The Impact of Pre-analytical Factors on the Reliability of miRNA Measurements

In this review, we highlight the importance of using standardized procedures and protocols for circulating miRNA isolation, detection, and quantification, in order to establish their role as non-invasive biomarkers in the clinical setting. Specific miRNAs have already been investigated as promising prognostic and diagnostic markers in various types of cancer. Circulating microRNAs detected in plasma are continuously and intensively explored as non-invasive prognostic and diagnostic markers in a variety of human diseases and mainly in cancer. These miRNAs are remarkably stable in biological fluids and their expression profiles have been shown to represent a compelling non-invasive biomarker for cancer diagnosis. Circulating miRNAs are remarkably stable, even in the extracellular environment with high RNAse activity. However, circulating miRNA quantitative measurements could be significantly influenced by several external and intra-individual factors.