Translating extracellular microRNA into clinical biomarkers for drug-induced toxicity: from high-throughput profiling to validation.

Over the past 5 years, extracellular microRNAs (miRNAs) are being vigorously explored as injury biomarkers, including drug-induced cardiotoxicity, hepatotoxicity and nephrotoxicity. Currently, the development of miRNAs as clinical biomarkers has been hindered by the lack of standardization. Therefore, extracellular miRNA-based biomarkers have not been embraced as diagnostic tools. Each platform has its strengths and weaknesses when working with low-input-amount RNA samples from body fluids; the selection of a miRNA quantification approach should be based on the study design. The following review provides a summary of the extracellular miRNA release and stability in body fluids, performances of different miRNA quantification platforms, existing clinical gold standards for drug-induced tissue damage and translation of the miRNA biomarkers from the nonclinical to clinical setting.