Abstract

Background Osteosarcoma (OS) is a common malignant bone tumor that predominantly affects adolescents and is highly invasive and metastatic. Current treatment options have suboptimal efficacy, highlighting the urgent need for novel therapeutic strategies. Cuproptosis, a recently discovered form of copper-dependent cell death, has demonstrated potential in cancer therapy, yet its clinical application remains to be fully explored. Ferroptosis, another iron-dependent programmed cell death pathway, has shown efficacy against certain cancers through its induction. Recent studies suggest that ferroptosis inducers can increase cuproptosis in other cancer cells, but this synergistic effect has not been elucidated in OS. The purpose of this study was to investigate the effects of ferroptosis inducers (FINs) on cuproptosis and immunogenic cell death (ICD) induced by elesclomol‑copper premix (ES-Cu 2+ ) in OS cells and to explore the underlying mechanisms and principles. Methods The effects of FINs+ES-Cu 2+ on cuproptotic osteosarcoma (OS) cell lines were investigated through in vitro cellular experiments. The in vivo antitumor efficacy of different drug regimens was further evaluated using an orthotopic osteosarcoma mouse model and micro-CT. RNA sequencing (RNA-Seq) was used to explore the relevant genes and pathways. Results In vitro cellular experiments demonstrated that low-dose FINs can sensitize OS cells to ES-Cu 2+ -induced cuproptosis, increasing the expression of ICD markers. Treatment of the orthotopic osteosarcoma model and micro-CT results showed effective inhibition of tumor progression and osteolytic destruction in vivo. RNA-Seq analysis revealed a marked enrichment in glutathione (GSH) metabolism. Further investigation revealed that the PPARγ-GPX4 axis serves as the primary pathway through which the drug combination influences GSH metabolism. Conclusions This study highlights FINs as effective cuproptosis potentiators and suggests a novel combinatorial re