Investigating the Vinblastine Induced-Chromosomal Abnormality in the Already Gamma Irradiated L929 Cell Line Using Micronucleus Assay in Cytokinesis Blocked Binucleated Cells

Abstract

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