Roles of FXR in Lipid Biochemistry within Hepatocellular Carcinoma Using MALDI MSI

Hepatocellular carcinoma (HCC) is a common type of cancer with a high mortality rate, which is affected by the farnesoid X receptor (FXR) in the liver. FXR is a ligand-activated nuclear receptor involved in lipid metabolism and homeostasis. Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) enables spatially resolved molecular analysis and is particularly suited to profiling lipid distributions within tissues. In this study, MALDI MSI was employed to investigate alterations in liver lipid composition associated with HCC and FXR expression with a focus on phosphatidylcholine (PC) species. Distinct spatial and compositional differences in PC lipids were observed between HCC and nontumorous regions. Furthermore, we hypothesize a role of PC(38:4) in HCC based on cell culture experiments in which Hep3B cells were incubated in the presence of PC(38:4).