Use of conformationally locking antisense oligonucleotides for the targeted inhibition of junction containing precursor microRNAs

One class of ASOs functions to enhance protein expression by sequestering the mature microRNA (miRNA) in a double-stranded structure within the RNA-induced silencing complex (RISC). An alternative approach for the targeted control of gene expression is to use ASOs that bind to the pre-elements of miRNAs (pre-miRNAs) and modulate their enzymatic processing.

Here, we demonstrate that ASOs directed at disrupting the junction of pre-miR-31, a region we previously identified as critical for regulating processing by the Dicer/TRBP complex, are potent inhibitors of Dicer/TRBP processing in vitro. Furthermore, we extend and validate this strategy to pre-miR-144, which has a similar junction-dependent structure-function relationship. Through analysis of pre-miRNA secondary structures, we find that nearly 20% of human pre-miRNAs are predicted to contain junctions and we validate our ASO approach on several members of this group.