Keloids are benign fibroproliferative tumors with features of raised scar tissue and excessive growth beyond the original border. Keloid scars show excessive extracellular matrix(ECM) deposition and rich vasculature. Recently, many studies have revealed the important pathways of keloid pathogenesis. Herein, we focus on the difference between traumatic and nontraumatic keloids in a transcriptomic level. To preclude intra-lesional heterogeneity, whole tissue was used for bulk RNA-sequencing. Three trauma induced keloids and 4 non-trauma related keloids were achieved by surgical excision from 7 different patients. All keloids were at a stable status without any inflammatory clinical characteristics. RNA extraction and sequencing was done using an Illumina sequencer. A total of 195 differentially expressed genes(DEGs) were identified with a cut-off value of p < 0.05, log2FC > 2. Pathway analysis showed that these genes(MMP13, COL5A3) were related to extracellular matrix organization suggesting prolonged ECM formation in non-trauma induced keloid. For further understanding of the differences, we have expanded DEGs based on a network analysis. With neighbors connected with more than 3 DEGs in very high confidence STRING network (confidence score > 0.9), expanded DEGs (n=461) were related to the inflammatory pathways including neutrophil degranulation, chemokine signaling pathway, and the JAK-STAT pathway (JAK2, STAT3, p<0.001). Also, HIF-1 pathway related genes, which was previously noted as hypoxia related pathway causing increase in collagen, were found as expanded DEGs in the non-trauma related keloids (p<0.001). In conclusion, this study suggests that keloids are heterogenous depending on the cause of keloid, at the transcriptomic level and may show different response rated to diverse therapeutics.

ESDR612 - Transcriptomic differences between surgical and non-surgical keloids

The scientific meeting of the European Society for Dermatological Research (ESDR) is held yearly, usually in September. With an international attendance of more than 1000 skin scientists from around the globe, the four-day event includes short oral presentations from peer-reviewed abstracts, keynote lectures from international experts, sponsored symposia, satellite programs, educational events as well as an important focus on posters, networking and building collaborations amongst scientists. For more information about this year’s meeting visit our website.