Photocaged Small Interfering RNA

Photoregulated systems are interesting and prospective instruments to affect gene expression. An approach to the synthesis of photoregulated siRNA has been proposed for RNA interference activated by light irradiation. For temporary protection, a bulky group has been introduced in siRNA through the photocleavable linker. We have used amino-modified cholesterol and trileucine as bulky ligands, which have been attached to siRNA by the interaction with the hydroxyl group activated with disuccinimidyl carbonate. The efficient UV-induced removal of the ligands introduced through the photocleavable linker has been demonstrated. Using the proposed approach, siRNA molecules bearing cholesterol residues at the 5'-terminus of sense- and/or antisense strands have been synthesized. They were targeted to mRNA of EGFP (enhanced green fluorescent protein). The photoinduced inhibition of the EGFP gene expression in the EGFP-expressing HEK293FT cells has been shown to be possible.