N-glycomic Profiling as a Tool to Separate Rectal Adenomas from Carcinomas*

Abstract

All human cells are covered by glycans, the carbohydrate units of glycoproteins, glycolipids, and proteoglycans. Most glycans are localized to cell surfaces and participate in events essential for cell viability and function. Glycosylation evolves during carcinogenesis, and therefore carcinoma-related glycan structures are potential cancer biomarkers. Colorectal cancer is one of the world's three most common cancers, and its incidence is rising. Novel biomarkers are essential to identify patients for targeted and individualized therapy. We compared the N-glycan profiles of five rectal adenomas and 18 rectal carcinomas of different stages by matrix-assisted laser desorption-ionization time-of-flight mass spectrometry. Paraffin-embedded tumor samples were deparaffinized, and glycans were enzymatically released and purified. We found differences in glycosylation between adenomas and carcinomas: monoantennary, sialylated, pauci-mannose, and small high-mannose N-glycan structures were more common in carcinomas than in adenomas. We also found differences between stage I–II and stage III carcinomas. Based on these findings, we selected two glycan structures: pauci-mannose and sialyl Lewis a, for immunohistochemical analysis of their tissue expression in 220 colorectal cancer patients. In colorectal cancer, poor prognosis correlated with elevated expression of sialyl Lewis a, and in advanced colorectal cancer, poor prognosis correlated with elevated expression of pauci-mannose. In conclusion, by mass spectrometry we found several carcinoma related glycans, and we demonstrate a method of transforming these results into immunohistochemistry, a readily applicable method to study biomarker expression in patient samples.

Human protein paucimannosylation: cues from the eukaryotic kingdoms

“…Recent glycomics and glycoproteomics‐centric studies have demonstrated that PMPs are also elevated glycosylation signatures associated with various human cancers including those of ovarian (Everest‐Dass et al ., ; Chen et al ., ), colorectal (Joosten et al ., ; Balog et al ., ; Sethi et al ., ; Kaprio et al ., ; Holst et al ., ), breast (Lee et al ., ; Chen et al ., ), lung (Hua et al ., ; Ruhaak et al ., ; Wang et al ., ), paraganglioma (Leijon et al ., ), glioblastoma multiforme (Becker et al ., ), skin (Moginger et al ., ) and prostate (Shah et al ., ) origin. By systematically interrogating a very large collection of nearly 500 N ‐glycomics LC‐MS/MS data sets obtained from 11 cancer types and subtypes, we have obtained solid evidence that PMGs are significant features of human cancers and, at least in part, expressed on cancer cell surfaces (S. Chatterjee, L. Y. Lee, R. Kawahara, J. L. Abrahams, B. Adamczyk, M. Anugraham, C. Ashwood, Z. Sumer‐Bayraktar, M. T. Briggs, J. H. L. Chik, A. Everest‐Dass, S. Förster, H. Hinneburg, K. R. M. Leite, I. Loke, U. Möginger, E. S. X. Moh, M. Nakano, S. Recuero, M. K. Sethi, M. Srougi, K. Stavenhagen, V. Venkatakrishnan, K. Wongtrakul‐Kish, S. Diestel, P. Hoffmann, N. G. Karlsson, D. Kolarich, M. P. Molloy, M. H. Muders, M. K. Oehler, N. H. Packer, G. Palmisano & M. Thaysen‐Andersen, in preparation).…”

Selectin Ligands Sialyl-Lewis a and Sialyl-Lewis x in Gastrointestinal Cancers

“…Taking into account the prevalence of pancreatic cancer, the expected number of CA19.9 determinations was calculated to be 10-fold lower than the number of tests actually performed in a western country [111]. This is probably due to the assumption that serum CA19.9 values may help the differential diagnosis of several gastrointestinal diseases, including cancers arising not only in the pancreas [114,115,116], but in the colon [117], stomach [118,119], and bile ducts [120]. In this regard, it is important to recall that the synthesis, expression, and secretion of CA19.9 was demonstrated in many healthy tissues, including the pancreas [121] and the bile ducts [122].…”

Human Neutrophils Secrete Bioactive Paucimannosidic Proteins from Azurophilic Granules into Pathogen-Infected Sputum

“…Consequently, exogenous origin(s) of paucimannosylation could not be ruled out. Mammalian paucimannosylation was supported by immunohistochemistry and immunocytochemistry of selected human and murine tissues and cells using paucimannose-reactive antibodies (12)(13)(14). In general, however, mammals including human and mice have usually been reported to lack protein paucimannosylation (15)(16)(17)(18)(19)(20)(21).…”