In an article entitled, “An ultraviolet-radiation-independent pathway to melanoma carcinogenesis in the red hair/fair skin background”, published on the 15th Nov. 491:449–453, Devarati Mitra and 19 of her associates affiliated mainly to Massachusetts General Hospital Cancer Center and Department of Chemistry, University of California, Riverside, began their article with the opening remark that red haired/fair skinned melanoma patients are at highest risk of developing melanoma, compared to all other pigmentation types. This occurs as a result of the inactivation of the melanocortin 1 receptor (MC1R) gene. It encodes a cyclic AMP-stimulating G-protein-coupled receptor involved in the production of pigment.
Of the two melanins, the shielding capacity of heomelanin against ultraviolet radiation is weaker compared to eumelanin, When exposed to ultraviolet it shows a higher rate of production of ultraviolet-A-induced reactive oxygen species. However, several subsequent observations reveal that the assumption cannot be drawn that the melanoma risk is entirely ultraviolet-radiation-dependent. For instance, unlike non-melanoma skin cancers, melanoma is not confined to sun-exposed skin. Further investigations have shown that ultraviolet radiation signs are not always oncogenic drivers, thereby showing that ultraviolet-radiation-independent events have also a significant role. For instance a high incidence of invasive melanomas was observed without inserting additional gene aberrations or exposing the tissue to ultraviolet radiation. The researchers have come to the conclusion that adoption of additional strategies may be required for optimal melanoma prevention in spite of the fact that protection from ultraviolet radiation remains important,.