Alterations in lipid metabolism in ovarian endometriosis and combined ovarian cancer revealed by untargeted lipidomics

Ovarian endometriosis (OEMs) is a complex condition with a rising rate of incidence. This study aimed to investigate the lipid components associated with the development and progression of OEMs, and to clarify the mechanisms underlying the development of EMs. For this, serum and urine samples were selected from ten women of childbearing age with OEMs (control group), ten with BOT (BOT group), and ten with OEMs+ovarian cancer (malignant group). These samples were analyzed using untargeted ultra-performance liquid chromatography-mass spectrometry. The lipid metabolism products were compared using a multivariate partial least squares discriminant analysis (PLS-DA) to identify differences among the three groups. Further KEGG annotation was used to screen the relevant metabolic pathways. Differences in the lipid metabolite contents of the serum and urine samples from the BOT and control groups were identified, with 13 in the serum and 9 in the urine varying markedly. KEGG annotation results revealed that the arachidonic acid substitution pathway was enriched in both serum and urine, and the autophagy pathway only in the serum. There were significant differences in lipid metabolites in both the serum and urine samples of the malignant and control groups, with 81 varying significantly in serum and 6 in urine. The lipid metabolites that differed conspicuously in both serum and urine samples were phosphatidic acid and phosphatidylcholines (PC). KEGG annotation results showed that the linoleic acid pathway was enriched in both serum and urine, while the sphingolipid signaling and arachidonic acid pathways were enriched only in the serum samples. There were differences in the levels of serum and urinary lipid metabolites in the malignant and BOT group patients compared to the OEM group. These results suggest that the occurrence of OEMs in combination with ovarian cancer may be related to lipid metabolism.