| IntroductionThe cause of fatality in most malignancies is the dissemination of the disease to distant sites. Metastasis is a multiple stages, multiple steps continual process with several kinds of molecules involved in. In order to metastasize to distant sites, turner cell must invade the basement membrane surrounding blood vessels, travel in the bloodstream, attach to distant endothelial cell surface, emigrate through the interen-dothelial junction, degrade basement membrane and ECM, migrate and proliferate.Generally speaking, AB is a benign odontogenic tumor, at the same time, there is a certain amount of local invasion of the surrounding bone. Therefore, the recurrance of AB is common. It also involves invasion and metastasis. Although AB has been under intensive research , the molecular mechanism has not been completely clarified. It may involves imbalance of ECM, change of cell adhesion and new blood vessels formation. Degradation of ECM is a key step , and MMPs are the most important enzymes in this process. MMP - 2, MMP - 9 are thought to play critical role in tumor" cell invasion and are frequently coexpressed in human cancers. We study the protein expression of MMP -2, MMP -9 and TIMP - 1 in AB and OKC using the immunohistochemistry technique to observe the relation of their expression with AB biological behavior, so as to bring some theoretic ba-sis for the prevention and therapy of AB.Materials and MethodsAll the samples used in immunohistochemical study were obtained from the patients admitted to the First Affiliated Hospital of China Medical University between 1987 -2001. We used a scoring system to evaluate semiquantitatively the immunoexpression, judging brown plasma staining as positive. A (The intensity score was categorized into the following 4 groups) ; 0, no staining; 1, slight staining; 2, mild staining; 3, strong staining. B ( The sum score of positive cell was classified into the following 3 groups) : 1, less than 25% positive; 2, more than 25% but less than 75% positive; 3, more than 75% . The product of sum score and intensity score ( A x B ) was classified into the following 2 groups: 0-4 , negative; > 4, positive. SPSS for windows 10.0 statistical software was used to analyze the data.ResultIn the 16 cases of normal epithelia , MMP -2 was expressed in 10 cases. There were no difference between normal epithelia and epithelia surrounding the cancer. MMP - 9 was not expressed in all cases of normal epithelia, but epithelia surrounding the cancer stained positively. TIMP - 1 was weakly expressed in normal epithelial, flbro-blast, endothelial cell, monocyte. MMP -2 was strong expressed in the central and peripheral cells of the tumor islands. The expression of MMP-9 was stronger than MMP -2 in AB. At the same tumor, it may have different expression. The stromal cells also stained positively. However, compared with AB, the staining of TIMP - 1 was very weak, or in some areas, not detectable. )(2 test indicated that therewere no significant differences between the expression of MMP - 2, MMP - 9 , TIMP - 1 and age, sex, histological type, X - ray and location.DiscussionTumor metastasis requires the proteolytic degradation of ECM components to faciliate the invasion of basement membrane and connective tissue matrices by the malignant cancer cell. Several groups of protease have been implicated in tumor cell invasion. The Mr 72,000 gelatinase A ( MMP -2) and Mr 92,000 gelatinase B ( MMP -9) are two members of the MMPs family postulated to play a critical role in tumor invasion and angiogenesis. Elevated levels of these enzymes have been reported in many human cancers.The data present in this study demonstrated that both MMPs and TIMPs made contribution to the process. There was no difference of TIMP - 1 expression in OKC and normal epithelia, but in AB, there was more negative expression, MMP -2 was expressed in the 28/41 cases of AB, the expression of MMP - 9 was stronger than MMP - 2 expression in AB. Therefore, the breaking of balance system MMPs/ TIMPs was th...
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