Abstract
RNA interference (RNAi) pathways utilize small non-coding RNAs (ncRNAs) to regulate diverse biological processes in eukaryotes. Different classes of small ncRNAs function through distinct RNAi pathways and the focus of this review will be on two of these: microRNAs (miRNAs) and small interfering RNAs (siRNAs). The siRNA pathway is triggered by viral infection and repetitive elements functioning as a defense system in eukaryotes. miRNAs, on the other hand, are encoded in the genome and regulate a myriad of biological processes such as embryonic development and tissue differentiation in plants and animals. These different small RNA pathways have great potential to be used as biomarkers of the biological processes they regulate. In this review, we describe the role RNAi pathways have in diverse pathological and physiological conditions and how the detection of specific small ncRNAs can be used as biomarkers for these conditions. We discuss other areas not yet explored for the use of small ncRNAs as biomarkers and review recent patents proposing to use small RNAs as biomarkers. These patents mainly include cases where changes in expression of miRNAs, individually or in groups, have been shown to correlate with disease or disease states, most commonly cancer.
Keywords: Biomarkers, miRNA, non-coding RNA, next-generation sequencing, RNA interference, siRNA
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