A team led by researchers at Weill-Cornell Medical Center profiled microRNAs (miRNAs) in cell-free serum and plasma samples from human volunteers using deep sequencing of barcoded small RNA cDNA libraries. By introducing calibrator synthetic oligonucleotides during library preparation, they were able to calculate the total as well as specific concentrations of circulating miRNA. Studying trios of samples from newborn babies and their parents they detected placental-specific miRNA in both maternal and newborn circulations and quantitated the relative contribution of placental miRNAs to the circulating pool of miRNAs. Furthermore, sequence variation in the placental miRNA profiles could be traced to the specific placenta of origin. These deep sequencing profiles, which may serve as a model for tumor or disease detection, allow the team to define the repertoire of miRNA abundance in the circulation and potential uses as biomarkers.
Williams Z, Ben-Dov IZ, Elias R, Mihailovic A, Brown M, Rosenwaks Z, Tuschl T. (2013) Comprehensive profiling of circulating microRNA via small RNA sequencing of cDNA libraries reveals biomarker potential and limitations. Proc Natl Acad Sci U S A [Epub ahead of print]. [article]