This study aims to explore lipidic mechanism towards
low-density lipoprotein receptor (LDLR)-mediated
platinum chemotherapy resistance. By using the
lipid profiling technology, LDLR knockdown was found to increase lysosomal
lipids and decrease membranous
lipid levels in EOC cells. LDLR knockdown also down-regulated
ether-linked
phosphatidylethanolamine (PE-O, lysosomes or peroxisomes) and up-regulated
lysophosphatidylcholine [LPC, lipid droplet (LD)]. This implies that the manner of using Lands cycle (conversion of
lysophospholipids) for LDs might affect
cisplatin sensitivity. The bioinformatics analyses illustrated that LDLR-related
lipid entry into LD, rather than an endogenous
lipid resource (eg Kennedy pathway), controls the EOC prognosis of
platinum chemotherapy patients. Moreover, LDLR knockdown increased the number of
platinum-
DNA adducts and reduced the LD
platinum amount. By using a manufactured LPC-
liposome-
cisplatin (LLC) drug, the number of
platinum-
DNA adducts increased significantly in LLC-treated insensitive cells. Moreover, the
cisplatin content in LDs increased upon LLC treatment. Furthermore,
lipid profiles of 22
carcinoma cells with differential
cisplatin sensitivity (9 sensitive vs 13 insensitive) were acquired. These profiles revealed low storage
lipid levels in insensitive cells. This result recommends that LD lipidome might be a common pathway in multiple
cancers for
platinum sensitivity in EOC. Finally, LLC suppressed both
cisplatin-insensitive human
carcinoma cell training and testing sets. Thus, LDLR-
platinum insensitivity can be due to a defective Lands cycle that hinders LPC production in LDs. Using lipidome assessment with the newly formulated LLC can be a promising
cancer chemotherapy method.