A frequent topic of biomedical research is the potential clinical use of non-coding (nc) RNAs as quantitative biomarkers for a broad spectrum of health and disease. However, ncRNA analyses have not been pressed into widespread diagnostic use. Strong preclinical evidence suggests obstacles in the translation and reproducibility of this type of biomarker which may result from preanalytical and analytical variation in the non-standardized processes used to collect, process, and store samples, as well as the substantive differences between small and long ncRNA. We performed a narrative review of selected literature, through the lens of key laboratory-developed test (LDT) regulations under the Clinical Laboratory Improvement Amendments (CLIA) in the United States, to study critical gaps in ncRNA validation studies. This review describes the leading candidate ncRNA subclasses, their biogenesis and cellular function, and identifies specific pre-analytical variables with disproportionate impact on testing performance. We summarize these findings with strategic recommendations to clinicians and biomedical scientists involved in the design, conduct, and translation of ncRNA biomarker development.
Keywords: in vitro clinical test; regulatory; reproducibility; transcriptome; validation.