title: Alpha-Particle-Induced Complex Chromosome Exchanges Transmitted through Extra-Thymic Lymphopoiesis In Vitro Show Evidence of Emerging Genomic Instability.
abstract: Human exposure to high-linear energy transfer α-particles includes environmental (e.g. radon gas and its decay progeny), medical (e.g. radiopharmaceuticals) and occupational (nuclear industry) sources. The associated health risks of α-particle exposure for lung cancer are well documented however the risk estimates for leukaemia remain uncertain. To further our understanding of α-particle effects in target cells for leukaemogenesis and also to seek general markers of individual exposure to α-particles, this study assessed the transmission of chromosomal damage initially-induced in human haemopoietic stem and progenitor cells after exposure to high-LET α-particles. Cells surviving exposure were differentiated into mature T-cells by extra-thymic T-cell differentiation in vitro. Multiplex fluorescence in situ hybridisation (M-FISH) analysis of naïve T-cell populations showed the occurrence of stable (clonal) complex chromosome aberrations consistent with those that are characteristically induced in spherical cells by the traversal of a single α-particle track. Additionally, complex chromosome exchanges were observed in the progeny of irradiated mature T-cell populations. In addition to this, newly arising de novo chromosome aberrations were detected in cells which possessed clonal markers of α-particle exposure and also in cells which did not show any evidence of previous exposure, suggesting ongoing genomic instability in these populations. Our findings support the usefulness and reliability of employing complex chromosome exchanges as indicators of past or ongoing exposure to high-LET radiation and demonstrate the potential applicability to evaluate health risks associated with α-particle exposure.
authors.affiliation: Medical Research Council, Didcot, Oxon, United Kingdom.
authors.forename: Natalia
authors.initials: N
authors.lastname: Sumption
authors.affiliation: Medical Research Council, Didcot, Oxon, United Kingdom.
authors.forename: Dudley T
authors.initials: DT
authors.lastname: Goodhead
authors.affiliation: Medical Research Council, Didcot, Oxon, United Kingdom; Division of Biosciences, Department of Life Sciences, College of Health and Life Sciences, Brunel University London, Uxbridge, United Kingdom.
authors.forename: Rhona M
authors.initials: RM
authors.lastname: Anderson
mesh_terms: D000328:Adult; D000512:Alpha Particles; D001854:Bone Marrow Cells / Q000528:radiation effects; D017252:CD3 Complex / Q000378:metabolism; D002454:Cell Differentiation / Q000528:radiation effects; D002478:Cells, Cultured; D002869:Chromosome Aberrations; D002877:Chromosomes, Human / Q000528:radiation effects*; D002999:Clone Cells; D005434:Flow Cytometry; D042822:Genomic Instability / Q000528:radiation effects*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007621:Karyotyping; D008212:Lymphocyte Depletion; D038041:Lymphopoiesis / Q000528:radiation effects*; D013997:Time Factors
chemical_list: D017252:CD3 Complex