Immunohistochemical localization of beta1,4-galactosyltransferase in human normal and neoplastic pancreatic tissues

β-1，4-半乳糖基转移酶(GalTase)是高尔基体中的一种糖基转移酶，它将半乳糖从UDP-半乳糖转移到N-乙酰氨基葡萄糖末端，形成β-1，4键。肿瘤本身的糖基转移酶的碳水化合物部分会发生不同的变化。这一过程也表明了糖基转移酶本身发生变化的可能性。因此，我们检测了抗GalTase的单抗(MAb8628)在正常和肿瘤外分泌组织中的结合模式。取自外科手术的10例正常人和II肿瘤人外分泌胰腺组织。冰冻切片与该抗体孵育。在光镜下，正常导管细胞和腺泡细胞的核上区和终末条示GalTase阳性染色。中央腺泡细胞核周区域呈阳性染色。肿瘤细胞在其核上区和终末杆处也有染色。与正常细胞相比，肿瘤细胞核上区较发达，染色较深。在电子显微镜水平上，核上区和终末分别对应于高尔基体的跨池和连接复合体(即紧密连接和粘着连接)。胰腺肿瘤性改变导致高尔基体GalTase表达增加，这可能对胰腺上皮细胞间的细胞间黏附和通讯有重要影响。该酶的测定有助于诊断胰腺外液肿瘤性改变。

beta1, 4-galactosyltransferase (GalTase) is the glycosyltransferase in the Golgi apparatus that transfers galactose from UDP-galactose to terminal N-acetylglucosamine residues in glycoconjugates with formation of beta1,4 linkage. Neoplasms undergo various changes in the carbohydrate moieties of their glycosyltransferase themselves. This process also indicates the possibility of changes in glycosyltransferase themselves. Therefore, we examined the binding pattern of a monoclonal antibody (MAb8628) against GalTase in both normal and neoplastic exocrine tissues. Ten normal and II neoplastic human exocrine pancreatic tissues obtained from surgical operations were used. Frozen sections were incubated with this antibody. Supra-nuclear regions and terminal bars of normal duct cells and acinar cells revealed positive staining for GalTase at the light microscopic level. Centroacinar cells revealed positive staining in their pen-nuclear region. Neoplastic cells were also stained in their supra-nuclear regions and terminal bars. Supra-nuclear regions were well developed in neoplastic cells and intensely stained compared with those in normal cells. The supra-nuclear regions and the terminal bars corresponded to the trans cistern of the Golgi apparatus and the junctional complex (i. e. , tight junction and adherens junction), respectively, seen at the electron microscopic level. Pancreatic neoplastic changes thus lead to an increase in the expression of GalTase in the Golgi apparatus, which increase may have an important effect on the intercelluar adhesion and communication among pancreatic epithelial cells. Measurement of this enzyme is useful for diagnois of exocnine pancreatic neoplastic change from normal tissues.