Kramer R H, Vogel K G
J Natl Cancer Inst. 1984 Apr;72(4):889-99.
The extracellular matrix deposited in culture by the mouse endodermal cell line (PF HR9) was used as an experimental model to study the interactions between basement membranes and several tumorigenic and nontumorigenic cell lines, including the metastatic B16 melanoma cell sublines. Analysis by biochemical and immunologic methods indicated that the isolated HR9 extracellular matrix was composed of laminin, type IV collagen, entactin, and heparan sulfate proteoglycans--all basement membrane-specific macromolecules. Ultrastructurally, the extracellular matrix elaborated by the HR9 cells appears as a meshwork of finely fibrillar material. B16 melanoma cells were found to adhere rapidly to the isolated HR9 matrix, but significant penetration into the structure was not observed. However, the melanoma cells did induce an extensive solubilization of 35S-sulfate-labeled heparan sulfate to fragments that were approximately one-third the size of the intact heparan sulfate chains. Only the B16 melanoma sublines exhibited this unique pattern of proteoglycan degradation, which suggests that they possess an endoglycosidase specific for heparan sulfate chains. B16 melanoma cells seeded onto HR9 matrices labeled with [1H]leucine or [3H]proline caused no detectable increase in matrix protein solubilization compared to controls. The results indicate that the metastatic tumor cells degrade the proteoglycans in the HR9 matrix more readily than the other matrix proteins.
小鼠内胚层细胞系（PF HR9）在培养中沉积的细胞外基质被用作实验模型，以研究基底膜与几种致瘤和非致瘤细胞系之间的相互作用，包括转移性B16黑色素瘤细胞亚系。通过生化和免疫方法分析表明，分离出的HR9细胞外基质由层粘连蛋白、IV型胶原、巢蛋白和硫酸乙酰肝素蛋白聚糖组成——所有这些都是基底膜特异性大分子。在超微结构上，HR9细胞产生的细胞外基质表现为精细纤维状物质的网络。发现B16黑色素瘤细胞能迅速黏附于分离出的HR9基质，但未观察到其显著穿透该结构。然而，黑色素瘤细胞确实诱导了大量35S-硫酸盐标记的硫酸乙酰肝素溶解为片段，这些片段大小约为完整硫酸乙酰肝素链的三分之一。只有B16黑色素瘤亚系表现出这种独特的蛋白聚糖降解模式，这表明它们拥有一种对硫酸乙酰肝素链具有特异性的内切糖苷酶。与对照组相比，接种到用[1H]亮氨酸或[3H]脯氨酸标记的HR9基质上的B16黑色素瘤细胞未导致基质蛋白溶解有可检测到的增加。结果表明，转移性肿瘤细胞比其他基质蛋白更容易降解HR9基质中的蛋白聚糖。
