RESUMO
BACKGROUND: p53 overexpression has been reported in photoaged skin. Meanwhile, p53 gene mutations have been implicated as an important factor in the pathogenesis of ultraviolet (UV) light-induced skin cancer. OBJECTIVE: The objective was to evaluate the effect of laser resurfacing on the epidermal thickness and expression of p53 in photoaged skin. METHODS: Specimens were obtained from the facial skin of 10 patients before and after 3 months and 1 year of treatment using CO(2) (five cases) and erbium (Er):YAG (five cases) lasers. Specimens were also obtained from six age-matched controls. These biopsies were used for routine histopathology, histometry, and p53 immunoperoxidase staining. RESULTS: Both CO(2) and Er:YAG lasers were found to induce a significant decrease in p53 expression in biopsies obtained after 3 months (p=.0004 and .002, respectively) followed by gradual increase (p=.01 in both groups). A significant increase (p<.01) in epidermal thickness was also observed after 1 year of resurfacing. This increase, however, is inversely correlated with the level of p53 expression in such patients. CONCLUSION: The decrease in epidermal p53 expression after CO(2) and Er:YAG lasers may account for some of the benefits of resurfacing on the epidermis, as well as prevention of actinic neoplasia by adjusting any disturbance in the proliferation/apoptosis balance observed in photoaged facial skin.
