Staffeldt Lisa, Maar Hanna, Beimdiek Julia, Chambers Samuel, Riecken Kristoffer, von Itzstein Mark, Buettner Falk F R, Everest-Dass Arun, Lange Tobias
Institute of Anatomy and Experimental Morphology, University Cancer Center Hamburg, University Medical Center Hamburg-Eppendorf, 20241, Hamburg, Germany.
Institute of Anatomy and Experimental Morphology, University Cancer Center Hamburg, University Medical Center Hamburg-Eppendorf, 20241, Hamburg, Germany; Institute of Anatomy I, Jena University Hospital, 07743, Jena, Germany; Comprehensive Cancer Center Central Germany (CCCG).
Neoplasia. 2025 Jan;59:101083. doi: 10.1016/j.neo.2024.101083. Epub 2024 Nov 14.
The commonly altered glycosylation of tumor cells is a hallmark of tumor progression and metastasis formation. One prominent example is the interaction of sialylated glycans at the tumor cell surface with endothelial (E)-selectin as an early event of an adhesion cascade that enables extravasation of circulating tumor cells (CTCs) into distant tissues. In a previous study, we identified GCNT3 (mucin-type core2/ core4 β1,6-N-acetylglucosaminyltransferase) highly over-expressed in gastrointestinal adenocarcinoma cells that facilitate the canonical E-selectin ligands sialyl-Lewis A and X (sLeA/X) for E-selectin binding and endothelial adhesion. Here we show that shRNA-mediated, stable depletion of GCNT3 reduced sLeA (tumor marker CA19-9) presentation on two out of three tested human gastrointestinal adenocarcinoma cell lines, concurrently showing reduced static E-selectin binding. Significant effects of GCNT3 depletion on dynamic, shear-resistant tumor cell adhesion on immobilized E-selectin as well as endothelial cells were only partially and inconsistently observable as were effects on tumor cell proliferation (2D) or 3D colony formation. Nevertheless, tumor cell migration was consistently reduced upon GCNT3 depletion in all tested cell lines. Detailed glycome analyses revealed that GCNT3 depletion caused cell line-specific alterations in N- and O-glycans as well as glycosphingolipids, collectively mainly associating with decreased Core-2 structures resulting in varied abundance of sialylation and Lewis antigen with consistent phenotypic changes. Distinctive N- and O-glycosylation features were found to be inherent to specific cell types. These findings suggest GCNT3 products as possible carriers of sLeA and static E-selectin binding sites as well as common pro-migratory glycans in human gastrointestinal cancer.
肿瘤细胞中常见的糖基化改变是肿瘤进展和转移形成的一个标志。一个突出的例子是肿瘤细胞表面唾液酸化聚糖与内皮（E）-选择素的相互作用，这是黏附级联反应的早期事件，可使循环肿瘤细胞（CTC）外渗至远处组织。在先前的一项研究中，我们发现GCNT3（粘蛋白型核心2/核心4β1,6-N-乙酰氨基葡萄糖转移酶）在胃肠道腺癌细胞中高度过表达，它有助于生成用于E-选择素结合和内皮黏附的经典E-选择素配体唾液酸化路易斯A和X（sLeA/X）。在此我们表明，shRNA介导的GCNT3稳定缺失降低了三种测试的人胃肠道腺癌细胞系中两种细胞系上sLeA（肿瘤标志物CA19-9）的表达，同时显示静态E-选择素结合减少。GCNT3缺失对固定化E-选择素以及内皮细胞上动态、抗剪切肿瘤细胞黏附的显著影响仅部分且不一致地观察到，对肿瘤细胞增殖（二维）或三维集落形成的影响也是如此。然而，在所有测试的细胞系中，GCNT3缺失后肿瘤细胞迁移均持续减少。详细的糖组分析表明，GCNT3缺失导致N-聚糖、O-聚糖以及糖鞘脂发生细胞系特异性改变，总体上主要与核心2结构减少相关，导致唾液酸化和路易斯抗原丰度变化以及一致的表型改变。发现特定的N-和O-糖基化特征是特定细胞类型所固有的。这些发现表明GCNT3产物可能是sLeA和静态E-选择素结合位点的载体，以及人类胃肠道癌中常见的促迁移聚糖。
