Anticancer Agents from Plant- and Lichen-Associated Fungi of the Sonoran Desert

描述（申请人提供）：天然产品对人类健康做出了巨大贡献。从天然来源寻找新的先导化合物仍然是现代抗癌药物发现的关键因素。我们的长期目标是从索诺兰沙漠的植物和地衣相关真菌中发现通过新机制发挥作用的抗癌药物，从而为我们的假设提供进一步的支持，即在这种独特的环境中相互关联的生物体阐述了一种相对未开发的有效生物活性化合物，以介导它们的相互作用并提高它们的生存率。这一跨学科和机构间项目的具体目标是：1.扩大我们独特的索诺兰沙漠植物和地衣相关真菌生物资源，优化500种选定真菌菌株的生物合成潜力，并制备2，500种提取物用于评估; 2.使用基于细胞的生物学和分子学方法筛选提取物的抗癌活性，包括：（a）在我们先前的授权期间建立的测定法，最近进行了修改以检测能够热休克诱导和抑制热休克诱导的化合物，随后进行与Hsp90直接相互作用的测定法，包括对使用热休克诱导测定法分离的化合物的酶重折叠和结合测定法;（c）在亚细胞毒性浓度下的细胞运动抑制剂的测定，和（d）基于五种前哨癌细胞系的抑制增殖/存活的常规染料还原测定，以避免发现一般细胞毒性剂;去复制活性提取物，每年大规模培养多达五种有前途的真菌菌株，并将其提取物进行生物测定指导的分级分离以分离和表征生物活性化合物;以及4.使用基因组学和蛋白质组学方法，根据化合物的活性、结构新颖性和效力，确定最有前途的化合物的分子作用机制。我们期望最有趣的化合物将作为进一步优化具有独特作用机制的新型抗癌药物开发的先导。然而，在更基础的科学层面上，我们提出的创新化学生物学方法应有助于确定（a）分子伴侣（如Hsp90）促进肿瘤发生的机制，以及（B）小分子抑制参与侵袭和转移的癌细胞迁移的机制，从而提高我们预防和治疗癌症的整体能力，从而对公共卫生产生重大影响。公共卫生相关性：该项目旨在从迄今尚未开发的天然资源中发现通过新机制发挥作用的抗癌药物，其结果将导致提高我们预防和治疗癌症的整体能力，因此对公共健康产生重大影响。

DESCRIPTION (provided by applicant): Natural products have made enormous contributions to human health. The search for new lead compounds from natural sources continues to be a crucial element in modern anticancer drug discovery. Our long-term goal is to discover anticancer drugs that act by novel mechanisms from plant- and lichen-associated fungi of the Sonoran desert, thereby providing further support for our hypothesis that organisms living in association with one another in this unique environment elaborate a relatively unexplored repertoire of potent bioactive compounds with which to mediate their interactions and enhance their survival. The specific aims of this interdisciplinary and inter-institutional project are to: 1. expand our unique bio-resource of Sonoran desert plant- and lichen-associated fungi and optimize biosynthetic potential of 500 selected fungal strains and prepare 2,500 extracts for evaluation; 2. screen extracts for anticancer activity using cell-based biological and molecular approaches including: (a) an assay established during our previous grant period and recently modified to detect compounds capable of heat shock induction and inhibition of heat shock induction, followed by assays for direct interaction with Hsp90 including luciferase-refolding and binding assays for compounds isolated using the heat shock induction assay; (c) an assay for inhibitors of cell motility at sub-cytotoxic concentrations, and (d) a conventional dye reduction assay for inhibition of proliferation/survival based on five sentinel cancer cell lines to avoid the discovery of general cytotoxic agents; 3. dereplicate active extracts, culture on large-scale up to five promising fungal strains per year and subject their extracts to bioassay-guided fractionation to isolate and characterize bioactive compounds; and 4. define molecular mechanisms of action using genomic and proteomic approaches for the most promising compounds based on their activity, structural novelty, and potency. We expect that the most interesting compounds will serve as leads for further optimization in the development of novel anticancer agents with unique mechanisms of action. At a more basic scientific level, however, the innovative chemical biology approach we propose should help define the mechanisms by which (a) chaperones such as Hsp90 facilitate oncogenesis, and (b) small-molecules inhibit cancer cell migration involved in invasion and metastasis, leading to enhancement of our overall ability to prevent and cure cancers, and therefore have a great impact on public health. PUBLIC HEALTH RELEVANCE: This project proposes to discover anticancer drugs that act by novel mechanisms from hitherto unexploited natural sources, the outcome of which will lead to enhancement of our overall ability to prevent and cure cancers, and therefore have a great impact on public health.