C6-ceramide nanoliposomes target the Warburg effect in chronic lymphocytic leukemia

PLoS One. 2013 Dec 19;8(12):e84648. doi: 10.1371/journal.pone.0084648. eCollection 2013.

Abstract

Ceramide is a sphingolipid metabolite that induces cancer cell death. When C6-ceramide is encapsulated in a nanoliposome bilayer formulation, cell death is selectively induced in tumor models. However, the mechanism underlying this selectivity is unknown. As most tumors exhibit a preferential switch to glycolysis, as described in the "Warburg effect", we hypothesize that ceramide nanoliposomes selectively target this glycolytic pathway in cancer. We utilize chronic lymphocytic leukemia (CLL) as a cancer model, which has an increased dependency on glycolysis. In CLL cells, we demonstrate that C6-ceramide nanoliposomes, but not control nanoliposomes, induce caspase 3/7-independent necrotic cell death. Nanoliposomal ceramide inhibits both the RNA and protein expression of GAPDH, an enzyme in the glycolytic pathway, which is overexpressed in CLL. To confirm that ceramide targets GAPDH, we demonstrate that downregulation of GAPDH potentiates the decrease in ATP after ceramide treatment and exogenous pyruvate treatment as well as GAPDH overexpression partially rescues ceramide-induced necrosis. Finally, an in vivo murine model of CLL shows that nanoliposomal C6-ceramide treatment elicits tumor regression, concomitant with GAPDH downregulation. We conclude that selective inhibition of the glycolytic pathway in CLL cells with nanoliposomal C6-ceramide could potentially be an effective therapy for leukemia by targeting the Warburg effect.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphate / metabolism
  • Animals
  • Blotting, Western
  • Cell Death / physiology*
  • Ceramides / metabolism*
  • Ceramides / pharmacology
  • DNA Primers / genetics
  • Gene Expression Regulation, Enzymologic / drug effects
  • Gene Expression Regulation, Enzymologic / physiology*
  • Glyceraldehyde-3-Phosphate Dehydrogenases / metabolism
  • Glycolysis / physiology*
  • In Situ Nick-End Labeling
  • Leukemia, Lymphocytic, Chronic, B-Cell / drug therapy
  • Leukemia, Lymphocytic, Chronic, B-Cell / physiopathology*
  • Liposomes / metabolism*
  • Liposomes / pharmacology
  • Mice
  • Microscopy, Phase-Contrast
  • Nanoparticles / metabolism*
  • Real-Time Polymerase Chain Reaction

Substances

  • Ceramides
  • DNA Primers
  • Liposomes
  • N-hexanoyldihydrosphingosine
  • Adenosine Triphosphate
  • Glyceraldehyde-3-Phosphate Dehydrogenases