MicroRNA fingerprints in serum and whole blood of sarcoid-affected horses as potential non-invasive diagnostic biomarkers.

This study suggests that certain microRNA (miRNA) fingerprints found in horse blood and serum could be used as non-invasive biomarkers for equine sarcoid (ES), a type of skin tumor in horses. The differentiation of these miRNAs in ES-affected horses versus control ones was observed. Further, some of these miRNAs were linked to cancer pathways, providing potential diagnostic significance.

Research Methodology

• The researchers compared miRNA fingerprints in the serum and whole blood of horses affected by ES to those in sarcoid tissue.
• A differential expression analysis was performed using high throughput sequencing between six ES-affected horses and five controls in serum and whole blood. A DESeq algorithm helped to account for possible influence from hemolysis (breakdown of red blood cells) and white blood cell count.
• This was followed by gene and pathway predictions and enrichment analyses performed via databases like TarBase, mirPath and GeneCodis.

Principal Findings

• After excluding four samples marred by hemolysis, it was found that nine miRNAs were differentially expressed in the serum of ES-affected horses versus the controls. In whole blood, 19 miRNAs were demonstrably differently expressed between ES-affected and control horses. Of these, 2 out of the 9 serum miRNAs and 7 out of the 19 whole blood ones also showed high expression at the tissue level.
• The target genes predicted for these highly expressed miRNAs were associated with cancer pathways.
• This miRNA expression in serum and whole blood made it possible to distinguish between ES and control horses.

Conclusions and Implications

• Given the favorable results, the study suggests that this investigative approach merits further validation with a larger study cohort.
• Moreover, the use of whole blood appeared superior, as it contained higher miRNA content and was less influenced by pre-analytical variables compared to serum.
• The concurrent dysregulation of single miRNAs in tissue and blood indicates a possible biological function of these circulating miRNAs, shedding light on the diagnostic potential of these miRNA ‘fingerprints’ for ES.