DNA-Methylation Biomarkers in Coronary Stenosis

Coronary Artery Disease (CAD) is the most common cause of death in industrialized countries. It is the manifestation of atherosclerosis in the coronary arteries, leading to the formation of flow-limiting coronary stenoses and further, coronary insufficiency. The early identification of these stenotic plaques poses major challenges for the healthcare system as current methods are expensive, invasive or involve high radiation exposure for the patient. DNA methylation plays a crucial role in the regulation of gene expression and has been implicated in coronary artery disease (CAD) pathogenesis. This study aimed to identify methylation biomarkers in patients with coronary stenosis through a two-stage approach. First, a genome-wide methylation analysis was conducted in a cohort of 72 patients to screen for relevant features. Based on these findings, assays were designed to focus on the most promising candidates. However, numerous challenges were encountered in assay design, which led to the loss of many features during assay development. In total, 139 assays were designed and their performance was evaluated, with the top 90 assays tested in a larger patient cohort (n=146) using MSRE-qPCR. The genes FAM120A, KLB, CACNA1C, and PRKCZ emerged as top candidates, showing reduced methylation in stenosis patients. Although the methylation differences were modest, they align with previous studies linking these genes to inflammatory processes and cardiovascular abnormalities. In general, a trend of decreasing methylation levels from control to sclerosis to stenosis groups was observed, but only the FAM120A assay reached statistical significance. Its role in vascular endothelial growth and angiogenesis (VEGF-A/VEGFR2 signaling pathway) highlights its biological and clinical relevance as a potential CAD biomarker. Nevertheless, the lack of significance in other assays underscores the challenges of translating methylation findings into clinical applications. Future research should address assay design limitations and validate the clinical utility of FAM120A and other candidates through larger, more refined studies