Ohtani H, Tabata N, Nagura H
Department of Pathology, Tohoku University School of Medicine, Sendai.
Jpn J Cancer Res. 1995 Mar;86(3):304-9. doi: 10.1111/j.1349-7006.1995.tb03055.x.
Previous reports revealed a discrepancy in gelatinase A localization in human cancers; i.e., protein localization in cancer cells and mRNA localization in stromal fibroblastic cells. To clarify this, we conducted immunoelectron microscopic study of gelatinase A in cancer and stromal cells in human gastrointestinal and skin carcinomas. Although both carcinoma cells and fibroblasts were positive for gelatinase A, the subcellular localizations were different. On immunoelectron microscopy, fibroblasts showed immunoreactivity in the lumen of the rough endoplasmic reticulum (rER) or in the cytosol on the surface of rER, demonstrating synthesis of the protein. Carcinoma cells showed diffuse deposition of gelatinase A in the cytosol, suggesting the accumulation of the antigen both in adenocarcinoma and squamous cell carcinoma. Immunoreactivity along the cell membrane was demonstrated in one case of skin carcinoma. Macrophages showed also diffuse deposition of gelatinase A in the cytosol. In conclusion, we found a qualitative difference of gelatinase A localization between carcinoma cells and fibroblasts, and concluded that carcinoma cells may not be important in the secretion of gelatinase A.
先前的报告显示，明胶酶A在人类癌症中的定位存在差异；即，蛋白质定位于癌细胞，而mRNA定位于基质成纤维细胞。为了阐明这一点，我们对人类胃肠道和皮肤癌的癌细胞和基质细胞中的明胶酶A进行了免疫电子显微镜研究。尽管癌细胞和成纤维细胞的明胶酶A均呈阳性，但亚细胞定位有所不同。在免疫电子显微镜下，成纤维细胞在粗面内质网（rER）腔内或rER表面的胞质溶胶中显示出免疫反应性，表明该蛋白的合成。癌细胞的胞质溶胶中显示出明胶酶A的弥漫性沉积，提示腺癌和鳞状细胞癌中均存在抗原积累。在一例皮肤癌中，细胞膜显示出免疫反应性。巨噬细胞的胞质溶胶中也显示出明胶酶A的弥漫性沉积。总之，我们发现癌细胞和成纤维细胞之间明胶酶A定位存在质的差异，并得出结论，癌细胞在明胶酶A的分泌中可能并不重要。
