It is well established that cell surface glycans play a vital role in biological processes and their altered form can lead to carcinogenesis. Mass spectrometry–based techniques have become prominent for analysing N-linked glycans, for example using matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS). Additionally, MALDI MS can be used to spatially map N-linked glycans directly from cancer tissue using a technique termed MALDI MS imaging (MALDI MSI). This powerful technique combines mass spectrometry and histology to visualise the spatial distribution of N-linked glycans on a single tissue section. Here, we performed N-glycan MALDI MSI on six endometrial cancer (EC) formalin-fixed paraffin-embedded (FFPE) tissue sections and tissue microarrays (TMA) consisting of eight EC patients with lymph node metastasis (LNM) and twenty without LNM. By doing so, several putative N-linked glycan compositions were detected that could significantly distinguish normal from cancerous endometrium. Furthermore, a complex core-fucosylated N-linked glycan was detected that could discriminate a primary tumour with and without LNM. Structural identification of these putative N-linked glycans was performed using porous graphitized carbon liquid chromatography tandem mass spectrometry (PGC-LC-MS/MS). Overall, we observed higher abundance of oligomannose glycans in tumour compared to normal regions with AUC ranging from 0.85–0.99, and lower abundance of complex N-linked glycans with AUC ranges from 0.03–0.28. A comparison of N-linked glycans between primary tumours with and without LNM indicated a reduced abundance of a complex core-fucosylated N-glycan (Hex)₂(HexNAc)₂(Deoxyhexose)₁+(Man)₃(GlcNAc)₂, in primary tumour with associated lymph node metastasis. In summary, N-linked glycan MALDI MSI can be used to differentiate cancerous endometrium from normal, and endometrial cancer with LNM from endometrial cancer without.

众所周知，细胞表面聚糖在生物过程中起着至关重要的作用，其改变的形式可导致癌变。基于质谱的技术已成为分析N-连接聚糖的重要方法，例如使用基质辅助激光解吸/电离质谱（MALDI MS）。另外，可以使用称为MALDI MS成像（MALDI MSI）的技术，将MALDI MS直接用于从癌症组织中直接绘制N-连接聚糖的空间图。这项强大的技术结合了质谱和组织学技术，可在单个组织切片上显示N-连接聚糖的空间分布。在这里，我们执行了N-聚糖MALDI MSI对6例子宫内膜癌（EC）福尔马林固定石蜡包埋（FFPE）的组织切片和组织微阵列（TMA）的影响，其中8例EC患者伴淋巴结转移（LNM），另外20例不伴LNM。通过这样做，检测到几种可能显着区别正常子宫内膜癌和N-连接聚糖基糖的组合物。此外，检测到一个复杂的核心岩藻糖基化的N-连接聚糖，可以区分是否患有LNM的原发肿瘤。这些推定的N-使用多孔石墨化碳液相色谱串联质谱（PGC-LC-MS / MS）进行连接的聚糖。总体而言，与正常区域的AUC范围为0.85–0.99的正常区域相比，我们观察到肿瘤中低聚甘露糖聚糖的丰度更高，而AUC范围为0.03–0.28的复杂N联聚糖的丰度较低。比较具有和不具有LNM的原发肿瘤之间的N-连接聚糖，表明复杂的核心岩藻糖基化N-聚糖（Hex）₂（HexNAc）₂（Deoxyhexose）₁ +（Man）₃（GlcNAc）_2的丰度降低了。原发性肿瘤伴有淋巴结转移。总之，N-连接的聚糖MALDI MSI可用于区分正常子宫内膜癌和LNM子宫内膜癌与正常子宫内膜癌。