Analysis Of MMP2 Expression In Human Gliomas And Effect Of Curcumin On Glioma Cells And HUVECs

BACKGROUND:Gliomas are the most common brain malignancy tumor and are marked by an extremely poor prognosis,despite advances in the traditional treatment.Thus,gliomas require much further research to understand the molecular and cellular clinical basis.Angiogenesis is needed in several physiological and pathological processes.The growth of solid tumors depends on new blood vessels.The most of gliomas is a kind of solid tumors which is among the best vascularized human tumors.The proliferation and invasion of them are dependent on the angiogenesis in order to acquire O2 and nutritive material.Furthermore,angiogenesis is crucial to the growth of malignant gliomas too.Therefore,antiangiogenic treatment may be a promising therapeutic modality for gliomas.But little is known about its regulatory mechanism of angiogenesis.To look for and identify a key regulator in this process may be very important.Matrix metalloproteinase -2(MMP-2) is a member of the protease family. MMP-2 is secreted by a variety of cells such as fibroblasts,Macrophages, endothelial cells and malignant cells and so on,as an inactive zymogen.Actived by activators,MMP-2 may turn into a mature enzyme.MMP-2 can not only degrade extracellular matrix,increase the gap of stromal cells in order to provide enough space for the formation of tumor blood vessels,but also can enhance the movement ability of endothelial cells,and promote angiogenesis indirectly by increasing angiogenesis factor,as well as a factor directly involved in the formation of neovascularization.So,MMP2 is expected to become a key target for the antiangiogenic therapy.At present,there are already some reports on the expression of MMP2 in kinds of tumors.But the relationship between MMP2 and angiogenesis is currently not reported in gliomas.We can only surmise that MMP2 play an important role in gliomas angiogenesis.Curcumin extracted from Curcuma longa is a kind of plant polyphenols, which is the most important ingredient to exert pharmacological effects.It is reported in recent years that the curcumin not only has traditional roles,such as antiinflammatory,antioxidant,anti human immunodeficiency virus,the protection of liver and kidney,antifibrosis,etc;but also has some new pharmacological effects,such as anticancer,antiangiogenesis.OBJECTIVE:The present study was carried out to investigate the expression of MMP2 in human glioma tissues and cells.Explore the effect of curcumin on the expression of MMP2 in glioma cells.Discuss the effect of curcumin on glioma cells and HUVEC biological characteristics.METHODS:Fresh tissues of 38 cases of glioma,including low malignance 18 (gradeⅠ～Ⅱ) and high malignance 20(gradeⅢ～Ⅳ),and fresh tissues of 7 cases of cerebral trauma were used in the present study.The expression of MMP2 mRNA by these glioma tissues was examined by RT-PCR.Another collection of these paraffin-embedded glioma specimens,were used to assess the expression status of MMP2 protein,FactorⅧand Ki-67 by immunohistochemical staining.The Ki-67 labeling index(LI) and microvessel density(MVD) were calculated.The correlation between MMP2 expression,the Ki-67 LI or the MVD and the pathological grade of glioma was investigated.Changes of the expression of MMP2 mRNA on glioma cells infected with curcumin was examined by RT-PCR.Transwell method in vitro to mimic the effect of tumor cells on endothelial cells in microecological environment of glioma in vivo.Infected with curcumin cell proliferative activity of glioma cells and HUVECs was measured by MTT assay.Adhesion and migration capability of HUVECs were evaluated by Methyl Violet staining.RESULTS:①The expression of MMP2 mRNA and protein in human gliomas was detected.MMP2 protein located in plasm of tumor cells and its expression correlated directly with the degree of malignancy(χ~2 = 3.993, P＜0.01),Ki-67 LI(r=0.661,P＜0.01) and MVD(r=0.557,P＜0.01).However,it was not detected in normal brain.②MMP2 mRNA exist in glioma cells.Effect of curcumin on the expression of glioma cells MMP2 mRNA has significant down regulation(P＜0.01).③Cell proliferation activity of glioma cells was inhibited significantly by curcumin group compared with that in negative control group(P＜0.01);Proliferative activity,migration capability were different between the two groups(P＜0.01) in culture system.CONCLUSION:1.Human glioma cells and glioma tissues can express MMP2.The level of MMP2 expression directly correlates with the degree of malignancy,Ki-67 LI and MVD.We prompt MMP2 play an important role in glioma growth, invasion.2.Curcumin can lower the expression of MMP2 mRNA.3.Curcumin can inhibit the proliferation of glioma cells.4.Curcumin can inhibit the proliferation,adhesion and migration of HUVECs.Curcumin has the role of antiangiogenesis.