Harris J P, Caleb M H, South M A
Cancer Res. 1975 Jul;35(7):1861-4.
Since secretory component is thought to be a normal glandular epithelial cell product, surgical specimens from patients with mammary carcinoma, an epithelial cancer, were studied with antisera to human free secretory component by indirect immunofluorescence microscopy. Normal breast tissue (10 cases) showed fluorescent epithelial cells confined to normal ducts. This was in marked contrast to ubvasive mammary carcinoma (20 cases), which showed intense staining of tumor cells and stromal cells in addition to the normal ductular epithelium. Metastases in axillary lymph nodes (2 cases) showed intense fluorescence for secretory component, whereas axillary nodes without metastases from 2 patients with breast cancer showed no fluorescence. In both normal and tumor tissue, antiimmunoglobulin A stained only ducts and subepithelial plasma cells, thus establishing that the secretory component in tumor cells was not part of an intact secretory immunoglobulin A molecule. This finding was not restricted to mammary carcinoma, since preliminary studies of colon, lung, and bladder carcinoma also demonstrated tumor cells with cytoplasmic fluorescence for secretory component. In contrast, the tumor cells in 2 cases of sarcoma, a nonepithelial cancer, did not exhibit fluorescence for secretory component.
由于分泌成分被认为是正常腺上皮细胞的产物，因此通过间接免疫荧光显微镜，用抗人游离分泌成分的抗血清对上皮癌——乳腺癌患者的手术标本进行了研究。正常乳腺组织（10例）显示荧光上皮细胞局限于正常导管。这与弥漫性乳腺癌（20例）形成鲜明对比，弥漫性乳腺癌除正常导管上皮外，肿瘤细胞和基质细胞也显示强烈染色。腋窝淋巴结转移灶（2例）显示分泌成分有强烈荧光，而2例乳腺癌患者无转移的腋窝淋巴结则无荧光。在正常组织和肿瘤组织中，抗免疫球蛋白A仅对导管和上皮下浆细胞染色，从而证实肿瘤细胞中的分泌成分不是完整分泌性免疫球蛋白A分子的一部分。这一发现并不局限于乳腺癌，因为对结肠癌、肺癌和膀胱癌的初步研究也显示肿瘤细胞胞质中有分泌成分的荧光。相比之下，2例肉瘤（一种非上皮癌）的肿瘤细胞未显示分泌成分的荧光。
