MiR-34a, miR-21 and miR-23a as potential biomarkers for coronary artery disease: a pilot microarray study and confirmation in a 32 patient cohort

The aim of this study was to investigate the expression of circulating microRNAs (miRNAs) in apolipoprotein E (apoE) knockout mice (apoE(-/-)) and to validate the role of these miRNAs in human coronary artery disease (CAD). Pooled plasma from 10 apoE(-/-) mice and 10 healthy C57BL/6 (B6) mice was used to perform the microarray analysis. The results showed that miR-34a, miR-21, miR-23a, miR-30a and miR-106b were differentially expressed in apoE(-/-) mice, and these expression changes were confirmed by real-time quantitative reverse-transcription PCR. Then, miR-34a, miR-21, miR-23a, miR-30a and miR-106b were detected in the plasma of 32 patients with CAD and of 20 healthy controls. Only miR-34a, miR-21 and miR-23a were significantly differentially expressed in the plasma of CAD patients (all P<0.01). In conclusion, miR-34a, miR-21 and miR-23a were elevated in CAD patients, which means that these miRNAs might serve as biomarkers of CAD development and progression.