The Mix of Two Worlds: Non-Coding RNAs and Hormones

The recent discovery of functional cell-free circulating microRNAs (miRNAs) in human body fluids has opened new avenues for the application of non-coding RNAs (ncRNAs) as noninvasive, specific and sensitive biomarkers for cancers and other human diseases. In this review, we explore the concept of circulating miRNAs as hormones, and discuss their potential functions in cellular communication and transferring of signals. We also provide a brief overview of their identification, processing, and potential functions and applications in human diseases.