Evaluation of quantitative miRNA gene expression platforms in the microRNA Quality Control (miRQC) study

MiRNAs are important negative regulators of protein coding gene expression, and have been studied intensively over the last few years. Several measurement platforms, designed to determine their relative RNA abundance levels in biological samples, have been developed. In this study, we systematically compared 12 commercially available miRNA expression platforms by measuring an identical set of 20 standardized positive and negative control samples, including human universal reference RNA, human brain RNA and titrations thereof, human serum samples, and synthetic spikes from miRNA family members with varying homology. We developed novel and robust quality metrics to objectively assess platform performance of very different technologies such as small RNA sequencing, RT-qPCR and (microarray) hybridization. We assessed reproducibility, sensitivity, accuracy, specificity, and concordance of differential expression. The results indicate that each method has its strengths and weaknesses, which helps to guide informed selection of a quantitative miRNA gene expression platform in function of particular study goals. Sequencing of 20 miRQC samples on Illumina Genome Analyzer IIx System