Deciphering the Metabolic Impact and Clinical Relevance of N‐Glycosylation in Colorectal Cancer through Comprehensive Glycoproteomic Profiling

Abstract Colorectal cancer (CRC) progression is driven by complex metabolic alterations, including aberrant N‐glycosylation patterns that critically influence tumor development. However, the metabolic and functional roles of N‐glycosylation in CRC remain poorly understood. Herein, comprehensive proteomic and N‐linked intact glycoproteomics analyses are performed on 45 CRC tumors, and normal adjacent tissues (NATs) are matched, identifying 7125 intact N‐glycopeptides from 704 glycoproteins. Through analysis of glycoform expression profiles and structural characteristics, a glycosylation site–protein function association network is constructed to uncover metabolic dysregulation driven by N‐glycosylation in CRC. Moreover, an arithmetic model is developed that integrates N‐glycan expression patterns, which effectively distinguishes tumors from NATs, reflecting metabolic reprogramming in cancer. These findings identify Chloride Channel Accessory 1 (CLCA1) and Olfactomedin 4 (OLFM4) as potential metabolic biomarkers for CRC diagnosis. Immunohistochemistry and Cox regression analyses validated the prognostic power of these markers. Notably, the critical role of specific N‐glycosylation at N196 of Adipocyte plasma membrane‐associated protein (APMAP) is highlighted, a key player in tumor metabolism and CRC progression, providing a potential target for therapeutic intervention. These findings offer valuable insights into the metabolic roles of N‐glycosylation in CRC, advancing biomarker discovery, enhancing metabolic‐based diagnostic precision, and improving personalized treatment strategies targeting cancer metabolism.