Si Liu1, Zhiwen Huang1, Qiwei Zhang2, Yang Fu1, Liming Cheng3, Bi-Feng Liu1, Xin Liu4. 1. The Key Laboratory for Biomedical Photonics of MOE at Wuhan National Laboratory for Optoelectronics-Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China. 2. Key Laboratory of Optoelectronic Chemical Materials and Devices of Ministry of Education, Institute for Interdisciplinary Research, Institute of Environment and Health, School of Chemical and Environmental Engineering, Jianghan University, Wuhan, China. 3. Clinical Laboratory, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology (HUST), No.1095 Jie Fang Avenue, Hankou, Wuhan 430030, China. 4. The Key Laboratory for Biomedical Photonics of MOE at Wuhan National Laboratory for Optoelectronics-Hubei Bioinformatics & Molecular Imaging Key Laboratory, Systems Biology Theme, Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, China. Electronic address: xliu@mail.hust.edu.cn.
Abstract
BACKGROUD: Given the increasing morbidity and mortality of colorectal cancer (CRC), it is urgent to develop a noninvasive screening strategy for early diagnosis of CRC. Altered IgG glycosylation is associated with CRC progression, whereas the association of IgG isomeric glycosylation with CRC were not investigated. METHODS: Methylamidation of IgG N-glycans was conducted prior to PGC-based nanoLC-ESI-MS/MS analysis. Data processing was operated by a self-developed application based on MATLAB solution. Statistical analysis including K-S test, t-test, ROC curve and OPLS-DA were successively performed. Additionally, an independent set was utilized to validate the results. RESULTS: Total 28 IgG glycans and 79 compositional isomers were identified, over half of which are firstly identified so far. Statistical analysis showed that CRC associates with increase in IgG agalactosylation, decrease in IgG sialylation and fucosylation of sialylated glycans. Additionally, it was found that three compositional isomers (H3N4F1-a, H3N4F1-b and H4N3S1F1-e) could distinguish CRC and early stages from controls with an accurate area under the receiver operating characteristic curve. Significantly, these results were validated in an independent set by multivariate statistical analysis. CONCLUSIONS: This is the first comprehensively profiling of isomer-specific IgG N-glycosylation, which could differentiate normal controls from colorectal disease patients. The candidate IgG glyco-biomarkers provide important screening indicators for early diagnosis of CRC. GENERAL SIGNIFICANCE: Colorectal cancer progression is strongly associated with isomer-specific IgG N-glycosylation.
BACKGROUD: Given the increasing morbidity and mortality of colorectal cancer (CRC), it is urgent to develop a noninvasive screening strategy for early diagnosis of CRC. Altered IgG glycosylation is associated with CRC progression, whereas the association of IgG isomeric glycosylation with CRC were not investigated. METHODS: Methylamidation of IgG N-glycans was conducted prior to PGC-based nanoLC-ESI-MS/MS analysis. Data processing was operated by a self-developed application based on MATLAB solution. Statistical analysis including K-S test, t-test, ROC curve and OPLS-DA were successively performed. Additionally, an independent set was utilized to validate the results. RESULTS: Total 28 IgG glycans and 79 compositional isomers were identified, over half of which are firstly identified so far. Statistical analysis showed that CRC associates with increase in IgG agalactosylation, decrease in IgG sialylation and fucosylation of sialylated glycans. Additionally, it was found that three compositional isomers (H3N4F1-a, H3N4F1-b and H4N3S1F1-e) could distinguish CRC and early stages from controls with an accurate area under the receiver operating characteristic curve. Significantly, these results were validated in an independent set by multivariate statistical analysis. CONCLUSIONS: This is the first comprehensively profiling of isomer-specific IgG N-glycosylation, which could differentiate normal controls from colorectal diseasepatients. The candidate IgG glyco-biomarkers provide important screening indicators for early diagnosis of CRC. GENERAL SIGNIFICANCE: Colorectal cancer progression is strongly associated with isomer-specific IgG N-glycosylation.