Relationship between the expression of matrix metalloproteinase-9 and angiogenesis in glioma and its clinical significance

Objective: To explore the role and significance of matrix metalloproteinase-9 (MMP-9) in angiogenesis through observing the relationship between the expression of MMP-9 and microvessel density (MVD) in glioma. Methods: The expressions of MMP-9 and CD₃₄ in 10 cases of normal brain tissues and 58 cases of glioma (14 cases of grade I, 20 cases of grade II, 15 cases of grade III, and 9 cases of grade IV) were detected by immunohistochemical streptavidin-peroxidase technique. The positive cells of MMP-9 and the positive microvessels were examined under binocular light microscope. Results: The positive expression of MMP-9 in glioma was located in the tumor-cell cytoplast and endothelial cells. The positive rate of MMP-9 in glioma of grade I, II, III and IV was 42.9%, 65.0%, 86.7% and 88.9%, respectively. The expression of MMP-9 was obviously higher than that of normal brain tissues (P<0.01) and positively correlated with glioma malignancy (r_s = 0.597, P<0.05). MVD was correlated with glioma malignancy (H = 47.865, P<0.05). The expression of MMP-9 was significantly correlated with MVD (r_s = 0.897, P<0.01). Conclusion: The expressions of MMP-9 and MVD are correlated with glioma malignancy, which may be helpful in judging the malignancy, invasion and prognosis. MMP-9 plays an important role in angiogenesis of glioma and accelerates glioma malignancy development by promoting angiogenesis.