School of Dental Science, Trinity College Dublin, Lincoln Place, Dublin D2, D02 F859, Ireland.
Characterisation and Comparability Laboratory, NIBRT - The National Institute for Bioprocessing Research and Training, Foster Avenue, Mount Merrion, Blackrock, Co., Dublin A94 X099, Ireland.
Glycobiology. 2019 Sep 20;29(10):726-734. doi: 10.1093/glycob/cwz046.
Reliable biomarkers for oral cancer (OC) remain scarce, and routine tests for the detection of precancerous lesions are not routine in the clinical setting. This study addresses a current unmet need for more sensitive and quantitative tools for the management of OC. Whole saliva was used to identify and characterize the nature of glycans present in saliva and determine their potential as OC biomarkers. Proteins obtained from whole saliva were subjected to PNGase F enzymatic digestion. The resulting N-glycans were analyzed with weak anion exchange chromatography, exoglycosidase digestions coupled to ultra-high performance liquid chromatography and/or mass spectrometry. To determine N-glycan changes, 23 individuals with or without cancerous oral lesions were analyzed using Hydrophilic interaction ultra performance liquid chromatography (HILIC-UPLC), and peak-based area relative quantitation was performed. An abundant and complex salivary N-glycomic profile was identified. The main structures present in saliva were neutral oligosaccharides consisting of high mannose, hybrid and complex structures, followed by smaller fractions of mono and di-sialylated structures. To determine if differential N-glycosylation patterns distinguish between OC and control groups, Mann-Whitney testing and principle component analysis (PCA) were used. Eleven peaks were shown to be statistically significant (P ≤ 0.05), while PCA analysis showed segregation of the two groups based on their glycan profile. N-glycosylation changes are active in the oral carcinogenic process and may serve as biomarkers for early detection to reduce morbidity and mortality. Identifying which N-glycans contribute most in the carcinogenic process may lead to their use in the detection, prognosis and treatment of OC.
用于口腔癌（OC）的可靠生物标志物仍然稀缺，并且在临床环境中，用于检测癌前病变的常规测试并不常见。本研究针对目前对更敏感和定量的 OC 管理工具的需求。使用全唾液来鉴定和表征唾液中存在的聚糖的性质，并确定它们作为 OC 生物标志物的潜力。对全唾液中获得的蛋白质进行 PNGase F 酶消化。用弱阴离子交换色谱法分析所得 N-聚糖，并进行外切糖苷酶消化，结合超高效液相色谱和/或质谱分析。为了确定 N-糖链的变化，分析了 23 名有或没有口腔癌性病变的个体，使用亲水作用超高效液相色谱法（HILIC-UPLC），并进行基于峰的面积相对定量。确定了丰富而复杂的唾液 N-糖组学图谱。唾液中存在的主要结构是由高甘露糖、杂种和复杂结构组成的中性寡糖，其次是单和二唾液酸化结构的较小部分。为了确定差异 N-糖基化模式是否区分 OC 和对照组，使用曼-惠特尼检验和主成分分析（PCA）。有 11 个峰显示具有统计学意义（P≤0.05），而 PCA 分析显示基于其聚糖图谱的两组分离。N-糖基化变化在口腔致癌过程中很活跃，可能作为早期检测的生物标志物，以降低发病率和死亡率。确定在致癌过程中贡献最大的 N-聚糖可能导致它们在 OC 的检测、预后和治疗中的应用。
