Engineering a DNA logic-gated theranostic multi-antisense oligonucleotide nanoactivator for cell subtype-specific molecular therapy.

Antisense oligonucleotides (ASOs) that can silence target mRNAs are highly appealing for molecular therapy of a variety of diseases, but their practical applications are still hindered by the off-target effect and low efficiency. Here, we report a DNA logic-gated multi-ASO nanoactivator (ASONA) that can achieve accurate cell subtype identification and cell subtype-specific molecular therapy in vitro and in vivo. The ASONA is constructed by assembling the nicked hairpin DNA and three kinds of three-way junction DNA probes with inactivated ASO drugs on the gold nanoparticles. As a paradigm, tumor-related thymidine kinase 1 (TK1) mRNA and microRNA-122 (miR-122) in hepatocellular carcinoma HepG-2 cells are chosen as "AND" gate inputs. The ASONA responds to these inputs to initiate cascade strand-displacement reactions, resulting in the generation of significantly amplified fluorescence and the continuous activation of three types of ASO drugs. This ASONA can discriminate HepG-2 tumor cells from normal cells and other types of tumor cells and achieve high silencing efficiency only in HepG-2 tumor cells for multiple target oncogenes. More importantly, it can distinguish the HepG-2 tumor subtype from other tumors in vivo and significantly inhibit HepG-2 tumor growth with no side effects on normal tissues. Overall, this ASONA provides a universal approach for accurate identification of specific cell subtype and precise in situ activation of multiple ASOs in specific cell subtype in vitro and in vivo and could be used to expand the applicability of ASOs in precision theranostics against a range of diseases.