title: Ionising irradiation alters the dynamics of human long interspersed nuclear elements 1 (LINE1) retrotransposon.
abstract: It is important to identify the mechanism by which ionising irradiation induces various genomic alterations in the progeny of surviving cells. Ionising irradiation activates mobile elements like retrotransposons, although the mechanism of its phenomena consisting of transcriptions and insertions of the products into new sites of the genome remains unclear. In this study, we analysed the effects of sparsely ionising X-rays and densely ionising carbon-ion beams on the activities of a family of active retrotransposons, long interspersed nuclear elements 1 (L1). We used the L1/reporter knock-in human glioma cell line, NP-2/L1RP-enhanced GFP (EGFP), that harbours full-length L1 tagged with EGFP retrotransposition detection cassette (L1RP-EGFP) in the chromosomal DNA. X-rays and carbon-ion beams similarly increased frequencies the transcription from L1RP-EGFP and its retrotransposition. Short-sized de novo L1RP-EGFP insertions with 5'-truncation were induced by X-rays, while full-length or long-sized insertions (>5 kb, containing ORF1 and ORF2) were found only in cell clones irradiated by the carbon-ion beams. These data suggest that X-rays and carbon-ion beams induce different length of de novo L1 insertions, respectively. Our findings thus highlight the necessity to investigate the mechanisms of mutations caused by transposable elements by ionising irradiation.
authors.affiliation: Department of Virology and Preventive Medicine, Gunma University Graduate School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan. atsushit@med.gunma-u.ac.jp
authors.forename: Atsushi
authors.initials: A
authors.lastname: Tanaka
authors.forename: Youko
authors.initials: Y
authors.lastname: Nakatani
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Hamada
authors.forename: Atsushi
authors.initials: A
authors.lastname: Jinno-Oue
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Shimizu
authors.forename: Seiichi
authors.initials: S
authors.lastname: Wada
authors.forename: Tomoo
authors.initials: T
authors.lastname: Funayama
authors.forename: Takahisa
authors.initials: T
authors.lastname: Mori
authors.forename: Salequl
authors.initials: S
authors.lastname: Islam
authors.forename: Sheikh Ariful
authors.initials: SA
authors.lastname: Hoque
authors.forename: Masahiko
authors.initials: M
authors.lastname: Shinagawa
authors.forename: Takahiro
authors.initials: T
authors.lastname: Ohtsuki
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Hiroo
authors.initials: H
authors.lastname: Hoshino
mesh_terms: D000818:Animals; D001483:Base Sequence; D045744:Cell Line, Tumor; D002880:Chromosomes, Human, Pair 11 / Q000737:chemistry / Q000235:genetics; D023061:Gene Order; D005822:Genetic Vectors / Q000235:genetics; D006801:Humans; D020084:Long Interspersed Nucleotide Elements / Q000528:radiation effects*; D051379:Mice; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D009154:Mutation / Q000235:genetics / Q000528:radiation effects; D011839:Radiation, Ionizing; D020079:Terminal Repeat Sequences; D014158:Transcription, Genetic / Q000528:radiation effects