Fig. 4

Sub-histological location of MMP2 (left) and MMP9 (right) expression in glioblastoma tissue. A Immunostaining of MMP2 expression (left) on glioblastoma (a, b) and cortectomy (c) tissues. Immunostaining of MMP9 expression (right) on glioblastoma (d, e) and cortectomy (f) tissues. Scale bars: a: 50 µm; b-c: 100 µm; d-f: 250 µm. B Semi-quantitative analysis of MMP2 and MMP9 immunostaining (high expression: score 2 or 3). Tumor: tumor cells; ECM: extracellular matrix; Endoth.: endothelial cells; MVP: microvascular proliferation; Infiltrative: infiltrative cells; Intravasc.: intravascular cells; Necrosis: necrosis cells. MMP9 is expressed by CD45+ cells in glioblastoma patient samples. C Immunofluorescent staining of CD31, CD45 and MMP9 on frozen glioblastoma samples. MMP9 is expressed by CD45 positive cells. Nuclei were stained by Hoechst. Scale bar: 50 µm. D Count of MMP9 positive cells in different tumor fractions. Tumors were processed to isolate individual cells; immunomagnetic sorting allowed to separate cells for CD31⁺ and CD45⁺ expression. Each fraction was analyzed for MMP9 expression by cytometry. MMP9 is significantly overexpressed by CD45⁺ fraction. E Relative expression of MMP9 by CD31 + and CD45+ fraction cells by cytometry (N = 3). F- MMP9 mRNA expression in CD31 + and CD45+ fraction cells. MMP9 mRNA expression is significantly higher in CD45⁺ fraction (N = 5). *p < 0.05; **p < 0.01