Introduction: The increased incidence of skin cancers is due to modifications of our behavior toward solar exposure. Photocarcinogenesis represents the sum of complex and intricate events that lead to the occurrence of skin cancers.
Current knowledge and key points: In epidermal cells UV light induces lesions of DNA that lead to modifications in oncogene and tumor suppressor gene expression. UV-induced immunosuppression is also important for tumoral promotion. UV exposure decreases the number of Langerhans cells in the epidermis and modifies their antigen-presenting cell capacity. Numerous experimental data obtained in animal models clearly indicate the existence of a relationship between UV-induced immune suppression and skin cancers. In humans, growing evidence suggests that skin cancers and photoimmunosuppression are linked.
Future prospects and projects: Better knowledge of mechanisms involved in UV-induced immune suppression is essential for developing new strategies aimed at photoprotection and cancer prevention.