α1,3 fucosyltransferase-VII up-regulates the mRNA of α5 integrin and its biological function

✍ Scribed by Qiu-yan Wang; Ying Zhang; Zong-hou Shen; Hui-li Chen

• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: English
• Weight: 263 KB
• Volume: 104
• Category: Article
• ISSN: 0730-2312
• DOI: 10.1002/jcb.21763

✦ Synopsis

Abstract

After transfection of α1,3fucosyltransferase (FucT)‐VII cDNA into H7721 human hepatocarcinoma cells, the expression of α5, but not β1 integrin was significantly up‐regulated. This was evidenced by the increase of α5 integrin on cell surface as well as the increase of α5 mRNA and protein in the cells. However, the expressions of sialyl Lewis X (SLe^x^, the product of α1,3FucT‐VII) on both α5 and β1 integrin subunits were unchanged. Concomitantly, the tyrosine autophosphorylated FAK and dephosphorylated Src (FAK and Src involve in the signal transduction of integrin α5β1) were up‐regulated, while the Tyr‐527 phosphorylated Src was down‐regulated. The above‐mentioned alterations were correlated to the expressions of α1,3FucT‐VII in different α1,3FucT‐VII transfected H7721 cell lines. In addition, after α1,3FucT‐VII transfection, cell adhesion to fibronectin (Fn) and chemotaxic cell migration were obviously promoted. The cell adhesion could be blocked by α5 integrin antibody, and cell migration was obviously attenuated by the antibodies to both α5 integrin and SLe^x^. These findings suggest that the increased surface α5 integrin caused by the up‐regulation of α5 mRNA promotes the cell adhesion to Fn, cell migratiom, and Fn‐induced signaling of α5β1 integrin. The up‐regulation of surface SLe^x^ originated from the over expression of α1,3FucT‐VII also led to the stimulation of cell migration. This is the first time to report that α1,3FucT‐VII can regulate the mRNA expression of integrin. J. Cell. Biochem. 104: 2078–2090, 2008. © 2008 Wiley‐Liss, Inc.