Does ultraviolet-evoked prostaglandin formation protect skin from actinic cancer?

The role of increased prostaglandin activity which results from exposure of human skin to ultraviolet light is uncertain. Evidence from the effects of prostaglandins on epithelial cells in vitro suggests that prostaglandin E reduces proliferative activity in the epidermis, probably through a cyclic-A.M.P.-dependent mechanism, thus reducing the vulnerability of epidermis to the mutagenic effects of ultraviolet exposure.