gms | German Medical Science

57th Annual Meeting of the German Society of Neurosurgery
Joint Meeting with the Japanese Neurosurgical Society

German Society of Neurosurgery (DGNC)

11 - 14 May, Essen

Angiogenin – its expression pattern and functional role in human gliomas

Angiogenin – sein Expressionsmuster und die funktionelle Rolle in humanen Gliomen

Meeting Abstract

  • corresponding author B. Lemke - Department of Neurosurgery, University of Heidelberg
  • A. Huppertz - Department of Neurosurgery, University of Heidelberg
  • F. Kashfi - Department of Neurosurgery, University of Heidelberg
  • N. Ketabi - Department of Internal Medicine VI, University of Heidelberg
  • A. Unterberg - Department of Neurosurgery, University of Heidelberg
  • C. Herold-Mende - Department of Neurosurgery, University of Heidelberg

Deutsche Gesellschaft für Neurochirurgie. Japanische Gesellschaft für Neurochirurgie. 57. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie e.V. (DGNC), Joint Meeting mit der Japanischen Gesellschaft für Neurochirurgie. Essen, 11.-14.05.2006. Düsseldorf, Köln: German Medical Science; 2006. DocP 05.67

The electronic version of this article is the complete one and can be found online at: http://www.egms.de/en/meetings/dgnc2006/06dgnc284.shtml

Published: May 8, 2006

© 2006 Lemke et al.
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Outline

Text

Introduction: Malignant gliomas are hallmarked by a pronounced angiogenic activity. Angiogenin, a 14 kDa protein, is known as a potent stimulator of angiogenesis. It is expressed in cancer cells, binds to the surface of endothelial cells and promotes their invasiveness. Since there is not much known about the role of angiogenin in gliomas we assessed its expression pattern and function in these tumors.

Material and Methods:We analyzed the expression of the angiogenin mRNA in 3 established glioma cell lines, 2 endothelial cell cultures and tumor cultures derived from 19 GBM patients by RT-PCR. In 16 of the GBMs we were able to obtain several tumor areas of the same patient differing in their vascularization and thus their angiogenic activity using a preoperative dynamic MRI. Secretion of angiogenin was quantified in the respective supernatants and lysates of the native tissues. The angiogenic role of angiogenin was investigated by analyzing the proliferative response to exogenous angiogenin, neutralizing antibodies or a synthetic inhibitor. Further, effects of angiogenin on tube formation and migration of HMEC-1 cells was assessed.

Results and conclusions:In all cell cultures analyzed the angiogenin mRNA was expressed and the protein secreted into the supernatant. Angiogenin levels were 1.3x higher in glioma cultures compared to endothelial cells. As expected, angiogenin was also detectable in all tissue lysates. GBM tissues showed a 5x higher expression level compared to normal brain and noteworthy angiogenin expression was 1.8x up-regulated in highly vascularized tumor areas compared to the areas of the same GBM patient with a lower angiogenic activity.

Neither in the investigated tumor cell lines nor in the endothelial cell lines we could observe clear effects of exogenous angiogenin on proliferation, tube formation and migration, but for the inhibition of angiogenin either by neutralizing antibodies or the synthetic angiogenin inhibitory effects were seen. Future studies are needed to further elucidate the functional role of angiogenin in tumor-induced angiogenesis and to confirm angiogenin as a possible therapeutical target for an anti-angiogenic therapy in gliomas. Future studies are needed to further elucidate the functional role of angiogenin in tumor-induced angiogenesis and to confirm angiogenin as a possible therapeutical target for an anti-angiogenic therapy in gliomas.