Plasma processing conditions substantially influence circulating microRNA biomarker levels.

摘要: Circulating, cell-free microRNAs (miRNAs) are promising candidate biomarkers, but optimal conditions for processing blood specimens miRNA measurement remain to be established. Our previous work showed that the majority of plasma miRNAs likely cell-derived. In course profiling lung cancer cases versus healthy controls, we observed a broad increase in circulating levels compared controls and higher expression correlated with platelet particle counts. We therefore hypothesized quantity residual platelets microparticles remaining after might impact measurements. To systematically investigate this, subjected matched from individuals stepwise differential centrifugation 0.22 µm filtration performed profiling. found major effect on miRNAs, (72%) detectable substantially affected by alone. Specifically, 10% 4–30x variation, 46% 30-1,000x 15% >1,000x variation solely processing. This was predominantly due contamination, which persisted despite using standard laboratory protocols. Importantly, show contamination archived samples could largely eliminated additional centrifugation, even frozen stored six years. minimize confounding effects microRNA biomarker studies, steps limit studies necessary. provide specific practical recommendations help attributable contamination.