Parotid saliva 1H-NMR analysis for colon cancer metabolomics

Background The key priority in cancer research is the identification of molecular biomarkers to improve early diagnosis, guide prognosis, and the design of new therapeutic approaches. Saliva is a powerful diagnostic biofluid that can be used to detect systemic alterations. Aim This study aimed to investigate the parotid saliva (PS) metabolic Proton Nuclear Magnetic Resonance (1H-NMR) profile of a patient diagnosed with colon cancer, and the subsequent changes 1 year after the end of chemotherapy. Materials and methods We describe the 1H-NMRPS spectrum of a 65-year-old woman diagnosed with colon cancer (G3 pT3 pN1c) (T0), and the changes in the spectrum from PS collected 1 year after the end of chemotherapy (XELOX: capecitabine plus oxaliplatin) (T1). The data was co-analyzed with blood test cancer antigens (S-CEA; S-CA19-9) and thyroid peroxidase antibody (TPOAb) measurements obtained simultaneously in order to identify peaks and interpret the spectra. The blood cancer antigens (S-CEA; S-CA19-9) and the PS 1H-NMR peaks for fatty acids, lactate, acetate, N-acetyl sugars, citrate, tyrosine, saccharides, and formate decreased at T1 compared to T0. Whereas, the thyroid peroxidase antibody (TPOAb) blood values increased at T1 compared to T0 reflecting the changes in the 1H-NMR spectral window of 1–3.5 ppm. Conclusion PS 1H-NMR profiling identified modified metabolites that revealed cancer cells metabolism disturbances that subsequently decreased with time throughout treatment. These altered metabolites are potential biomarkers, providing a molecular diagnostic approach for clinical diagnosis, and prognosis of human colon cancer. KEYWORDS 1H-NMR analysis, colon cancer, saliva