mBAND analysis of chromosome aberrations in lymphocytes exposed in vitro to α-particles and γ-rays

• Published in: International journal of radiation biology 2008, Vol.84 (6), p.447-453
• Main Authors: Tawn, E. Janet, Whitehouse, Caroline A., Holdsworth, Duncan, De Ruyck, Kim, Vandenbulcke, Katia, Thierens, Hubert
• Format: Article
• Language: English
• Subjects: Alpha Particles - adverse effects; Cells, Cultured; Chromosome Aberrations; Chromosome Breakage - radiation effects; Chromosomes, Human - radiation effects; Chromosomes, Human - ultrastructure; Gamma Rays - adverse effects; Humans; Lymphocytes - radiation effects; Lymphocytes - ultrastructure; mBAND; Space life sciences; α-particles; γ-rays
• ISSN: 0955-3002; 1362-3095
• DOI: 10.1080/09553000802078412

Purpose: To investigate the profiles of chromosome damage induced in vitro by exposure to α-particles and γ-rays. Materials and methods: Human peripheral blood lymphocytes were exposed to three dose regimes: α-particle doses of 0.2 and 0.5 Gy and a γ-ray dose of 1.5 Gy. After culturing for 47 hours, chromosome aberrations involving the number 5 chromosomes were identified using a multi-coloured banding (mBAND) technique. Results: Analysis of the frequencies of chromosome 5 breaks within aberrant cells and within aberrant number 5 chromosomes demonstrated that α-particle irradiation is more likely to result in multiple breaks in a chromosome than γ-irradiation. Additionally, overdispersion was observed for all doses for the distribution of breaks amongst all cells analysed and breaks amongst total number 5 chromosomes, with this being greatest for the 0.2 Gy α-particle dose. The ratio of interchanges to intrachanges (F ratio) was 1.4 and 2.4 for 0.2 and 0.5 Gy α-particles respectively and 5.5 for 1.5 Gy γ-rays. Evaluation of simple versus complex exchanges indicated ratios of 1.9 and 2.7 for 0.2 and 0.5 Gy α-particles respectively and 10.6 for 1.5 Gy γ-rays. The majority of the intrachanges involving chromosomes 5 induced by α-particle radiation were associated with more complex exchanges. Conclusions: This study has confirmed that exchanges induced by exposure to high linear energy transfer (LET) α-particle radiation comprise a greater proportion of intrachanges than those induced by exposure to low LET γ-rays. However, since the majority of these are associated with complex rearrangements and likely to be non-transmissible, this limits their applicability as a marker of past in vivo exposure.