Identification of unique gene expression patterns within different lesional sites of keloids.

Keloid disease is a significant clinical problem, especially in black populations, with an estimated incidence of 4-16%. Keloids are fibroproliferative dermal tumors developing as a result of deregulated wound healing. The dynamic nature of keloids is illustrated by clinical regression in the center, while the margin remains active growing into the surrounding healthy skin. Therefore, the gene expression profiles of fibroblasts from different sites of the keloids were characterized using Affymetrix microarrays covering the whole human genome. This study revealed 105 genes that were differentially regulated (79 genes were up-regulated and 26 down-regulated) in a unique gene expression profile in different sites of keloids where progression or regression of the process was in progress. The apoptosis inhibitor AVEN was found to be up-regulated at the active margin of keloids, while apoptosis-inducing genes such as ADAM12 and genes inducing extracellular matrix (ECM) degradation such as matrix metalloproteinase-19 were up-regulated in the regressing keloid center. We identified genes previously not described in the development of keloids. Activating proapoptotic genes or inhibiting ECM-inducing genes as INHBA or monocyte chemoattractant protein-1 might be possible target genes for new treatment strategies for keloid disease.