gms | German Medical Science

125. Kongress der Deutschen Gesellschaft für Chirurgie

Deutsche Gesellschaft für Chirurgie

22. - 25.04.2008, Berlin

Clinical impact of secreted hGBP-1

Meeting Abstract

  • corresponding author N. Gonin-Laurent - Division of Molecular and Experimental Surgery, Department of Surgery, University of Erlangen-Nürnberg, Erlangen, Germany
  • K. Lipnik - University of Veterinary Medicine, Research Institute of Virology and Biomedicine
  • E. Naschberger - Division of Molecular and Experimental Surgery, Department of Surgery, University of Erlangen-Nürnberg, Erlangen, Germany
  • N. Meyer - Division of Molecular and Experimental Surgery, Department of Surgery, University of Erlangen-Nürnberg, Erlangen, Germany
  • S. Reipschläger - Division of Molecular and Experimental Surgery, Department of Surgery, University of Erlangen-Nürnberg, Erlangen, Germany
  • C. Hohenadl - University of Veterinary Medicine, Research Institute of Virology and Biomedicine
  • W. Hohenberger - Department of Surgery, University of Erlangen-Nürnberg
  • M. Stürzl - Division of Molecular and Experimental Surgery, Department of Surgery, University of Erlangen-Nürnberg, Erlangen, Germany

Deutsche Gesellschaft für Chirurgie. 125. Kongress der Deutschen Gesellschaft für Chirurgie. Berlin, 22.-25.04.2008. Düsseldorf: German Medical Science GMS Publishing House; 2008. Doc08dgch9200

Die elektronische Version dieses Artikels ist vollständig und ist verfügbar unter: http://www.egms.de/de/meetings/dgch2008/08dgch386.shtml

Veröffentlicht: 16. April 2008

© 2008 Gonin-Laurent et al.
Dieser Artikel ist ein Open Access-Artikel und steht unter den Creative Commons Lizenzbedingungen (http://creativecommons.org/licenses/by-nc-nd/3.0/deed.de). Er darf vervielf&aauml;ltigt, verbreitet und &oauml;ffentlich zug&aauml;nglich gemacht werden, vorausgesetzt dass Autor und Quelle genannt werden.


Gliederung

Text

Introduction: The human guanylate binding protein 1 (hGBP-1) is a large GTPase which mediates the anti-proliferative and anti-angiogenic effects of pro-inflammatory cytokines (IC), such as IFNγ, TNFα and IL1α/β, on endothelial cells in vitro. In addition, it is now well established that hGBP-1 is selectively secreted from endothelial cells, via a non classical pathway.The expression of hGBP-1 has been investigated in human colorectal carcinoma (CRC). A recent and unpublished study of our laboratory showed that hGBP-1 was expressed in stromal endothelial cells of about one third of CRC. This expression was correlated with a better outcome for patients with hGBP-1 expression. In order to better characterize the in vivo anti-angiogenic and anti-tumorigenic effects of hGBP-1, we developed a tumour mouse model using a tumoral cell line which stably expresses and secretes hGBP-1.

Materials and methods: First, an expression construct based on the pMCV2.2 vector was cloned, which allows GBP-1 to be expressed under the control of the CMV promoter and to be secreted from the transfected cells. This expression construct codes for a fusion protein which consists of the human osteonectin secretion signal (Ost), an immunologically detectable Flag-Tag epitope (Flag) and full-length hGBP-1. The pMCV2.2-Ost-Flag-GBP-1 construct and the control empty vector were then stably transfected into the DLD-1 human colon carcinoma cell line which is endogenously not able to express or secrete hGBP-1. Finally, stable DLD-1 clones, which expressed and released recombinant hGBP-1, and respective control cells (transfected with the empty vector plasmid) were xenotransplanted into immunodeficient mice (Hsd:Athymic Nude-FoxN1 nu).

Results: After 36 days, tumour volumes in the Ost-Flag-hGBP-1 group were significantly smaller than in the control group (p<0.0001). This experiment was repeated with identical outcome. Immunohistochemistry stainings and Western blot analyses of the tumours showed that hGBP-1 was highly expressed in Ost-Flag-hGBP-1 tumours and absent in control tumours. The haemoglobin content of every tumour was assayed in order to determine the perfusion of the two groups of tumours and was significantly reduced in the Ost-Flag-hGBP-1 group (p<0,001).

Conclusion: These results show that hGBP-1 expression and secretion can inhibit tumour growth in an animal mouse model, what corroborates clinical data from human CRC and reinforces the importance of hGBP-1 as a usefull marker for colorectal carcinoma.