Coetzee M L, Dolan M L, Ove P
Oncology. 1975;32(1):38-46. doi: 10.1159/000225048.
A serum protein present in normal rat serum and absent from the serum of hepatoma-bearing animals at advanced stages has a stimulatory effect on 3H-thymidine incorporation into hepatoma cells in suspension. Liver cells maintained in a similar suspension are not affected by the factor. The stimulation appears to be at the level of chromatin or DNA. Isolated membrane-denuded nuclei from Morris hepatoma 7777 incorporate more 3H-TTP when the factor is present in the incubation mixture. Nuclei from host liver are not stimulated. The factor also stimulates incorporation of 3H-TTP in a system using calf thymus DNA as primer and an extracted DNA polymerase. In this system incorporation is stimulated with DNA polymerase from both tissues, host liver and hepatoma 7777. It is concluded that the factor does not act on the DNA polymerase but on chromatin or DNA.
一种存在于正常大鼠血清中而在晚期荷瘤动物血清中缺失的血清蛋白，对悬浮培养的肝癌细胞摄取³H-胸腺嘧啶核苷具有刺激作用。维持在类似悬浮状态的肝细胞不受该因子影响。这种刺激作用似乎发生在染色质或DNA水平。当孵育混合物中存在该因子时，从莫里斯肝癌7777分离得到的无膜核摄取更多的³H-TTP。宿主肝脏的细胞核不受刺激。该因子还能在以小牛胸腺DNA为引物和提取的DNA聚合酶的系统中刺激³H-TTP的掺入。在这个系统中，来自宿主肝脏和肝癌7777这两种组织的DNA聚合酶都能刺激掺入。结论是该因子不作用于DNA聚合酶，而是作用于染色质或DNA。
