Hyper-O-GlcNAcylation is anti-apoptotic and maintains constitutive NF-κB activity in pancreatic cancer cells

J Biol Chem. 2013 May 24;288(21):15121-30. doi: 10.1074/jbc.M113.470047. Epub 2013 Apr 16.


Cancer cell metabolic reprogramming includes a shift in energy production from oxidative phosphorylation to less efficient glycolysis even in the presence of oxygen (Warburg effect) and use of glutamine for increased biosynthetic needs. This necessitates greatly increased glucose and glutamine uptake, both of which enter the hexosamine biosynthetic pathway (HBP). The HBP end product UDP-N-acetylglucosamine (UDP-GlcNAc) is used in enzymatic post-translational modification of many cytosolic and nuclear proteins by O-linked β-N-acetylglucosamine (O-GlcNAc). Here, we observed increased HBP flux and hyper-O-GlcNAcylation in human pancreatic ductal adenocarcinoma (PDAC). PDAC hyper-O-GlcNAcylation was associated with elevation of OGT and reduction of the enzyme that removes O-GlcNAc (OGA). Reducing hyper-O-GlcNAcylation had no effect on non-transformed pancreatic epithelial cell growth, but inhibited PDAC cell proliferation, anchorage-independent growth, orthotopic tumor growth, and triggered apoptosis. PDAC is supported by oncogenic NF-κB transcriptional activity. The NF-κB p65 subunit and upstream kinases IKKα/IKKβ were O-GlcNAcylated in PDAC. Reducing hyper-O-GlcNAcylation decreased PDAC cell p65 activating phosphorylation (S536), nuclear translocation, NF-κB transcriptional activity, and target gene expression. Conversely, mimicking PDAC hyper-O-GlcNAcylation through pharmacological inhibition of OGA suppressed suspension culture-induced apoptosis and increased IKKα and p65 O-GlcNAcylation, accompanied by activation of NF-κB signaling. Finally, reducing p65 O-GlcNAcylation specifically by mutating two p65 O-GlcNAc sites (T322A and T352A) attenuated the induction of PDAC cell anchorage-independent growth. Our data indicate that hyper-O-GlcNAcylation is anti-apoptotic and contributes to NF-κB oncogenic activation in PDAC.

Keywords: Apoptosis; NF-kappa B (NF-κB); O-GlcNAc; O-GlcNAcylation; Pancreatic Cancer; Warburg Effect.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Active Transport, Cell Nucleus / genetics
  • Acylation / genetics
  • Amino Acid Substitution
  • Animals
  • Apoptosis*
  • Carcinoma, Pancreatic Ductal / genetics
  • Carcinoma, Pancreatic Ductal / metabolism*
  • Carcinoma, Pancreatic Ductal / pathology
  • Cell Line, Transformed
  • Cell Nucleus / genetics
  • Cell Nucleus / metabolism*
  • Cell Nucleus / pathology
  • Cell Proliferation
  • Gene Expression Regulation, Neoplastic*
  • Humans
  • Mice
  • Mutation, Missense
  • Neoplasm Proteins / genetics
  • Neoplasm Proteins / metabolism*
  • Pancreatic Neoplasms / genetics
  • Pancreatic Neoplasms / metabolism*
  • Pancreatic Neoplasms / pathology
  • Transcription Factor RelA / genetics
  • Transcription Factor RelA / metabolism*
  • Transcription, Genetic / genetics
  • Uridine Diphosphate N-Acetylgalactosamine / genetics
  • Uridine Diphosphate N-Acetylgalactosamine / metabolism*


  • Neoplasm Proteins
  • RELA protein, human
  • Rela protein, mouse
  • Transcription Factor RelA
  • Uridine Diphosphate N-Acetylgalactosamine