Chemistry of Probes and Therapeutics

7.2.1.核心A。探针和治疗化学 核心领导人：Paul Wender 调查员：劳伦斯·马内特、大卫·奥斯特罗夫 目标1：审查主要项目和特定任务项目的探头设计，包括基于 肽和考克斯-2抑制剂，并优化荧光和拉曼标记的共轭化学（图 25）。 人们普遍认为，早期发现可提高癌症治疗的存活率。 胃肠道中癌症和癌前息肉的检测得到了改善， 内窥镜手术，但这种方法可能会错过难以观察的组织和扁平瘤。在 此外，对于某些情况，正常组织和癌前组织之间的差异仅在 分子水平。这就需要使用分子探针来观察组织差异。 Wender实验室在药物/探针输送系统的创新和使用方面拥有相当丰富的专业知识， 其中包括肽和探针化学的发展，以及它们的结合方法 以及在细胞和动物中的评估。这种专业知识将被用于设计和合成新的 探针缀合物，以及必要时开发甚至发明合成方法。一 多种连接策略以制备不可释放的和可释放的化合物，以及 已经开发了可选择性释放的缀合物。实验室在以下方面提供了丰富的经验： 分子探针的设计、合成和评价是分子生物学中不可或缺的工具。 成像策略。 在开发用于光学成像的探针中的一个重大挑战是在用于光学成像的标记物的附接中。 侦测荧光团的选择以及它们如何与特异性探针结合， 改变所选肽或小分子的特异性和有用性。我们的目标是解决这个问题 挑战，通过使用基于结构的分子动力学模拟，以评估优先取向的 探针与靶蛋白结合。这一过程是从分子对接方法，我们 以高通量模式利用以选择对靶蛋白特异的小分子（通过平行 在佛罗里达大学高性能计算中心使用DOCK 6处理）。 在确定与靶蛋白结合的探针的最可能的取向后（图25），溶剂 选择探针中暴露的原子作为标记的连接点（图25）。实时 先导化合物的自动组合启发式增强，RACHEL（Tripos，Inc.）是药物 优化软件包旨在优化弱结合的先导化合物， 组合时尚我们通常使用雷切尔添加化学基团，如荧光团，铅 以微摩尔范围内的Kd值结合以增加其比活性的化合物 (Fig. 25）。这一过程可以应用于5 ROX和大量潜在的荧光团，以最大限度地 识别保持特异性的优化标记探针的可能性。 目标2：设计下一代治疗剂并开发具有定向递送和 控制释放。 Wender实验室在探针的设计、合成和评估方面拥有丰富的经验 能够或增强细胞和组织进入的缀合物。制定了程序和制度 其允许在细胞和转基因动物中真实的时间内定量摄取。这些研究 已经转化为药物递送的缀合物的开发，包括已经 已进入第二阶段人体临床试验。这项工作的大部分已应用于交付过多的 通过分子转运蛋白，最具体地但不限于八精氨酸。这种分子 转运蛋白已被用于递送治疗剂如紫杉醇、环孢霉素A、SN-38、雷帕霉素 肽、蛋白质、siRNA、质粒DMA、金属、成像剂和甚至磁性颗粒。各种 已经开发了释放机制。转运体技术和生物降解连接体策略 在我们的实验室开发的有许多应用程序，超越了这一特定的重点， 努力，并可应用于整个领域的药物输送以及共轭化学。 随着选择性在治疗药物递送中的重要性日益增加，我们可以应用方法 以前在我们实验室开发的与药物输送相关的方法，并扩展这种方法以实现目标 有选择性地治疗胃肠道癌症以及其他疾病。此应用程序的所有方面 依靠分子检测和可视化的技术可以通过访问 核心实验室的设计和合成专业知识。 目标3：与研究人员和FDA合作，首先开发新的药物，然后获得批准。 可用于胃肠道成像和治疗的试剂。 用于检测和治疗的新型选择性探针和治疗剂的开发 胃肠道癌症的治疗旨在最终应用于临床环境。温德实验室 在这一领域的经验与发展的octagonine环孢素A剂的局部 治疗银屑病，结合物进入II期人体临床试验。研究也 已经基于IP、眼部、口腔和肺部给药进行了改进， 建议的结肠研究涉及局部给药。这种专门知识可以帮助和促进 根据需要设计、合成和评估新的探针和药物缀合物，以实现以下目标： 节目

7.2.1. Core A. Chemistry of probes and therapeutics Core Leader: Paul Wender Investigators: Lawrence Marnett, David Ostrov Aim 1: Review probe designs for the major projects and task-specific projects including those based on peptides and cox-2 inhibitors, and optimize conjugation chemistries for fluorescent and Raman tags (Fig 25). It is generally accepted that early detection leads to improved survival rates in the treatment of cancers. Detection of cancers and precancerous polyps in the gastrointestinal tract has been improved with endoscopy procedures, but this approach can miss difficult to observed tissue and flat neoplasias. In addition for some situations the difference between normal and precancerous tissue is only detectable at the molecular level. This necessitates the use of molecular probes for visualization of tissue differences. The Wender lab has considerable expertise in the innovation and use of drug/probe delivery systems, which includes the development of peptide and probe chemistry, as well as methods for their conjugation and evaluation in cells and in animals. This expertise will be employed in the design and synthesis of novel probe conjugates, as well as the development and even invention of synthetic methods as necessary. A variety of linkage strategies to make both non-releasable and releasable compounds as well as selectively releasable conjugates has been developed. The laboratories offer considerable experience in the design, synthesis, and evaluation of molecular probes that are indispensable tools for molecular imaging strategies. A significant challenge in the development of probes for optical imaging is in the attachment of labels for detection. The selection of fluorophores .and how they are conjugated to specific probes can drastically alter the specificity and usefulness of selected peptides or small molecules. We aim to address this challenge by using structure-based molecular dynamic simulations to assess the preferred orientation of the probe bound to the target protein. This process is adapted from the molecular docking method we utilize in the high-throughput mode to select small molecules specific for target proteins (by parallel processing using DOCK6 at the University of Florida High Performance Computing Center). After determining the most likely orientation of the probe bound to the target protein (Fig. 25), solvent exposed atoms in the probe are selected as points of attachment for the label (Fig. 25). Real-time Automated Combinatorial Heuristic Enhancement of Lead compounds, RACHEL (Tripos, Inc.) is a drug optimization package designed to optimize weak binding lead compounds in an automated, combinatorial fashion. We routinely use RACHEL to add chemical groups, such as fluorophores, to lead compounds that bind with Kd values in the micromolar range in order to increase their specific activities (Fig. 25). This process can be applied to 5ROX and a large number of potential fluorophores to maximize the likelihood of identifying optimized labeled probes that retain specificity. Aim 2: Design next generation therapeutic agents and develop conjugates with directed delivery and controlled release. The Wender lab has considerable experience with the design, synthesis and evaluation of probe conjugates that enable or enhance cell and tissue entry. Procedures and systems have been developed that allow for quantification of uptake in real time in cells and in transgenic animals. These studies have been translated into the development of conjugates for drug delivery, including studies that have progressed to phase II human clinical trials. Much of this work has been applied the delivery of a plethora of therapeutics via a molecular transporter, most specifically but not limited to octaarginine. This molecular transporter has been used to deliver therapeutic agents such as taxol, cyclosporine A, SN-38, rapamycin, peptides, proteins, siRNA, plasmid DMA, metals, imaging agents and even magnetic particles. A variety of release mechanisms have been developed. The transporter technology and bioreleasable linker strategies developed in our laboratories have numerous applications which transcend the focus of this particular effort and could have applications for the entire field of drug delivery as well as conjugation chemistry. With the growing importance of selectivity in the delivery of therapeutic agents, we can apply methods previously developed in our lab related to drug delivery and expand on this methodology to realize the goal of selective delivery to gastrointestinal cancers, as well as other diseases. All facets of this application that rely on molecular detection and visualization can be facilitated and enhanced through access to design and synthetic expertise available in the core laboratory. Aim 3: Work with investigators and the FDA to first develop and then get approval for new reagents that can be used in the Gl tract for imaging and therapy. Development of new selective probe and therapeutic agents for the detection and treatment of gastrointestinal cancers is intended for eventual application in a clinical setting. The Wender lab has experience in this area with the development of octaarginine-cyclosporine A agents for the topical treatment of psoriasis, with conjugates advancing into Phase II human clinical trials. Studies have also been advanced based on IP, ocular, buccal, and lung drug administration, procedures that not unlike the proposed colon studies involve local administration. This expertise is available to enable and facilitate the design, synthesis, and evaluation of new probes and drug conjugates as needed to achieve the aims of the program.