TNFα regulates the localization of CD40 in lipid rafts of glioma cells

Mol Biol Rep. 2012 Sep;39(9):8695-9. doi: 10.1007/s11033-012-1726-5. Epub 2012 Jun 15.

Abstract

Resistance of glioblastoma multiforme (GBM) to TNFα induced apoptosis is attributed to NFκB activation. As TNF-receptor family member CD40 regulates NFκB activation, we investigated the role of CD40 in NFκB activation in GBM. We observed elevated CD40 levels in human glioma samples as compared to the surrounding normal tissue. Treatment with TNFα elevated CD40 levels in glioma cells and inhibition of CD40 signaling failed to abrogate TNFα induced NFκΒ activity. While TNFα increased the interaction between TRAF2/6, IκBα, IKKα/β in the CD40 signalosome, the level of CD40 in the signalosome remained unaffected upon TNFα treatment. Interestingly, TNFα decreased the spatial localization of CD40 and increased TRAF2/6 co-localization with lipid raft marker Caveolin. As localization of CD40 signalosome in lipid raft is crucial for NFκB activation, TNFα mediated decreased clustering of CD40 in lipid rafts could have possibly contributed to its non-involvement in NFκB activation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • CD40 Antigens / genetics
  • CD40 Antigens / metabolism*
  • Cell Line, Tumor
  • Enzyme Activation
  • Gene Expression Regulation, Neoplastic
  • Glioma / genetics
  • Glioma / metabolism*
  • Humans
  • Membrane Microdomains / metabolism*
  • NF-kappa B / metabolism
  • Protein Transport / drug effects
  • Tumor Necrosis Factor-alpha / metabolism*
  • Tumor Necrosis Factor-alpha / pharmacology

Substances

  • CD40 Antigens
  • NF-kappa B
  • Tumor Necrosis Factor-alpha