Radiodynamic Therapy Using 5-Aminolevulinic Acid as a New Treatment Option for Osteosarcoma: An <i>In Vitro</i> and <i>In Vivo</i> Study

BACKGROUND/AIM: in several malignancies. However, its application in bone and soft tissue sarcomas has not been sufficiently explored. In this study, we aimed to elucidate the efficacy of 5-ALA RDT in osteosarcoma cell lines. MATERIALS AND METHODS: studies utilized human (143B) and mouse (LM8) osteosarcoma cells. Cultured cells were either untreated (control) or exposed to 5-ALA (0-1,000 μg/ml) followed by X-ray irradiation (a single dose of 5 Gy). Cell viability was measured 48 h post-irradiation. Both 143B and LM8 cells were inoculated subcutaneously into the backs of BALB/c mice. Mice were assigned to untreated (control), Rx (irradiation alone), or 5-ALA RDT groups. Mice in the Rx group received X-ray irradiation (5 Gy) after macroscopic tumor formation, while those in the 5-ALA RDT group received 5-ALA (250 mg/kg) intraperitoneally, followed by 5 Gy X-ray irradiation. The mice were sacrificed 14 days after treatment, and changes in tumor volume were evaluated. RESULTS: , 5-ALA RDT treatment of osteosarcoma cells at 200, 500 and 1,000 μg/ml significantly inhibited cell proliferation at 48 h post-treatment, compared to control cells. In mice injected with osteosarcoma cells, the 5-ALA-RDT group showed a significant reduction in tumor volume compared to the control and Rx groups. No significant changes in body weight or abnormal behavior were observed. CONCLUSION: osteosarcoma models. These findings suggest its potential as a therapeutic approach for osteosarcoma.