Human circulating ribosomal dna content significantly increases while circulating satellite iii (1q12) content decreases under chronic occupational exposure to low-dose gamma- neutron and tritium Βeta-radiation

Publication date: Available online 7 September 2016 Source:Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis Author(s): Inna B. Korzeneva, Svetlana V. Kostuyk, Elizaveta S. Ershova, Elena N. Skorodumova, Veronika F. Zhuravleva, Galina V. Pankratova, Irina V. Volkova, Elena V. Stepanova, Lev N. Porokhovnik, Natalia N. Veiko A single exposure to ionizing radiation (IR) results in an elevated cell-free DNA (cfDNA) content in the blood plasma. In this case, the cfDNA concentration can be a marker of the cell death in the organism. However, a chronic exposure to a low-dose IR enhances both the endonuclease activity and titer of antibodies to DNA in blood plasma, resulting in a decrease of the total concentration of circulating cfDNA in exposed people. In this case, the total cfDNA concentration should not be considered as a marker of the cell death in an exposed body. We assumed that a pool of the cfDNA circulating in the exposed people contains DNA fragments, which are resistant to a double-strand break formation in the environment of the elevated plasma endonuclease activity, and can be accumulated in the blood plasma. In order to test this hypothesis, we studied the content of GC-rich sequences (69%GC) of the transcribed region of human ribosomal repeat (rDNA), as well as the content of AT-rich repeat (63%AT) of satellite III (1q12) in the cfDNA samples obtained from 285 individuals. We have found that a chronic exposure to gamma-neutron radiatio...
Source: Mutation Research Fundamental and Molecular Mechanisms of Mutagenesis - Category: Cytology Source Type: research