Programmable miRNA-guided RNA-toxin switch for selective elimination of cancer cells.

Cancer patients receiving chemotherapy and targeted therapy often experience severe side effects due to systemic damage of healthy cells throughout the body. Here, inspired by the programmable design of RNA molecules, we present microRNA (miRNA)-guided RNA-toxin constructs (miR-RTCs), a novel therapeutic platform that achieves superior tumor selectivity through miRNA-controlled toxin expression. miR-RTCs operate as miRNA-responsive molecular switches that specifically respond to dysregulated intracellular miRNA expression profiles in tumor cells to conditionally express toxic proteins, enabling precise cancer cell elimination while sparing healthy tissues. In vivo, systemic delivery of miR-RTCs effectively restricts protein expression to tumor regions in hepatocellular carcinoma models, resulting in significant tumor regression with minimal off-target effects. This study establishes miR-RTCs as a programmable RNA therapeutic platform that overcomes the selectivity limitations of traditional chemotherapy while maintaining potent antitumor efficacy, with potential for further enhancement through immunotherapy combinations.