Core--Biology

该项目的总体目标是鉴定和评价新型天然产物癌症化学预防剂。在发现过程中，采用活性导向分馏，利用短期生物测定作为监测。该核心的第一个目标是提供生理相关性的生物测定支持。如前所述，目前的试验组合包括设计用于监测起始阶段（例如，细胞培养物中醌还原酶活性的诱导），促进（例如，环加氧酶活性的抑制），和进展（例如，诱导细胞分化）。最近设计了基于机制的高通量测定系统，例如抑制芳香酶的荧光测定，以及用ARE、ERE、PPAR和NF-κ B报告基因稳定转染的HepG 2细胞。实际用于特定分馏的试验材料和测定程序也由该核心提供，取决于二次鉴别。一旦对电极导线材料进行了结构表征，则在该核心中进行额外的研究，以更全面地表征测试试剂在临床干预中成功的潜力 审判使用半制备量的活性电极导线（0.05-1 g），将进行初步的机械评价。除了体外方法学，这将涉及短期 设计用于评估对致癌生物标志物的影响的动物研究（例如，II相酶的诱导）。此外，使用相对少量的供试品，将在两阶段小鼠皮肤模型中测定肿瘤发生的抑制作用。最后，根据构造、活动、自然丰度等总体概况，最有希望的测试材料将在实验室动物的全程致癌模型中评估其化学预防活性。具体的动物模型和给药方案将基于 探员的整体情况采用的全期肿瘤发生系统包括两阶段小鼠皮肤模型、致癌物（DMBA或NMU）诱导的大鼠乳腺模型、雄性Noble大鼠的PIN（前列腺上皮内瘤形成）前列腺模型和A系小鼠中苯并（a）芘诱导的肺肿瘤模型。将编制完整的数据集，并将其传送给能够促进更高级发展阶段的组织，如国家癌症研究所。

The overall goal of this program project is to identify and evaluate novel natural product cancer chemopreventive agents. In the discovery process, activity-guided fractionation is employed, utilizing short-term bioassays as a monitor. The first goal of this core is to provide bioassay support of physiological relevance. As validated previously, the current test battery is comprised of assays designed to monitor inhibition of carcinogenesis at the stages of initiation (e.g., induction of quinone reductase activity in cell culture), promotion (e.g., inhibition of cyclooxygenase activity), and progression (e.g., induction of cell differentiation). Mechanistic-based high throughput assay systems have recently been devised, such as a fluorometric assay for inhibition of aromatase, and stably transfected HepG2 cells with reporter genes for ARE, ERE, PPAR, and NF-kappaB. Test materials and assay procedures actually used for specific fractionations are keyed on secondary discriminations also provided by this core. Once lead materials are structurally characterized, additional studies are performed in this core to more fully characterize the potential of the test agent to succeed in clinical intervention trials. With semi-preparative quantities of active leads (0.05-1 g), preliminary mechanistic evaluations will be performed. In addition to in vitro methodologies, this will involve short-term animal studies designed to assess effects on biomarkers of carcinogenesis (e.g., induction of phase II enzymes). In addition, with relatively small quantities of test materials, inhibition of tumorigenesis will be determined in the two-stage mouse skin model. Finally, based on the overall profile of structure, activity, natural abundance, etc., the most promising test materials will be evaluated for chemopreventive activity in full-term models of carcinogenesis with laboratory animals. The specific animal model and administration protocol will be based on the overall profile of the agent. The full-term tumorigenesis systems to be employed include the two-stage mouse skin model, the carcinogen (DMBA or NMU)-induced rat mammary model, the PIN (prostatic intraepithelial neoplasia) prostate model with male Noble rats, and the benzo(a)pyrene-induced lung tumor model in strain A mice. Complete data sets will be prepared and transmitted to organizations capable of promoting more advanced stages of development, such as the National Cancer Institute.