By downregulating MMP-9
Related researchs have showed that EBP50 could inhibit the migration and invasion of breast cancer cells by down-regulating MMPs and interacting with β-catenin(30,33). Since FLS migration and invasion are essential steps leading to joint destruction of RA, we evaluated the effect of EBP50 on these aggressive phenotypes of FLS in vitro. The primary FLS were left untreated (CON) or transfected with LV-EBP50 or LV-Plvx for 72 h, then the migration and invasion of FLS were evaluated using the transwell assay. FLS overexpressing EBP50 displayed dramatic reduction in the number of migrating and invading cells across transwell assay (Fig. 3A-3B). As we known, the FLS could express MMPs and a variety of surface adhesion molecules to influence the migration and invasion. To study the potential mechanisms underlying the biological effect of EBP50 in FLS, the expression of β-catenin , E-cadherin , MMP2 and MMP9 were analyzed in LV-EBP50 and LV-Plvx transfected cells and untreated cells. The results have showed that protein levels of β-catenin were unchanged and E-cadherin were not expressed (Fig. 3C-3D), and the expression of MMP-9 in the EBP50-overexpressing cells were significantly decreased, whereas MMP-2 remained the same (Fig. 3E-3F-3G).These results have indicated that overexpression of EBP50 impaired both the migratory and invasive ability of FLS by downregulating MMP-9.