Association Between Hypermethylation of Gene Promoters and Cytogenetic Disturbances in Humans Exposed to Radiation as a Result of the Chernobyl Accident
The estimation of association between hypermethylation of gene promoters (<i>RASSF1A</i>, <i>p16/INK4A</i>, <i>p14/ARF</i> cell cycle genes and <i>GSTP1</i> involved in xenobiotic detoxification) in blood leukocytes and cytogenetic disturbances in humans exposed to radiation as a result of the Chernobyl accident (98 subjects: the accident liquidators liquidators – 76 subjects, adult residents of the territories with radionuclide contamination, 135–688 kBq/m<sup>2</sup> – 22 subjects) was carried out. The results of multiple regression analysis (“frequency of aberrations ~ age + number of hypermethylated genes”) demonstrate the correlation of the total level of chromosomal type aberrations with the considered epigenetic disturbances (β = 0.256; <i>p</i> = 0.011), but not with age (β = –0.138; <i>p</i> = 0.165). The frequency of these cytogenetic disorders increases with the number of methylated loci. Thus, a positive association between the damages of genome induced by radiation exposure (the range of small and medium doses) long time ago, and hypermethylation of CpG-islands in promoters of genes involved in the basic protective functions of cells was revealed.