Ultraviolet radiation induces p16(CDKN2A) expression in human skin

The loss of the tumor suppressor gene product p16 in melanoma is well docum ented, although the normal physiological function of p16 in skin melanocyte s is unknown. Zn this report, we demonstrate that when human skin was irrad iated with suberythemal doses of UV radiation, levels of p16 were dramatica lly increased by 16 h postirradiation, peaking at 24 h, and declining by 72 h, p16 was expressed in the nucleus and cytoplasm of melanocytes and kerat inocytes within the epidermis, and the pattern of p16 expression within the epidermis was dependent on the penetrative ability of the different UV wav ebands. The existence of a UV-induced response pathway involving up-regulat ed p16 expression may provide a mechanism linking the loss of p16 and UV ex posure with the development of melanoma.