Dumbbell-Shaped Antisense Oligonucleotide Prodrugs Showed Improved Antinuclease Stability and Anticancer Efficacy

Abstract

Antisense oligonucleotides (ASONs) have generated widespread interest as antitumor agents. Nevertheless, the utility of natural ASONs is limited due to their rapid degradation by intracellular and extracellular nucleases. In this work, we proposed a novel prodrug-type ASON with a dumbbell conformation and a responsive disulfide switch. A degradation assay showed that the dumbbell-shaped ASON (DS-ASON) exhibited stronger stability against enzymatic degradation compared with that of the linear or single-end looped ASON. The native ASON could dissociate via breakage of the disulfide switch when in the reductive microenvironment of a tumor. In addition, an optimal DS-ASON, L2, displayed robust antitumor activity both in vitro and in vivo. This paper presents a new design of nucleic acid-based therapeutics featuring a conformational change that provides improved stability and biological efficacy.

Synthesis, Biophysical Properties, and Antitumor Activity of Antisense Oligonucleotides Conjugated with Anisamide

“…These results indicate that double-ended AA-ASON conjugation greatly improves stability against enzymatic degradation. The resistance to enzymatic degradation was comparable to that achieved in our previous research, which utilized spatial conformation modification at the 3 and 5 ends [17].…”

“…To provide additional validation of T6′s antitumor properties, the apoptosis of tumor cells was measured using our previously reported method [ 17 ]. In brief, the ASONs were incubated with MCF-7 cells for 24 h. After this incubation period, 1 × 10 5 cells were collected and suspended in 100 μL of binding buffer containing annexin V–fluorescein isothiocyanate (FITC) and propidium iodide (PI) for a 15 min period.…”

Synthesis, Biophysical Properties, and Antitumor Activity of Antisense Oligonucleotides Conjugated with Anisamide

“…To further confirm the antitumor effect of T6, the apoptosis of tumor cells was measured. Cell apoptosis was analyzed using our previously reported method [16]. Briefly, prepared ASONs were incubated with MCF-7 cells for 24 h. Cells (1 × 10 5 ) were collected and resuspended in 100 μL binding buffer complemented with annexin V-fluorescein isothiocyanate (FITC) and propidium iodide (PI) for 15 min.…”