Ewing tumor metastasis – in vivo and in vitro analysis

The most adverse prognostic factor for Ewing tumor patients is the presence of metastasis in the lung and/or bone/bone marrow. The feasibility of „small animal PET“ was evaluated in a well established mouse model for Ewing tumor metastasis in order to study the mechanisms involved in metastasis in vivo. This method allows monitoring of molecular pathways in a non-invasive manner over time. Visualizing glucose utilization and bone metabolism clearly identified subcutaneous tumors as well as metastases derived from i.v. transplanted Ewing tumor cell lines. Little is known about the matrix metalloproteinases (MMP) involved in Ewing tumor cell metastasis. A preliminary study analyzing EFS and expression of MMP-9 revealed that MMP-9 expression indicates a poor prognosis. We performed RT-PCR and zymograms to identify MMPs expressed by Ewing tumor cell lines. Using MMP-specific PET-tracers the involvement of MMPs in Ewing tumor metastasis will be analyzed in vivo.