Brief Article
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World J Gastroenterol. Jan 14, 2011; 17(2): 219-225
Published online Jan 14, 2011. doi: 10.3748/wjg.v17.i2.219
Angiogenic markers endoglin and vascular endothelial growth factor in gastroenteropancreatic neuroendocrine tumors
Patricia Kuiper, Lukas JAC Hawinkels, Eveline SM de Jonge-Muller, Izäk Biemond, Cornelis BHW Lamers, Hein W Verspaget
Patricia Kuiper, Eveline SM de Jonge-Muller, Izäk Biemond, Cornelis BHW Lamers, Hein W Verspaget, Department of Gastroenterology and Hepatology, Leiden University Medical Centre, 2300 RC Leiden, The Netherlands
Lukas JAC Hawinkels, Department of Molecular Cell Biology and Centre for Biomedical Genetics, Leiden University Medical Centre, 2300 RC Leiden, The Netherlands
Author contributions: Kuiper P and Verspaget HW designed the research; Kuiper P, de Jonge-Muller ESM and Hawinkels LJAC performed the research; Kuiper P, Biemond I, Hawinkels LJAC, Lamers CBHW and Verspaget HW analyzed the data; Kuiper P and Verspaget HW wrote the paper; Biemond I, Lamers CBHW and Verspaget HW supervised the research.
Supported by Centre for Biomedical Genetics and Dutch Cancer Society RUL2005-3371 (Hawinkels LJAC)
Correspondence to: Patricia Kuiper, MD, Department of Gastroenterology and Hepatology, Leiden University Medical Center, Building 1, D4-29, PO Box 9600, 2300 RC Leiden, The Netherlands. p.kuiper@lumc.nl
Telephone: +31-71-5265718 Fax: +31-71-5248115
Received: August 26, 2010
Revised: September 9, 2010
Accepted: September 16, 2010
Published online: January 14, 2011
Abstract

AIM: To investigate the expression and potential prognostic role of vascular endothelial growth factor (VEGF) and endoglin in gastroenteropancreatic neuroendocrine tumors (GEP-NETs).

METHODS: Microvessel density (MVD) in GEP-NETs was evaluated using endoglin and CD31 immunohistochemistry. In addition, tissue levels of endoglin and VEGF were determined in homogenates by ELISA.

RESULTS: Endoglin was highly expressed on tumor endothelial cells. CD31 MVD in GEP-NETs was significantly higher compared to endoglin MVD (P < 0.01). Two- to four-fold higher tissue levels of endoglin and VEGF were seen in tumors compared to associated normal tissue. This increased endoglin tissue expression in tumors was significantly related to tumor size (P < 0.01), presence of metastases (P = 0.04), and a more advanced tumor stage (P = 0.02), whereas expression of VEGF was not.

CONCLUSION: We suggest that endoglin is a potential marker to indicate and predict metastases, which might be useful in the post-resection therapeutic approach of patients with GEP-NETs.

Keywords: Neuroendocrine tumor, Carcinoid tumor, Angiogenesis factors, Endoglin, Vascular endothelial growth factor