gms | German Medical Science

77. Jahresversammlung der Deutschen Gesellschaft für Hals-Nasen-Ohren-Heilkunde, Kopf- und Hals-Chirurgie e. V.

Deutsche Gesellschaft für Hals-Nasen-Ohren-Heilkunde, Kopf- und Hals-Chirurgie e. V.

24.05. - 28.05.2006, Mannheim

Erythropoietin and Erythropoietin Receptor Expression in Vestibular Schwannoma

Expression des neurotrophen Faktors Erythropoetin und seines Rezeptors im Akustikusneurinom

Meeting Abstract

German Society of Otorhinolaryngology, Head and Neck Surgery. 77th Annual Meeting of the German Society of Otorhinolaryngology, Head and Neck Surgery. Mannheim, 24.-28.05.2006. Düsseldorf, Köln: German Medical Science; 2006. Doc06hno097

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Veröffentlicht: 7. September 2006

© 2006 Diensthuber 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

Background: Erythropoietin expression is regulated by the transcription factor hypoxia-inducible factor-1a [1]. Erythropoietin signaling via erythropoietin receptor results in stimulation of cell proliferation and elevated expression of the antiapoptotic protein bcl-2 followed by inhibition of apoptosis. Erythropoietin has been shown to be associated with Schwann cell proliferation [2] and a recent report suggested a role in vestibular schwannoma growth [3].

Methods: Immunohistochemical examination of hypoxia-inducible factor-1a, erythropoietin, erythropoietin receptor and bcl-2 was performed on formalin-fixed, paraffin-embedded archival surgical specimens. Microvessel density and Ki-67-labeling index of vestibular schwannoma were determined and correlated with the immunoreactivity pattern of the examined factors.

Results: Immunoreactivity data demonstrate expression for hypoxia-inducible factor-1a, erythropoietin, erythropoietin receptor and bcl-2 in vestibular schwannoma. Sixty-six percent of the cases showed erythropoietin expression and erythropoietin receptor was found in 86% of tumor samples. A significantly positive correlation of the immunoreactivity scores of Epo/EpoR and bcl-2 expression could be noted. In case of tumor specimens with high levels of hypoxia-inducible factor-1a expression a significantly higher Ki-67-labeling index was observed.

Conclusion: Expression of erythropoietin and erythropoietin receptor might indicate a functional role in vestibular schwannoma biology. The observed correlation of Epo/EpoR and bcl-2 expression levels may suggest a proliferative and antiapototic role of the Epo/EpoR system in VS.


References

1.
Acs G, Acs P, Beckwith SM, Pitts RL, et al. Erythropoietin and erythropoietin receptor expression in human cancer. Cancer Res 2001;61:3561-5.
2.
Li X, Gonias SL, Campana WM. Schwann cells express erythropoietin receptor and represent a major target for Epo in peripheral nerve injury. Glia 2005;51:254-65.
3.
Falcioni M, Taibah A, De Donato G, et al. Fast-growing vestibular schwannoma. Skull Base Surg 2000;10:95-9