Mapping Osteosarcoma Biology With CRISPR/Cas: From Gene Function to Therapeutic Targets

Osteosarcoma is a highly aggressive primary bone malignancy characterized by rapid proliferation, chemoresistance, and early metastasis. Recent advances in CRISPR/Cas (clustered regularly interspaced short palindromic repeats/CRISPR-associated proteins) genome editing have enabled precise targeting of oncogenes, tumor suppressors, and regulators of epigenetic, metabolic, and signaling pathways, providing new insights into osteosarcoma biology. CRISPR-mediated knockout of cell-cycle regulators, including CDK11, impairs proliferation, while restoration of TP53 and suppression of TERT promoter activity inhibits tumor growth. Other line of studies has revealed that chemoresistance mechanisms mediated by ABCB1/MDR1, CD44, ATR, RAD18, and autophagy-related genes have been effectively reversed through CRISPR interventions, restoring sensitivity to cisplatin and doxorubicin. Furthermore, CRISPR applications in immune modulation, such as PD-L1 knockout, may enhance antitumor immunity. Importantly, high-throughput CRISPR screens also may identify essential genes, novel oncogenic drivers, and synthetic lethal targets, thus informing potential precision therapeutic strategies. This review aims to critically summarize CRISPR/Cas-mediated studies in osteosarcoma, focusing on targeting oncogenes and tumor suppressors, overcoming chemoresistance, modulating immune responses, regulating metabolism and autophagy, and identifying essential genes and vulnerabilities, providing a translational framework for precision therapy.