Iron metabolism has emerged as a critical regulator of cancer biology, with mounting evidence linking iron dysregulation to tumor initiation, progression, and resistance mechanisms. Osteosarcoma (OS) is the most common primary bone malignancy and a leading cause of cancer-related death in children and young adults; recent studies have identified profound alterations in iron homeostasis at both cellular and microenvironmental levels in OS. These include increased iron uptake, disrupted storage and export, and a reliance on iron-dependent metabolic pathways that promote proliferation, metastasis, and immune evasion. Despite advances in surgical and chemotherapeutic approaches, survival outcomes in OS have stagnated, underscoring the need for novel therapeutic strategies. Targeting iron metabolism represents a promising avenue, with strategies such as iron chelation, transferring receptor inhibition, ferroptosis induction, and modulation of ferritinophagy, showing preclinical efficacy. In this review, we provide an updated and integrated overview of the multifaceted role of iron in OS pathogenesis, dissect emerging therapeutic approaches aimed at disrupting iron regulatory networks, and highlight innovative delivery platforms including nanomedicine. By integrating current insights on iron metabolism with the molecular complexity of OS, we present a comprehensive perspective, while acknowledging that the limited clinical translatability of current findings still hinders progress toward clinical application. A deeper understanding of iron-driven mechanisms may guide future studies toward the development of safe and effective iron-targeted therapies for OS.

Osteosarcoma (OS), the most common primary malignant bone tumor arising in the highly mechanosensitive bone tissue, exhibits marked heterogeneity and resistance to conventional therapies. While molecular drivers have been extensively characterized, the role of mechanical stimuli in OS progression remains underexplored. In this study, we identify the transient receptor potential vanilloid 1 (TRPV1) channel as a key regulator of mechanotransduction and drug responsiveness in OS cells. Using uniaxial cyclic stretch, we show that the highly aggressive U-2 OS cell model undergoes TRPV1-dependent perpendicular reorientation, in contrast to the inert response observed in the less aggressive SAOS-2 cells. Through confocal microscopy, immunohistochemistry, and atomic force microscopy, we demonstrate that nanomolar concentrations of capsaicin—a well-characterized TRPV1 agonist—chemically replicate the mechanical phenotype, altering metastatic traits such as cell adhesion, edge architecture, migration rate, nuclear-to-cytoplasmic ratio, and chemotherapeutic sensitivity to doxorubicin and cisplatin. TRPV1 activation, whether mechanical or chemical, elicits subtype-specific effects absent in healthy hFOB osteoblasts. Notably, it differentially regulates nuclear localization of the pro-to-oncogene Src in U-2 OS versus SAOS-2 cells. Parallel changes in Src and acetylated histone H3 (acH3) levels support a role for TRPV1 as a molecular switch in the Src–acH3 mechanosignaling axis. These TRPV1-mediated effects were not observed in non-malignant cells, underscoring their tumor specificity. Our findings position TRPV1 as a mechanosensitive signaling hub that integrates mechanical and chemical cues to drive epigenetic remodeling and phenotypic plasticity in OS, offering a potential therapeutic target—particularly in aggressive, drug-resistant subtypes.

Osteosarcoma (OS), the most common primary malignant bone tumor, arises in highly mechanosensitive tissue and exhibits marked heterogeneity and resistance to conventional therapies. While molecular drivers have been extensively characterized, the role of mechanical stimuli in OS progression remains underexplored. Here, we identify the transient receptor potential vanilloid 1 (TRPV1) channel as a key regulator of mechanotransduction and drug responsiveness in OS cells. Using uniaxial cyclic stretch, we show that aggressive U-2 OS cells undergo TRPV1-dependent perpendicular reorientation, unlike the inert SAOS-2 cells. Confocal microscopy, immunohistochemistry, and atomic force microscopy reveal that nanomolar concentrations of capsaicin—a well-characterized TRPV1 agonist—chemically mimic this mechanical phenotype, altering metastatic traits including adhesion, edge architecture, migration, nuclear-to-cytoplasmic ratio, and sensitivity to doxorubicin and cisplatin. TRPV1 activation, whether mechanical or chemical, induces subtype-specific effects absent in healthy hFOB osteoblasts. Notably, it differentially regulates nuclear localization of the proto-oncogene Src in U-2 OS versus SAOS-2 cells. Corresponding changes in Src and acetylated histone H3 (acH3) levels support a role for TRPV1 in modulating the Src–acH3 mechanosignaling axis. These effects are tumor-specific, positioning TRPV1 as a mechanosensitive signaling hub that integrates mechanical and chemical cues to drive epigenetic remodeling and phenotypic plasticity in OS, with potential as a therapeutic target in aggressive, drug-resistant subtypes

Iron metabolism has emerged as a critical regulator of cancer biology, with mounting evi-dence linking iron dysregulation to tumor initiation, progression, and resistance mecha-nisms. In osteosarcoma (OS), the most common primary bone malignancy and a leading cause of cancer-related death in children and young adults, recent studies have identified profound alterations in iron homeostasis at both cellular and microenvironmental levels. These include increased iron uptake, disrupted storage and export, and a reliance on iron-dependent metabolic pathways that promote proliferation, metastasis, and immune evasion. Despite advances in surgical and chemotherapeutic approaches, survival out-comes in OS have stagnated, underscoring the need for novel therapeutic strategies. Tar-geting iron metabolism represents a promising avenue, with strategies such as iron chela-tion, transferrin receptor inhibition, ferroptosis induction, and modulation of ferritinoph-agy, showing preclinical efficacy. In this review, we explore the multifaceted role of iron in OS pathogenesis, dissect emerging therapeutic approaches aimed at disrupting iron reg-ulatory networks, and highlight innovative delivery platforms including nanomedicine. By integrating current knowledge on iron metabolism with the molecular complexity of OS, we present a comprehensive perspective that may help in the development of new treatments aimed at overcoming drug resistance, ultimately improving clinical outcomes for OS patients.