Screening of circulating microRNA biomarkers for prevalence of abdominal aortic aneurysm and aneurysm growth

Anders Wanhainen, Kevin Mani, Emina Vorkapic, Rachel De Basso, Martin Björck, Toste Länne, Dick Wågsäter

MicroRNA (miR) are important regulators of gene expression and biological processes and have recently been suggested as possible biomarkers for abdominal aortic aneurysm (AAA) disease. The aim of the present study was to assess the role of miR as biomarkers for initiation and progression of AAA disease, through evaluation of a wide range of miRs in a large population-based cohort, with AAA patients with linked clinical data regarding risk factors, AAA size and growth, as well as controls. The expression of the 172 most commonly expressed miRs in plasma was analyzed by real-time PCR in samples from 169 screening-detected AAA patients and 48 age-matched controls. For 103 miRs, there was a significant difference in expression between AAA and controls. Of these, 20 miRs were differently expressed between fast and slow growing aneurysms. These miRs target genes known to be involved in AAA disease as well as novel genes and pathways. By combining the top altered miRs together with clinical variables, strong predictive values, determining growth of AAA, were obtained (area under curve = 0.86, p < 0.001). This large cohort study identified several novel miRs with altered expression in AAA patients when compared to controls. Assessment of miR expression may offer an opportunity to predict disease progression and aneurysm growth.