Klin Onkol 2018; 31(4): 249-259. DOI: 10.14735/amko2018249.
Background: A modern approach to identify biomarkers of solid cancers in tissues and body fluids is based on microRNA (miRNA) expression profiling. miRNAs are a group of approximately 3.000 short noncoding RNAs containing 18–25 nucleotides that regulate gene expression at the post-transcriptional (mRNA) level. The abilities of miRNAs to inhibit the translation or induce degradation of oncogenes and tumor suppressors indicate that they are involved in carcinogenesis. There is increasing evidence that miRNAs regulate apoptosis, cell proliferation, differentiation, and invasion. miRNA expression profiles are therefore often analyzed for molecular diagnostics of solid cancers, similar to analyses based on mRNA profiling. It is important that miRNAs are highly stable and present at high levels in body fluids, including saliva, for analytic usage. miRNAs in saliva have been successfully tested as potential diagnostic biomarkers of many solid cancers. The main advantage of these miRNAs is that saliva samples can be collected non-invasively. Aim: This review aims to summarize current knowledge of circulating miRNAs in solid cancers, with a focus on the use of miRNAs in saliva for oncology diagnostics