The Potential Effect of Different Doses of Ionizing Radiation on Genes and Disease

Abstract

Aim: The chromosomal aberrations induced by radiation appear about nonrandomly distributed across the whole genome. Previous studies have shown that chromosomes with high DNA content are less frequently involved in the formation of symmetrical translocations and dicentric chromosomes than expected, whereas smaller chromosomes are more frequently involved. We hypothesized that these translocation regions are linked to radiation sensitivity. Materials and methods: We investigated the frequencies of chromosome translocations induced by radiation exposure and adjusted the results according to chromosome length. We specifically analyzed whole blood samples from 3 participants. The samples were irradiated using 60 Co at doses of 0.5, 1, 2.5, and 5 Gy. Traditional Giemsa-trypsin-Wright band staining was performed to identify the translocations in the chromosomes, and results were compared with microarray data generated in our previous study. Results: Our analysis indicated that chromosomes 9q were the most sensitive to translocations after various doses of radiation, and such translocations occurred in the euchromatin region. Chromosomes 1, 9, 15, and 17 were more sensitive to radiation doses of 0.5 Gy. This observation could be useful when selecting sensitive reference chromosomes in the low-dose region. The results of expression profiling analysis for radiation-sensitive regions were similar to those of chromosome translocation analysis. Conclusion: This study shows that some chromosomes or genomic regions are more sensitive to alteration by radiation exposure.

Telomere fragility in radiology workers occupationally exposed to low doses of ionising radiation

“…Dicentric chromosomes without accompanying fragments and pericentric inversions were also detected, both representing long-lived chromosome aberrations from past exposure ( 21 , 22 ). Numerous studies support our findings of increased rate of chromosome aberrations and high interindividual variability ( 23 , 24 , 25 ), which is attributed to differences in genetic susceptibility towards ionising radiation ( 26 , 27 , 28 , 29 , 30 , 31 , 32 ), activation of DNA repair ( 33 , 34 ), and anti-inflammatory processes ( 35 ). Lymphocyte chromosome aberrations in our occupationally exposed participants whose annual doses did not exceed risk limits can also be attributed to cumulative effects of chronic exposure to low-dose ionising radiation ( 36 ).…”

Genome-Wide DNA Alterations in X-Irradiated Human Gingiva Fibroblasts

“…In keeping with a previous study, where IR-induced DNA damage was detected as large-scale rearrangement of the genome, and sensitive chromosome regions were identified [25], we also found evidence that some chromosomes appear more sensitive to radiation than others.…”

Assessment of Genomic Instability in Medical Workers Exposed to Chronic Low-Dose X-Rays in Northern China

“…28 Ionizing radiation also induces changes in gene expression that are critical for a cell deciding between resuming normal functioning or undergoing apoptosis. 29 The increasing use of IR in medical diagnosis and treatment has raised concerns about its potential long-term effects on human health. 30 The results of our study sought to assess the association between IR and genomic stability in the peripheral blood of adults exposed to chronic low-dose IR.…”