Global gene expression profiling of human osteosarcomas of primary and metastatic origin reveals alterations in chemokine pattern

Global gene expression analysis was performed on a panel of 23 osteosarcoma samples of primary and metastatic origin using the Applied Biosystems Gene Expression Array System. When comparing the primary tumours with the metastases, we found a significantly increased expression of genes involved in immunological processes, e.g. coding for cytokines and chemokines, in the metastatic samples, suggesting that these signal molecules play an important role in promoting metastasis. In addition, a comparison of the gene expression in primary samples from patients with or without metastases demonstrated that patients who later developed metastases had high expression of the chemokine (C-X-C motif) receptor 4 (CXCR4), similar to the metastatic samples. Increased knowledge of mechanisms and interactions between specified molecular signalling pathways in osteosarcomas could lead to a more rational strategy for development of targeted therapy. Total RNA was isolated from tumor tissue of osteosarcoma patients. Gene expression patterns of metastatic versus primary samples were compared, as well as primary samples from patients who did or did not later develop metastases.