Evaluation of Somatostatin, CXCR4 Chemokine and Endothelin A Receptor Expression in a Large Series of Paragangliomas — ASN Events
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  3. Evaluation of Somatostatin, CXCR4 Chemokine and Endothelin A Receptor Expression in a Large Series of Paragangliomas

Evaluation of Somatostatin, CXCR4 Chemokine and Endothelin A Receptor Expression in a Large Series of Paragangliomas (#16)

Daniel Kaemmerer 1 , Joerg Saenger 2 , Ruza Arsenic 3 , Jan G. D'Haese 4 , Jens Neumann 5 , Aviral Singh 6 , Richard P. Baum 6 , Stefan Schulz 7 , Amelie Lupp 7
  1. Department of General and Visceral Surgery, Zentralklinik Bad Berka, Bad Berka, Germany
  2. Laboratory of Pathology and Cytology Bad Berka, Bad Berka, Germany
  3. Institute of Pathology, Charité University Hospital Berlin, Berlin, Germany
  4. Department of General, Visceral Transplantation, Vascular and Thoracic Surgery, Hospital of the University of Munich, Munich, Germany
  5. Department of Pathology, Ludwig-Maximilians-University Munich, Munich, Germany
  6. Theranostics Center for Molecular Radiotherapy and Molecular Imaging, Zentralklinik Bad Berka, Bad Berka, Germany
  7. Institute of Pharmacology and Toxicology, Jena University Hospital, Jena, Germany

Background: Paragangliomas are predominantly benign tumors, but in some cases invasive growth and also metastasis is observed. Given the limited number of nonsurgical treatment options, novel target structures for diagnostics and therapy of this tumor entity are urgently needed.

Aims: In the present study the expression of the five somatostatin receptor (SSTR) subtypes as well as of the chemokine receptor CXCR4 and of the endothelin receptor A (ETA) was evaluated.

Methods: Receptor expression was assessed by means of immunohistochemistry using a panel of novel rabbit monoclonal antibodies in a total of 54 paraffin-embedded paraganglioma tumor samples from 43 patients. The stainings were rated by means of the Immunoreactive Score and correlated to clinical data.

Results: The SSTR2 was by far the most prominent receptor in the paragangliomas investigated. It was present in all samples at a high intensity, followed by the SSTR5, the SSTR1, the SSTR3 and the SSTR4. The CXCR4 and the ETA were seen only in a few cases on the tumor cells. However, with respect to the tumor blood vessels, in all cases an exceptionally strong staining for the ETA and in the majority of the samples also for the CXCR4 was noticed.

Conclusions: Due to the high expression rate found in the present study, paragangliomas seem to be well suited for SSTR2-based diagnostics and therapies. Additionally, an indirect targeting of these highly vascularized tumors via the CXCR4 or the ETA may represent a promising future strategy.