The cytokinesis-blocked micronucleus assay: Good choice for detection and evaluation of genotoxity in human cells

Abstract

Introduction: Measurement of micronucleus (MN) frequency in lymphocytes is extensively used in molecular epidemiology and cytogenetics to evaluate the presence and the extent of chromosomal damage in human populations exposed to genotoxic agents or bearing a susceptible genetic profile.

The aim of this study was to evaluate the genotoxicity of ionizing radiation on medical personnel using the micronucleus assay and to determine the human health risk. The study population included 20 individuals in the exposed group of medical workers who are professionally exposed to ionizing rays and 20 individuals in the control group (healthy people who have never been exposed to ionizing rays and other chemical or physical agents).

Results: Paired Student’s t-test shows significant statistical difference between the total number of binucleated (BN) cells with micronuclei within the two groups (exposed and control) (t=6,812; p<0,05). The mean of MN frequencies in the exposed group increased in comparison with the mean of MN frequencies in the control group. Clear evidence of increased number of MN formation appeared in smoking women within the control group. Although men dominated the exposed group, all the women from this group showed increased MN frequency. Also, we found BN cells with nucleoplasmic bridges (NPBs) and binucleated cell with nuclear buds (NBUDs).

Conclusion: The formation of small and large micronuclei indicates that medical personnel who are exposed on radiation in their work place, have a chromosomal instability and a risk of cancer.