Lipidomics profiling reveals differential alterations after FAS inhibition in 3D colon cancer cell culture models
Fries, B. D. et al. (2023) Lipidomics Profiling Reveals Differential Alterations after FAS Inhibition in 3D Colon Cancer Cell Culture Models. Journal of Proteome Research. DOI: https://doi.org/10.1021/acs.jproteome.3c00593
It is projected that by 2023, colorectal cancer (CRC) will be the third leading cause of cancer-related death. Metabolism within cancer cells such as these is quite distinct, due to rapid growth and proliferation demands. One mechanism to sustain this quick development is the de novo formation of lipids, instead of uptake from extracellular sources. This results in consistent upregulation of Fatty acid synthase (FAS), a key enzyme in the lipogenesis pathway. Fries et al. explored two generations of FAS inhibitors, cerulenin, and TVB-2640 (Denifanstat) to better understand their mechanism of action within CRC multicellular tumor spheroids. Spheroids provide many benefits over 2D cultures, such as distinct layers of cellular populations, provide better penetration efficiency for therapeutic drugs, and fit into recent legislative change moving experimental design away from animal testing.
Two different CRC spheroid models were utilized within this study- HT-29, a P53 mutant microsatellite stable cell line established from colorectal adenocarcinomas, and HCT 116, a KRAS mutant established from colorectal carcinomas. The spheroids were cultured and treated with cerulenin and TVB-2640, followed by lipidomics profiling using reversed-phase chromatography coupled to a high-resolution mass spectrometer. The CellTiter-Glo® 3D assay was utilized to assess the viability of the spheroids. The study found that cerulenin caused drastic changes to spheroid morphology and lipid droplets within CRC spheroids, while TVB-2640 led to higher abundances of polyunsaturated fatty acids (PUFAs). The increase in PUFAs in TVB-2640 exposed spheroids indicated a ferroptotic mechanism of cell death, different from the conventional apoptotic or necrotic mechanisms.
Additionally, the study investigated alterations in various lipid classes and subclasses, including glycerophospholipids, sphingolipids, and glycerolipids. The Triglyceride-Glo™ Assay was used to decipher differences in lipid concentrations observed in each spheroid. Notably, there was an upregulation of triglycerides and diacylglycerols in HCT 116 spheroids treated with both inhibitors. Also, sphingolipids, which regulate cellular signaling pathways related to growth, migration, proliferation, and cell death, showed significant upregulation of certain lipid species after cerulenin exposure in HCT 116 spheroids. The study highlights the complexity of lipidomic alterations upon FAS inhibition and suggests that these changes may have implications for the development of cancer therapies targeting lipid metabolism.
Keywords: Lipid metabolism, lipogenesis, 3D cell model, spheroid
