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

Objectives: Vast number of studies show the relationship between aneuploidy and cancer. Ionizing radiation inaddition to induce all kinds of damages to the cells and structure of chromosomes, is also able to induce aneuploidythrough direct damages to chromosome division apparatus. Also irradiation of the cells induces mutations in severalgenes 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 gammairradiated with the dose of 2 Gy. Cells were left to recover from the harmful effect of irradiation. They were treated withlow dose of vinblastine (0.5 ng.ml-1) 72h post-gamma irradiation. Finally, the induced chromosomal abnormalitieswere scored using micronucleus assay in cytokinesis-blocked binucleated cells (MnBi). Results: Irradiation-recoveredL929 cells treated with vinblastine showed a statistically higher frequency of MnBi compared to non-irradiated andvinblastine treated cells. Conclusion: The results indicate that gamma irradiation, in addition to direct induction ofchromosomal damages, is also able to create persisting genomic sensitivity in the cells to chromosomal instability,which is detectable when exposed to the second stimulus.