FIG. 3.

Increased gelatinolytic activity of MMP-9 in C33a cells containing EBNA3C and Nm23-H1 as shown by zymography. Serum-free conditioned medium was collected from C33a-transfected cells after 48 h and subsequently concentrated by a Centricon 10 filter. The concentrated samples were then electrophoresed on an 8% SDS-PAGE gel containing 0.1% gelatin, followed by a 1-h wash in a 2.5% Triton X solution and then incubation at 37°C for 24 h. Gelatinolytic activity was resolved as white bands on a Coomassie blue R250-stained background at the predicted molecular mass of MMP-9 of 92 kDa. Protein levels of Nm23-H1 and EBNA3C were measured by Western blot assay.