In Vivo and In Vitro Detection of Dopamine D2 Receptors in Uveal Melanomas

Lisa Bodei, Leo J. Hofland, Diego Ferone, Cornelia M. Mooy, Johan M. Kros, Dion A. Paridaens, Seerp G. Baarsma, Marco Ferdeghini, Martin P. Van Hagen, Eric P. Krenning, Dik J. Kwekkeboom

Research output: Contribution to journalArticle

Abstract

Scintigraphy with radiolabeled benzamides was used in melanoma patients. Studies with a newer benzamide called 123I-epidepride, a high-affinity D2 receptor (D2R) antagonist, showed high sensitivity in D2R-positive pituitary adenomas. We evaluated the presence of D2R in patients with uveal melanomas in vivo with 123I-epidepride, and in vitro in melanomas, using immunohistochemistry (IHC) and 125I-epidepride autoradiography. We studied the in vivo tumor-to-background (TB) ratios in six patients with posterior uveal melanoma (one previously enucleated). IHC was performed in 3 of 6 tumors after enucleation and in another 20 uveal melanomas, 7 metastatic lymph nodes from skin melanoma, and 2 normal specimens. 125I-epidepride autoradiography was performed in 10 uveal melanomas (3 of which were studied in vivo), 7 metastases, and 2 normal samples. Radioligand uptake was present in the affected eye of 5 patients with uveal melanoma (TB = 3.1-6.1) and absent in the operated one (TB = 1). Eight uveal tumors were positive at IHC (35%), 14 weakly positive (61%), and 1 negative (4%). Two metastases were positive (29%), 2 weakly positive (29%), and 3 negative (42%). Two uveal tumors were positive at autoradiography (20%), 7 had nonspecific binding (70%), and 1 was negative (10%). One metastasis was positive (14%), while 6 were negative (86%). 123I-epidepride scintigraphy in uveal melanomas seems promising for sensitivity and image quality. D2R was demonstrated in a significant proportion of the melanomas, although 123I-epidepride uptake might also be nonspecific and unrelated to D2R binding. Although further studies on larger series are needed, 123I-epidepride could represent a future tool to study the expression of D2R in other classes of neuroendocrine tumors.

Original languageEnglish
Pages (from-to)895-902
Number of pages8
JournalCancer Biotherapy and Radiopharmaceuticals
Volume18
Issue number6
Publication statusPublished - 2003

Keywords

  • I-epidepride
  • Autoradiography
  • D receptor
  • Immunohistochemistry
  • Melanoma

ASJC Scopus subject areas

  • Cancer Research
  • Pharmacology
  • Oncology

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  • Cite this

    Bodei, L., Hofland, L. J., Ferone, D., Mooy, C. M., Kros, J. M., Paridaens, D. A., Baarsma, S. G., Ferdeghini, M., Van Hagen, M. P., Krenning, E. P., & Kwekkeboom, D. J. (2003). In Vivo and In Vitro Detection of Dopamine D2 Receptors in Uveal Melanomas. Cancer Biotherapy and Radiopharmaceuticals, 18(6), 895-902.