Comparison of N-glycans expressed in tumor tissues with those expressed in adjacent non-tumor tissues of colorectal cancer patients

Abstract

Background: The associations between colorectal cancer (CRC) progression and changes in N-glycan expression suggest the potential for new biomarkers and targeted cancer therapies. This study was performed to analyze N-glycans and to compare their expression profiles in tumor and corresponding adjacent non-tumor (control) tissues in stage I and IV CRC patients to examine N-glycans as potential prognostic markers. Materials and methods: Six adult CRC patients, including 3 in stage I and 3 in stage IV who underwent curative surgery were enrolled in this study. The tumor and control tissue samples were collected during surgery. Tissue samples were analyzed using liquid chromatography-tandem mass spectrometry as well as database searching. Results: In this study, 76 N-glycans from 12 tissues of 6 CRC patients were profiled. There were 6 high mannose, 3 mannose, 1 core, 14 hybrid, 30 hybrid/complex, and 22 complex type N-glycans. There were 44 N-glycans in stage I control, 29 in stage I tumor, 43 in stage IV control, and 54 in stage IV tumor. Tumor-and stage-specific N-glycans were also identified. The relative abundance of N-glycans varied across the divided group. Conclusion: N-glycans presented only in stage I tumor from the biopsy sample for the diagnosis of CRC or in stage I control obtained during the surgery showed potential as biomarkers to predict CRC prognosis. Further high-throughput glycomic study should be performed with a larger sample size.