GBP1-CDK9-STAT3 signaling axis promotes osteosarcoma PD-L1 expression and immune escape.

Osteosarcoma is a common malignant bone tumor, characterized by its high invasiveness and propensity for lung metastasis. Despite advances in treatment, clinical outcomes remain poor, and patient prognosis is still unsatisfactory. Therefore, the development of more effective therapies is urgently needed. Here, we demonstrate that differential expression of GBP1 significantly influences PD-L1 expression and mediates immune escape in osteosarcoma. Specifically, our results reveal that GBP1 regulates PD-L1 expression by activating CDK9 and promoting STAT3 phosphorylation. These findings suggest that targeting GBP1 may represent a promising therapeutic strategy for the treatment of osteosarcoma by impairing tumor immune evasion.