Emerging role of microRNAs in cancer stem cells: Implications in cancer therapy

Figure 1 MicroRNA biogenesis, activity and potential therapeutic targets. Mature miRNAs are generated from hairpin-like longer primary transcripts by two sequential processing steps mediated by a nuclear (Drosha) and a cytoplasmic (Dicer) RNAase III endonuclease. MiRNA then directs RISC to target mRNAs which share sequence complementation between seed region at 5’ end of mature miRNA and 3’UTR of target mRNA. Stability of miRNA:mRNA recognition and degree of complementation leads to translational activation but more commonly mRNA degradation and translational repression. Potential therapeutic target sites are shown which include steps during miRNA biogenesis and target mRNA recognition. 3’UTR: 3’ untranslated region; RISC: RNA-induced silencing complex; miRNA: MicroRNAs; Ago: Agronaute.