Figure 2

Design of chemically modified antimiR oligonucleotides. (A) Structures of the most commonly used chemical modifications in antimiR oligonucleotides. Locked nucleic acid (LNA) is a bicyclic RNA analogue in which the ribose is locked in a C3'-endo conformation by introduction of a 2'-O,4'-C methylene bridge. The 2'-fluoro (2'-F), 2'-O-methoxyethyl (2'-MOE) and 2'-O-methyl (2'-O-Me) nucleotides are modified at the 2' position of the ribose moiety, whereas a six-membered morpholine ring replaces the sugar moiety in morpholino oligomers. In the phosphorothioate (PS) linkage, sulfur replaces one of the non-bridging oxygen atoms in the phosphate group. (B) Design of chemically modified antimiR oligonucleotides described in this review. (C) Schematic overview of the miRNA inhibition approach using a fully complementary antimiR and a seed-targeting tiny LNA.