The miRNAs are powerful post-transcriptional regulators of mRNA expression (Jirtle and Skinner, 2007, Filipowicz et al. 2008). They are small (19–25nt), non-coding RNAs belonging to an important class of endogenous repressors of gene expression (Ambros, 2004; Bartel, 2004). They control expression of target mRNAs by binding to miRNA Response Elements (MREs) located in the 3’UTR region of target mRNA.
