In the present study, we have used plasmid-based RNAi to simultaneously down-regulate the expression of uPAR and uPA in SNB19 glioma cell lines and epidermal growth factor receptor (EGFR)--overexpressing 4910 human glioma xenografts in vitro and in vivo, and evaluate the i.p. route for RNAi-expressing plasmid administered to target intracranial glioma.