Sheela S, Kennedy A R
Carcinogenesis. 1986 Feb;7(2):201-5. doi: 10.1093/carcin/7.2.201.
Early-passage human foreskin fibroblasts were exposed to X-ray doses ranging from 100 to 600 rad. The X-ray treatments resulted in cell killing in a dose-dependent manner as judged by the colony-forming efficiency of the cells. When cultures exposed to radiation were serially passaged and checked at various times for growth in semi-solid medium they showed the presence of cells with the ability to grow under anchorage-independent conditions (in agarose) at 24 population doublings. The frequencies of colonies with the ability to grow in agarose increased with increasing doses of X-rays above the levels observed for control cultures under similar conditions. When assayed for plasminogen activator levels, the X-ray-treated cultures at various passages showed insignificant differences from levels observed in control cultures. However, the amounts of collagenase (type IV collagen-specific) increased significantly by 32 population doublings in the X-ray-treated cultures compared with control cultures. Our results suggest that the production of type IV collagen-specific collagenase could be useful as an in vitro marker for the transformation of human diploid fibroblasts by X-irradiation.
将早期传代的人包皮成纤维细胞暴露于100至600拉德的X射线剂量下。根据细胞的集落形成效率判断，X射线处理以剂量依赖的方式导致细胞死亡。当将暴露于辐射的培养物进行连续传代，并在不同时间检查其在半固体培养基中的生长情况时，发现在24次群体倍增时存在能够在非锚定依赖条件下（在琼脂糖中）生长的细胞。在类似条件下，与对照培养物相比，能够在琼脂糖中生长的集落频率随着X射线剂量的增加而增加，且高于对照培养物中观察到的水平。当检测纤溶酶原激活剂水平时，不同传代的X射线处理培养物与对照培养物中观察到的水平无显著差异。然而，与对照培养物相比，X射线处理的培养物在32次群体倍增时，IV型胶原酶（特异性针对IV型胶原）的量显著增加。我们的结果表明，IV型胶原特异性胶原酶的产生可能作为体外X射线照射诱导人二倍体成纤维细胞转化的标志物。
