Department of Molecular Biochemistry and Clinical Investigation, Osaka University Graduate School of Medicine, Osaka 565-0871, Japan.
J Biol Chem. 2011 Aug 12;286(32):28303-11. doi: 10.1074/jbc.M111.220376. Epub 2011 Jun 22.
N-Acetylglucosaminyltransferase V (GnT-V) catalyzes the β1,6 branching of N-acetylglucosamine on N-glycans. GnT-V expression is elevated during malignant transformation in various types of cancer. However, the mechanism by which GnT-V promotes cancer progression is unclear. To characterize the biological significance of GnT-V, we established GnT-V transgenic (Tg) mice, in which GnT-V is regulated by a β-actin promoter. No spontaneous cancer was detected in any organs of the GnT-V Tg mice. However, GnT-V expression was up-regulated in GnT-V Tg mouse skin, and cultured keratinocytes derived from these mice showed enhanced migration, which was associated with changes in E-cadherin localization and epithelial-mesenchymal transition (EMT). Further, EMT-associated factors snail, twist, and N-cadherin were up-regulated, and cutaneous wound healing was accelerated in vivo. We further investigated the detailed mechanisms of EMT by assessing EGF signaling and found up-regulated EGF receptor signaling in GnT-V Tg mouse keratinocytes. These findings indicate that GnT-V overexpression promotes EMT and keratinocyte migration in part through enhanced EGF receptor signaling.
N-乙酰氨基葡萄糖基转移酶 V(GnT-V)催化 N-乙酰葡萄糖胺在 N-聚糖上的β1,6 分支。GnT-V 在各种类型癌症的恶性转化过程中表达上调。然而,GnT-V 促进癌症进展的机制尚不清楚。为了表征 GnT-V 的生物学意义,我们建立了 GnT-V 转基因(Tg)小鼠,其中 GnT-V 受β-肌动蛋白启动子调控。在 GnT-V Tg 小鼠的任何器官中都没有检测到自发的癌症。然而,GnT-V 在 GnT-V Tg 小鼠皮肤中表达上调,并且来自这些小鼠的培养角质形成细胞显示出增强的迁移能力,这与 E-钙粘蛋白定位和上皮-间充质转化(EMT)的变化有关。此外,EMT 相关因子 snail、twist 和 N-钙粘蛋白上调,体内皮肤伤口愈合加快。我们通过评估表皮生长因子(EGF)信号进一步研究了 EMT 的详细机制,发现 GnT-V Tg 小鼠角质形成细胞中 EGF 受体信号上调。这些发现表明,GnT-V 过表达通过增强 EGF 受体信号促进 EMT 和角质形成细胞迁移。