title: Direct visualization of de novo lipogenesis in single living cells.
abstract: Increased de novo lipogenesis is being increasingly recognized as a hallmark of cancer. Despite recent advances in fluorescence microscopy, autoradiography and mass spectrometry, direct observation of de novo lipogenesis in living systems remains to be challenging. Here, by coupling stimulated Raman scattering (SRS) microscopy with isotope labeled glucose, we were able to trace the dynamic metabolism of glucose in single living cells with high spatial-temporal resolution. As the first direct visualization, we observed that glucose was largely utilized for lipid synthesis in pancreatic cancer cells, which occurs at a much lower rate in immortalized normal pancreatic epithelial cells. By inhibition of glycolysis and fatty acid synthase (FAS), the key enzyme for fatty acid synthesis, we confirmed the deuterium labeled lipids in cancer cells were from de novo lipid synthesis. Interestingly, we also found that prostate cancer cells exhibit relatively lower level of de novo lipogenesis, but higher fatty acid uptake compared to pancreatic cancer cells. Together, our results demonstrate a valuable tool to study dynamic lipid metabolism in cancer and other disorders.
authors.affiliation: 1] Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907 [2] Department of Biological Sciences, Purdue University, West Lafayette, IN 47907.
authors.forename: Junjie
authors.initials: J
authors.lastname: Li
authors.affiliation: 1] Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN 47907 [2] Center for Cancer Research, Purdue University, West Lafayette, IN 47907.
authors.forename: Ji-Xin
authors.initials: JX
authors.lastname: Cheng
mesh_terms: D002460:Cell Line; D005227:Fatty Acids / Q000378:metabolism; D006801:Humans; D050356:Lipid Metabolism; D050155:Lipogenesis; D018613:Microscopy, Confocal; D057054:Molecular Imaging; D059010:Single-Cell Analysis / Q000379:methods*; D013059:Spectrum Analysis, Raman
chemical_list: D005227:Fatty Acids