The DANCR/miR-145-5p/CD133 Axis Drives Osteosarcoma Stemness and Progression: Implications for Tumor Biology and...

Characterized by its highly aggressive behavior and propensity for metastasis, osteosarcoma remains a formidable clinical challenge with restricted treatment modalities. Cancer stem-like cells (CSCs) are widely recognized as central orchestrators of oncogenic progression and therapeutic intractability; however, the precise epigenetic regulations governing these processes are yet to be fully elucidated. Here, we investigated the role of the long non-coding RNA DANCR in regulating osteosarcoma stemness. DANCR expression was significantly upregulated in human osteosarcoma tissues and positively correlated with the stemness markers CD133, SOX2, and CD90. Functional assays demonstrated that DANCR overexpression enhanced stem-like properties, including an enriched CD133+/CD44+ cellular fraction and enhanced spheroid-forming capacity, concurrently accelerating in vitro cellular proliferation, migration, and invasive potential. In a xenograft mouse model, DANCR upregulation promoted in vivo tumor growth and lung metastasis. Mechanistically, dual-luciferase reporter assays and RNA immunoprecipitation (RIP) revealed that DANCR acts as a competing endogenous RNA (ceRNA) by sponging miR-145-5p, thereby facilitating the de-repression of CD133 and contributing to Akt/mTOR signaling activation. In addition, DANCR/miR-145-5p modulation was associated with changes in autophagy-associated markers. Collectively, these findings identify the DANCR/miR-145-5p/CD133 axis as a regulator of osteosarcoma stemness and progression, providing new insights into tumor biology and highlighting a potential molecular target for therapeutic investigation.