A Search for Small Molecule Inhibitors of the Hypoxia Response Pathway

低氧诱导转录因子（HIF）在大量癌症中被诱导， 上调超过100种基因的表达，其中许多基因预计会促进肿瘤进展， 对传统疗法产生抵抗力。项目4的目标是阐明和验证目标 用于发现调节这种反应的小分子，目的是使用这些试剂来 评估HIF在体内模型系统中对肿瘤发生的贡献。生物健全的细胞基础高 利用HIF调节的氧依赖性模式的知识的通量筛选已经导致了 鉴定siRNA和拮抗或激动细胞凋亡的有效（纳摩尔）小分子。 通路虽然已经成功地确定了其中一些药物的分子靶点，但目标1 提出了生物化学，分子生物学和遗传学的方法来追求的作用模式， 作为其靶点的剩余化合物可能代表缺氧反应的未鉴定组分 通路同时，结构，生物化学和生物学方法已经严格表征了 HIF Per-ARNT-Sim（PAS）结构域负责介导HIF亚基之间的相互作用 异二聚体。目的2扩展了这些研究，以研究HIF组装的工作模型。使用这种 信息，这些PAS结构域的原理证明配体已被鉴定并显示作为 HIF异源二聚化的变构抑制剂， 高通量，用于未来筛选的分析。此外，每个目标的最佳化合物将是 进行系统的化学努力，以提高其效力、稳定性和溶解度，用于研究， 研究它们在人类疾病的体内模型中的功效。这些互补的路线提供独特的 有机会深入了解HIF的功能和机制，它可能是人为调节。 与公共卫生的相关性：在几种人类肿瘤中观察到HIF水平升高， 与肿瘤侵袭性、治疗抵抗性和死亡率有关。此外，HIF在几个细胞中被诱导， 氧可用性受损的疾病，包括贫血和局部缺血。因此，小 HIF活性的分子调节可在包括癌症在内的一系列疾病中具有治疗效用。

The Hypoxia Inducible transcription Factors (HIFs) are induced in a large number of cancers where they upregulate the expression of over 100 genes, many of which are expected to promote tumor progression and confer resistance to traditional therapies. The goals of Project 4 are the elucidation and validation of targets for the discovery of small molecules that modulate this response with the objective of using these reagents to assess the contribution of HIF to tumorigenesis in in vivo model systems. Biologically sound cell-based high throughput screens exploiting knowledge of oxygen-dependent modes of HIF regulation have led to the identification of both siRNAs and potent (nanomolar) small molecules that either antagonize or agonize the pathway. Though the molecular targets for some of these agents have been successfully identified, Aim 1 proposes biochemical, molecular biological and genetic approaches to pursue the modes-of-action of the remaining compounds as their targets may represent unidentified components of the hypoxic response pathway. Concurrently, structural, biochemical, and biological approaches have rigorously characterized the HIF Per-ARNT-Sim (PAS) domains responsible for mediating interactions between subunits of the HIF heterodimer. Aim 2 extends these studies to investigate a working model for HIF assembly. Using such information, proof-of-principle ligands for these PAS domains have been identified and shown to function as allosteric inhibitors of HIF heterodimerization in vitro and provide justification for the development of new, high throughput, assays for future screens. Furthermore, the best compounds from each Aim will be subjected to systematic chemical efforts to improve their potency, stability, and solubility for use in studies to interrogate their efficacy in in vivo models of human diseases. These complementary routes offer unique opportunities to gain insight into HIF function and mechanisms by which it may be artificially regulated. Relevance to public health: Increased levels of HIF are observed in several human tumors and correlated with tumor aggressiveness, resistance to treatment and mortality. In addition, HIF is induced in several diseases in which oxygen availability is compromised, including anemias and ischemias. As such, small molecule modulation of HIF activity may have therapeutic utility in a range of diseases including cancer.