Holzer C, Maier P, Zbinden G
Exp Cell Biol. 1986;54(5-6):237-44. doi: 10.1159/000163362.
Rat tumor cells isolated from 2 fibrosarcomas which differed in their degree of differentiation were exposed to growth-stimulating influences in soft agar. The effects of growth factors (epidermal growth factor, fibrosarcoma growth factor and insulin), of fetal calf serum and of cocultured normal mesenchymal cells of rats and nude mice were compared. Each of the 3 growth factors exerted a specific response and dose dependence. Increasing concentrations of serum stimulated the number of cells which formed clones in soft agar. Experiments using combinations of growth factors and fetal calf serum demonstrated that a complex optimal mixture of growth stimuli was responsible for the efficient growth-promoting activity of the serum. In cocultures with normal cells, cloning efficiency of tumor cells was enhanced and growth of tumor cells was accelerated. This stimulus was due to the constant release of an agar-diffusible growth-stimulating factor by the normal, nondividing cells. Cocultured mouse cells showed an even higher growth-stimulating activity than rat fibroblasts. Cells obtained from the poorly differentiated fibrosarcoma responded, in relative terms, better to all growth-stimulating influences, than those derived from the well-differentiated tumor.
从两例分化程度不同的纤维肉瘤中分离出的大鼠肿瘤细胞，在软琼脂中受到生长刺激影响。比较了生长因子（表皮生长因子、纤维肉瘤生长因子和胰岛素）、胎牛血清以及大鼠和裸鼠共培养的正常间充质细胞的作用。这三种生长因子中的每一种都产生了特定的反应和剂量依赖性。血清浓度的增加刺激了在软琼脂中形成克隆的细胞数量。使用生长因子和胎牛血清组合的实验表明，生长刺激的复杂最佳混合物是血清有效促生长活性的原因。在与正常细胞的共培养中，肿瘤细胞的克隆效率提高，肿瘤细胞的生长加速。这种刺激是由于正常的、不分裂的细胞持续释放一种可扩散到琼脂中的生长刺激因子。共培养的小鼠细胞比大鼠成纤维细胞表现出更高的生长刺激活性。相对而言，从低分化纤维肉瘤中获得的细胞比从高分化肿瘤中获得的细胞对所有生长刺激影响的反应更好。
