Jakab Csaba, Rusvai Miklós, Gálfi Péter, Mándoki Míra, Demeter Zoltán, Szabó Zoltán, Kulka Janina
Department of Pathology and Forensic Veterinary Medicine, Faculty of Veterinary Science, Szent István University, István utca 2, Budapest H-1078, Hungary.
Vet Dermatol. 2010 Jun;21(3):276-81. doi: 10.1111/j.1365-3164.2009.00798.x. Epub 2010 Feb 3.
Claudins are integral membrane proteins involved in the structure of the tight junctions found in epithelial and endothelial cells. This study evaluated the expression of claudin-5 in 67 hyperplastic and neoplastic lesions of canine hepatoid glands. These included normal hepatoid glands (n = 10), nodular hyperplasia (n = 10), adenomas (n = 12), epitheliomas (n = 15), differentiated carcinomas (n = 15) and anaplastic carcinomas (n = 15). There was intense lateral membrane expression of claudin-5 on epithelial cells from normal hepatoid glands, nodular hyperplasia and adenomas, but expression was weaker in hepatoid gland epitheliomas. Basal reserve cells from normal glands, nodular hyperplasia, adenomas and epitheliomas never expressed claudin-5. There was membrane-bound immunoreactivity for claudin-5 in selected areas of the epitheliomas where the cells exhibited typical hepatoid features. The weak expression of claudin-5 molecule in epitheliomas may nevertheless lead to cellular disorientation, detachment and invasion. Claudin-5 expression seemed to be helpful in distinguishing poorly differentiated carcinomas, differentiated carcinomas and epitheliomas of the hepatoid glands. Increased claudin-5 expression by invasive anaplastic carcinomas may facilitate invasion and metastasis through the activation of matrix metalloproteinases.
紧密连接蛋白是存在于上皮细胞和内皮细胞紧密连接结构中的整合膜蛋白。本研究评估了紧密连接蛋白-5在67例犬类肝样腺增生性和肿瘤性病变中的表达情况。这些病变包括正常肝样腺（n = 10）、结节性增生（n = 10）、腺瘤（n = 12）、上皮瘤（n = 15）、分化型癌（n = 15）和未分化癌（n = 15）。正常肝样腺、结节性增生和腺瘤的上皮细胞中紧密连接蛋白-5在细胞膜侧面呈强表达，但在肝样腺上皮瘤中表达较弱。正常腺体、结节性增生、腺瘤和上皮瘤的基底储备细胞从未表达紧密连接蛋白-5。在表现出典型肝样特征的上皮瘤的特定区域存在紧密连接蛋白-5的膜结合免疫反应性。然而，上皮瘤中紧密连接蛋白-5分子的弱表达可能导致细胞排列紊乱、脱离和侵袭。紧密连接蛋白-5的表达似乎有助于区分肝样腺的低分化癌、分化型癌和上皮瘤。侵袭性未分化癌中紧密连接蛋白-5表达增加可能通过激活基质金属蛋白酶促进侵袭和转移。
