B A P METABOLISM & MODIFICATION OF DNA IN SKIN XENOGRAFT

实验室动物已被广泛用于研究 聚芳烃致皮肤肿瘤机制的研究进展 碳氢化合物；但这些研究对人类皮肤的意义 是未知的。我们已经成功地建立了人类皮肤 使用新生包皮的异种移植到裸鼠身上 脾切除导致免疫抑制。我们这几年的 研究BP和BPDE代谢的体会-- 在体外人类细胞中的DNA加合物，允许我们扩展我们的 人皮肤异种移植体内系统的研究。我们 建议对新陈代谢进行详细调查 异种移植的表皮和真皮中的BP。有机食品 可溶的代谢物将用乙酸乙酯提取， 用高效液相色谱分离，并用真品鉴定和定量 标准。对表皮细胞中DNA的修饰和 真皮细胞将通过32P后标记法进行测量。 加合物在一段时间内的持久性也将是 调查过了。新陈代谢、DNA修饰和持久性 在人类异种移植的真皮和表皮中，当 在苯甲酰胺及其类似物存在下处理的B(A)P 也将进行研究。聚腺苷二磷酸核糖聚合酶--苯甲酰胺 抑制剂，已经被我们证明可以干扰形成 形成位点特异性DNA加合物的关键DNA碱基，没有 影响DNA修饰的程度。我们预计， 上述研究应该为我们提供关于 可疑的环境基因组如何作用于人类细胞 代用宿主上的功能组织系统允许我们进一步 对人类环境诱导机制的洞察 遗传毒性。

Laboratory animals have been extensively used to study the mechanisms of cutaneous tumorigenesis by polyaromatic hydrocarbons; but the significance of these studies on human skin is unknown. We have been successful in establishing human skin xenograft, using neonatal foreskins, on nude mice further immunosuppressed by splenectomy. Our several years of experience in studying the metabolism of BP as well as BPDE- DNA adducts in human cells in vitro, permits us to extend our studies to the in vivo system of human skin xenografts. We proposed to undertake a detailed investigation of the metabolism of BP in the epidermis and dermis of the xenograft. The organic soluble metabolites will be extracted with ethyl acetate, separated by HPLC and identified and quantitated using authentic standards. Modification of the DNA in the epidermal cells and dermal cells will be measured by the 32P post-labelling method. Persistence of the adducts over a period of time will also be investigated. The metabolism, DNA modification and persistence of adducts, in the dermis and epidermis of human xenografts when treated with B(a)P in the presence of benzamide and its analogues will also be studied. Benzamide, a poly-ADP-ribose polymerase inhibitor, has been shown, by us, to interfere with the formation of critical DNA bases to form site specific DNA adducts, without affecting the extent of DNA modification. We expect that the above mentioned studies should provide us with information on how suspect environmental genobiotics act on human cells in a functional tissue system on a surrogate host permitting us further insight into mechanisms of human environmental induced genotoxicity.