DNA microarrays in dermatology and skin biology.

Because of its accessibility, skin has been among the first organs analyzed using DNA microarrays. Skin cancers, melanomas, and basal and squamous cell carcinomas have been intensely investigated because they are very frequent and can be fatal. Psoriasis, one of the most common human inflammatory diseases, has been studied comprehensively using DNA microarrays. In addition, epidermal keratinocytes have been the target of many studies because they respond to a rich variety of inflammatory and immunomodulating cytokines, hormones, vitamins, ultraviolet (UV) light, toxins, and physical injury. Because of the ethical considerations, the effects of harmful or dangerous agents on skin have been studied using artificial skin substitutes. Transcriptional mechanisms that regulate epidermal differentiation and cornification have begun to yield their mysteries, and very exciting recent studies identified the genes specifically expressed in epidermal stem cells. Thus, skin has everything: stem cells, differentiation, signaling, inflammation, diseases, and cancer. All these exciting facets of skin have been explored using DNA microarrays. Researchers in skin biology and dermatology were among the first to implement this technology and we expect that they will continue to generate exciting and useful new knowledge.