Marine Actinomycetes as a Resource for Anticancer Natural Products

描述（由申请人提供）：从放线菌和其他细菌中提取的天然产物发酵已经成为药物发现的重要组成部分，激发了50%的临床批准药物，并被证明是癌症研究中的宝贵工具。天然产物通常能发挥其强大的作用，并表现出高特异性，这使得它们有助于探测与癌症相关的信号通路。因此，继续努力识别与人类癌症有关的具有强大生物活性的新天然产物是一项重要的努力。该项目的目标是鉴定新的天然产物，这些产物可以作为开发新型癌症疗法或生化探针的先导结构。将采用多方面的方法，结合微生物学、天然产物化学以及与癌症生物学专家的合作来实现这一目标。具体而言，我们建议利用pH、pO2和化学信号等环境因素，开发新的经验和生化技术来培养海洋生境中的放线菌。由于人们普遍认为只有一小部分细菌是可培养的，因此需要新的技术来分离产生次生代谢物的细菌。海洋细菌的收集将为建立生物筛选的天然产物片段库奠定基础。我们将结合生化靶标分析、细胞表型分析和选择性细胞毒性研究来识别与信号转导途径相互作用的分子(例如：凋亡，坏死，Wnt/？-catenin， HIF)和调节表观遗传因子，如DNA甲基转移酶和组蛋白去乙酰化酶。作为一个特定生物靶点的例子，我们将利用基于细胞的检测来发现在Wnt通路中特异性相互作用的分子，使用Wnt应答细胞系，这在大量癌症中是重要的（最明显的是高达90%的结肠癌）。为了适应大量生物测定中活性hit的化学评价，我们将开发基于LC-SPE-NMR技术的分析化学技术，用于快速定量和定性分析。最后，我们将使用传统的天然产物化学技术来表征我们在生物筛选中发现的新的次生代谢物。

DESCRIPTION (provided by applicant): Fermentation derived natural products from actinomycetes and other bacteria have been an important component of drug discovery inspiring 50% of clinically approved drugs and proven to be invaluable tools in cancer research. Natural products often exert their effects potently and exhibit high specificity - making them useful to probe signaling pathways related to cancer. As such, a continued effort to identify new natural products with potent biological activity relevant to human cancers is an important endeavor. The goal of this project is to identify new natural products that can be lead structures for the development of novel cancer therapeutics or biochemical probes. A multi-faceted approach that combines microbiology, natural products chemistry and collaboration with experts in cancer biology will be used to accomplish this goal. Specifically, we propose to develop new empirical and biochemical techniques to culture actinomycetes from marine habitats, by taking advantage of environmental factors such as pH, pO2 and chemical signaling. As it is widely believed that only a small percentage of bacteria are culturable, new techniques to isolate secondary metabolite producing bacteria are necessary. The collection of marine bacteria will serve as the foundation to build a natural product fraction library for biological screening efforts. We will use a combination of biochemical target-based assays, cell-based phenotypic assays and selective cytotoxicity studies to identify molecules that interact with signal transduction pathways (eg. apoptosis, necrosis, Wnt/?-catenin, HIF) and modulate epigenetic factors such as DNA methyltransferase and histone deacetylase. An example of a specific biological target, we will utilize a cell-based assay to discover molecules that interact specifically in the Wnt pathway using a Wnt responsive cell line, which is important in large number of cancers (most notably up to 90% of colon cancer). To accommodate the chemical evaluation of active hits in the large number of bioassays proposed, we will develop analytical chemistry techniques based on LC-SPE-NMR technology for rapid quantitative and qualitative analysis. Finally, we will use traditional natural products chemistry techniques to characterize new secondary metabolites that we identify in our biological screening.