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The thyroid cancer is one of the common malignant tumors inneck and about 1% of the systemic malignant tumors. The tumorsinvasion and metastasis is the main reason of patients death , and it’scommitted step is that the matrix metrlloproteinases damageextracellular matrix(ECM) composed by intercellular stroma andbasement membrane.ECM is made up of collagen protein ,elastin,glucoprotein,protein polysaccharide.MMP-2 and MMP-9 are twosubsets of type IV collagenase.After they are activated ,they candegrade type IV,V,VII,X collagen,glutin,elastin and fibronectin,damage extracellular matrix barrier,accelerate tumor cells to invadeand metastasize. Consequently it’s very clinic significance for theresearch of MMP-2 and MMP-9 affecting thyroid cancer invasion andmetastasis.This experiment is that expression of MMP-2 and -9 wasobserved by SP immunohistochemical technique in thyroid carcinoma(include 4 types of pathology),thyroid adenoma ,Hashimoto’sstruma,nodular goiter and normal thyroid tissue, and analyse the resultwith statistics.This experiment can substantiated that the expressintensity of MMP-2,MMP-9 in thyroid cancer increases with tumorinvasion rage extending.The more tumor cells secreteMMP-2,MMP-9,the more invade and transfer.MMP-2,MMP-9degrading matrix is benefit that tumor cells get rid of bondage ofECM and extend,this is a biochemical foundation of turmor cellsinvasion.We could discover from this experiment that the positivecells of MMP-2,MMP-9 expression between tumor and matrix aremore than in the center. This shows that MMP-2,MMP-9 aresignificant factor of turmor cells invading basement membrance andtransferring around.We also discovered the expression ofMMP-2,MMP-9 is negative or weakly positive in normal thyroidtissue beside tumor.It’s can be explained that tumor cells canexchange communication with follicular epithelial cells and interstitialcells by the some mediator, produce and accommodateMMP-2,MMP-9. MMP-2,MMP-9 may play an important role in theinvasion and metastasis of thyroid cancer.The expression level of MMP-2,MMP-9 increasing is correlativewith the happening of thyroid cancer.It’s same to the researchconsequence of Maruyama,Hofmann,Li huiyun. It’s generallyconsidered in correlative civil domestic articles that It’s highexpression in papillary thyroid carcinoma(PTC). but no much researchin other pathological types of thyroid cancer, this experiment focusedmainly on research of MMP-2 MMP-9 expression in the four commonpathological types of thyroid cancer , and concluded MMP-2,MMP-9have a high expression in papillary thyroid carcinoma,follicularthyroid carcinoma, undifferentiated thyroid carcinoma,medullarlythyroid carcinoma, but no obvious difference between them. Inaddition papillary thyroid carcinoma and follicular thyroid carcinomabelong to differentiated carcinoma,their malignant degree is belowundifferentiated thyroid carcinoma and medullarly thyroidcarcinoma,and this experiment confirms MMP-2 MMP-9 expressionin thyroid cancer is unrelated with the malignant degree oforganization. Cell differentiation refers to the process of homogeneouscells developing to another type cells with stable cell structure,physiological functions ,biochemical characteristics. Tumor cells tendto dedifferentiation, the tumor cells with poor differentiation are highmalignant degree, prognosis is poor. Studies show that the expressionof MMPs in breast cancer, colon cancer, stomach cancer and bladdercancer is associated with tumor cell differentiation.Naylor’sexperiment shows by enzymoelectrophoresis quantitative analysis thatthe expression of MMP-2 and MMP-9 in ovarian cancer isindependent of tumor cell differentiation. This is similar to theexperimental results, the reason of causing inconsistent results is notyet clear, and may be relevant to the specimens and experimentalmethods. I think the result in thyroid cancer is possible relevant tolymph node metastasis in papillary thyroid carcinoma of earlierperiod ,it’s required further study.Conclusion : (1) MMP-2 and MMP-9 have a high expression inthyroid cancer (including papillary thyroid carcinoma, follicularthyroid carcinoma, undifferentiated thyroid carcinoma, medullarlythyroid carcinoma) ,and a low expression in non-thyroid cancerorganization (thyroid adenoma ,Hashimoto’s struma, nodular goiterand normal thyroid organization. thyroid adenoma, Hashimoto’sthyroiditis), there are significant differences in the two groups;(2)MMP-2 and –9 may play an important role in the invasion andmetastasis of thyroid cancer. (3) The expression of MMP-2 andMMP-9 is not correlated to malignancy degree , the age and gender ofpatients in thyroid cancer .
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