Tissue metabolic profiling of lymph node metastasis of colorectal cancer assessed by 1H NMR

Lymph node metastasis is a decisive prognostic and therapeutic staging factor for colorectal cancer (CRC), which is one of the most prevalent types of cancer and a malignant tumor. The metabolic profiling of tissue samples from a large cohort of lymph node non-metastatic CRC patients (n=73), lymph node metastatic CRC patients (n=52) and normal controls (n=41) was performed using H-1 nuclear magnetic resonance (NMR) together with multivariate statistical analyses. Excellent separation was obtained between CRC patients and normal controls, and CRC patients were also perfectly classified according to lymph node metastasis. Forty-two distinguishing metabolites were identified, which revealed disturbance of glycolysis, glutaminolysis, fatty acid metabolism, choline metabolism and amino acids, suggesting that cellular functions in energy production, macromolecular synthesis, oxidative stress and immune escape of cancer cells are affected in CRC. In total, 10 tissue metabolites were significantly disturbed between non-metastatic and metastatic CRC patients. The present study firstly staged CRC patients by lymph node metastasis by metabolomic approach. The identified metabolites may be associated with the neoplasia, invasion and metastasis of the tumor. The results suggest the promising application of these metabolites in clinical therapy, and further understanding of the related mechanism warrants further investigation.