Circulating MicroRNAs as Promising Biomarkers in Forensic Body Fluids Identification

In the last 20 years, DNA molecular analysis has become an important tool in forensic investigations. Currently, it is possible to genotype all types of biological traces or micro-traces containing nucleated cells if they are not entirely destroyed, chemically or bacterial. The DNA profiling is based on the short tandem repeats (STR) and aids in human identification from biological samples, but due to the recent advances in molecular genetics, other biomarkers have been proposed to be used in forensic identifications, such as: messenger RNA(mRNA), microRNA (miRNA), and DNA methylation. MicroRNAs are part of a class of small, non-coding RNAs that contain 19 - 23 nucleotides. MicroRNAs play an important role in the regulation of biochemical mechanisms, cell proliferation and other cellular mechanisms in the human body. The level of microRNAs in blood and other body fluids (urine, saliva, sweat) increases as a consequence of altered pathophysiological mechanisms and tissue insult. Moreover, the stability and specificity of microRNAs make them ideal candidates for circulating biomarkers in forensic bioanalytical procedures. In this review, we want to present a brief overview of biogenesis, functions, and applications of miRNAs in the identification of forensic body fluids.