C-->T transition mutations are not solely UVB-signature mutations, because they are also generated by UVA.
In this issue, Ikehata et al. confirm data from cell culture models by showing that the C-->T transition mutation is also the most common UVA-generated mutation in vivo. This indicates that DNA photoproducts are the most important premutagenic lesions not only in UVB mutagenesis, but also in UVA mutagenesis. C-->T transitions cannot therefore be considered solely UVB-signature mutations. In addition, there is no consistent evidence for a separate UVA-generated UVA signature mutation. We hypothesize that weaker anti-mutagenic cellular responses to UVA, as compared to UVB, may result in higher rates of mutation formation for UVA-induced dimers.
Rünger
Thomas M
TM
Department of Dermatology, Boston University School of Medicine, Boston, Massachusetts, USA. truenger@bu.edu
D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D002478:Cells, Cultured; D003596:Cytosine / Q000378:metabolism*; D004247:DNA / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects; D004249:DNA Damage / Q000235:genetics / Q000528:radiation effects; D004273:DNA, Neoplasm / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects; D051379:Mice; D008822:Mice, Transgenic; D009154:Mutation / Q000235:genetics / Q000528:radiation effects*; D009381:Neoplasms, Radiation-Induced / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D020641:Polymorphism, Single Nucleotide / Q000235:genetics / Q000528:radiation effects*; D012867:Skin / Q000166:cytology / Q000378:metabolism* / Q000528:radiation effects*; D012878:Skin Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D013941:Thymine / Q000378:metabolism*; D014466:Ultraviolet Rays / Q000009:adverse effects*
D004273:DNA, Neoplasm; D003596:Cytosine; D004247:DNA; D013941:Thymine