Amlodipine Suppresses Lung Metastasis by Increasing Cell Stiffness

Background/Aim: Osteosarcoma is the most common primary malignant bone tumor in children and adolescents, and lung metastasis is the major cause of death. Highly metastatic osteosarcoma cells are mechanically softer than low-metastatic cells, and calcium ions are known to regulate cytoskeletal organization and cell stiffness. We tested whether clinically available ion channel blockers could increase the stiffness of LM8 osteosarcoma cells and prevent lung metastasis in vivo. Materials and Methods: We evaluated the actin cytoskeletal structure and polymerization in ion channel blocker-treated LM8 cells using actin staining. Cell stiffness was measured using atomic force microscopy. Metastasis-related cellular functions were analyzed using cell proliferation, wound healing, and cell adhesion assays. Furthermore, lung metastasis and tumor volume were measured in LM8-bearing mice treated with an ion channel blocker. Results: Treatment with ion channel blockers significantly increased actin staining intensity and stiffness in LM8 cells compared to that in untreated LM8 cells (p