Warburton M J, Ormerod E J, Monaghan P, Ferns S, Rudland P S
J Cell Biol. 1981 Dec;91(3 Pt 1):827-36. doi: 10.1083/jcb.91.3.827.
A clonal, myoepithelial-like cell line has been obtained from a primary culture established from the mammary gland of a 7-d-old rat. In a number of respects, this cell line, termed Rama 401, resembles the myoepithelial cells of the mammary gland, especially when grown on floating collagen gels. The cells grow as multilayers on the gel surface and form branching structures that do not appear to contain a lumen. They are rather elongated, with irregular-shaped, flattened nuclei that contain large amounts of peripheral chromatin. Elongated processes project from the cell surface and numerous membrane pinocytotic vesicles can be seen. The cytoplasm is filled with linear arrays of 5- to 7-nm filaments with occasional dense foci. Cell junctions with associated 8- to 11-nm tonofilaments are also observed. Immunofluorescence techniques reveal actin and myosin filaments and also intermediate filaments of both prekeratin and vimentin types. Rama 401 cells secrete an amorphous material that, when an immunoperoxidase technique is used, stains with antibodies to basement membrane-specific type IV collagen. Localized densities of the cell membrane, which resemble hemidesmosomes, are located adjacent to these extracellular deposits. Immunofluorescence staining and immunoprecipitation techniques reveal that the cells also synthesize two other basement membrane proteins, laminin and fibronectin. The type IV collagen consists of two chains with molecular weights of 195,000 and 185,000.
从7日龄大鼠乳腺建立的原代培养物中获得了一种克隆性的肌上皮样细胞系。在许多方面，这种称为Rama 401的细胞系类似于乳腺的肌上皮细胞，尤其是在漂浮的胶原凝胶上生长时。细胞在凝胶表面呈多层生长，并形成似乎没有管腔的分支结构。它们相当细长，细胞核形状不规则且扁平，含有大量周边染色质。细长的突起从细胞表面伸出，可见许多膜结合的胞饮小泡。细胞质中充满了5至7纳米的丝状线性阵列，偶尔有致密的聚集点。还观察到带有相关8至11纳米张力丝的细胞连接。免疫荧光技术显示有肌动蛋白和肌球蛋白丝，还有前角蛋白和波形蛋白类型的中间丝。Rama 401细胞分泌一种无定形物质，当使用免疫过氧化物酶技术时，该物质用针对基底膜特异性IV型胶原的抗体染色。类似于半桥粒的细胞膜局部致密区位于这些细胞外沉积物附近。免疫荧光染色和免疫沉淀技术显示，这些细胞还合成另外两种基底膜蛋白，层粘连蛋白和纤连蛋白。IV型胶原由两条分子量分别为195,000和185,000的链组成。
