Assessing fatty acid-induced lipotoxicity and its therapeutic potential in glioblastoma using stimulated Raman microscopy

Sci Rep. 2021 Apr 1;11(1):7422. doi: 10.1038/s41598-021-86789-9.

Abstract

Glioblastoma multiforme (GBM) is the most aggressive primary brain tumor. The effectiveness of traditional therapies for GBM is limited and therefore new therapies are highly desired. Previous studies show that lipid metabolism reprogramming may be a potential therapeutic target in GBM. This study aims to evaluate the therapeutic potential of free fatty acid-induced lipotoxicity for the suppression of glioma growth. U87 glioma cells are treated with three fatty acids (FAs): palmitic acid (PA), oleic acid (OA), and eicosapentaenoic acid (EPA). Uptake of the FAs and formation of lipid droplets (LDs) are imaged and quantified using a lab-built stimulated Raman scattering (SRS) microscope. Our results show that a supply of 200 µM PA, OA, and EPA leads to efficient LDs accumulation in glioma cells. We find that inhibition of triglycerides (TAGs) synthesis depletes LDs and enhances lipotoxicity, which is evidenced by the reduced cell proliferation rates. In particular, our results suggest that EPA treatment combined with depletion of LDs significantly reduces the survival rate of glioma cells by more than 50%, indicating the therapeutic potential of this approach. Future work will focus on understanding the metabolic mechanism of EPA-induced lipotoxicity to further enhance its anticancer effects.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Biomarkers
  • Brain Neoplasms
  • Cell Line, Tumor
  • Cell Survival / drug effects
  • Diacylglycerol O-Acyltransferase / metabolism
  • Fatty Acids / adverse effects
  • Fatty Acids / chemistry*
  • Fatty Acids / pharmacology*
  • Glioblastoma
  • Humans
  • Image Processing, Computer-Assisted
  • Lipid Metabolism / drug effects*
  • Lipogenesis / drug effects
  • Metabolic Networks and Pathways / drug effects
  • Microscopy, Fluorescence / methods
  • Nonlinear Optical Microscopy* / methods
  • Optical Imaging / methods

Substances

  • Biomarkers
  • Fatty Acids
  • DGAT1 protein, human
  • DGAT2 protein, human
  • Diacylglycerol O-Acyltransferase