Figure 2.

MMP-9 expression in PC-3 tumor sections and collagen IV quantification. Intratumoral expression of MMP-9 (red) was visualized using MMP-9 labeled PC-3 tumor sections. Nuclei (white) were stained with Hoechst 33258 dye. GFP (green) is a VACV reporter gene. Tumors were obtained at 7 days p.i. from PC-3 tumor-bearing mice injected with PBS, GLV-1h68 or GLV-1h255. All images are representative examples. (B) Quantification of MMP-9 expression was done by microscopic analysis. Mean fluorescence intensities were measured with ImageJ. (C) Quantification of collagen IV 7 days p.i. in GLV-1h68 or GLV-1h255 infected areas of PC-3 tumor sections. Images were taken at a 100× magnification (Leica MZ16 FA) and converted from RGB to grayscale using Photoshop. For image analysis ImageJ was used, the threshold value was 8/255.