UVA-induced DNA damage and mutations in human melanocytes

UVA accounts for 95 percent of the UV radiation energy that reaches the ground. However, the contribution of UVA to melanoma formation has remained unclear. To understand the role of UVA radiation in melanoma etiology, we planned to determine what types of DNA damage and mutations are induced by UVA in human melanocytes and whether damage and mutations are reflected in mutational signatures that have been established by melanoma tumor sequencing. Here, we have used human melanocytes as the relevant cells and performed the first comprehensive analysis of DNA damage and mutations at single-base resolution and genome-wide using the circle-damage sequencing method and whole genome sequencing in this cell type following exposure to UVA rays.