N-glycomic profiling as a tool to separate rectal adenomas from carcinomas

Area of Science:

• Biochemistry
• Oncology
• Glycomics

Background:

• Cell surfaces are covered by glycans, essential for cell function.
• Changes in glycosylation patterns occur during cancer development.
• Colorectal cancer requires novel biomarkers for personalized therapy.

Purpose of the Study:

• To identify and validate novel glycan biomarkers for colorectal cancer.
• To compare N-glycan profiles in rectal adenomas and carcinomas.
• To correlate glycan expression with clinical outcomes.

Main Methods:

• N-glycan profiling of adenoma and carcinoma samples using mass spectrometry.
• Enzymatic release and purification of glycans from paraffin-embedded tissues.
• Immunohistochemical analysis of selected glycan biomarkers in a large patient cohort.

Main Results:

• Carcinomas showed distinct N-glycan profiles compared to adenomas, with increased monoantennary, sialylated, pauci-mannose, and high-mannose structures.
• Differences in glycosylation were observed between early (Stage I-II) and advanced (Stage III) colorectal carcinomas.
• Elevated expression of sialyl Lewis a correlated with poor prognosis in all colorectal cancer patients.
• Elevated expression of pauci-mannose correlated with poor prognosis in advanced colorectal cancer.

Conclusions:

• Mass spectrometry identified several glycan structures associated with colorectal carcinoma.
• Pauci-mannose and sialyl Lewis a are promising prognostic biomarkers for colorectal cancer.
• The study demonstrates a viable method for translating mass spectrometry findings into immunohistochemical analysis for clinical application.