A Vasoactive Intestinal Peptide Antagonist Inhibits the Growth of Glioblastoma Cells

J Mol Neurosci. 2001 Dec;17(3):331-9. doi: 10.1385/jmn:17:3:331.

Abstract

The effects of a vasoactive intestinal peptide (VIP) receptor antagonist (VIPhyb) on human glioblastoma cells were characterized. Pituitary adenylate cyclase activating polypeptide (125I-PACAP-27) bound with high affinity to U87, U118, and U373 cells. Specific 125I-PACAP-27 binding to U87 cells was inhibited, with high affinity, by PACAP but not VIP or VIPhyb (IC50 = 10, 1500, and 500 nM, respectively). By reverse transcriptase-polymerase chain reaction (RT-PCR), a major 305 bp band was observed indicative of PAC1 receptors. PACAP-27 caused cAMP elevation and the increase in cAMP caused by PACAP-27, was inhibited by the VIPhyb. Also, PACAP-27 caused cytosolic Ca2+ elevation in Fura-2AM loaded U87 cells and the VIPhyb inhibited this increase. Using the MTT growth assay, the VIPhyb was shown to inhibit glioblastoma growth in a concentration-dependent manner. Using a clonogenic assay in vitro, 10 microM VIPhyb significantly inhibited proliferation of U87, U118, and U373 cells. In vivo, 0.4 microg/kg VIPhyb inhibited U87 xenograft proliferation in nude mice. These results suggest that the VIPhyb antagonizes PAC1 receptors on glioblastoma cells and inhibits their proliferation.

MeSH terms

  • Animals
  • Calcium / metabolism
  • Cyclic AMP / metabolism
  • Cytosol / metabolism
  • Dose-Response Relationship, Drug
  • Glioblastoma / metabolism*
  • Humans
  • Mice
  • Mice, Nude
  • Neuropeptides / antagonists & inhibitors*
  • Neuropeptides / metabolism
  • Neurotensin / metabolism
  • Neurotensin / pharmacology*
  • Pituitary Adenylate Cyclase-Activating Polypeptide
  • Receptors, Vasoactive Intestinal Peptide / antagonists & inhibitors
  • Receptors, Vasoactive Intestinal Peptide / drug effects*
  • Receptors, Vasoactive Intestinal Peptide / metabolism
  • Recombinant Fusion Proteins / metabolism
  • Recombinant Fusion Proteins / pharmacology*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Time Factors
  • Transplantation, Heterologous
  • Tumor Cells, Cultured / drug effects
  • Vasoactive Intestinal Peptide / metabolism
  • Vasoactive Intestinal Peptide / pharmacology*

Substances

  • ADCYAP1 protein, human
  • Adcyap1 protein, mouse
  • Neuropeptides
  • Pituitary Adenylate Cyclase-Activating Polypeptide
  • Receptors, Vasoactive Intestinal Peptide
  • Recombinant Fusion Proteins
  • (VIP-neurotensin) hybrid antagonist
  • Vasoactive Intestinal Peptide
  • Neurotensin
  • Cyclic AMP
  • Calcium