p-MMP-2 transfection inhibits radiation-enhanced glioma cell invasion.

<p>U-251 and U-87 cells were transfected with mock, p-SV or p-MMP-2, and irradiated as described earlier. Cells were trypsinized and counted, and 5×10⁵ cells from each treatment condition were allowed to invade transwell inserts containing 12-µm-pore polycarbonate membranes pre-coated with Matrigel for 24 h at 37°C. Afterwards, cells were fixed and stained with Hema-3. Cells that had migrated to the lower side of the membrane were photographed under a light microscope at 20× magnification. Percentages of invading cells were quantified by counting five fields from each treatment condition. <i>Columns</i>: mean of triplicate experiments; <i>bars</i>: SD; *<i>p</i><0.01, **<i>p</i><0.001, significant difference from mock or irradiated controls.