed all or partial deletions of exons, while among gamma-ray-induced mutants 30% showed no deletions, 30% partial deletions and 40% complete deletions. These results suggested that the dose-response curves of neon-ion-induced mutations were dependent upon LET values, but the deletion pattern of DNA was not.
authors.affiliation: International Space Radiation Laboratory, National Institute of Radiological, Sciences, 4-9-1 Anagawa, Chiba-shi 263-8555, Japan. m_suzuki@nirs.go.jp
authors.forename: Masao
authors.initials: M
authors.lastname: Suzuki
authors.forename: Chizuru
authors.initials: C
authors.lastname: Tsuruoka
authors.forename: Tatsuaki
authors.initials: T
authors.lastname: Kanai
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kato
authors.forename: Fumio
authors.initials: F
authors.lastname: Yatagai
authors.forename: Masami
authors.initials: M
authors.lastname: Watanabe
mesh_terms: D002460:Cell Line; D017357:Cyclotrons; D004247:DNA / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D005347:Fibroblasts / Q000528:radiation effects*; D006801:Humans; D007041:Hypoxanthine Phosphoribosyltransferase / Q000172:deficiency / Q000235:genetics; D007477:Ions; D018499:Linear Energy Transfer; D009154:Mutation / Q000528:radiation effects*; D009356:Neon
chemical_list: D007477:Ions; D009356:Neon; D004247:DNA; D007041:Hypoxanthine Phosphoribosyltransferase