Journal of Neuro-Oncology

, Volume 40, Issue 2, pp 137–150

Verotoxins inhibit the growth of and induce apoptosis in human astrocytoma cells

  • Sara Arab
  • Masaji Murakami
  • Peter Dirks
  • Beth Boyd
  • Sherri Lynn Hubbard
  • Clifford A. Lingwood
  • Clifford A. Lingwood
  • James T. Rutka
Article

DOI: 10.1023/A:1006010019064

Cite this article as:
Arab, S., Murakami, M., Dirks, P. et al. J Neurooncol (1998) 40: 137. doi:10.1023/A:1006010019064

Abstract

Verotoxin 1 (VT1) is an E. coli toxin comprising an A subunit with N-glycanase activity, and five smaller B subunits capable of binding to the functional receptor globotriaosylceramide (Galα1-4-Galβ1-4-Glcceramide-Gb3). VT is implicated in hemorrhagic colitis and the more serious hemolytic uremic syndrome. VT1 is active against various tumor cell lines in vitro and in vivo. To extend the anti-cancer spectrum of activity of VT to human brain tumors, in the present analysis we studied the effects of VT on the growth of 6 permanent human astrocytoma cell lines. All astrocytoma cell lines analyzed express Gb3 and were sensitive to VT-1 at a dose of 50 ng/ml, but sensitivity was not proportional to the relative Gb3 concentration. VT induced apoptosis in these cells was shown by electron microscopy. Morphological evidence (nuclear shrinkage and chromatin condensation) of apoptosis could be clearly distinguished 1.5 hrs after toxin addition. Ultrastructural preservation of organelles was observed in conjunction with blebbing of the plasma membrane, condensation of chromatin within the nucleus and nuclear shrinkage. Apoptosis was also induced by the recombinant toxin B subunit alone, suggesting that the ligation of Gb3 is the primary induction mechanism. These studies indicate that verotoxin/Gb3 targetting may provide a novel basis for the inhibition of astrocytoma tumour cell growth.

glycolipid receptorglobotriaosyl ceramideα2 interferon

Copyright information

© Kluwer Academic Publishers 1998

Authors and Affiliations

  • Sara Arab
    • 1
  • Masaji Murakami
    • 1
  • Peter Dirks
    • 1
  • Beth Boyd
    • 1
  • Sherri Lynn Hubbard
    • 1
  • Clifford A. Lingwood
    • 1
  • Clifford A. Lingwood
    • 2
  • James T. Rutka
    • 1
  1. 1.Brain Tumour Research Laboratory, Department of Microbiology, Research Institute, Hospital for Sick ChildrenUniversity of TorontoCanada
  2. 2.Department of Biochemistry and MicrobiologyUniversity of TorontoCanada