LC-MS-based lipid profile in colorectal cancer patients: TAGs are the main disturbed lipid markers of colorectal cancer progression.

Colorectal cancer (CRC) is one of the most common causes of cancer-related death worldwide. Emerging evidence has shown that lipid metabolism plays important roles in the occurrence and progression of CRC. The identification of potential biomarkers for CRC progression is critical for precise diagnosis and treatment. Therefore, the aim of this study is to explore the potential lipid markers in relation to CRC progression. The plasma of patients with stage I/II CRC (n = 20) and stage III/IV CRC (n = 20) was collected. Lipidomic screening was performed by ultrahigh-performance liquid chromatography-mass spectrometry. After multivariate data analysis, including orthogonal partial least squares discriminant analysis, determination of the fold change, and the Mann-Whitney U test, eight lipid species with altered levels with p < 0.05 and fold change greater than 2 were selected as potential lipid biomarkers. Compared with patients with early-stage CRC, patients with advanced-stage CRC showed significantly higher levels of cholesteryl ester (20:4) and some triglycerides with a saturated fatty acid chain and a lower level of fatty acid ester of hydroxy fatty acid 27:1 (9:0-18:1) in plasma. Furthermore, the receiver operating characteristic including these potential lipid biomarkers yielded a sensitivity of 85% and specificity of 80% for separation of early-stage CRC patients from advanced-stage CRC patients. In all, this is the first report showing that the levels of triglycerides, the major contents of lipid droplets, increase in plasma of advanced-stage CRC patients compared with early-stage CRC patients. These data indicate that lipid droplets may be target organelles for the study of CRC progression and treatment. Graphical abstract.