Small RNAs as therapeutic agents: From catalytic motifs to regulatory pathways

RNA molecules have long been recognized for their central role in protein synthesis, primarily as messengers (mRNAs), ribosomal components, and adaptors (transfer RNAs). Over the past few decades, however, the discovery of small RNAs with regulatory or catalytic functions has dramatically expanded our understanding of RNA biology. These small RNAs can target specific transcripts for cleavage, alter mRNA translation, direct epigenetic changes at gene promoters, or even guide enzyme complexes to their substrates. In this review, we highlight and discuss the therapeutic potential of key classes of small RNAs, including ribozymes, RNA interference elements, antisense oligonucleotides, small nuclear-targeting RNAs, and transfer RNA-derived small RNAs.