title: Radiation-induced changes in DNA methylation and their relationship to chromosome aberrations in nuclear power plant workers.
abstract: OBJECTIVE
  We investigated the association between occupational radiation exposure and DNA methylation changes in nuclear power plant workers. We also evaluated whether radiation- induced DNA methylation alterations are associated with chromosome aberrations.
  
  
  METHODS
  The study population included 170 radiation-exposed workers and 30 controls. We measured global, long interspersed nuclear element-1 (LINE-1), and satellite 2 methylation levels in blood leukocyte DNA. The analysis of chromosome aberrations was performed on peripheral lymphocytes.
  
  
  RESULTS
  Global DNA methylation levels were lower in radiation-exposed workers than in controls. The methylation levels were negatively associated with the recent 1.5-year radiation dose in a multiple linear regression model (β = - 0.0088, p ≤ 0.001); the levels increased proportionally with the total cumulative dose in radiation-exposed workers. LINE-1 methylation levels were higher in radiation-exposed workers than in controls and were significantly associated with the total cumulative radiation dose in a multiple linear regression model (β = - 0.031, p = 0.035). Global DNA methylation levels were also correlated with chromosome aberrations among workers. Workers with low global methylation levels had a higher frequency of chromosome aberrations than did subjects with high global methylation levels.
  
  
  CONCLUSIONS
  Occupational exposure to low-dose radiation could affect DNA methylation levels, and the radiation-induced DNA methylation alterations may be associated with chromosome aberrations.
authors.affiliation: School of Public Health and Institute of Health and Environment, Seoul National University , Gwanak-gu, Seoul , Republic of Korea.
authors.forename: Younghyun
authors.initials: Y
authors.lastname: Lee
authors.forename: Yang Jee
authors.initials: YJ
authors.lastname: Kim
authors.forename: Young Joo
authors.initials: YJ
authors.lastname: Choi
authors.forename: Joong Won
authors.initials: JW
authors.lastname: Lee
authors.forename: Sunyeong
authors.initials: S
authors.lastname: Lee
authors.forename: Yoon Hee
authors.initials: YH
authors.lastname: Cho
authors.forename: Hai Won
authors.initials: HW
authors.lastname: Chung
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D002869:Chromosome Aberrations / Q000528:radiation effects*; D019175:DNA Methylation / Q000528:radiation effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D055848:Nuclear Power Plants; D016273:Occupational Exposure / Q000009:adverse effects*; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics
keywords: DNA methylation; Radiation; chromosome aberrations; nuclear power plant workers