A single‐molecule prodrug synergistically suppresses MYC‐amplified osteosarcoma through sequential nitric oxide release and photodynamic therapy

MYC-amplified osteosarcoma, a poor-prognosis molecular subtype, presents formidable therapeutic challenges due to its aggressive phenotype, chemoresistance, and the "undruggable" oncogenic driver MYC. A single-molecule prodrug, DHU-NO3, was developed to achieve precise synergy between photodynamic therapy (PDT) and nitric oxide (NO) gas therapy for the treatment of MYC-amplified osteosarcoma. This prodrug covalently links the clinically approved photosensitizer methylene blue (MB) to an NO donor and undergoes a sequential activation cascade: reactive oxygen species-triggered MB release, 405 nm light-controlled NO generation, and PDT initiation under 650 nm laser irradiation. In 143B osteosarcoma cells, this temporally coordinated regimen efficiently induces apoptosis and potently suppresses the MYC signaling network. In the 143B osteosarcoma subcutaneous xenograft model, DHU-NO3-mediated sequential phototherapy demonstrated robust tumor growth inhibition with favorable biosafety. This work establishes a spatiotemporally programmable prodrug platform and provides a potent strategy to combat MYC-amplified osteosarcoma by indirect pathway suppression.