R(+)-methanandamide elicits a cyclooxygenase-2-dependent mitochondrial apoptosis signaling pathway in human neuroglioma cells

Pharm Res. 2006 Jan;23(1):90-4. doi: 10.1007/s11095-005-8815-2. Epub 2006 Nov 8.


Purpose: Cannabinoids have been associated with tumor regression and apoptosis of cancer cells. Recently, we have shown that R(+)-methanandamide (R(+)-MA) induces apoptosis of H4 human neuroglioma cells via a mechanism involving de novo expression of the cyclooxygenase-2 (COX-2) enzyme. The present study investigated a possible involvement of a mitochondrial-driven pathway in this process.

Methods: Cell death was determined by the WST-1 cell viability test, and changes in apoptotic parameters [i.e., release of mitochondrial cytochrome c, activation of caspases, cleavage of poly(ADP-ribose) polymerase (PARP)] were detected by Western blotting.

Results: H4 cells treated with R(+)-MA showed typical signs of mitochondrial apoptosis, i.e., release of mitochondrial cytochrome c into the cytosol and activation of initiator caspase-9. Moreover, activation of the executor caspase-3 was observed following cannabinoid treatment. Cells were fully protected from apoptotic cell death by the caspase-3 inhibitor Ac-DEVD-CHO, indicating a crucial role for caspase-3 activation in R(+)-MA-elicited apoptosis. Furthermore, cleavage of the caspase-3 target protein PARP was registered. All of the aforementioned effects were substantially reduced by the selective COX-2 inhibitor celecoxib (1 muM) at a pharmacologically relevant, nonapoptotic concentration.

Conclusion: R(+)-MA-induced apoptosis is mediated via a mitochondrial-dependent pathway that becomes activated, at least in part, through up-regulation of the COX-2 enzyme.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects*
  • Arachidonic Acids / pharmacology*
  • Blotting, Western
  • Brain Neoplasms / pathology*
  • CHO Cells
  • Caspase 3
  • Caspase 9
  • Caspases / metabolism
  • Celecoxib
  • Cell Survival / drug effects
  • Cricetinae
  • Cyclooxygenase 2 / metabolism*
  • Cyclooxygenase 2 Inhibitors / pharmacology
  • Cytochromes c / metabolism
  • Glioma / pathology*
  • Humans
  • Mitochondria / drug effects*
  • Poly(ADP-ribose) Polymerases / metabolism
  • Pyrazoles / pharmacology
  • Signal Transduction / drug effects*
  • Sulfonamides / pharmacology


  • Arachidonic Acids
  • Cyclooxygenase 2 Inhibitors
  • Pyrazoles
  • Sulfonamides
  • methanandamide
  • Cytochromes c
  • Cyclooxygenase 2
  • Poly(ADP-ribose) Polymerases
  • CASP3 protein, human
  • CASP9 protein, human
  • Caspase 3
  • Caspase 9
  • Caspases
  • Celecoxib