MMP9 and central nervous system cancer: Hence, in the present study, we investigated the effect of downregulating MMP-9, uPAR and ctahepsin B using both single as well as MMP-9/uPAR and MMP-9/cathepsin B bicistronic shRNA plasmid constructs on the expression of integrins and on the migrating and invasive potential of glioma xenograft cells.