Epithelial–Mesenchymal Transition in Osteosarcoma as a Key Driver of Pulmonary Metastasis

Abstract

Background: Osteosarcoma is an aggressive bone tumor with a high risk of lung metastasis, which severely affects patient survival. EMT plays a major role in tumor spread, therapy resistance, and cancer stemness. This review explores how EMT contributes to osteosarcoma metastasis and the underlying molecular mechanisms. Methods: We reviewed recent studies on EMT-related signaling pathways, transcription factors, and regulatory RNAs in osteosarcoma. We also examined the role of the tumor microenvironment. Results: EMT promotes cell detachment, migration, and lung colonization. Key pathways such as TGF-β, MAPK, PI3K/Akt, STAT3, Notch, and Wnt/β-catenin are involved. Non-coding RNAs further regulate EMT by interacting with these pathways. The tumor microenvironment, including hypoxia and immune cells, also supports EMT and metastasis. Conclusions: EMT is a key driver of metastasis and poor outcomes in osteosarcoma. Targeting EMT and its regulators may help prevent lung spread and improve treatment. Future strategies combining EMT inhibition with existing therapies could be promising for clinical application.