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Updated: Jul 3, 2026
Implantation and Evaluation of Melanoma in the Murine Choroid via Optical Coherence Tomography
Published on: December 2, 2022
Expression of the SST receptor 2 in uveal melanoma is not a prognostic marker
Mariam Kouch-el Filali1, Emine Kilic, Marleen Melis
1Department of Ophthalmology, Erasmus MC, Rotterdam, The Netherlands. m.el_filali@lumc.nl
Introduction:
Uveal melanoma (UM) cells and neurohormone-producing cells both originate from the neural crest. Somatostatin receptors subtype 2 (SSTR2) are over-expressed in several tumors, often from neuroendocrine origin, and synthetic antagonists like octreotide and octreotate are being used as diagnostic or therapeutic agents. We investigated the SSTR2 expression in UM, and determined whether this expression was related to prognosis of the disease.
Materials And Methods:
UM cell lines and fresh primary UM samples were tested for SSTR2 expression by autoradiography (AR) using 125I-Tyr3-octreotate. Furthermore, UM cell lines were analyzed for SSTR2 mRNA expression with quantitative real-time RT-PCR.
Results:
Using AR, cell-surface SSTR2 expression was demonstrated in two UM metastatic cell lines, but no expression was detected in three cell lines derived from primary UM. However, all primary and metastatic UM cell lines showed mRNA expression levels for SSTR2 using quantitative real-time RT-PCR. Only three of 14 primary UM demonstrated moderate SSTR2 expression, and this expression was not significantly associated with tumor-free survival or any tested prognostic factor.
Conclusions:
Based on the rare and low expression of SSTR2 found in primary UM specimens and in UM cell lines, we conclude that SSTR2 is not widely expressed in UM. Furthermore, SSTR2 expression was not associated with tumor-free survival and prognostic factors. Therefore SSTR2 is not suited as prognostic marker or therapeutic target in UM.
Insights
Somatostatin receptor subtype 2 (SSTR2) expression is rare in uveal melanoma (UM) and not linked to prognosis. This suggests SSTR2 is not a viable target for UM therapy or as a prognostic marker.
Area of Science:
- Oncology
- Molecular Biology
Background:
- Uveal melanoma (UM) and neuroendocrine cells share neural crest origins.
- Somatostatin receptors subtype 2 (SSTR2) are implicated in various tumors, particularly neuroendocrine ones.
- Synthetic somatostatin analogs are used in diagnostics and therapeutics.
Purpose of the Study:
- To investigate SSTR2 expression in UM.
- To determine if SSTR2 expression correlates with UM prognosis.
Main Methods:
- SSTR2 expression in UM cell lines and primary samples was assessed using autoradiography (AR) with 125I-Tyr3-octreotate.
- SSTR2 mRNA levels were quantified via real-time RT-PCR in UM cell lines.
Main Results:
- Cell-surface SSTR2 expression was detected in metastatic UM cell lines but not in primary UM cell lines via AR.
- All UM cell lines exhibited SSTR2 mRNA expression.
- Only 3 of 14 primary UM samples showed moderate SSTR2 expression, with no significant association to tumor-free survival or prognostic factors.
Conclusions:
- SSTR2 expression is infrequent and low in primary UM specimens and cell lines.
- SSTR2 expression does not correlate with tumor-free survival or prognostic factors in UM.
- SSTR2 is not a suitable prognostic marker or therapeutic target for UM.