Prostate cancer is one of the most common cancers in men, and 10–20% of cases progress to a hormone-resistant form, posing a major therapeutic challenge. The microsomal prostaglandin E2 synthase-1 (mPGES-1), a key enzyme in prostaglandin E2 biosynthesis from arachidonic acid, has been predicted as a therapeutic target in suppressing prostate cancer. However, the impact of mPGES-1 on the cellular lipidome has not been systematically investigated. Here, this study applied LC-MS/MS analysis and high-spatial single-cell mass spectrometry imaging (MSI) analysis using atmospheric pressure matrix-assisted laser desorption/ionization-MSI (AP-MALDI-MSI) to investigate the role of the mPGES-1 gene in altering the lipidome of hormone-resistant DU145 prostate cancer cells. LC-MS/MS results revealed significant downregulation of phosphatidylcholine (PC) and triglyceride (TG) species, and upregulation of ceramide species in KD (stable knockdown of the mPGES-1 gene) compared to controls. Upregulation of PCs is the signature of the tumor microenvironment of prostate cancer cells, and the upregulated ceramides are associated with programmed cell death. Consistent findings were observed in high-spatial single-cell MSI analysis for PC(16:0_16:0) and PC(18:0_18:1), which were significantly (p 

Prostate cancer is one of the most common cancers in men, and 10–20% of cases progress to a hormone-resistant form, posing a major therapeutic challenge. The microsomal prostaglandin E2 synthase-1 (mP...