title: 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 beta-radiation.
abstract: 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 radiation (N=88) and tritium β-radiation (N=88) evokes an increase of the rDNA content (RrDNA index) and a decrease of the satellite III content (RsatIII index) in the circulating cfDNA as compared with the cfDNA of non-exposed people (N=109). Such index that simultaneously displays both the increase of rDNA content and decrease of satellite III content in the cfDNA (RrDNA/RsatIII) can be recommended as a marker of chronic processes in the body that involve the elevated cell death rate and/or increased blood plasma endonuclease activity.
authors.affiliation: Russian Federal Nuclear Center - All-Russian Research Institute of Experimental Physics (RFNC-VNIIEF) 607190 Sarov, 37 Mira ave., Nizhniy Novgorod Region, Russia. Electronic address: inna.korzeneva@molgen.vniief.ru.
authors.forename: Inna B
authors.initials: IB
authors.lastname: Korzeneva
authors.affiliation: Research Centre for Medical Genetics, 115478 Moscow, 1 Moskvorechye str., Russia.
authors.forename: Svetlana V
authors.initials: SV
authors.lastname: Kostuyk
authors.affiliation: Research Centre for Medical Genetics, 115478 Moscow, 1 Moskvorechye str., Russia; V. A. Negovsky Research Institute of General Reanimatology, Moscow, 107031, Russia.
authors.forename: Elizaveta S
authors.initials: ES
authors.lastname: Ershova
authors.affiliation: Russian Federal Nuclear Center - All-Russian Research Institute of Experimental Physics (RFNC-VNIIEF) 607190 Sarov, 37 Mira ave., Nizhniy Novgorod Region, Russia.
authors.forename: Elena N
authors.initials: EN
authors.lastname: Skorodumova
authors.affiliation: Russian Federal Nuclear Center - All-Russian Research Institute of Experimental Physics (RFNC-VNIIEF) 607190 Sarov, 37 Mira ave., Nizhniy Novgorod Region, Russia.
authors.forename: Veronika F
authors.initials: VF
authors.lastname: Zhuravleva
authors.affiliation: Russian Federal Nuclear Center - All-Russian Research Institute of Experimental Physics (RFNC-VNIIEF) 607190 Sarov, 37 Mira ave., Nizhniy Novgorod Region, Russia.
authors.forename: Galina V
authors.initials: GV
authors.lastname: Pankratova
authors.affiliation: Russian Federal Nuclear Center - All-Russian Research Institute of Experimental Physics (RFNC-VNIIEF) 607190 Sarov, 37 Mira ave., Nizhniy Novgorod Region, Russia.
authors.forename: Irina V
authors.initials: IV
authors.lastname: Volkova
authors.affiliation: Russian Federal Nuclear Center - All-Russian Research Institute of Experimental Physics (RFNC-VNIIEF) 607190 Sarov, 37 Mira ave., Nizhniy Novgorod Region, Russia.
authors.forename: Elena V
authors.initials: EV
authors.lastname: Stepanova
authors.affiliation: Research Centre for Medical Genetics, 115478 Moscow, 1 Moskvorechye str., Russia.
authors.forename: Lev N
authors.initials: LN
authors.lastname: Porokhovnik
authors.affiliation: Research Centre for Medical Genetics, 115478 Moscow, 1 Moskvorechye str., Russia; V. A. Negovsky Research Institute of General Reanimatology, Moscow, 107031, Russia.
authors.forename: Natalia N
authors.initials: NN
authors.lastname: Veiko
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001610:Beta Particles / Q000009:adverse effects*; D015331:Cohort Studies; D053903:DNA Breaks, Double-Stranded; D004275:DNA, Ribosomal / Q000097:blood* / Q000235:genetics; D004276:DNA, Satellite / Q000097:blood* / Q000235:genetics; D004307:Dose-Response Relationship, Radiation; D020862:GC Rich Sequence; D005720:Gamma Rays / Q000009:adverse effects*; D006801:Humans; D008875:Middle Aged; D009502:Neutrons; D016273:Occupational Exposure / Q000009:adverse effects* / Q000032:analysis; D011829:Radiation Dosage; D000069079:Radiation Exposure / Q000009:adverse effects* / Q000032:analysis; D060888:Real-Time Polymerase Chain Reaction; D012426:Russia; D020080:Tandem Repeat Sequences / Q000235:genetics; D014316:Tritium; D055815:Young Adult
chemical_list: D004275:DNA, Ribosomal; D004276:DNA, Satellite; D014316:Tritium
keywords: Cell-free DNA; Gamma-neutron radiation; Low-dose irradiation; Ribosomal gene; Satellite III (1q12); Tritium β- radiation