Malignant transformation is often associated with abnormal protein glycosylation expressed, amongst others, by the accumulation of simple mucin‐type carbohydrates namely Tn and Sialyl‐Tn (STn) antigens. These are usually limited in normal tissues and their increased expression has been associated with cancer progression and poor prognosis. This study aims to evaluate the role of Tn and STn antigens in the neoplastic transformation of the canine gastric mucosa and to correlate their putative immunoexpression alterations with some pathological features. Tn and STn antigens expression were immunohistochemically evaluated in canine normal gastric mucosa (n = 3), gastric polyps (n = 9) and gastric carcinomas (n = 25), neoplastic emboli (n = 12) and metastases (n = 8). In normal gastric mucosa, Tn antigen was detected in the gastric epithelial cells, while STn antigen was absent. Similarly, all gastric polyps expressed Tn antigen, but none displayed STn antigen immunostaining. In carcinomas, Tn antigen was expressed in 96% of the cases and STn antigen in 68% of the neoplasms. STn antigen was significantly higher in carcinomas compared with normal mucosa (P < .05). No correlation was found between each antigen and the different subtypes of tumours according to WHO classification, tumour differentiation, lymph vascular invasion or metastasis. All neoplastic emboli expressed both antigens, and the expression score was similar or higher than that displayed by the neoplastic cells of the primary tumour. The high prevalence of STn antigen in gastric carcinomas compared with normal mucosa highlights the cancer‐associated nature of this antigen. Our results link STn antigen expression to neoplastic transformation and suggest that it may be a useful marker of gastric cancer progression in dogs.

中文翻译：

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犬胃组织中的 Tn 和唾液酸-Tn 抗原

恶性转化通常与异常的蛋白质糖基化有关，其中包括简单的粘蛋白型碳水化合物，即 Tn 和 Sialyl-Tn (STn) 抗原的积累。这些通常仅限于正常组织，并且它们的表达增加与癌症进展和不良预后有关。本研究旨在评估 Tn 和 STn 抗原在犬胃黏膜肿瘤转化中的作用，并将其推定的免疫表达改变与某些病理特征相关联。在犬正常胃黏膜 (n = 3)、胃息肉 (n = 9) 和胃癌 (n = 25)、肿瘤栓塞 (n = 12) 和转移瘤 (n = 8) 中，对 Tn 和 STn 抗原的表达进行了免疫组织化学评估。在正常胃黏膜中，在胃上皮细胞中检测到 Tn 抗原，而STn抗原不存在。类似地，所有胃息肉都表达了 Tn 抗原，但没有一个显示出 STn 抗原免疫染色。在癌中，Tn 抗原在 96% 的病例中表达，STn 抗原在 68% 的肿瘤中表达。与正常粘膜相比，癌中的 STn 抗原显着更高（P  < .05）。根据WHO分类、肿瘤分化、淋巴血管侵犯或转移，每种抗原与不同亚型的肿瘤之间没有发现相关性。所有肿瘤栓子都表达两种抗原，并且表达评分与原发肿瘤的肿瘤细胞显示的评分相似或更高。与正常粘膜相比，胃癌中 STn 抗原的高流行突出了该抗原的癌症相关性质。我们的结果将 STn 抗原表达与肿瘤转化联系起来，并表明它可能是犬胃癌进展的有用标志物。