Splice Redirection as a Convenient Assay to Monitor CPP–ON Efficiency and Mechanism

Abstract

Several strategies based on synthetic oligonucleotides (ON) have been proposed to control gene expression. As for most biomolecules, however, delivery has remained a major roadblock for in vivo applications. Conjugation of steric-block neutral DNA mimics, such as peptide nucleic acids (PNA) or phosphorodiamidate morpholino oligonucleotides (PMO), to cell-penetrating peptides (CPP) has recently been proposed as a new delivery strategy. It is particularly suitable for sequence-specific interference with pre-mRNA splicing, thus offering various applications in fundamental research and in therapeutics. The chemical synthesis of these CPP–ON conjugates will be described as well as easy-to-implement assays to monitor cellular uptake, endosome leakage, and efficiency of splicing redirection.