PNAs targeting the "RNA world" : Micro RNA next?

Since non-viral gene therapy was developed and employed in different in vitro and in vivo experimental systems as an effective way to control and modify gene expression, RNA has been considered as a molecular target of great relevance. Due to the recent identification and characterization of micro RNA as molecules of great interest in the control of several biological functions, this new class of RNA molecules have been proposed as potential target of molecular intervention finalized to control gene expression. Accordingly, the novel class of chemically engineered oligonucleotides, termed "anta-gomirs", are efficient and specific silencers of endogenous micro RNAS. Peptide nucleic acids (PNAs) and PNA-peptide conjugates are under study as micro RNA inhibitors, and are expected to be more effective than standard 2′-O-methyl oligonucleotides in binding and inhibitory effects on micro RNA action.