Influence of aging and malignant transformation on keratinocyte gene expression

Skin cancer is the most common malignancy in humans (Yuspa 1987). Most skin cancers are strongly linked to UV exposure (Aubry and MacGibbon 1985; Stoll and Schwartz 1987; Streilein 1991), but other agents such as chemical carcinogens and immunosuppressants (Yuspa et al. 1980) may also contribute. In addition, age-specific skin cancer incidence rises exponentially during adulthood and available data suggest that advanced age itself, independent of exposure history, may be a risk factor (Lin et al. 1989).