Abstract
Recently we reported differential miRNA signatures in blood cells of lungcancer patients and healthy controls. With the present study we wanted to investigate if miRNA blood signatures are also suited to differentiate lungcancer patients from COPD patients. We compared the expression of 863 human miRNAs in blood cells of lungcancer patients, COPD patients, and healthy controls. The miRNA pattern from patients with lungcancer and COPD were more similar to each other than to the healthy controls. However, we were able to discriminate lungcancer patients and COPD patients with 90.4% accuracy, 89.2% specificity, and 91.7% sensitivity. In total, 140 miRNAs were significant for the comparison COPD and controls, 61 miRNAs were significant for the comparison lungcancer and controls, and 14 miRNAs were significant for the comparison lungcancer and COPD. Screening target databases yielded over 400 putative targets for those 14 miRNAs. The predicted mRNA targets of three of the 14 miRNAs were significantly up-regulated in PBMCs of lungcancer patients compared to patients with non-malignant lung diseases. In conclusion, we showed that blood miRNA signatures are suitable to distinguish lungcancer from COPD.