Potential pitfalls in microRNA profiling

MicroRNAs (miRNAs) are small, noncoding RNAs that post-transcriptionally influence a wide range of cellular processes such as the host response to viral infection, innate immunity, cell cycle progression, migration, and apoptosis through the inhibition of target mRNA translation. Owing to the growing number of miRNAs and identification of their functional roles, miRNA profiling of many different sample types has become more expansive, especially with relevance to disease signatures. In this review, we address some of the advantages and potential pitfalls of the currently available methods for miRNA expression profiling. Some of the topics discussed include isomiRNAs, comparison of different profiling platforms, normalization strategies, and issues with regard to sample preparation and experimental analyses.