miRNA is a single-stranded RNA fragment 18-24 nucleotides in length, which can regulate stability or translational efficiency of target mRNA. These regulatory RNAs function by acting as sequence-specific guides which recruit a large protein complex known as the RNA-induced silencing complex (RISC) to target mRNA which are subsequently silenced. They play an important role in celluar differentiation, proliferation and apoptosis which have elicited great interest in research.