Rapid assessment of high-dose radiation exposures through scoring of cell-fusion-induced premature chromosome condensation and ring chromosomes

• Published in: Mutation research Vol. 757; no. 1; pp. 45 - 51
• Main Authors: Lamadrid Boada, A.I., Romero Aguilera, I., Terzoudi, G.I., González Mesa, J.E., Pantelias, G., García, O.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 18-09-2013; Elsevier BV
• Subjects: Animals; Biodosimetry; Cell Fusion; CHO Cells - radiation effects; Chromosome rings; Chromosomes; Chromosomes - radiation effects; Condensation; Cricetulus; Gamma Rays; High-dose radiation exposures; Humans; Lymphocyte test system; Lymphocytes - radiation effects; Mutation; Premature chromosome condensation by cell fusion; Radiation; Radiation Dosage; Ring Chromosomes; Premature chromosome condensation by cell fusion; PCC; PCC-Rf; Biodosimetry; PCC-Rch; Chromosome rings; CHO cells; High-dose radiation exposures; Lymphocyte test system; Chinese hamster ovary cells; premature chromosome condensation; rings in chemically induced lymphocyte prematurely condensed chromosomes; rings in lymphocyte prematurely condensed chromosomes mediated by cell fusion
• ISSN: 1383-5718; 0027-5107; 1879-3592
• DOI: 10.1016/j.mrgentox.2013.06.021

•Cell fusion mediated PCC methodology can be used for biodosimetry purposes at high radiation doses.•The yield of radiation-induced PCC rings is an appropriate biomarker for rapid estimation of absorbed dose.•Rings can be easily scored using image analysis systems or directly at the microscope at least after 8h incubation time.•The results can be obtained shortly after the reception of irradiated blood samples without need to culture the lymphocytes.•The yield of excess PCC fragments increase with dose but decrease with post exposure incubation time.
Analysis of premature chromosome condensation (PCC) mediated by fusion of G0-lymphocytes with mitotic CHO cells in combination with rapid visualization and quantification of rings (PCC-Rf) is proposed as an alternative technique for dose assessment of radiation-exposed individuals. Isolated lymphocytes or whole blood from six individuals were γ-irradiated with 5, 10, 15 and 20Gy at a dose rate of 0.5Gy/min. Following either 8- or 24-h post-exposure incubation of irradiated samples at 37°C, chromosome spreads were prepared by standard PCC cytogenetic procedures. The protocol for PCC fusion proved to be effective at doses as high as 20Gy, enabling the analysis of ring chromosomes and excess PCC fragments. The ring frequencies remained constant during the 8–24-h repair time; the pooled dose relationship between ring frequency (Y) and dose (D) was linear: Y=(0.088±0.005)×D. During the repair time, excess fragments decreased from 0.91 to 0.59 chromatid pieces per Gy, revealing the importance of information about the exact time of exposure for dose assessment on the basis of fragments. Compared with other cytogenetic assays to estimate radiation dose, the PCC-Rf method has the following benefits: a 48-h culture time is not required, allowing a much faster assessment of dose in comparison with conventional scoring of dicentrics and rings in assays for chemically-induced premature chromosome condensation (PCC-Rch), and it allows the analysis of heavily irradiated lymphocytes that are delayed or never reach mitosis, thus avoiding the problem of saturation at high doses. In conclusion, the use of the PCC fusion assay in conjunction with scoring of rings in G0-lymphocytes offers a suitable alternative for fast dose estimation following accidental exposure to high radiation doses.