Using β-Elemene to reduce stemness and drug resistance in osteosarcoma: A focus on the AKT/FOXO1 signaling pathway and immune modulation

Objective

Osteosarcoma, a highly malignant bone tumor, poses significant treatment challenges due to its propensity for stemness and drug resistance, particularly against doxorubicin (DOX). This study aims to investigate the mechanism by which β-elemene reduces the stemness of osteosarcoma stem cells and ultimately decreases DOX resistance by inhibiting the Akt/FoxO1 signaling pathway and activating a macrophage-mediated inflammatory microenvironment.

Methods

Osteosarcoma stem cells were isolated and induced for DOX resistance. In vitro and in vivo models were employed to assess β-elemene’s impact on cell viability, stemness, and drug resistance. Bioinformatics analysis, flow cytometry, and immunofluorescence staining were used to evaluate signaling pathway activity and macrophage polarization. Additionally, an osteosarcoma xenograft mouse model was established to confirm the therapeutic effects of β-elemene.

Results

In vivo animal experiments demonstrated that β-elemene reduces osteosarcoma resistance. Bioinformatics analysis revealed that AKT1 is a key core gene in osteosarcoma progression, acting through the FOXO signaling pathway. Additionally, AKT inhibits immune cell infiltration in osteosarcoma and suppresses immune responses during osteosarcoma progression. β-elemene may influence osteosarcoma progression by mediating TP53 to regulate PTEN and subsequently AKT1. In vitro experiments showed that β-elemene promotes M1 macrophage activation by inhibiting the Akt/FoxO1 signaling axis, thereby reducing the stemness of osteosarcoma stem cells. Finally, in vivo animal experiments confirmed that β-elemene reduces osteosarcoma resistance by promoting M1 macrophage activation through inhibition of the Akt/FoxO1 signaling axis.

Conclusion

β-Elemene demonstrates promising potential in reducing osteosarcoma stemness and drug resistance via dual mechanisms: targeting the AKT/FOXO1 pathway and modulating the tumor immune microenvironment. These findings suggest β-elemene as a potential adjunct therapy for osteosarcoma, providing novel therapeutic strategies to overcome chemotherapy resistance and improve patient outcomes.