Letnansky K
Osterr Z Onkol. 1977 Oct 20;4(2-3):42-5.
A fraction was isolated from the maternal part of bovine placenta, which significantly inhibits the incorporation of thymidine into the DNA of tumour cells. This factor has, however, only a limited effect on the same reaction in bone marrow cells or in fibroblasts. It is suggested that the factor enters the cell by an active transport mechanism and that the active part thereof is a protein. The protein pattern of the chromatin is not influenced by the factor as is the phosphorylation or acetylation of nuclear proteins.
从牛胎盘的母体部分分离出一种成分，它能显著抑制胸腺嘧啶核苷掺入肿瘤细胞的DNA中。然而，该因子对骨髓细胞或成纤维细胞的相同反应仅有有限的影响。据推测，该因子通过主动转运机制进入细胞，其活性部分是一种蛋白质。染色质的蛋白质模式并不像核蛋白的磷酸化或乙酰化那样受该因子影响。
