Faculty of Veterinary Science, Department of Pathology and Forensic Veterinary Medicine, Szent István University, Budapest, Hungary.
Histol Histopathol. 2011 Sep;26(9):1121-6. doi: 10.14670/HH-26.1121.
Claudins, integral membrane proteins are components of the tight junction structures between epithelial and endothelial cells. These transmembrane proteins create a primary barrier to prevent paracellular transport of solutes, and also restrict the lateral diffusion of membrane lipids and proteins to maintain the cellular polarity. The aim of the present study was to characterise the expression pattern of claudin-4 tight junction molecule in canine normal pancreatic tissues and in the well-differentiated and poorly-differentiated pancreatic acinar cell carcinomas in canines.
The necropsy samples included canine intact pancreatic tissues, and canine well-differentiated and poorly-differentiated pancreatic acinar cell carcinomas samples. Claudin-4 was detected as an intense lateral membrane labelling of acinar cells in all intact pancreatic tissues. The intact epithelial cells of the different ducts were negative for the claudin-4 molecule. All primary and secondary canine well-differentiated exocrine pancreatic acinar cell carcinoma tissues showed intense apical lateral positivity for the claudin-4 molecule. All primary and secondary poorly-differentiated pancreatic acinar cell carcinoma tissues showed diffusely the loss of claudin-4 expression.
Consequently, we hypothesize that the loss of expression of claudin-4 plays a role in the progression of canine pancreatic acinar cell carcinoma and may lead to cellular detachment, disorientation and invasion of these pancreatic cancers. Furthermore, claudin-4 can be used as an immunohistochemical marker to distinguish canine well-differentiated and undifferentiated exocrine pancreatic acinar cell carcinomas.
紧密连接蛋白是上皮细胞和内皮细胞之间紧密连接结构的组成部分。这些跨膜蛋白形成了阻止溶质旁细胞转运的主要屏障，并且还限制了膜脂质和蛋白质的侧向扩散，以维持细胞极性。本研究的目的是研究犬正常胰腺组织和分化良好及分化不良的胰腺腺泡细胞癌中紧密连接分子 Claudin-4 的表达模式。
尸检样本包括犬完整的胰腺组织和犬分化良好和分化不良的胰腺腺泡细胞癌样本。 Claudin-4 在所有完整的胰腺组织中均被检测为腺泡细胞的强烈侧向膜标记。不同导管的完整上皮细胞对 Claudin-4 分子呈阴性。所有原发性和继发性分化良好的犬外分泌胰腺腺泡细胞癌组织均表现出 Claudin-4 分子的强烈顶端侧向阳性。所有原发性和继发性分化不良的胰腺腺泡细胞癌组织均表现出 Claudin-4 表达的弥漫性丧失。
因此，我们假设 Claudin-4 的表达缺失在犬胰腺腺泡细胞癌的进展中起作用，并可能导致这些胰腺癌的细胞脱落、定向丧失和侵袭。此外，Claudin-4 可用作鉴别犬分化良好和未分化的外分泌胰腺腺泡细胞癌的免疫组织化学标志物。
