Chemistry of artificial nucleic acid and oligonucleotide therapeutics based on natural nucleic acids

Triplex DNA is a powerful tool for the genome researches and genome targeting technologies. However, there is an intrinsic limitation to form the stable triplex DNA at any duplex DNA sequence. Recently, we have developed the artificial nucleoside analogue to recognize the CG base pair that cannot be stabilized by natural nucleic acids. Interestingly, the artificial nucleic acid was designed on the basis of the natural T-CG triplex formation. Consequently, we succeeded in expanding the triplex DNA recognition code and achieved the inhibition of the gene expression by the novel antigene triplex forming oligonucleotides.