Expressions of matrix metalloproteinase-2 and its inhibitor in human glioma

Objective To investigate the expressions of matrix metalloproteinase-2(MMP-2, gelatinase A)and its inhibitor,tissue inhibitor of metalloproteinase-2(TIMP-2),in human glioma. Methods The samples from 35 cases of glioma were divided into four groups according to the WHO classification: grade Ⅰ (n=7), grade Ⅱ (n=12), grade Ⅲ (n=10), and grade Ⅳ (n=6), 4 normal brain samples were served as the control. The expressions of MMP-2 and TIMP-2 protein were determined with immunohistochemistry in the samples, and the correlation between the expressions of MMP-2, TIMP-2 and malignant degree of the gliomas was analyzed. Results The positive staining was localized in the cytoplasm of glioma cells and extracellular matrix. In the gliomas from gradeⅠ to gradeⅣ, the positive staining rates (%)(10.42±3.95,29.92±7.69,45.40±9.01, and 57.17±11.39, respectively) and the expression intensities (2.14±0.38,3.17±0.71,4.00±0.70, and 5.83±0.41, respectively) of MMP-2 were significantly elevated with the malignant grade of the gliomas, while the positive staining rates (%)(51.81±12.28,36.42±9.68,22.10±7.71, and 4.33±1.63, respectively) and immunostaining intensities (5.57± 0.53,3.92±0.29,2.70±0.50, and 2.17±0.41, respectively) of TIMP-2 were markedly reduced with increasing the grade of glioma malignancy. The ratioes of MMP-2/TIMP-2 were obviously increased when the malignant grades of the gliomas were elevated. There was a negative correlation (r=-0.69,P0.05) between MMP-2 and TIMP-2 expressions in the gliomas. Conclusion MMP-2 and TIMP-2 together play an important role in invasiveness of human glioma.