MicroRNAs in Hepatocellular Carcinoma: Regulation, Function, and Clinical Implications

Figure 1

The biogenesis of microRNAs is summarized. Genes encoding microRNAs are transcribed mainly by Pol II (DNA-dependent RNA polymerase II) with the products as the pri-miRNAs that are processed into pre-miRNA by DGCR8/Drosha. Pre-miRNAs are exported into the cytoplasm where they are further converted into the mature forms by the TRBP/Dicer. Mature miRNAs bind to the target mRNAs to inhibit their expression. ORF: open-reading frame; RISC: RNA-induced silencing complex.