Induction and disappearance of γH2AX foci and formation of micronuclei after exposure of human lymphocytes to 60Co γ-rays and p(66)+ Be(40) neutrons. (February 2014)

• Record Type: Journal Article
• Authors: Vandersickel, Veerle; Beukes, Philip; Van Bockstaele, Bram; Depuydt, Julie; Vral, Anne; Slabbert, Jacobus
• Is Part Of: International journal of radiation biology. Volume 90:Number 2(2014:Feb.)
• Page Start: 149
• Page End: 158
• Publication Date: 2014-02
• Subjects: Radiation -- Physiological effect -- Periodicals; Radiobiology -- Periodicals; 571.45
• DOI: 10.3109/09553002.2014.860252
• Languages: English
• ISSNs: 0955-3002

Abstract

<abstract> <title>Abstract</title> <p> <italic>Purpose</italic>: To investigate both the formation of micronuclei (MN) and the induction and subsequent loss of phosphorylated histone H2AX foci (γH2AX foci) after in vitro exposure of human lymphocytes to either <sup>60</sup>Co γ-rays or p(66)+ Be(40) neutrons.</p> <p> <italic>Materials and methods:</italic> MN dose response (DR) curves were obtained by exposing isolated lymphocytes of 10 different donors to doses ranging from 0–4 Gy γ-rays or 0–2 Gy neutrons. Also, γH2AX foci DR curves were obtained following exposure to doses ranging from 0–0.5 Gy of either γ-rays or neutrons. Foci kinetics for lymphocytes for a single donor exposed to 0.5 Gy γ-rays or neutrons were studied up to 24 hours post-irradiation.</p> <p> <italic>Results</italic>: Micronuclei yields following neutron exposure were consistently higher compared to that from <sup>60</sup>Co γ-rays. All MN yields were over-dispersed compared to a Poisson distribution. Over-dispersion was higher after neutron irradiation for all doses > 0.1 Gy. Up to 4 hours post-irradiation lower yields of neutron-induced γH2AX foci were observed. Between 4 and 24 hours the numbers of foci from neutrons were consistently higher than that from γ-rays. The half-live of foci disappearance is only marginally longer for neutrons compared to that from γ-rays. Foci formations were more likely to be over-dispersed for neutron irradiations.</p> <p> <italic>Conclusion</italic>: Although neutrons are more effective to induce MN, the absolute number of induced γH2AX foci are less at first compared to γ-rays. With time neutron-induced foci are more persistent. These findings are helpful for using γH2AX foci in biodosimetry and to understand the repair of neutron-induced cellular damage.</p> </abstract>