MicroRNA inhibitors are effective at repressing both cleavage and translational attenuation pathways. The effect of inhibition of miR-21 was determined using three types of microRNA assays (24 h post-transfection). Black bars indicate cleavage assay; white and gray bars indicate attenuation assays with constructs containing one and three attenuation sites, respectively. Inhibition was determined at the protein level (A) as detected by luciferase activity and at the mRNA level (B) as detected by branched-DNA assay of luciferase. A dose curve of two inhibitor designs, reverse complement to mature (RC) and a longer inhibitor reverse complement to pri-miRNA (16 + RC + 16) were tested. Controls include no inhibitor (inhibitor [−]), siRNA pool against hRluc gene and negative control siRNA (targeting the nonplasmid protein, PPIB).
