Human Skin: Before and 8 weeks after Isotretinoin Treatment

The pathogenesis of acne has been linked to multiple factors such as increased sebum production, inflammation, follicular hyperkeratinization, and the action of Propionibacterium acnes within the follicle. 13-cis Retinoic Acid (13-cis RA, isotretinoin) is the most potent agent in acne treatment. Surprisingly, its mechanism of action in acne is still unknown. Gene expression profiling of skin from 8 patients treated with isotretinoin was performed to gain insights into its mechanism of action. Skin biopsies were obtained from the patients at baseline and at 8 weeks isotretinoin treatment. Gene array expression profiling was conducted using Affymetrix HG-U133A 2.0 arrays in order to examine changes in gene expression as a result of treatment. After treatment, 784 genes were significantly changed: 197 up-regulated and 587 down-regulated. The majority of genes that were up-regulated at 8 weeks encode structural proteins of the extracellular matrix such as collagens, fibulin and fibronectin. The preponderance of genes that were down-regulated at 8 weeks are involved in the metabolism of steroids, cholesterol and fatty acids. Keywords: drug treatment effects Total 16 chips: 8 baseline/before isotretinoin and 8 after 8 weeks isotretinoin treatment.