Role of UVA in the pathogenesis of melanoma and non-melanoma skin cancer -A short review

It is well established, at least in mice, that not only ultraviolet C (UVC) or ultraviolet B (UVB), but also ultraviolet A (UVA) is able to induce squ amous cell carcinomas. Results from animal models, epidemiological studies, and clinical observations suggest that UVA might play an important role in the pathogenesis of malignant melanoma as well. In contrast to UVC or WE, UVA is hardly able to excite the DNA molecule directly and produces only fe w pyrimidine dimers. Oxidative DNA base damage, generated indirectly throug h photosensitizers, might be responsible for the mutagenic and carcinogenic properties of UVA. This is supported by differences in mutation spectra in duced by UVA and UVB in mammalian cells and tumors. Avoidance of natural an d artificial UVA sources is recommended, especially for melanoma-prone indi viduals.