Table 2.

A summary of the main advantages and disadvantages of using miRs as biomarkers of drug toxicity

miRs as biomarkers for use in drug-safety assessment
Potential Advantages	Potential Disadvantages
Ubiquitous appearance in biofluids—serum, plasma, urine, saliva—enabling non-invasive sampling Tissue-specific expression patterns of certain miRs High sequence homology between animal models and humans facilitates translation of miR biomarkers – an important feature for pre-clinical development Enhanced stability in biofluids Availability on robust detection platforms such as RT-qPCR, next generation RNA sequencing, microarray platforms and biosensors enabling parallel quantification of multiple miRs Novel miR quantification methods being employed in research such as dynamic chemical labelling could facilitate point-of-care clinical detection Signatures unique to different aetiologies Can be measured in panels Prognostic and mechanistic value Knowledge of a wide range of expression levels of miRs as reflected in databases means miRs with low expression can be incorporated into panels	Measurement subject to sample quality and pre-analytical/analytical variability Lack of consensus regarding controls and standardization of assays Similar miR signatures resulting from many differing aetiologies Biological variability can be high and potentially influenced by smoking, diet and other environmental factors. Normal reference ranges therefore difficult to determine for some miRs No current clinical point-of-care assay Low levels of expression of many individual miRs