(0.26105 cells/mL) under isofluorane anesthesia with the aid of a stereotactic frame. After two weeks, mice were separated into three groups in each cell line. The first, second and third groups served as the control, MU-sh-treated (150 mg), and MC-sh-treated (150 mg) groups respectively. MU-sh and MC-sh plasmid DNAs were injected into the brains of nude mice using Alzet mini pumps at the rate of 0.2 mL/h. The concentration of the plasmid solution was 2 mg/mL (100 ml per mouse, six mice in each group). After five weeks, the mice were sacrificed by intracardiac perfusion, first with PBS and then with 4% paraformaldehyde in normal saline. The brains were removed, stored in 4% paraformaldehyde, processed, embedded in paraffin, and sectioned (5 mm thick) using a microtome. Paraffin embedded sections were stained with hematoxylin and eosin to visualize tumor cells and to examine tumor volume. 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