Abstract
Approximately 25% of osteosarcoma patients present with clinically detectable metastatic disease at the time of initial diagnosis. High-dose chemotherapy and/or surgery for the treatment of primary metastatic osteosarcoma is ineffective, and <20% of patients will survive 5 years from diagnosis. Therefore, the treatment of metastases is critical for the improvement of the prognosis of primary metastatic osteosarcoma patients. We have previously observed that overexpression of interleukin-24 (IL-24) inhibits neuroblastoma cell proliferation, migration and invasion in vitro. The present study investigated whether IL-24 may be a novel agent for osteosarcoma metastasis-suppressive treatment. It was observed that IL-24 is able to inhibit migration and invasion in spontaneously metastasizing human 143B osteosarcoma cells via the c-Jun N-terminal kinase (JNK)/c-Jun signaling pathway. IL-24 was effective in inhibiting JNK and c-Jun phosphorylation to downregulate matrix metalloproteinase (MMP)-2 and MMP-9, which contributed to the suppression of cell migration and invasion. It was concluded that IL-24 may be a potent agent in the inhibition of highly metastatic 143B osteosarcoma cells, and IL-24 may have translational potential as an effective therapeutic agent for the treatment of metastatic osteosarcoma.