Ohashi Y, Ueda K, Hayaishi O, Ikai K, Niwa O
Proc Natl Acad Sci U S A. 1984 Nov;81(22):7132-6. doi: 10.1073/pnas.81.22.7132.
Poly(ADP-ribose) synthesizing activity in mouse teratocarcinoma EC-A1 cells decreased markedly during differentiation induced by retinoic acid; the activities assayed in permeabilized cells decreased to 25% and 10% of the activity of control (uninduced cells) 2 and 3 days, respectively, after the addition of 0.1 microM retinoic acid to the culture medium. This change preceded changes in morphology and DNA synthesis, which became prominent after 4 days. The decrease in poly(ADP-ribose) synthesizing activity appeared to be caused by a diminution of the synthetase protein and not by a decrease in its catalytic activity, because the full activity disclosed by DNase I treatment decreased in parallel, albeit at about 20 times higher levels. When 8 mM 3-aminobenzamide or 10 mM nicotinamide, specific inhibitors of poly(ADP-ribose) synthetase, was added to the culture medium, the cells underwent differentiation after 7-9 days. An analogue, 3-aminobenzoic acid, which is not inhibitory to the synthetase, induced differentiation much less efficiently than did 3-aminobenzamide, and the effect of 3-aminobenzoic acid appeared to be ascribable to its potent cytotoxicity. Immunohistochemical analysis using anti-poly(ADP-ribose) antibody confirmed the marked reduction in poly(ADP-ribose) synthesizing activity in nuclei of the cells treated with retinoic acid or 3-aminobenzamide but not with 3-aminobenzoic acid. These results suggest that a decrease in poly(ADP-ribose) synthesis triggers differentiation of teratocarcinoma cells.
在视黄酸诱导的分化过程中，小鼠畸胎癌EC - A1细胞中的聚（ADP - 核糖）合成活性显著降低；向培养基中添加0.1微摩尔视黄酸后，在通透细胞中检测到的活性分别在2天和3天后降至对照（未诱导细胞）活性的25%和10%。这种变化先于形态和DNA合成的变化，4天后这些变化变得明显。聚（ADP - 核糖）合成活性的降低似乎是由合成酶蛋白的减少引起的，而不是其催化活性的降低，因为经DNA酶I处理后所显示的全部活性也平行降低，尽管水平约高20倍。当将聚（ADP - 核糖）合成酶的特异性抑制剂8毫摩尔3 - 氨基苯甲酰胺或10毫摩尔烟酰胺添加到培养基中时，细胞在7 - 9天后发生分化。一种对合成酶无抑制作用的类似物3 - 氨基苯甲酸诱导分化的效率远低于3 - 氨基苯甲酰胺，并且3 - 氨基苯甲酸的作用似乎归因于其强大的细胞毒性。使用抗聚（ADP - 核糖）抗体的免疫组织化学分析证实，在用视黄酸或3 - 氨基苯甲酰胺处理的细胞的细胞核中聚（ADP - 核糖）合成活性显著降低，但用3 - 氨基苯甲酸处理的细胞则没有。这些结果表明聚（ADP - 核糖）合成的减少触发了畸胎癌细胞的分化。
