Fig. 1From: Recent insights into the microRNA-dependent modulation of gliomas from pathogenesis to diagnosis and treatmentProcessing of miRNAs, from biogenesis to therapeutic strategies. miRNAs are transcribed from particular genes inside the nucleus through the action of RNA polymerase II. After the formation of pri-miRNA, this is developed to pre-miRNA by the Drosha–DGCR complex. Then, the pre-miRNA leaves the nucleus for the cytoplasm via exportin 5. Following particular cytoplasmic processing and the action of the Dicer–TRBP complex, pre-miRNA is converted into duplex miRNA, which then undergoes an unwinding to produce mature miRNA. Mature miRNA, using the Ago-2 protein, forms a complex with RISC to cleave the mRNA of interest, or suppresses the translation process. In the case of therapeutic strategies attributed to miRNAs, there are four distinct strategies: A AntagomiRs that bind to and inhibit the action of oncomiRs by blocking miRNA-to-mRNA attachment, through a process called antisense action. AntagomiRs are also responsible for further degradation of miRNAs; B miRNA mimics, which help anticarcinogenic miRNAs to induce tumor-suppressive activities by reversing the epigenetic silencing; C miRNA masks that prevent miRNAs from acting on mRNAs by masking the 3′-UTR sequence on the mRNA strand; D miRNA sponges, whose behavior prevents miRNAs from acting on mRNAs by occupying the binding sites of a particular miRNA or even a set of miRNAs with similar seed sequences by a complementary RNA sequence. Ago2 Argonaute RISC catalytic component 2; DGCR DiGeorge syndrome critical region; GTP guanosine triphosphate; RISC RNA-induced silencing complex; RNA poly RNA polymerase; TRBP TAR RNA binding proteinBack to article page