Targeted nanoparticle-mediated Co-delivery of IFITM3 KO and ponatinib reverses TKI resistance in chronic myeloid leukemia.

Resistance to tyrosine kinase inhibitors (TKIs) is a core limitation in the clinical treatment of chronic myeloid leukemia (CML). Although ponatinib can cover the T315I mutation, its clinical application is limited by severe adverse reactions at high doses. On the basis of the USP28-BCR-ABL-IFITM3 resistance signaling axis first identified in our previous study, a ginger-derived lipid carrier-mediated targeted nanodelivery system (IP@GLPs@εF) was constructed, which codelivers CRISPR/Cas9-mediated IFITM3 knockout (IFITM3 KO) plasmid and ponatinib, establishing a new synergistic intervention mode of gene editing and targeted chemotherapy. When modified with ε-polylysine and fucoidan via layer-by-layer self-assembly technology, the carrier has an average particle size of 226.1 nm, a drug encapsulation efficiency of 84.2%, and excellent biocompatibility. In vitro experiments confirmed that the optimal ratio (2.5 μg IFITM3-sg3 + 5 μM ponatinib) significantly reversed the drug resistance of K562R cells, promoted apoptosis and inhibited proliferation. In vivo experiments using ectopic and orthotopic xenograft models verified that this system can efficiently target tumor tissues and significantly suppress the progression and metastasis of drug-resistant tumors, with no obvious toxic side effects on major organs. Mechanistically, this study revealed that IFITM3 mediates CML resistance by interacting with HSPA9 to activate the MET/AKT/BCL2 pathway and that IFITM3 KO can block this pathway and exert a synergistic antiresistance effect with ponatinib. This research provides a novel IFITM3-targeted synergistic therapeutic strategy and technical support for the clinical treatment of CML resistance.