Chondrosarcoma Organoids Reveal Targetable SHH Pathway Activation via PTCH1 Alterations

Purpose Chondrosarcoma is the second most common malignant bone tumor, characterized by the production of cartilaginous matrix and a high degree of resistance to conventional therapies such as chemotherapy and radiotherapy. Effective treatment options remain limited, highlighting the urgent need for preclinical models to explore novel therapeutic approaches. This study aimed to establish patient-derived chondrosarcoma organoid models and to investigate their utility in elucidating molecular mechanisms and drug responses. Methods Chondrosarcoma specimens were collected from patients and cultured using a modified air–liquid interface (ALI) organoid method. The resulting organoids were serially expanded in vitro and transplanted into NOD-SCID IL2Rgnull mice for in vivo validation. Histological and genetic analyses were performed to compare organoids with the corresponding primary tumors. Whole-exome profiling was used to identify genetic alterations. Organoid-based drug sensitivity testing was conducted using vismodegib, a Sonic Hedgehog (SHH) pathway inhibitor. Results Two patient-derived organoid lines were successfully established. Organoid-derived xenografts preserved the histological and genetic features of the parental tumors. Genomic profiling revealed loss-of-function mutations in PTCH1 and BCOR , suggesting activation of the SHH signaling pathway. Consistently, vismodegib exhibited strong in vitro antitumor activity, indicating functional pathway dependence. Conclusion We established the first patient-derived chondrosarcoma organoid models that faithfully recapitulate key tumor features. These models provide a valuable preclinical platform for dissecting molecular pathogenesis and for advancing the development of targeted therapeutic strategies in this intractable malignancy.