gms | German Medical Science

59th Annual Meeting of the German Society of Neurosurgery (DGNC)
3rd Joint Meeting with the Italian Neurosurgical Society (SINch)

German Society of Neurosurgery (DGNC)

1 - 4 June 2008, Würzburg

Expression of alphavbeta3 integrin in gliomas is not restricted to tumor vasculature and correlates with tumor grade

Die Expression des Integrins alphavbeta3 ist in Gliomen nicht auf Tumorgefäße beschränkt und korreliert mit dem Tumorgrad

Meeting Abstract

  • corresponding author O. Schnell - Department of Neurosurgery, Klinikum der Universität München-Großhadern, Munich, Germany
  • B. Krebs - Center for Neuropathology and Prion Research, Ludwig-Maximilians-Universität München, Munich, Germany
  • A. Beer - Department of Nuclear Medicine, Klinikum rechts der Isar, Technische Universität München, Munich, Germany
  • H. A. Kretzschmar - Center for Neuropathology and Prion Research, Ludwig-Maximilians-Universität München, Munich, Germany
  • J.-C. Tonn - Department of Neurosurgery, Klinikum der Universität München-Großhadern, Munich, Germany
  • R. H. Goldbrunner - Department of Neurosurgery, Klinikum der Universität München-Großhadern, Munich, Germany

Deutsche Gesellschaft für Neurochirurgie. Società Italiana di Neurochirurgia. 59. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC), 3. Joint Meeting mit der Italienischen Gesellschaft für Neurochirurgie (SINch). Würzburg, 01.-04.06.2008. Düsseldorf: German Medical Science GMS Publishing House; 2008. DocDI.03.08

The electronic version of this article is the complete one and can be found online at: http://www.egms.de/en/meetings/dgnc2008/08dgnc165.shtml

Published: May 30, 2008

© 2008 Schnell et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.en). You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.


Outline

Text

Objective: The integrin alpha v beta 3 (αvβ3) has been appointed a key player in the angiogenesis of malignant gliomas. However, there is still a controversy about the expression and distribution of αvβ3 integrin dependent on malignancy. The aim of our study was to assess the extent and pattern of αvβ3 integrin expression within primary glioblastomas and low grade gliomas.

Methods: Immunohistochemical staining from tumor samples (GBM: n=12; LGG: n=4) for detection of αvβ3 integrin (clone LM609) were performed simultaneously and automatically to reach a maximum of accuracy. Staining was quantified by a special imaging software, which was calibrated for this purpose to xenotransplanted human melanoma cells (M21) expressing αvβ3. Within a selected area, we measured i) the mean intensity of the immunohistochemical staining and ii) the immunohistochemically positive fraction at distinct immunohistochemical staining intensities. To further analyze the distribution of the integrin subunits αv and β3, Western Blot analysis from corresponding histological sections (GBM: n=20; LGG: n=5), was performed. The microvascular distribution to αvβ3 expression in these tumors was determined by co-staining with endothelial cell specific markers (CD31).

Results: The expression of αvβ3 was found to be significantly higher in glioblastomas than in low grade gliomas. Focal strong reactivity was restricted to glioblastomas only. Moreover, Western Blot analysis demonstrated a significant difference in the expression of the β3-integrin subunit between glioblastomas and low grade gliomas. Different glioblastomas show a very heterogeneous expression of αvβ3 integrin, which ranges from slightly to very strong integrin expression similar to highly expressing non-CNS tumors. Subsequent analysis revealed that not only endothelial cells contribute to the overall amount of αvβ3 integrin in the tumors: In many malignant gliomas, about 85 percent of the overall integrin expression was derived from glial tumor cells.

Conclusions: The presented data lead to new insights in the pattern of αvβ3 integrin in gliomas. Since anti-angiogenic therapy with integrin αvβ3-antagonists has reached clinical trials for patients with malignant gliomas, minute detection and quantification of αvβ3 integrin expression could be a prerequisite for selection of patients suitable for this kind of additional therapy.