Structural basis for GnT-V therapeutic inhibitors

描述（由申请人提供）：这些项目的长期目标 实验的目的是确定一种特定的糖基转移酶，称为 GlcNAc-T V（GnT-V）或Mgat 5，调节N-连接的寡糖表达， 引起细胞粘附和肿瘤进展变化的粘附蛋白。 研究已经证明了N-连锁的特定变化之间的关联 具有B（1，6）分支的寡糖和致癌转化，增加 肿瘤细胞侵袭性和转移潜力。B（1，6）分支的标高 在人类乳腺癌和结肠癌的进展中也有记录， 癌催化该N-连接的寡糖分支的合成 通过GlcNAc-T V，该酶的活性在 用几种致癌基因转化培养的细胞。GnT-V的转染 cDNA进入几种细胞类型导致与细胞外基质的粘附减少。 基质糖蛋白纤连蛋白和IV型胶原，表明B（1，6） 整联蛋白的分支可以改变整联蛋白配体结合亲和力。我会瞄准的 研究N-连接寡糖13（1，6） 分支调节整联蛋白配体结合。Aim II将回答这个问题： GnT-V活性的消除和N-连接（1，6）分支的表达 糖蛋白影响MMTV-neu诱导的乳腺癌形成或 进展？不表达GnT-V活性的转基因小鼠将被 与MMTV-neu小鼠杂交，分析雌性后代的肿瘤 形成、进展和转移。在Aim III中，粘合剂和信号 这些肿瘤细胞、小鼠胚胎成纤维细胞和具有 将详细研究和比较过表达的GnT-V。

DESCRIPTION(provided by applicant): The long-term objective of these experiments is to determine if a particular glycosyltransferase, termed GIcNAc-T V (GnT-V) or Mgat5, regulates N-linked oligosaccharide expression on adhesion proteins that cause changes in cell adhesion and tumor progression. Studies have documented an association between specific changes in N-linked oligosaccharides with b(1,6) branches and oncogenic transformation, increased tumor cell invasiveness, and metastatic potential. Elevation of b(1,6) branches has also been documented in the progression of human mammary and colon carcinomas. The synthesis of this N-linked oligosaccharide branch is catalyzed by GIcNAc-T V, and the activity of this enzyme is selectively increased after transformation of cultured cells with several oncogenes. Transfection of GnT-V cDNA into several cell types causes reduced adhesion to the extracellular matrix glycoproteins fibronectin and collagen type IV, suggesting that b(1,6) branching of integrins can alter integrin ligand binding affinities. Aim I will investigate the mechanisms by which changes in N-linked oligosaccharide 13(1,6) branching regulates integrin ligand binding. Aim II will answer the question: Does elimination of GnT-V activity and expression of the N-linked (1,6) branch on glycoproteins influence MMTV-neu-induced breast carcinoma formation or progression? A transgenic mouse that does not express GnT-V activity, will be crossed with the MMTV-neu mouse and the female offspring analyzed for tumor formation, progression, and metastases. In Aim Ill, the adhesive and signaling properties of these tumor cells, mouse embryo fibroblasts, and cells with over-expressed GnT-V will be studied in detail and compared.