Pathological Function and Clinical Significance of Microrna- 10b in Cancer

MicroRNAs (miRNAs) are small, non-coding RNA molecules encoded in the genomes, with length in range of 18-25 nucleotides. These molecules are transcribed from hairpin-loop primary ribonucleotides (pri-miRNA) by RNA polymerase II [1,2]. Pri-miRNAs are processed by RNase-III family enzyme, Dorsha, and then become 70nt precursor miRNA (pre-miRNA). The pre-miRNA is exported out to the cytoplasm by Exportin-5, in a Ran-GTP-dependent manner. In the cytoplasm, the pre-miRNA is cleaved by Dicer to generate a 20-bp duplex intermediate [2,3], and further unwound to mature miRNA. In order to control target gene expression, the single strand mature miRNA must associate with the RNA-induced silencing complex (RISC) [4]. Once miRNA incorporates into RISC, the miRNA guides the complex to its target by base-pairing with the target mRNA.