A constitutively active form of neurokinin 1 receptor and neurokinin 1 receptor-mediated apoptosis in glioblastomas

J Neurochem. 2009 May;109(4):1079-86. doi: 10.1111/j.1471-4159.2009.06032.x. Epub 2009 Mar 11.


Previous studies have shown that neurokinin 1 receptor (NK1R) occurs naturally in human glioblastomas and its stimulation causes cell proliferation. In the present study we show that stimulation of NK1R in human U373 glioblastoma cells by substance P increases Akt phosphorylation by 2.5-fold, with an EC(50) of 57 nM. Blockade of NK1R lowers basal phosphorylation of Akt, indicating the presence of a constitutively active form of NK1R; similar results are seen in U251 MG and DBTRG-05 glioblastoma cells. Linkage of NK1R to Akt implicates NK1R in apoptosis of glioblastoma cells. Indeed, treatment of serum-starved U373 cells with substance P reduces apoptosis by 53 +/- 1% (p < 0.05), and treatment with NK1R antagonist L-733,060 increases apoptosis by 64 +/- 16% (p < 0.01). Further, the blockade of NK1R in human glioblastoma cells with L-733,060 causes cleavage of Caspase-3 and proteolysis of poly (ADP-ribose) polymerase. Experiments designed to elucidate the mechanism of NK1R-mediated Akt phosphorylation revealed total involvement of non-receptor tyrosine kinase Src and phosphatidyl-3-kinase, a partial involvement of epidermal growth factor receptor, and no involvement of mitogen-activated protein/extracellular signal-related kinase. Taken together, the results of the present study indicate a key role for NK1R in glioblastoma apoptosis.

Publication types

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

MeSH terms

  • Apoptosis / drug effects
  • Apoptosis / physiology*
  • Brain Neoplasms / pathology*
  • Cell Line, Tumor
  • Culture Media, Conditioned / analysis
  • Dose-Response Relationship, Drug
  • Glioblastoma / pathology*
  • Humans
  • Immunohistochemistry
  • Neurokinin-1 Receptor Antagonists
  • Oncogene Protein v-akt / metabolism
  • Phosphorylation
  • Proto-Oncogene Proteins c-akt / metabolism
  • Receptors, Neurokinin-1 / metabolism*
  • Receptors, Neurokinin-1 / physiology*
  • Substance P / analysis
  • Substance P / pharmacology


  • Culture Media, Conditioned
  • Neurokinin-1 Receptor Antagonists
  • Receptors, Neurokinin-1
  • Substance P
  • Oncogene Protein v-akt
  • Proto-Oncogene Proteins c-akt