Abstract
The “photogenotoxicity” is generally defined the property of chemicals to induce genotoxic effects under ultraviolet (UV) and/or visible-light. In this review, I'd like to propose another possibility of photogenotoxicity; that is, the epigenetic alteration in nucleus by chemicals affects genotoxicity of UV.
UV is well-known to be genotoxic due to the formation of pyrimidine dimers. Pyrimidine dimers are effectively repaired by nucleotide excision repair (NER), in which relaxation of nucleosome interactions is considered to be needed. Histone modifications like acetylation are a cause of the change of nucleosome interactions, and some articles and reviews have indicated that the modifications altered the generation of DNA damage and its repair. In our previous study, hyperacetylation of histones enhanced sensitivity to UV and suppressed NER. Some chemicals, metals, pesticides, hormones, etc. are reported to acetylate histone residues. Dysregulation of histone modifications by those chemicals might affect the formation of pyrimidine dimers after exposure to UV and the repair ability, suggesting the new concept of “photogenotoxicity”.
