Sonodynamic therapy augmented by glycolysis inhibition: a novel metabolic reprogramming strategy for enhanced...

A metabolic reprogramming strategy, considered an efficient way to enhance current therapies, has provided renewed hope for treating osteosarcoma (OS), which has reached a bottleneck in clinical practice. In this study, SHK@Mn-TiO₂ were developed as novel sonodynamic therapy (SDT) agents with glycolysis-inhibiting properties. By reducing the expression of pyruvate kinase isozyme M2 (PKM2) and hexokinase-2 (HK-2), SHK@Mn-TiO₂ effectively inhibited glycolysis, thereby reversing the hypoxic tumor microenvironment (TME), as evidenced by a more than ∼50% decrease in hypoxia-inducible factor-1α (HIF-1α) and lactate (LA) levels compared with those of Mn-TiO₂. Under this O₂-enriched TME, SHK@Mn-TiO₂ enhanced intracellular reactive oxygen species (ROS) levels by ∼53% and increased K7M2 tumor inhibition under ultrasound (US). Furthermore, the combination of glycolysis inhibition and SDT initiated a cascade of immune responses, promoting an ∼98% increase in the maturation of dendritic cells and ∼280% increase in the infiltration of IFN-γ⁺ CD8⁺ T cells compared with those in the control. The typically immunosuppressive TME induced by conventional SDT was significantly reversed, as indicated by the reduction in the proportions of regulatory T cells to ∼18% and myeloid-derived suppressor cells (MDSCs) to ∼49% in the Mn-TiO₂ groups. Moreover, a long-term immune memory effect was observed in the murine osteosarcoma cell line (K7M2) tumor rechallenge model as a result of strong immune activation. Overall, this study highlights a sono-immune strategy for OS treatment based on the synergistic effects of glycolysis inhibition combined with SDT, offering a promising solution to the current therapeutic challenges in clinical OS management.