fig4

Figure 4. RNA-based therapeutics. This illustration shows the different types of RNA-based therapeutics. Antisense oligonucleotides can act by degrading paired mRNA through the activity of RNase H endonuclease or by directly binding to proteins through their 3D structure, acting as aptamers. siRNAs can be introduced directly or produced from short hairpin RNAs through the action of the enzyme Dicer. siRNAs then bind with complete affinity to mRNAs and mediate their degradation through RISC cleavage. MicroRNA mimics, on the other hand, bind with partial affinity to mRNAs and follow the same pathway. Other types of microRNAs interfere with this type of binding by either directly binding with microRNAs through oligonucleotides, using sponges to sequester multiple microRNAs at once, or indirectly by blocking the binding site on mRNA targets. lncRNAs can be used to stimulate agonistic functions through mimics or targeted for antagonistic functions. ASOs: Antisense oligonucleotides; LncRNAs: long non-coding RNAs; miRNAs: microRNAs; shRNA: short hairpin RNA; siRNAs: small interfering RNAs; RISC: RNA-induced silencing complex; Dicer: RNAase III enzyme.