miR-27a/b Level is Associated with ABCA1 Expression and is a Potential PBMC-Based Biomarker for Coronary Artery Disease

Abstract Background: Coronary artery disease (CAD) is the most common form of cardiac disease with high morbidity and mortality rates. Objectives: In this study, we evaluated the expression of miR-27a and miR-27b as biomarkers in peripheral blood mononuclear cells (PBMCs) of patients with CAD and investigated its correlation with cholesterol-efflux transporter, ATP-binding cassette transporter A1 (ABCA1). Method: This study was performed on 54 men with CAD and 51 healthy, sex- and age-matched control participants. The expression of miR-27a/b and ABCA1 genes in PBMCs were measured by quantitative real-time polymerase chain reaction (qRT-PCR). The protein expression of ABCA1 was assessed by Western blotting. Concurrently, the specificity and sensitivity of miR-27a/b was evaluated through receiver operating characteristic (ROC) curve. The significance level adopted in the statistical analysis was 5%. Results: We found that miR-27a and miR-27b expression were significantly increased, while both mRNA and protein expression of ABCA1 were markedly reduced in the PBMCs of CAD patients in comparison to non-CAD controls. miR-27a/27b expression was also shown to be inversely correlated with ABCA1. ROC analysis showed that the miR-27a had an area under the ROC curve (AUC) of about 92.6 (sensitivity 83.3٪ and specificity 86.6٪) and miR-27b had an AUC of about 93.0 (sensitivity 86.6٪ and specificity 80.0 (%, suggesting the diagnostic potential of miR-27a/b in CAD patients. Conclusions: Our data suggested a possible role of miR-27a/b in CAD pathogenesis. Additionally, we proposed that miR-27a/b expression in PBMCs may have potential clinical implications in the diagnosis of CAD patients, but further validations in large cohorts are required.