title: Early and Delayed Induction of DSBs by Nontargeted Effects in ICR Mouse Lymphocytes after In Vivo X Irradiation.
abstract: The goal of this study was to determine whether in vivo X irradiation induces nontargeted effects, such as delayed effects and bystander effects in ICR mouse lymphocytes. We first examined the generation of DNA double-strand breaks (DSBs) in lymphocytes, isolated from ICR mice exposed to 1 Gy X irradiation, by enumeration of p53 binding protein 1 (53BP1) foci, and observed that the number of 53BP1 foci reached their maximum 3 days postirradiation and decreased to background level 30 days postirradiation. However, the number of 53BP1 foci was significantly increased in lymphocytes isolated from ICR mice 90-365 days postirradiation. This result indicates that in vivo X irradiation induced delayed DSBs in ICR mouse lymphocytes. We next counted the number of 53BP1 foci in lymphocytes isolated from sham-irradiated ICR mice that had been co-cultured with lymphocytes isolated from 1 Gy X-irradiated ICR mice, and observed a significant increase in the number of 53BP1 foci 1-7 days postirradiation. This result indicates that in vivo X irradiation induced bystander effects in ICR mouse lymphocytes. These findings suggest that in vivo X irradiation induces early and delayed nontargeted effects in ICR mouse lymphocytes.
authors.affiliation: a   Department of Environmental Health Science, Oita University of Nursing and Health Sciences, Oita 840-1201, Japan.
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Ojima
authors.affiliation: a   Department of Environmental Health Science, Oita University of Nursing and Health Sciences, Oita 840-1201, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Iwashita
authors.affiliation: b   Advanced Molecular Center, Faculty of Medicine, Oita University, Yufu 879-5593, Japan.
authors.forename: Genro
authors.initials: G
authors.lastname: Kashino
authors.affiliation: b   Advanced Molecular Center, Faculty of Medicine, Oita University, Yufu 879-5593, Japan.
authors.forename: Shinko
authors.initials: S
authors.lastname: Kobashigawa
authors.affiliation: a   Department of Environmental Health Science, Oita University of Nursing and Health Sciences, Oita 840-1201, Japan.
authors.forename: Noriko
authors.initials: N
authors.lastname: Sasano
authors.affiliation: a   Department of Environmental Health Science, Oita University of Nursing and Health Sciences, Oita 840-1201, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Takeshita
authors.affiliation: c   Tokyo Healthcare University, Tokyo 152-8558, Japan.
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Ban
authors.affiliation: a   Department of Environmental Health Science, Oita University of Nursing and Health Sciences, Oita 840-1201, Japan.
authors.forename: Michiaki
authors.initials: M
authors.lastname: Kai
mesh_terms: D000818:Animals; D024201:Bystander Effect / Q000528:radiation effects*; D018920:Coculture Techniques; D053903:DNA Breaks, Double-Stranded / Q000528:radiation effects*; D005260:Female; D008214:Lymphocytes / Q000166:cytology / Q000378:metabolism* / Q000528:radiation effects*; D051379:Mice; D008813:Mice, Inbred ICR; D013997:Time Factors; D000071857:Tumor Suppressor p53-Binding Protein 1 / Q000378:metabolism; D014965:X-Rays / Q000009:adverse effects
chemical_list: D000071857:Tumor Suppressor p53-Binding Protein 1