title: In-depth N-glycome profiling of paired colorectal cancer and non-tumorigenic tissues reveals cancer-, stage- and EGFR-specific protein N-glycosylation.
abstract: Glycomics may assist in uncovering the structure-function relationships of protein glycosylation and identify glycoprotein markers in colorectal cancer (CRC) research. Herein, we performed label-free quantitative glycomics on a carbon-liquid chromatography-tandem mass spectrometry-based analytical platform to accurately profile the N-glycosylation changes associated with CRC malignancy. N-Glycome profiling was performed on isolated membrane proteomes of paired tumorigenic and adjacent non-tumorigenic colon tissues from a cohort of five males (62.6 ± 13.1 y.o.) suffering from colorectal adenocarcinoma. The CRC tissues were typed according to their epidermal growth factor receptor (EGFR) status by western blotting and immunohistochemistry. Detailed N-glycan characterization and relative quantitation identified an extensive structural heterogeneity with a total of 91 N-glycans. CRC-specific N-glycosylation phenotypes were observed including an overrepresentation of high mannose, hybrid and paucimannosidic type N-glycans and an under-representation of complex N-glycans (P < 0.05). Sialylation, in particular α2,6-sialylation, was significantly higher in CRC tumors relative to non-tumorigenic tissues, whereas α2,3-sialylation was down-regulated (P < 0.05). CRC stage-specific N-glycosylation was detected by high α2,3-sialylation and low bisecting β1,4-GlcNAcylation and Lewis-type fucosylation in mid-late relative to early stage CRC. Interestingly, a novel link between the EGFR status and the N-glycosylation was identified using hierarchical clustering of the N-glycome profiles. EGFR-specific N-glycan signatures included high bisecting β1,4-GlcNAcylation and low α2,3-sialylation (both P < 0.05) relative to EGFR-negative CRC tissues. This is the first study to correlate CRC stage and EGFR status with specific N-glycan features, thus advancing our understanding of the mechanisms causing the biomolecular deregulation associated with CRC.
authors.affiliation: Department of Chemistry and Biomolecular Sciences.
authors.forename: Manveen K
authors.initials: MK
authors.lastname: Sethi
authors.affiliation: Department of Pathology, Yonsei University College of Medicine, Seoul 120-752, Korea.
authors.forename: Hoguen
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Pathology, Yonsei University College of Medicine, Seoul 120-752, Korea.
authors.forename: Cheol Keun
authors.initials: CK
authors.lastname: Park
authors.affiliation: Department of Biomedical Sciences, Macquarie University, North Ryde NSW 2109, Australia.
authors.forename: Mark S
authors.initials: MS
authors.lastname: Baker
authors.affiliation: Yonsei Proteome Research Center, Yonsei University, Seoul 120-749, Korea.
authors.forename: Young-Ki
authors.initials: YK
authors.lastname: Paik
authors.affiliation: Department of Chemistry and Biomolecular Sciences.
authors.forename: Nicolle H
authors.initials: NH
authors.lastname: Packer
authors.affiliation: Department of Biomedical Sciences, Macquarie University, North Ryde NSW 2109, Australia Barnett Institute and Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA 02115, USA.
authors.forename: William S
authors.initials: WS
authors.lastname: Hancock
authors.affiliation: Department of Biomedical Sciences, Macquarie University, North Ryde NSW 2109, Australia.
authors.forename: Susan
authors.initials: S
authors.lastname: Fanayan
authors.affiliation: Department of Chemistry and Biomolecular Sciences morten.andersen@mq.edu.au.
authors.forename: Morten
authors.initials: M
authors.lastname: Thaysen-Andersen
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism*; D000328:Adult; D000368:Aged; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D015179:Colorectal Neoplasms / Q000378:metabolism*; D066246:ErbB Receptors / Q000378:metabolism*; D006023:Glycoproteins / Q000378:metabolism*; D006031:Glycosylation; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D011499:Protein Processing, Post-Translational; D020543:Proteome / Q000378:metabolism; D012794:Sialic Acids / Q000737:chemistry / Q000378:metabolism
chemical_list: D006023:Glycoproteins; D020543:Proteome; D012794:Sialic Acids; C512478:EGFR protein, human; D066246:ErbB Receptors
keywords: Colorectal cancer; EGFR; N-glycosylation; glycome; glycomics