Studies on the Role of Poly (ADP-ribosyl) Action in Cell Differentiation and Oncogenesis

1. poly （adp -核糖）合成酶编码cDNA的克隆：通过cDNA克隆确定了牛poly （adp -核糖）合成酶的完整氨基酸序列。与人类和小鼠酶序列的比较表明，在整个进化过程中，对酶功能（如dna结合、自修饰和nadd结合）重要的各种结构单元（如锌结合指）几乎完全保守。为了在区域或结构域的水平上使用同源性分析，我们发明了一种称为“同源性剖面”的新图。发现poly （adp -核糖）作用的特异性抑制剂：从300个测试的化合物中，我们发现了许多有效的poly （adp -核糖）合成酶抑制剂，包括1,8-萘酰亚胺，6 (5H) -phenanthridinone， 1-羟基异喹啉及其衍生物和4-羟基喹唑啉；它们比已知的抑制剂如烟酰胺和苯酰胺衍生物更有效和特异性。我们还发现维生素K和新生物素对单核苷酸的作用比多核苷酸（adp -核糖基）的作用更特异。诱导肿瘤细胞分化：我们通过使用我们的新的聚adp -核糖基化抑制剂，如4-羟基喹唑啉和花生四烯酸，在培养中成功地诱导了畸胎瘤细胞的分化。

1. Cloning of cDNA coding for poly (ADP-ribose) synthetase : A complete amino acid sequence of bovine poly (ADP-ribose) synthetase was determined by cDNA cloning. A comparison of the sequence with those of human and mouse enzymes revealed that various structural units (e. g., Zn-binding fingers) important to enzymatic functions such as DNA-binding, automodification, and NAD-binding have been almost completely conserved throughout evolution. For the use of homology analysis at levels of regions or domains, we invented a new plot termed "homology profile".2. Discovery of specific inhibitors of poly (ADP-ribosyl) action : From among 300 compounds tested, we found a number of potent inhibitors of poly (ADP-ribose) synthetase, including 1,8-naphthalimide, 6 (5H) -phenanthridinone, 1-hydroxyisoquinoline, their derivatives, and 4-hydroxyquinazoline ; theywee more potent and specific than known inhibitors such as nicotinamide and benzamide derivatives. We also found that vitamin K as well as novobiocin was much more specific for mono- than poly (ADP-ribosyl) action.3. Induction of tumor cell differentiation : We succeeded in inducing differentiation of teratocarcinoma cells in culture by administrating our new inhibitors of poly (ADP-ribosyl) ation, such as 4-hydroxyquinazoline and arachidonic acid.