title: Dose-dependence, sex- and tissue-specificity, and persistence of radiation-induced genomic DNA methylation changes.
abstract: Radiation is a well-known genotoxic agent and human carcinogen that gives rise to a variety of long-term effects. Its detrimental influence on cellular function is actively studied nowadays. One of the most analyzed, yet least understood long-term effects of ionizing radiation is transgenerational genomic instability. The inheritance of genomic instability suggests the possible involvement of epigenetic mechanisms, such as changes of the methylation of cytosine residues located within CpG dinucleotides. In the current study we evaluated the dose-dependence of the radiation-induced global genome DNA methylation changes. We also analyzed the effects of acute and chronic high dose (5Gy) exposure on DNA methylation in liver, spleen, and lung tissues of male and female mice and evaluated the possible persistence of the radiation-induced DNA methylation changes. Here we report that radiation-induced DNA methylation changes were sex- and tissue-specific, dose-dependent, and persistent. In parallel we have studied the levels of DNA damage in the exposed tissues. Based on the correlation between the levels of DNA methylation and DNA damage we propose that radiation-induced global genome DNA hypomethylation is DNA repair-related.
authors.affiliation: Division of Biochemical Toxicology, National Center for Toxicological Research, Jefferson, AR 72079, USA.
authors.forename: Igor
authors.initials: I
authors.lastname: Pogribny
authors.forename: Joe
authors.initials: J
authors.lastname: Raiche
authors.forename: Mark
authors.initials: M
authors.lastname: Slovack
authors.forename: Olga
authors.initials: O
authors.lastname: Kovalchuk
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D000818:Animals; D004247:DNA / Q000235:genetics* / Q000528:radiation effects*; D004249:DNA Damage; D019175:DNA Methylation / Q000528:radiation effects*; D004260:DNA Repair / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D005260:Female; D042822:Genomic Instability / Q000528:radiation effects*; D008099:Liver / Q000528:radiation effects; D008168:Lung / Q000528:radiation effects; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009928:Organ Specificity; D011829:Radiation Dosage; D011836:Radiation Tolerance / Q000235:genetics / Q000528:radiation effects; D012737:Sex Factors; D013154:Spleen / Q000528:radiation effects; D014916:Whole-Body Irradiation
chemical_list: D004247:DNA