Terranova V P, Rohrbach D H, Martin G R
Cell. 1980 Dec;22(3):719-26. doi: 10.1016/0092-8674(80)90548-6.
Measurements of the attachment of the PAM 212 line of mouse epithelial cells to various collagen substrates show that these cells adhere preferentially to type IV, basement membrane collagen. Neither serum nor fibronectin stimulated the attachment of these cells (unlike fibroblasts) to type IV collagen. Preincubation of the PAM 212 cells with cycloheximide prevented attachment. Thus these cells do not attach by means of a macromolecule present inserum, but instead synthesize an attachment factor. Extracts of the EHS tumor, which produces an extracellular matrix containing basement membrane components, were tested for their ability to promote attachment to cycloheximide-treated PAM 212 cells. Saline extracts of the tumor stimulated the attachment of the PAM 212 cells to type IV collagen in the presence of cycloheximide. Laminin, a high molecular weight glycoprotein constituent of basement membrane, was purified from the salt extract and was found to be the active species at concentrations as low as 1-5 microgram/ml. When laminin was preincubated on plates coated with either type I, II, III, IV, or V collagen and the plates subsequently washed, high levels of attachment were seen only on type IV collagen-coated plates. Affinity purified antibody directed against laminin inhibited the attachment of PAM 212 cells to a type IV collagen substrate. Laminin appears to be a specific attachment protein for epithelial cells since it did not stimulate the attachment of fibroblasts to type I or to type IV collagen substrates. These data suggest that lamin is produced and utilized by these epithelial cells to attach to basement membrane collagen.
对小鼠上皮细胞系PAM 212与各种胶原底物的附着情况进行测量，结果表明这些细胞优先附着于IV型基底膜胶原。血清和纤连蛋白均未刺激这些细胞（与成纤维细胞不同）附着于IV型胶原。用环己酰亚胺对PAM 212细胞进行预孵育可阻止其附着。因此，这些细胞并非通过血清中存在的大分子进行附着，而是合成一种附着因子。对产生含有基底膜成分的细胞外基质的EHS肿瘤提取物促进附着于经环己酰亚胺处理的PAM 212细胞的能力进行了测试。肿瘤的盐提取物在存在环己酰亚胺的情况下刺激了PAM 212细胞附着于IV型胶原。层粘连蛋白是基底膜的一种高分子量糖蛋白成分，从盐提取物中纯化得到，发现其在低至1 - 5微克/毫升的浓度下即为活性物质。当层粘连蛋白在涂有I型、II型、III型、IV型或V型胶原的平板上预孵育，随后冲洗平板时，仅在涂有IV型胶原的平板上观察到高水平的附着。针对层粘连蛋白的亲和纯化抗体抑制了PAM 212细胞附着于IV型胶原底物。层粘连蛋白似乎是上皮细胞的一种特异性附着蛋白，因为它并未刺激成纤维细胞附着于I型或IV型胶原底物。这些数据表明这些上皮细胞产生并利用层粘连蛋白附着于基底膜胶原。
