Department of Pathology, Johns Hopkins Medical Center, Weinberg 2268 East Baltimore Campus 401 N Broadway, Baltimore, MD 21231, USA.
Endocr Pathol. 2011 Sep;22(3):150-4. doi: 10.1007/s12022-011-9162-y.
Neuroendocrine secretory protein-55 (NESP-55) is a recently described member of the chromogranin family and appears to be a marker of the constitutive secretory pathway in certain neural, neuroendocrine, and endocrine cell types. It has been shown to be selectively expressed in tumors differentiating towards the adrenal chromaffin and pancreatic islet cell phenotypes. The highest levels of NESP-55 expression, at least in animals, appear to be in the adrenal medulla and the pituitary gland. However, very little is known about the status of NESP-55 expression in pituitary adenomas. We therefore studied the immunohistochemical profile of NESP-55 expression in a series of 30 well-characterized pituitary adenomas (five each of FSH/LH and ACTH, four GH, three TSH, seven prolactin, and six null cells). All tumors were positive for one or more generic marker(s) (chromogranin A, synaptophysin, neuron-specific enolase) of neuroendocrine differentiation. All pituitary adenomas selected for study were stained for NESP-55 with appropriate positive and negative controls. NESP-55 immunoreactivity, seen as brown finely granular cytoplasmic staining of the tumor cells with prominent perinuclear accentuation, was graded as focal (<10% tumor cells staining), moderate (10-50% tumor cells staining), and diffuse (>50% tumor cell staining). Four of seven prolactinomas were positive for NESP-55 (one focal, two moderate, and one diffuse). Two of four GH adenomas were also positive (one focal and one diffuse) while only 1/5 FSH tumors showed a moderately intense immunoreactivity. All other pituitary adenomas were completely negative for NESP-55. Our results indicate that, in human pituitary adenomas, NESP-55 has a more restricted pattern of expression than that of chromogranins A and B. Since immunohistochemical expression of NESP-55 is largely confined to prolactinomas and GH adenomas, it raises the possibility that NESP-55 may somehow be involved in the secretory pathways of these specific cell types.
神经内分泌分泌蛋白-55（NESP-55）是最近描述的一种嗜铬粒蛋白家族成员，似乎是某些神经、神经内分泌和内分泌细胞类型组成性分泌途径的标志物。已经表明它在向肾上腺嗜铬细胞和胰岛细胞表型分化的肿瘤中特异性表达。至少在动物中，NESP-55 表达水平最高的似乎是肾上腺髓质和垂体。然而，关于垂体腺瘤中 NESP-55 表达的状态知之甚少。因此，我们研究了一系列 30 个特征明确的垂体腺瘤（FSH/LH 和 ACTH 各 5 个、GH 4 个、TSH 3 个、PRL 7 个和 6 个无细胞）中 NESP-55 表达的免疫组织化学特征。所有肿瘤均对一种或多种神经内分泌分化的通用标志物（嗜铬粒蛋白 A、突触素、神经元特异性烯醇化酶）呈阳性。所有选择用于研究的垂体腺瘤均使用适当的阳性和阴性对照进行 NESP-55 染色。NESP-55 免疫反应性，表现为肿瘤细胞的棕色细颗粒细胞质染色，伴有明显的核周强调，被评为局灶性（<10%肿瘤细胞染色）、中度（10-50%肿瘤细胞染色）和弥漫性（>50%肿瘤细胞染色）。7 例催乳素瘤中有 4 例对 NESP-55 呈阳性（1 例局灶性、2 例中度、1 例弥漫性）。4 例 GH 腺瘤中有 2 例也是阳性（1 例局灶性和 1 例弥漫性），而 5 例 FSH 肿瘤中仅有 1 例显示中度强免疫反应性。所有其他垂体腺瘤均对 NESP-55 完全呈阴性。我们的结果表明，在人类垂体腺瘤中，NESP-55 的表达模式比嗜铬粒蛋白 A 和 B 更具局限性。由于 NESP-55 的免疫组织化学表达主要局限于催乳素瘤和 GH 腺瘤，这表明 NESP-55 可能以某种方式参与这些特定细胞类型的分泌途径。
