Poger M E, Hirsch B R, Lamm M E
Am J Pathol. 1976 Feb;82(2):327-38.
The secretory component (SC) polypeptide chain of secretory immunoglobulin A can be considered as a differentiation marker in that it is normally synthesized in the non-mucus-containing columnar epithelial cells, but not goblet cells, of the large intestine. With this in mind, we have studied the expression of SC in 36 colonic adenocarcinomas and 15 polyps (adenomatous and villous) by the fluorescent antibody technique. As in the normal mucosa, the synthesis of SC in tumors found in non-mucus-containing columnar cells and was absent from goblet cells. However, in several well-differentiated carcinomas it appeared that columnar cells contained both SC and mucin; these cells could be analogous to the normal mucosal precursor of both cell types. SC was synthesized throughout all adenomatous polyps and villous adenomas with the exception of some atypical nonmucinous areas of adenomatous polyps. Secretory component synthesis by carcinomas was associated with mucus production, although goblet cells did not contain SC. The presence of SC also correlated with the degree of differentiation. Secretory component was absent from half of the carcinomas as well as from atypical nonmucinous areas of polyps, and this could represent one of the earliest changes associated with the development of malignancy.
分泌型免疫球蛋白A的分泌成分（SC）多肽链可被视为一种分化标志物，因为它通常在大肠不含黏液的柱状上皮细胞而非杯状细胞中合成。基于此，我们采用荧光抗体技术研究了36例结肠腺癌和15例息肉（腺瘤性和绒毛状）中SC的表达情况。与正常黏膜一样，在不含黏液的柱状细胞中发现肿瘤能合成SC，而杯状细胞中则没有。然而，在一些高分化癌中，柱状细胞似乎同时含有SC和黏蛋白；这些细胞可能类似于这两种细胞类型的正常黏膜前体细胞。除了腺瘤性息肉的一些非典型非黏液区域外，所有腺瘤性息肉和绒毛状腺瘤均能合成SC。癌组织合成SC与黏液产生有关，尽管杯状细胞不含SC。SC的存在也与分化程度相关。一半的癌组织以及息肉的非典型非黏液区域均未检测到SC，这可能是与恶性肿瘤发生相关的最早变化之一。
