Single-cell and longitudinal transcriptomics-guided engineering of FZD1-targeting precision nanotherapy against...

Osteosarcoma is the most prevalent primary malignant bone tumor in children and adolescents. Osteosarcoma cancer stem cells (OCSCs) critically drive tumorigenesis and progression through their self-renewal capacity and therapy resistance. Understanding mechanisms maintaining OCSC stemness and identifying key therapeutic targets are thus critical for effective intervention. Here, we systematically analyzed OCSC transcriptomic features using single-cell and longitudinal RNA-sequencing, identifying transcription factor 7 like 1 (TCF7L1)-associated transcriptional activity in relation to OCSC stemness and frizzled class receptor 1 (FZD1)-associated Wnt/β-catenin signaling as a putative upstream pathway. FZD1 expression significantly correlated with clinical malignancy progression in osteosarcoma. Leveraging these transcriptional signatures, we screened and validated homoharringtonine as a potent therapeutic agent against osteosarcoma and OCSCs. To enhance efficacy while reducing systemic toxicity, an FZD1-targeted, pH/glutathione dual-responsive nanoplatform was engineered to achieve precise drug delivery to OCSC-derived tumors via high-affinity binding of UM206 peptide to FZD1, concurrently enabling tumor microenvironment-triggered homoharringtonine release in acidic, glutathione-rich niches. This integrated approach characterizes OCSC-associated transcriptional regulation and supports further development of OCSC-targeted precision nanotherapies for osteosarcoma.