Low-dose radiation-induced responses: Focusing on epigenetic regulation

Abstract

Purpose: With the widespread use of ionising radiation, the risks of low-dose radiation have been increasingly highlighted for special attention. This review introduces the potential role of epigenetic elements in the regulation of the effects of low-dose radiation.

Materials and methods: The related literature has been analysed according to the topics of DNA methylation, histone modifications, chromatin remodelling and non-coding RNA modulation in low-dose radiation responses.

Results: DNA methylation and radiation can reciprocally regulate effects, especially in the low-dose radiation area. The relationship between histone methylation and radiation mainly exists in the high-dose radiation area; histone deacetylase inhibitors show a promising application to enhance radiation sensitivity, both in the low-dose and high-dose areas; phosphorylated histone 2 AX (H2AX) shows a low sensitivity with 1–15 Gy irradiation as compared with lower dose radiation; and histone ubiquitination plays an important role in DNA damage repair mechanisms. Moreover, chromatin remodelling has an integral role in the repair of DNA double-strand breaks and the response of chromatin to ionising radiation. Finally, the effect of radiation on microRNA expression seems to vary according to cell type, radiation dose, and post-irradiation time point.

Conclusion: Small advances have been made in the understanding of epigenetic regulation of low-dose radiation responses. Many questions and blind spots deserve to be investigated. Many new epigenetic elements will be identified in low-dose radiation responses, which may give new insights into the mechanisms of radiation response and their exploitation in radiotherapy.

Keywords:

• Low dose radiation
• epigenetics
• non-coding RNA

Acknowledgements

This work was supported by the National Natural Science Foundation of China (NSFC, grants 30770649 and 30970682) and Program for New Century Excellent Talents in University (NCET 2009).

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