Malignant melanoma can be caused by ultraviolet exposure that is both independent and dependent on the degree of pigmentation in the skin reports a paper in Nature Communications this week. These findings provide new insights into the relationship between skin cancer and sunlight radiation.
Malignant melanoma is associated with ultraviolet exposure of genetically susceptible individuals to sunlight or artificial sources such as tanning beds. However, the roles of specific wavelengths of ultraviolet energy in skin cancers are not well understood.
Edward De Fabo and colleagues design and use an ultraviolet delivery system together with a transgenic mouse model of ultraviolet-induced melanoma, to investigate the roles of UVA and UVB in melanoma. They find that UVA requires the pigment melanin for its characteristic DNA damaging effects whereas UVB does not require melanin.
The authors conclude that fair skin is not only vulnerable to UVB, but if stimulated by tanning to produce melanin, then it may also be susceptible to UVA. These findings highlight the potential need to redefine tanning safety limits.