Therkildsen M H, Mandel U, Christensen M, Dabelsteen E
Department of Pathology, Rigshospitalet, University of Copenhagen, Denmark.
Cancer. 1993 Aug 15;72(4):1147-54. doi: 10.1002/1097-0142(19930815)72:4<1147::aid-cncr2820720403>3.0.co;2-a.
Neoplastic transformation is associated frequently with changes in the glycosylation process. Simple mucin-type glycosylation in cancer cells has been found to be characterized by incomplete synthesis with precursor accumulation, leading to the exposure of the structures Tn and sialosyl-Tn, which are normally cryptic in human cells and secretions, including saliva and salivary glands.
Paraffin sections from 50 salivary gland carcinomas of different histologic types were investigated with immunohistologic studies and a panel of monoclonal antibodies with well-defined specificity for Tn and sialosyl-Tn.
Tn and sialosyl-Tn antigens were expressed in the cytoplasm of glandular differentiated cells; in the luminal membranes and mucinous content of the glandular differentiated areas in almost all mucoepidermoid carcinomas and adenocarcinomas; and in carcinoma in pleomorphic adenoma, when the malignant component was an adenocarcinoma. In contrast, acinic cell carcinomas and adenoid cystic carcinomas expressed only minimal amounts of Tn and sialosyl-Tn, and the staining was seen only in relation to the luminal membrane and mucin of a few glandular structures.
Mucin-type Tn and sialosyl-Tn may be regarded as markers of a glandular differentiation pattern in salivary gland carcinomas. The cellular location of the antigen-antibody complex indicates that they are synthesized and secreted from the tumor cells into saliva or serum.
肿瘤转化常与糖基化过程的改变相关。已发现癌细胞中的简单粘蛋白型糖基化的特征是合成不完全且前体积累，导致Tn和唾液酸基-Tn结构暴露，这些结构在包括唾液和唾液腺在内的人体细胞和分泌物中通常是隐蔽的。
采用免疫组织学研究及一组对Tn和唾液酸基-Tn具有明确特异性的单克隆抗体，对50例不同组织学类型的涎腺癌石蜡切片进行研究。
Tn和唾液酸基-Tn抗原在腺管分化细胞的细胞质中表达；在几乎所有黏液表皮样癌和腺癌的腺管分化区域的腔膜和黏液成分中表达；在多形性腺瘤中的癌（当恶性成分是腺癌时）中表达。相比之下，腺泡细胞癌和腺样囊性癌仅表达少量的Tn和唾液酸基-Tn，且染色仅见于少数腺管结构的腔膜和黏液。
粘蛋白型Tn和唾液酸基-Tn可被视为涎腺癌中腺管分化模式的标志物。抗原-抗体复合物的细胞定位表明它们是由肿瘤细胞合成并分泌到唾液或血清中的。
