Radiation Biology

Epigenetic changes and DNA damage repair

Multiple environmental factor-induced histone modifications alter UV-induced DNA damage repair

DNA damage induced by the ultraviolet rays (UV) in sunlight is the main cause of skin cancer which has had significantly increased morbidity over the last two or three decades. Since humans are usually co-exposed to several wavelengths of UV with several environmental factors such as food components, pharmaceuticals, hormones, and metals, it is important to examine the influence of multiple exposures to the factors on UV-induced skin cancer. We are focusing on epigenetic changes, especially histone modifications. Histone modifications induced by several environmental factors influence chromatin structure, which change the amount of UV-induced DNA damage and the ability to repair DNA damage. Our goals and objectives are to classify the patterns of histone modifications by multiple environmental factors and the responses to DNA damage, and ultimately to protect humans from cancers wherein histone modifications are implicated.

1. Study of the epigenetic changes induced by environmental factors and establishment of new methods for environmental risk evaluation.
Changes in histone modifications regulate gene expression and are related to certain diseases including cancer. We have analyzed the histone modifications induced by several environmental factors to establish new evaluation methods to assess their effects on human health.
2. Study on the relationship between histone modifications and UV-induced DNA damage repair
Humans are exposed to multiple environmental factors such as chemicals and UV radiation. Histone modifications due to environmental factors change the structure of chromatin. We hypothesize that the structural change of chromatin influences the amount of UV-induced DNA damage and the ability to repair DNA damage.
3. Study on carcinogenic effects of ultraviolet A (UVA)
Apoptosis is required to avoid photocarcinogenesis. We have recently discovered that UVA regulates the apoptosis induced by a shorter wavelength of UV. We have examined the relationship between carcinogenesis and UVA-induced specific histone modifications.


Yuko IbukiPhD


Yukako KomakiPhD

Details are here




Histone modifications alters the ability to repair UV-induced DNA damage


Histone modifications by concomitant exposure to chemicals and UV.


  1. Mutagenesis 28, 7-14 (2013)
  2. Environ. Sci. Tech. 46, 7629-7636 (2012)
  3. J. Invest. Dermatol. 131,1313-1321 (2011)
  4. Mutat. Res. 702, 70-77 (2010)
  5. Cancer Res. 69, 3492-3500 (2009)