| Objective Meningiomas are commonly neoplasms of central nervous system. Most meningiomas are benign and grow slowly, about 0.9%~10.6% of them are malignant and have invasiveness, so it is difficult to resect them completely and recur frequeutly after operation. Malignant meningiomas are highly invasive, which can invade menings, skull and extracranial tissues, some of them even metastasize extracranialy. Some meningiomas are benign in histology but have the invasive behavior biologically. This can make it difficult to resect them completely and become the reason for recuring after operation. At present, studies on the invasive behavior of meningiomas are still less and the exact mechanisms of which are not understood completely. Studies show that meningiomas have the same mechanisms of invasiveness as other tumors, which include three steps: (1) Tumor cells cling to extracellular matrix (ECM) .(2) The local ECM is degraded by enzymes which are secreted from tumor cells. (3) Tumor cells migrate to the regions where the matrix has been degraded by enzymes of tumor cells. Matrix metalloproteinases (MMPs) are a family ofZn2+-depedant endopeptidases, which are capable of degrading essentially all of components of ECM except polysaccharede. MMP-2 and MMP-9 belong to the type IV collagenases, which can degrade type IV, typeV , type VII and type Kcollagen as well as fibronectin, fibrillin, osteonectin and elastin, ect. So they are important enzymes for degrading ECM, and are responsible for the tumor invasion and metastasis. Tissue inhibitors of MMPs (TIMPs) are main regulators which can inhibit the activity of MMPs. At present, four TIMPs have been cloned. Of them, TIMP-1 inhibits the activity of MMP-9 while TIMP-2 inhibits the activity of MMP-2 selectively. In this study, immunohistochemistry assay was used to research the expression of MMP-2 MMP-9 TIMP-land TIMP-2 in meningiomas to evaluate the relationship between the four indexes and the malignance and the invasiveness of meningiomas. The aim of this study is to discuss the meningiomas, and to search the moleculobiological markers for judgement of malignance, invasive biological behavior of meningiomas.Methods: (l)Sixty surgically resected meningiomas samples and 10 normal arachnoid membrane tissues were collected from the first affiliated hospital of Zheng zhou University. All of these tissues were fixed in 10% neutral formalin and embedded in paraffin. Four-micrometer sections were prepared and mounted on slides. The sections were stored at 4C prior to use.(2)According to WHO'S tumor classification of nervous system in 1999, of the 60 cases, typical meningiomas (WHO grade I ) are 25 cases; atypical meningiomas (WHO grade II) are 20 cases and malignant meningiomas are 15 cases. According to the inrasiveness of the tumor, of the 60 cases, noninvasive meningiomas are 28 cases and 32 cases are invasive meningiomas. (3)Streptavidin-Peroxidase (S-P) immunostaining technique was used to examine the expression of MMP-2 9, TIMP-1,2 in all of the tissues. (4)Statistical analysis: Rank sum test (Kruskal-wallis mothod) was used, a =0.05 was the level of test.Results: (1)in normal arachnoid membrane tissues, no positive expression of MMP-2 was found. In benign, atypical and malignant meningiomas, the positive rates of MMP-2 were 64% (16/25) , 75% (15/20) and 80%(12/15) respectively. An increasing tendency was found in the expression level of MMP-2 from benign to atypical and to malignant meningiomas, which was higher in thase three groups than that in normal arachnoid membrane tissues, but there was no significant difference among the three groups (P>0.05).(2)In normal arachnoid membrane tissues, noninvasive memingiomas and invasive meningiomas, the positive rates of MMP-2 were 0 (0/10) , 53.6%(15/28) and 84.4%(27/32) respectively. The expression level of MMP-2 in invasive meningiomas was significantly higher than that in noninvasive meningiomas (P<0.05) and than that in arachnoid membrane tissues (P<0.05) respectively, but there was no difference between... |
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