Functional Analysis of HOXA13 Small Molecule Antagonists

项目总结/摘要 该项目将集中于小分子抑制剂的开发和体内表征， HOXA 13作为减少肿瘤血管形成的疗法。在胚胎发生期间，HOX蛋白指导组织 和器官发育，通过调节基因簇，其产物控制组织规格， 分化我们已经确定HOXA 13调节一组促血管生成基因，这些基因是血管生成所必需的。 发育中的胚胎中的脉管发育。更重要的是，我们已经确定， 在肝癌的发展中血管系统中，相同的血管原基因受HOXA 13调控。 由于HOXA 13以多效性的方式调节血管发育，我推测HOXA 13的作用可能与血管发育有关。 破坏HOXA 13的转录功能将有效地抑制肿瘤血管形成， 同时影响肿瘤血管发生所需的一组基因的表达。 认识到HOXA 13的转录功能需要DNA结合，我们开发了一个小的 分子筛选以鉴定能够阻止HOXA 13与其靶DNA相互作用的化合物 顺序从该筛选中，我们鉴定了化合物B（CpdB），其是一种可以部分抑制 HOXA 13调节一组前血管基因的能力。通过仔细修改CpdB的初始 结构，我假设这种小分子的功效可以提高，以抑制HOXA 13功能， 发展肿瘤。为了检验这一假设，将实现以下具体目标： 目标1.确定CpdB对HOXA 13的特异性。 目标2.定量CpdB对HOXA 13的亲和力，并确定CpdB内的哪些氨基酸残基与HOXA 13的亲和力相关。 HOXA 13 DNA结合结构域与CpdB接触。 目标3。测定HOXA 13和CpdB的构效关系，优化CpdB效价， 以及CpdB溶解度的改善。 目标4。确定CpdB类似物干扰H 0XA 13调节的前血管基因表达的功效， 发展肿瘤。

Project Summary/Abstract This project will focus on the development and in vivo characterization of small molecule inhibitors of HOXA13 as a therapy for reducing tumor vascularization. During embryogenesis, HOX proteins direct tissue and organ development by regulating clusters of genes whose products control tissue specification and differentiation. We have established that HOXA13 regulates a cluster of pro-vascular genes necessary for vascular development in the developing embryo. More importantly, we have determined that many of the same provascular genes are regulated by HOXA13 in the developing vasculature of hepatocarcinomas. Because HOXA13 functions in a pleiotropic manner to regulate vascular development, I hypothesize that the disruption of HOXA13's transcriptional function would effectively inhibit tumor vascularization by simultaneously affecting the expression of a cohort genes required for tumor vasculogenesis. Recognizing that DNA binding is required for HOXA13's transcriptional function, we developed a small molecule screen to identify compounds capable of preventing HOXA13 from interacting with its target DNA sequence. From this screen, we identified Compound B (CpdB), a small molecule that can partially inhibit HOXA13's ability to regulate a group of provascular genes. Through careful modifications to CpdB's initial structure, I hypothesize that the efficacy of this small molecule can be improved to inhibit HOXA13 function in developing tumors. To test this hypothesis, the following specific aims will be accomplished: Aim 1. Determine the specificity of CpdB for HOXA13. Aim 2. Quantitate the affinity of CpdB for HOXA13 and determine which amino acid residues within the HOXA13 DNA binding domain are contacted by CpdB. Aim 3. Determination of structure activity relationships for HOXA13 and CpdB, optimization of CpdB potency, and improvement of CpdB solubility. Aim 4. Determine the efficacy of CpdB analogs to perturb HOXA13-regulated provascular gene expression in developing tumors.