Cytogenetic characterization of low-dose hyper-radiosensitivity in Cobalt-60 irradiated human lymphoblastoid cells

Mutation Research
Gnanada S JoshiJames D Tucker

Abstract

The dose-effect relationships of cells exposed to ionizing radiation are frequently described by linear quadratic (LQ) models over an extended dose range. However, many mammalian cell lines, when acutely irradiated in G2 at doses ≤0.3Gy, show hyper-radiosensitivity (HRS) as measured by reduced clonogenic cell survival, thereby indicating greater cell lethality than is predicted by extrapolation from high-dose responses. We therefore hypothesized that the cytogenetic response in G2 cells to low doses would also be steeper than predicted by LQ extrapolation from high doses. We tested our hypothesis by exposing four normal human lymphoblastoid cell lines to 0-400cGy of Cobalt-60 gamma radiation. The cytokinesis block micronucleus assay was used to determine the frequencies of micronuclei and nucleoplasmic bridges. To characterize the dependence of the cytogenetic damage on dose, univariate and multivariate regression analyses were used to compare the responses in the low- (HRS) and high-dose response regions. Our data indicate that the slope of the response for all four cell lines at ≤20cGy during G2 is greater than predicted by an LQ extrapolation from the high-dose responses for both micronuclei and bridges. These results sugges...Continue Reading

References

Aug 10, 2000·Radiation Research·D A Pierce, D L Preston
Dec 13, 2000·Mutation Research·M Fenech
Feb 15, 2001·International Journal of Radiation Oncology, Biology, Physics·M C JoinerI Turesson
Nov 12, 2003·Proceedings of the National Academy of Sciences of the United States of America·David J BrennerMarco Zaider
Jun 16, 2004·Cancer Metastasis Reviews·George D Wilson
Feb 24, 2007·Radiation Research·S A KruegerB Marples
Oct 31, 2007·International Journal of Radiation Oncology, Biology, Physics·Sarah A KruegerBrian Marples
Apr 1, 2008·International Journal of Radiation Oncology, Biology, Physics·Brian Marples, Spencer J Collis
Dec 18, 2008·Dose-response : a Publication of International Hormesis Society·Bobby R Scott
Jul 1, 2004·Nonlinearity in Biology, Toxicology, Medicine·S I ZaichkinaD Y Klokov
Jul 20, 2010·International Journal of Radiation Oncology, Biology, Physics·Sarah A KruegerBrian Marples
Apr 9, 2013·Radiation Research·William F Morgan, William J Bair
May 23, 2013·Cancer Letters·Lynn M MartinLaure Marignol
Jun 25, 2013·Radiotherapy and Oncology : Journal of the European Society for Therapeutic Radiology and Oncology·Joshua T DilworthBrian Marples

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Citations

Mar 27, 2015·Environmental and Molecular Mutagenesis·Gnanada S JoshiJames D Tucker
Jul 16, 2020·Environmental Science and Pollution Research International·Abdu SaeedEman Abdulqader Al-Shahari
Jul 7, 2018·Dose-response : a Publication of International Hormesis Society·Noriko Shimura, Shuji Kojima
Dec 19, 2017·International Journal of Radiation Oncology, Biology, Physics·Dorota SłoninaBeata Biesaga

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