Here, we demonstrate that astrocyte-conditioned tumor cells display highly invasive and metastatic behavior in vitro and in vivo. MMP-2 and -9 are two factors in the astrocyte secretome that are partially responsible for this response, and blocking MMP-2 and -9 proteins partially prevents the invasion and metastasis of tumor cells in vitro and in vivo. Here, MMP2 is linked to neoplasm.