title: N-glycosylation of colorectal cancer tissues: a liquid chromatography and mass spectrometry-based investigation.
abstract: Colorectal cancer is the third most common cancer worldwide with an annual incidence of ~1 million cases and an annual mortality rate of ~655,000 individuals. There is an urgent need for identifying novel targets to develop more sensitive, reliable, and specific tests for early stage detection of colon cancer. Post-translational modifications are known to play an important role in cancer progression and immune surveillance of tumors. In the present study, we compared the N-glycan profiles from 13 colorectal cancer tumor tissues and corresponding control colon tissues. The N-glycans were enzymatically released, purified, and labeled with 2-aminobenzoic acid. Aliquots were profiled by hydrophilic interaction liquid chromatography (HILIC-HPLC) with fluorescence detection and by negative mode MALDI-TOF-MS. Using partial least squares discriminant analysis to investigate the N-glycosylation changes in colorectal cancer, an excellent separation and prediction ability were observed for both HILIC-HPLC and MALDI-TOF-MS data. For structure elucidation, information from positive mode ESI-ion trap-MS/MS and negative mode MALDI-TOF/TOF-MS was combined. Among the features with a high separation power, structures containing a bisecting GlcNAc were found to be decreased in the tumor, whereas sulfated glycans, paucimannosidic glycans, and glycans containing a sialylated Lewis type epitope were shown to be increased in tumor tissues. In addition, core-fucosylated high mannose N-glycans were detected in tumor samples. In conclusion, the combination of HILIC and MALDI-TOF-MS profiling of N-glycans with multivariate statistical analysis demonstrated its potential for identifying N-glycosylation changes in colorectal cancer tissues and provided new leads that might be used as candidate biomarkers.
authors.affiliation: Biomolecular Mass Spectrometry Unit, Department of Parasitology, Leiden University Medical Center, Leiden, The Netherlands. C.I.A.Balog@lumc.nl
authors.forename: Crina I A
authors.initials: CI
authors.lastname: Balog
authors.forename: Kathrin
authors.initials: K
authors.lastname: Stavenhagen
authors.forename: Wesley L J
authors.initials: WL
authors.lastname: Fung
authors.forename: Carolien A
authors.initials: CA
authors.lastname: Koeleman
authors.forename: Liam A
authors.initials: LA
authors.lastname: McDonnell
authors.forename: Aswin
authors.initials: A
authors.lastname: Verhoeven
authors.forename: Wilma E
authors.initials: WE
authors.lastname: Mesker
authors.forename: Rob A E M
authors.initials: RA
authors.lastname: Tollenaar
authors.forename: André M
authors.initials: AM
authors.lastname: Deelder
authors.forename: Manfred
authors.initials: M
authors.lastname: Wuhrer
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D015179:Colorectal Neoplasms / Q000378:metabolism*; D005260:Female; D006031:Glycosylation; D006801:Humans; D008297:Male; D008358:Mannose / Q000737:chemistry; D008875:Middle Aged; D011134:Polysaccharides / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D014408:Biomarkers, Tumor; D011134:Polysaccharides; D008358:Mannose