Serum N-glycome characterization and anti-carbohydrate antibody profiling in oral squamous cell carcinoma patients

Abstract

Glycosylation is a protein post translational modification which plays important role in protein function, stabilization, trafficking, and turnover. Alteration of protein glycosylation is a common phenomenon during tumor progression, migration, invasion, angiogenesis, as well as metastasis. Hence, aberrant glycan structures and the induced corresponding anti-carbohydrate antibodies are potential biomarkers for cancer diagnosis. In this study, serum N-glycomes and anti-carbohydrate antibodies from normal populations and oral squamous cell carcinoma (OSCC) patients were investigated. Total serum proteins were lyophilized and subjected to chemical reduction, alkylation and trypsin digestion. The N-glycans were released, purified, permethylated, and analyzed using MALDI-TOF-Mass spectrometry. In addition, the serum anti-carbohydrate antibody profiles were also investigated by carbohydrate microarray. We found that the relative abundances of seven N-glycans were decreased or increased in serum of OSCC with diagnostic accuracy greater than 75%. The relative abundances of total tri-antennary and tetra-antennary glycans with varying degrees of fucosylation and sialylation were also increased in serum N-glycomes of OSCC. In an independent validation group of forty-eight OCCC patients, most of the high-molecular weight serum N-glycans showed significantly high sensitivity and specificity according to the identified cutoff values. Furthermore, the serum levels of two IgM antibodies were elevated accompanied with the decreased levels of nine IgG antibodies in patient serum. Taken together, these serum N-glycans and antibodies identified in this study should be considered as the candidates of potential biomarkers for OSCC diagnosis.

Tongue Cancer Patients Can be Distinguished from Healthy Controls by Specific N‐Glycopeptides Found in Serum

“…For example, no studies describing the specific glycopeptide profiles of head and neck cancers exist. Only one study with released serum N ‐glycans (as opposed to N ‐glycopeptides in our study) in OSCC has been published . This study had only three glycan compositions common with our study:…”

Glycoproteomic identification of novel plasma biomarkers for oral cancer

“…In our previous studies we found that fucosylation and especially core-fucosylation is enhanced in oral cancer cells relative to normal gingival keratinocytes [ 22 ]. We have also identified several serum N -glycans that can serve as valuable biomarkers for oral cancer diagnosis [ 23 ]. To further identify novel biomarkers for the early diagnosis of oral cancer, corefucosylated serum glycoproteins of normal volunteers and patients were purified by lectin chromatography, and the alteration of glycoproteins was analyzed by electrophoresis and mass spectrometry.…”

Comprehensive glycoprofiling of oral tumours associatesN-glycosylation with lymph node metastasis and patient survival

“…Previous studies have investigated the glycosylation patterns in oral cancer within diverse biological specimens including in cell lines ( 12, 20 ), tumour tissues ( 24 ), saliva ( 13, 21, 25 ), blood ( 13 ), plasma ( 26 ) and serum ( 27, 28 ) in attempts to uncover changes related to cell transformation ( 12 ) and with disease progression ( 13 ). Most of those studies evaluated the total levels of specific glycans or glycan features ( 13, 21, 24, 26 ) using relatively simple analytical techniques such as lectin-based strategies ( 24, 26, 27 ) and MALDI-MS profiling ( 12, 20, 27, 28 ) not able to survey the glycoproteome in an unbiased and quantitative manner with glycan fine structure and site-specific information ( 29 ). Our study is the first to use integrated glycomics and glycoproteomics to provide detailed insights into the heterogenous N -glycoproteome of OSCC tumour tissues obtained from a valuable cohort of patients with and without lymph node metastasis, a principal prognostic factor in OSCC ( 3, 30, 31 ).…”