Department of Pathology, G. Gennimatas Athens General Hospital, 154 Mesogeion Avenue, 115 27 Athens, Greece.
Endocr Pathol. 2011 Mar;22(1):24-30. doi: 10.1007/s12022-011-9149-8.
Somatostatin and its synthetic analogs act through five specific somatostatin receptors (sstr1-5), found on the cell membrane of various tumors, including endocrine ones. Dopamine--a known neurotransmitter--acts through five membranous dopamine receptors (D1R-D5R) which have recently been found to be expressed in endocrine tumors. We evaluated the immunohistochemical expression of the sstrs and D2R in a large series of gastroenteropancreatic neuroendocrine tumors (GEP-NETs). A total of 22 (28.94%) well-differentiated NETs (WDNETs), 6 (7.89%) WDNETs of uncertain biology, 26 (34.21%) well-differentiated neuroendocrine carcinomas, and 22 (28.94%) poorly differentiated neuroendocrine carcinomas were studied. Overall, 76.31% of the tumors were positive for different types of sstrs with variable intensity of the membranous staining whereas 36.95% were positive for D2R alone. The sstr2A was the most frequently expressed, followed by sstr2B, sstr1, and sstr5. Co-expression of sstrs and D2R was seen in 88.23% of positive tumors. The high rates of sstr2A and sstr2B and in a lower extent of sstr5 expression are of great importance for more accurate imaging, staging and targeted therapy of the disease. The co-expression of sstrs and D2R in a significant number of the studied cases offers a potential therapeutic alternative for GEP-NETs.
生长抑素及其合成类似物通过存在于各种肿瘤细胞膜上的五个特定生长抑素受体（sstr1-5）发挥作用，包括内分泌肿瘤。多巴胺——一种已知的神经递质——通过五个膜多巴胺受体（D1R-D5R）发挥作用，最近发现这些受体在内分泌肿瘤中表达。我们评估了一系列胃肠胰神经内分泌肿瘤（GEP-NETs）中 sstrs 和 D2R 的免疫组织化学表达。共有 22 例（28.94%）分化良好的神经内分泌肿瘤（WDNETs）、6 例（7.89%）生物学不确定的 WDNETs、26 例（34.21%）分化良好的神经内分泌癌和 22 例（28.94%）低分化神经内分泌癌。总体而言，76.31%的肿瘤对不同类型的 sstrs 呈阳性，膜染色强度不同，而 36.95%的肿瘤仅对 D2R 呈阳性。sstr2A 是最常表达的，其次是 sstr2B、sstr1 和 sstr5。在 88.23%的阳性肿瘤中观察到 sstrs 和 D2R 的共表达。sstr2A 和 sstr2B 的高表达率以及 sstr5 表达程度较低对疾病的更准确成像、分期和靶向治疗具有重要意义。在研究病例中，sstrs 和 D2R 的共表达为数众多，为 GEP-NETs 提供了一种潜在的治疗选择。
