TRANSFECTION OF CDNAS FOR DRUG METABOLISM INTO MAMMALIAN CELLS

哺乳动物细胞的致癌物/诱变剂代谢能力 突变和转化试验正在通过感染 含有编码药物代谢的cDNA的逆转录病毒载体的细胞 内切酶 编码细胞色素P450 2A 3、2B 1、4 B1和一种细胞色素P450 2A 3、2B 1、4 B1的cDNA， 将黄素单加氧酶插入载体并感染小鼠， 胚胎C3 H/10 T-（一半）细胞和仓鼠卵巢AS 52细胞。 西方 分析和/或酶活性已经证明酶是 在感染细胞中表达。 在过去的一年里， 置于细胞色素P450 2A 3表达细胞上。 C3 H/10 T-（一半）细胞 具有增加的细胞毒性敏感性， 转化为III型病灶的亚硝胺，NNK（烟草烟雾 组分），以及二甲基和二乙基亚硝胺。 父母10 T-（一个- 半），细胞不受细胞毒性或转化作用的影响， 这些化学品。 表达10 T-（一半）的2A 3细胞也发生突变 NNK对哇巴因的耐药性 AS 52细胞（与Ken Tindall）表达P450 2A 3，并且突变和 突变谱的研究已经开始。 总体而言，这些研究仍在继续 提高培养的哺乳动物细胞的有效性， 环境化学品的作用方式。

The carcinogen/mutagen metabolism capability of mammalian cells used in mutation and transformation assays is being increased by infecting the cells with retroviral vectors containing cDNAs coding for drug metabolizing enzymes. The cDNAs coding for the cytochromes P450 2A3, 2B1, 4B1, and a flavin monoxygenase have been inserted into vectors and infected into mouse embryo C3H/10T-(one-half) cells and hamster ovary AS52 cells. Western analysis and/or enzyme activities have demonstrated that the enzymes are expressed in the infected cells. During this last year, emphasis has been placed on cytochrome P450 2A3 expressing cells. C3H/10T-(one-half) cells expressing 2A3 activity have an increased cytotoxic sensitivity and are transformed to type III foci by the nitrosamines, NNK (a tobacco smoke component), and dimethyl- and diethylnitrosamine. The parental 10T-(one- half), cells are not subject to the cytotoxic or transforming effects of these chemicals. The 2A3 expressing 10T-(one-half), cells are also mutated to ouabain resistance by NNK. AS52 cells (in collaboration with Ken Tindall) expressing P450 2A3 have recently been obtained and mutation and mutational spectra studies are beginning. Overall, these studies continue to improve the usefulness of cultured mammalian cells to identify and study the modes of action of environmental chemicals.