NITRIC OXIDE AND TUMOR PROMOTION

描述：这是一项调查被动反应作用的建议 氮素在促进小鼠皮肤肿瘤中的作用。相当近 证据表明，活性氮和氧都是形成的。 在肿瘤促进剂十四酰佛波醇醋酸酯(TPA)治疗的皮肤中 多阶段致癌(DMBA/TPA)模型及皮肤慢性治疗 含有完全致癌物质DMBA。要研究的假设 该项目是由活性氮中间体生产的 真皮和真皮/表皮中存在炎性白细胞 连接导致氧化DNA损伤，导致突变并影响 通过选择性地克隆扩增启动的细胞群体 诱导细胞凋亡。这一假说将通过三个方面来阐述 明确的目标。目标1中的研究将表征表达的变化 诱导型一氧化氮合酶和内皮型一氧化氮合酶基因 (ENOS)及对小鼠表皮细胞凋亡的诱导作用 至DMBA/TPA方案或仅使用DMBA的多个治疗。研究项目： 目标2将调查通过调节NO产生的影响 一氧化氮合酶抑制剂L精氨酸单乙酯(NMMA)或NO释放 DMBA/TPA或仅DMBA协议中的复合DETA/NO。参数应为 研究内容包括一氧化氮合酶基因表达、血管通透性、皮肤 厚度、血管内皮生长因子与血管通透性 因子诱导，一氧化氮和过氧亚硝酸盐的产生，白细胞的渗透， 细胞凋亡和DNA氧化损伤。AIM 3的研究将尝试 确定所涉及的活性氮物种的性质 体外共培养体系中的诱变及其产生的突变 使用暴露于氧化剂或与AS52共培养的AS52细胞 从DMBA/TPA或DMBA处理的小鼠分离外周血白细胞。 AS52细胞的gpt基因突变将被描述。

DESCRIPTION: This is a proposal to investigate the role of reactive nitrogen species in skin tumor promotion in mice. Considerable recent evidence indicates that both reactive nitrogen and oxygen species are formed in skin treated with tumor promoter tetradecanoylphorbol acetate (TPA) in a multistage carcinogenesis (DMBA/TPA) model and in skin treated chronically with the complete carcinogen DMBA. The hypothesis to be investigated in this project is that reactive nitrogen intermediates produced by inflammatory leukocytes present in the dermis and the dermal/epidermal junction cause oxidative DNA damage that leads to mutations and affects clonal expansion of initiated cell populations through the selective induction of apoptosis. This hypothesis will be addressed through three specific aims. Studies in aim 1 will characterize changes in the expression of genes for inducible nitric oxide synthase (iNOS) and endothelial NOS (eNOS) as well as the induction of apoptosis in epidermis of mice subjected to a DMBA/TPA protocol or multiple treatments with DMBA alone. Studies in Aim 2 will investigate the effects of modulation of NO production with the NOS inhibitor monomethyl-L-arginine monoacetate (L-NMMA) or the NO-releasing compound DETA/NO in the DMBA/TPA or DMBA-only protocols. Parameters to be investigated include NOS gene expression, vascular permeability, skin thickness, vascular endothelial growth factor and vascular permeability factor induction, NO and peroxynitrite production, leukocyte infiltration, apoptosis, and oxidative DNA damage. Studies in aim 3 will attempt to determine the nature of the reactive nitrogen species involved in mutagenesis and the mutations they produce in an in vitro co-culture system employing AS52 cells exposed to oxidants or incubated in co-culture with peripheral leukocytes isolated from DMBA/TPA or DMBA treated mice. Mutations in the gpt gene of the AS52 cells will be characterized.