Document Type : Research Articles
Department of Biology, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad, Iran.
Department of Biology and Institute of Biotechnology, Cell and Molecular Biotechnology Research Group, Ferdowsi University of Mashhad, Mashhad, Iran.
Medical Physics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
Objectives: Vast number of studies show the relationship between aneuploidy and cancer. Ionizing radiation in
addition to induce all kinds of damages to the cells and structure of chromosomes, is also able to induce aneuploidy
through direct damages to chromosome division apparatus. Also irradiation of the cells induces mutations in several
genes which might be involved in cell division fidelity and play a role in reversing the effect of aneugens. Therefore,
irradiation of cells and tissues might produce sensitivity to agents with aneugenic capability in irradiated cells. Methods:
To investigate the persistent genomic effect of ionizing irradiation on chromosomal instability, L929 cells were gamma
irradiated with the dose of 2 Gy. Cells were left to recover from the harmful effect of irradiation. They were treated with
low dose of vinblastine (0.5 ng.ml-1) 72h post-gamma irradiation. Finally, the induced chromosomal abnormalities
were scored using micronucleus assay in cytokinesis-blocked binucleated cells (MnBi). Results: Irradiation-recovered
L929 cells treated with vinblastine showed a statistically higher frequency of MnBi compared to non-irradiated and
vinblastine treated cells. Conclusion: The results indicate that gamma irradiation, in addition to direct induction of
chromosomal damages, is also able to create persisting genomic sensitivity in the cells to chromosomal instability,
which is detectable when exposed to the second stimulus.