Elevated chromosome translocation frequencies in New Zealand nuclear test veterans

Abstract

In 1957/58 the British Government conducted a series of nuclear tests in the mid-Pacific codenamed Operation Grapple, which involved several naval vessels from Britain and New Zealand. Two New Zealand frigates with 551 personnel onboard were stationed at various distances between 20 and 150 nautical miles from ground zero. In the present study we applied the cytomolecular technique mFISH (multicolour fluorescent in situ hybridisation) to investigate a potential link between chromosome abnormalities and possible past radiation exposure in New Zealand nuclear test veterans who participated in Operation Grapple. Compared to age matched controls, the veterans showed significantly higher (P < 0.0001) frequencies of chromosomal abnormalities (275 translocations and 12 dicentrics in 9,360 cells vs. 96 translocations and 1 dicentric in 9,548 cells in the controls), in addition to a significant excess of CCRs (complex chromosomal rearrangements) in the veterans. A Kolmogorov-Smirnoff test showed that the distributions of translocations for the two groups were significantly different.

Genome chaos: Survival strategy during crisis

“…1,43 Third, large-scale genome rearrangement has been observed in developmental processes, in blood samples of veterans with a history of nuclear exposure, in the punctuated phase of cancer evolution and in various cancer patients. 31,44,45 Finally, our model linking stress, C-frag, genome reorganization, and the selection of a stable new genome suggests that the survival of cells that begin but do not complete mitotic cell death represents a main mechanism of genome chaos that ensures survival during times of crisis. Since C-frag is a key stage of genome chaos, and C-Frag is very different from PCC, proposed models based on PCC might not represent the primary mechanism of genome chaos.…”

“…1,4 For example, chaotic chromosomes are frequently observed in tumors, in lymphocytes of cancer patients, and in individuals with histories of radiation exposure. 31 It appears that the highly dynamic change of genome chaos indicates an active struggle for survival. To chronicle the selection process following genome chaos and leading to stable new genomes, extended time courses were performed.…”

Ionizing radiation biomarkers for potential use in epidemiological studies

“…The presence of CCRs is considered to be a signature for high LET and heavy ion exposure [58,59]. There have been several reports that past irradiation can leave a permanent signature in the genome even several years after the exposure, as evident in plutonium workers exposed in 1949 in the Mayak Production Association near Ozyorsk, Russia [23], New Zealand nuclear test veterans exposed in 1957-1958 [60], patients treated with X-ray irradiation for ankylosing spondylitis [61], Hodgkin lymphoma patients treated with chemotherapy associated to radiation therapy [62], Hiroshima atomic bomb survivors [63,64], and Chernobyl cleanup workers [65][66][67]. However, currently there is no study assessing the usefulness of this potential biomarker after low dose exposure and further studies are needed to investigate the effect of low-LET radiation exposure on its occurrence.…”

Karyotype Heterogeneity and Unclassified Chromosomal Abnormalities

“…The types of chromosomal aberrations of a chaotic phenotype are diverse and include chromatid breakage, translocations, rings, individual chromatids, C-Frag, large-scale chromosome fusion, rings formed by chromatids, combinations of structural and numerical changes, and other striking phenotypes. Genome chaos has been observed in various cancer progression and drug resistant models as well as in clinical samples [Wahab et al, 2008].…”