Hino-Fe Chelate Suppresses Osteosarcoma Progression through Dual Induction of Ferroptosis and NLRC4-mediated Pyroptosis: Mechanisms and Therapeutic Implications.

Osteosarcoma remains a challenging malignancy with poor prognosis, particularly in metastatic cases. This study investigates the therapeutic potential and molecular mechanisms of the Hinokitiol-iron complex (Fe(hino)) against osteosarcoma. Fe(hino)3 induced dose-dependent cell death in osteosarcoma cell lines (HOS, 143b, and K7M2) through multiple pathways. At moderate doses, Fe(hino)3 triggered ferroptosis by disrupting mitochondrial function, enhancing ROS generation and lipid peroxidation, downregulating GSS and GPX4, and upregulating HO1 and Ferritin expression. At higher doses, Fe(hino) activated the NLRC4/Caspase-1/GSDMD pathway, leading to pyroptosis and the release of inflammatory factors. Mechanistically, Fe(hino)3 acted as a dual-mode cell death inducer through iron overload-mediated ferroptosis and NLRC4-dependent pyroptosis while modifying the immunosuppressive tumor microenvironment. In actual clinical application, Fe(hino)3 might be used as an alternative to chemotherapy or other targeted therapies for advanced osteosarcoma at a relatively low dose to improve biosafety and reduce side effects. However, when considering it in combination with immunotherapy for advanced osteosarcoma, a relatively safe high dose is more appropriate due to the pyroptosis-mediated inflammatory response but it still needs to consider the biosafety of combination therapy. These findings provide new insights into the development of Fe(hino)3 dose-dependent therapeutic strategies for advanced osteosarcoma treatment.