Gene correction by 5'-tailed duplexes with short editor oligodeoxyribonucleotides

Various diseases, including cancer, are caused by genetic mutations. A 5'-tailed duplex (TD) DNA, consisting of a long single-stranded (ss) editor DNA and a short (∼35-base) ss assistant oligodeoxyribonucleotide, can introduce a base-substitution in living cells and thus correct mutated genes. Previously, several hundred-base DNAs were employed as the editor DNAs. In this study, 5'-TDs were prepared from various editor DNAs with different lengths and examined for their gene correction abilities, using plasmid DNA bearing a mutated copepod green fluorescent protein (copGFP) gene, in human cells. High-throughput analysis was performed by the reactivated fluorescence of the wild-type protein encoded by the corrected gene as the indicator. The analysis revealed that 5'-TDs with ∼100-base ss editor DNAs enabled gene editing at least as efficiently as those with longer editor DNAs. Moreover, the antisense strand was more effective as the editor than the sense strand, in contrast to the 5'-TDs with longer editor strands. These results indicated that the 5'-TD fragments with shorter editor strands than those used in previous studies are useful nucleic acids for gene correction.