Lipidomic analysis of phospholipids from human mammary epithelial and breast cancer cell lines

Alterations of phospholipid (PL) profiles have been associated to disease and specific lipids may be involved in the onset and evolution of cancer; yet, analysis of PL profiles using mass spectrometry (MS) in breast cancer cells is a novel approach. Previously, we reported a lipidomic analysis of PLs from mouse mammary epithelial and breast cancer cells using off-line thin layer chromatography (TLC)-MS, where several changes in PL profile were found to be associated with the degree of malignancy of cells. In the present study, lipidomic analysis has been extended to human mammary epithelial cells and breast cancer cell lines (MCF10A, T47-D, and MDA-MB-231), using TLC-MS, validated by hydrophilic interaction liquid chromatography-MS. Differences in phosphatidylethanolamine (PE) content relative to total amount of PLs was highest in non-malignant cells while phosphatidic acid was present with highest relative abundance in metastatic cells. In addition, the following differences in PL molecular species associated to cancer phenotype, metastatic potential, and cell morphology were found: higher levels of alkylacyl PCs and phosphatidylinositol (PI; 22:5/18:0) were detected in migratory cells, epithelial cells had less unsaturated fatty acyl chains and shorter aliphatic tails in PE and sphingomyelin classes, while PI (18:0/18:1) was lowest in non-malignant cells compared to cancer cells. To date, information about PL changes in cancer progression is scarce, therefore results presented in this work will be useful as a starting point to define possible PLs with prospective as biomarkers and disclose metabolic pathways with potential for cancer therapy.