Effect of low-dose X-ray irradiation on micronucleus formation in human embryo, newborn and child cells

Abstract

Purpose: It is well known that a high-dose of ionizing radiation is sufficient to break DNA strands, which leads to elevated genotoxic risks; however, the risks associated with low doses of ionizing radiation remain unclear. In addition, there is little data about the effect of low-dose ionizing radiation on human-derived embryo, newborn and child cells. We investigated the frequency of micronucleus (MN) formation in these cells to understand the genotoxic effects of ionizing radiation.

Materials and methods: We irradiated the cells with X-rays from 0.02–2 Gy at a rate of 0.0635 Gy/min. After irradiation, we investigated the effect of low-dose X-ray irradiation on cellular viability and frequency of MN formation.

Results: Increases in MN formation were largely dose-dependent; however, there were no differences between controls and doses lower than 0.2 Gy, except in KMST-6 human transformed embryo cells.

Conclusion: We could not detect an obvious effect of low-dose X-ray irradiation at doses lower than 0.1 Gy. The embryonic cells were more sensitive to X-ray irradiation than newborn and child cells. The threshold for X-ray-induced MN formation appears to be in the range of 0.05–0.1 Gy in cultured human embryo, newborn and child cells.

Keywords:

• Cellular genotoxicity
• low-dose
• micronucleus (MN)
• X-rays

Acknowledgements

The authors would like to thank Ms Yoko Shimizu for her devoted technical support.

Disclosure statement

The authors report no conflicts of interest. The authors alone are response for the content and writing of the paper.