Down-regulation of the expression of β1,4-galactosyltransferase V promotes integrin β1 maturation

In previous study, we have shown that beta 1,4-galactosyltransferase V (GaIT V) functions as a positive growth regulator in glioma. Here, we reported that down-regulation of the expression of GaIT V in SHG44 cells by transfection with antisense cDNA specifically up-regulated the expression of cell surface integrin beta I without the change of its mRNA, and with integrin beta 1 125 kDa mature form increased and 105 kDa precursor form decreased. It is well known that the N-glycans of integrins modulate the location and functions of integrins. The SHG44 cells transfected with antisense cDNA of GaIT V demonstrated decreased Golgi localization of integrin beta 1, strengthened the interaction between integrin alpha 5 and beta 1 subunit, and enhanced the adhesion ability to fibronectin and the level of focal adhesion kinase phosphorylation. Our results suggested that the down-regulation of the expression of GaIT V could promote the expression of cell surface integrin beta 1 and subsequently inhibit glioma malignant phenotype. (c) 2006 Elsevier Inc. All rights reserved.