Methionine sulfoxide reductase B1 regulates proliferation and invasion by affecting mitogen-activated protein kinase pathway and epithelial-mesenchymal transition in u2os cells.

Methionine sulfoxide reductase B1 (MsrB1), a member of the selenoprotein family and contributes significantly to the reduction of methionine sulfoxides produced from reactive oxygen species (ROS). However, few studies have examined the role of MsrB1 in tumors. Here We tested the proliferation and invasion in MsrB1 knockdown u2os cells under H2 O2 /thioredoxin. As shown in our result, knockdown of MsrB1 inhibited the proliferation of u2os cells and regulates mitogen-activated protein kinase (MAPK) pathway by down-regulation of Erk, MeK phosphorylation and p53 expression in u2os cells. In a xenograft tumorigenicity mice, MsrB1 knockdown effectively inhibited tumor growth. Furthermore, MsrB1 knockdown resulted in migration and invasion reducement of u2os cells. MsrB1 regulates epithelial-mesenchymal transition (EMT) via affecting cytoskeleton by increasing E-cadherin expression and decreasing N-cadherin, TGF-β1, slug, fibronectin, vimentin, c-myc, snail and β-catenin expressions. In vivo, MsrB1 shRNAi can inhibit lung metastasis in metastasis model. In conclusion, MsrB1 regulates proliferation and invasion of u2os cells by affecting MAPK pathway and EMT, and MsrB1 gene may be a novel therapeutic target against tumors.