Characteristics of microRNA expression profile of equine sarcoid samples

We report the application of next-generation sequencing for high-throughput profiling of microRNA expression characterictic for horse sarcoid, which is a skin tumor. With the use of HiScanSQ system (Illumina), we obtained over 124 million sequence reads from microRNA libraries. As a result, we identified over 200 known, as well as around 500 potentially novel, miRNA sequences. The analysis of differential expression of the identified miRNAs revealed that over 100 miRNAs were up- or downregulated in the sarcoid tissue in comparison to the control. The analysis of pathways showed e.g. pathways in cancer, viral carcinogenesis or transcriptional misregulation in cancer. Furthermore, microRNAs associated with carcinogenesis in humans were identified, such as: miR-10a, miR-21, miR-200 family. Concluding, our results suggest that microRNAs are largely involved in the neoplastic transformation of horse sarcoids. Overall design: Identification of microRNAs expressed in sarcoid tissue samples and tumor-distant skin (control) samples obtained from five horses.