Five-Step Process for Screening Antisense Compounds for Efficacy: Gene Target IL-12Rb2

Abstract

Antisense technologies are widely used for the inhibition of gene expression. Although traditionally the AUG start codon of the open reading frame is targeted to disrupt ribosome assembly and initiation, an emerging approach is targeting sequences to disrupt pre-mRNA splicing. The primary advantage to using this approach is a positive read-out for an antisense effect through detection of a novel splice product, but additional benefit can be found in generating a novel splice product with altered functional properties. The antisense compounds used here are phosphorodiamidate morpholino oligomers conjugated to an arginine-rich cell penetrating peptide (P-PMO). We describe a five-step process for selecting the best candidate antisense compound for altering IL-12Rb2 expression including (1) detecting mRNA splice products by RT-PCR, (2) measuring protein expression, (3) evaluating protein function, (4) checking cellular viability, and (5) validating efficacy of the final candidate compound. The significance of targeting exons composed of a number of base pairs divisible by 3 is also discussed. The five steps described here for selecting the best candidate P-PMO to alter IL-12Rb2 expression should be applied for designing and screening antisense compounds for other gene targets.