Development and Crosslinking Properties of Psoralen‐Conjugated Triplex‐Forming Oligonucleotides as Antigene Tools Targeting Genome DNA

Abstract

AbstractPsoralen‐conjugated triplex‐forming oligonucleotides (Ps‐TFOs) have been utilized for genome editing and anti‐gene experiments for over thirty years. However, the research on Ps‐TFOs employing artificial nucleotides is still limited, and their photo‐crosslinking properties have not been thoroughly investigated in relation to biological activities. In this study, we extensively examined the photo‐crosslinking properties of Ps‐TFOs to provide fundamental insights for future Ps‐TFO design. We developed novel Ps‐TFOs containing 2′‐O,4′‐C‐methylene‐bridged nucleic acids (Ps‐LNA‐mixmer) and investigated their photo‐crosslinking properties using stable cell lines that express firefly luciferase constitutively to evaluate the anti‐gene activities of Ps‐LNA‐mixmer. As a result, Ps‐LNA‐mixmer successfully demonstrated suppression activity, and we presented the first‐ever correlation between photo‐crosslinking properties and their activities. Our findings also indicate that the photo‐crosslinking process is insufficient under cell irradiation conditions (365 nm, 2 mW/cm2, 60 min). Therefore, our results highlight the need to develop new psoralen derivatives that are more reactive under cell irradiation conditions.