DNA Methylation and Its Effects on TRIM29 Gene Expression in the Equine Sarcoid Tissue

Sarcoids are the most frequently diagnosed dermatological tumour in horses. It is a disease that can affect various species of equids, such as donkeys, mules and zebras. This type of tumour can develop in all horse breeds, regardless of age and gender. Treatment options depend on many factors, such as the type of lesion, location, extent, owner preference and financial considerations. In the present study, we investigated the TRIM29 expression, the methylation status of its first exon and its involvement in the formation of equine sarcoids. Bisulfite sequencing PCR (BSP) was used to determine DNA methylation at CpG sites and real-time quantitative polymerase chain reaction (qPCR) was used to detect TRIM29 expression level. Our results showed that TRIM29 is significantly downregulated in lesional samples (FC = -3.72; p < 0.001). Furthermore, TRIM29 expression was significantly correlated (R = -0.73; p < 0.001) with hypermethylation of its specific CpG sites in the first exon of this gene. Our research has demonstrated that the identification of increased methylation of CpG sequences in horse sarcoids, along with the decreased expression of the TRIM29 gene, is an important step towards understanding the molecular mechanisms underlying the disease. These findings can serve in the future as a diagnostic biomarker for horse sarcoids and help in detecting the disease.