Inhibitors of Tyrosine Kinase-Dependent Signalling as An

酪氨酸激酶依赖性信号传导抑制剂

• 批准号: 7290820
• 负责人: TERRENCE BURKE
• 金额: --
• 依托单位: DIVISION OF BASIC SCIENCES - NCI
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7290820
• 关键词: Inhibitors; Tyrosine; Kinase; Dependent; Signalling

Pharmacological agents are being developed to modulate phosphotyrosyl (pTyr) dependent cell signalling. Emphasis is on inhibitors of pTyr dependent binding interactions, which are mediated by src homology 2 (SH2) domains and on protein tyrosine phosphatase (PTP) inhibitors. In the SH2 domain area, development of cell permeable growth factor receptor-bound protein 2 (Grb2) antagonists is being undertaken as potential new therapeutics for a variety of cancers including erbB-2 and Met dependent cancers. During the reporting period novel macrocycles were prepared that represented conformationally constrained tetrapeptide-mimicking variants of our earlier tripeptide inhibitors. In an effort to explore and extend the macrocyclization approach a variety of new chemistries were examined. These include a several different olefin methasis reactions, [2+3] azide - alkyne cycloaddition reactions and ring closure using beta-aminomethylene groups. These investigations have advanced the field of macrocyclic peptidomimetic synthesis. As part of a collaborative effort with NCI clinical investigators, Grb2 signaling inhibitors were studied against von Hippel-Lindau (VHL)-dependent kidney cancers that rely on Grb dependent signaling pathways. In cellular studies, certain of these agents inhibit hepatocyte growth factor (HGF)-induced cell migration in Met containing fibroblasts at nanomolar concentrations and inhibit tubule formation potentially involved in angiogenesis. Metastasis model animal studies are currently ongoing. Biotinylated variants of select potent Grb2 SH2 domain signaling inhibitors were also prepared and are being used as pharmacological tools to identify intracellular targets. Efforts were also begun to develop SH2 domain-directed peptide mimetic inhibitors of Shc-dependent signaling. Shc proteins are non-catalytic SH2 domain-containing docking modules that participate in a variety of cell-regulatory processes associated with proliferation, survival and apoptosis. Shc as well as Grb2 proteins are particularly important for down stream signaling of receptor tyrosine kinases (RTKs), where they have been shown to link activation of the cytoplasmic kinase domains with Ras effectors. Shc has also been shown to serve as a critical angiogenic switch for VEGF production downstream from the Met and ErbB2 RTK oncoproteins, where recruitment of Shc but not Grb2 has been shown to be a required event. Accordingly, disruption of Shc-dependent signaling through blockade of its SH2 domain interactions may afford a new therapeutic approach to cancers reliant on disregulation of such RTKs. In the phosphatase area, a structure-based approach toward PTP inhibitor design has been pursued. Using as a display platform, a tripeptide sequence derived from an epidermal growth factor receptor (EGFr) autophosphorylation site, we had previously examined a panel of synthetic pTyr mimetics for inhibitory potencies against YopH, which is a pathogenic PTP component of Yersinia pestis, the causative agent of plague. Certain of these tripeptides exhibited binding constants in the single-digit micromolar range. Work during the reporting period continued to optimize these tripeptide leads as potential therapeutics for the treatment of plague. Currently, known high affinity YopH inhibitors are being prepared for co-crystallography with the YopH protein and X-ray crystallographic structure determination. Information gained in this way will be used to design focused libraries of inhibitors. Inhibitors derived from this work may have therapeutic value against the use of Yersinia pestis as a bioterrorism agent.

正在开发用于调节磷酸酪氨酸（pTyr）依赖性细胞信号传导的药理学试剂。重点是pTyr依赖性结合相互作用的抑制剂，这是由src同源2（SH 2）结构域介导的和蛋白酪氨酸磷酸酶（PTP）抑制剂。在SH 2结构域领域，正在开发细胞渗透性生长因子受体结合蛋白2（Grb 2）拮抗剂，作为多种癌症（包括erbB-2和Met依赖性癌症）的潜在新疗法。在本报告期间，制备了新型大环化合物，其代表我们早期三肽抑制剂的构象受限的四肽模拟变体。为了探索和扩展大环化方法，研究了各种新的化学。这些包括几种不同的烯烃甲基化反应、[2+3]叠氮化物-炔环加成反应和使用β-氨基亚甲基的闭环反应。这些研究推进了大环肽模拟物的合成领域。作为与NCI临床研究人员合作的一部分，研究了Grb 2信号传导抑制剂对依赖Grb依赖性信号传导途径的von Hippel-Lindau（VHL）依赖性肾癌的作用。在细胞研究中，这些药物中的某些在纳摩尔浓度下抑制含Met的成纤维细胞中肝细胞生长因子（HGF）诱导的细胞迁移，并抑制可能参与血管生成的小管形成。转移模型动物研究目前正在进行中。还制备了选择有效Grb 2 SH 2结构域信号传导抑制剂的生物素化变体，并将其用作鉴定细胞内靶点的药理学工具。还开始努力开发SH 2结构域定向的Shc依赖性信号传导的肽模拟物抑制剂。Shc蛋白是一种非催化性的含SH 2结构域的对接模块，参与与增殖、存活和凋亡相关的多种细胞调节过程。Shc以及Grb 2蛋白对于受体酪氨酸激酶（RTK）的下游信号传导特别重要，其中它们已显示将胞质激酶结构域的激活与Ras效应物连接。Shc也被证明是Met和ErbB 2 RTK癌蛋白下游VEGF产生的关键血管生成开关，其中Shc而不是Grb 2的募集被证明是必需的事件。因此，通过阻断其SH 2结构域相互作用来破坏Shc依赖性信号传导可以为依赖于这种RTK失调的癌症提供新的治疗方法。在磷酸酶领域，已经追求了PTP抑制剂设计的基于结构的方法。使用作为展示平台，来自表皮生长因子受体（EGFr）自磷酸化位点的三肽序列，我们以前研究了一组合成的pTyr模拟物对YopH的抑制效力，YopH是鼠疫耶尔森氏菌的致病性PTP组分，鼠疫的病原体。这些三肽的结合常数在个位数微摩尔范围内。本报告所述期间的工作继续优化这些三肽先导物作为治疗鼠疫的潜在疗法。目前，正在制备已知的高亲和力YopH抑制剂，用于与YopH蛋白的共晶体学和X射线晶体结构测定。以这种方式获得的信息将用于设计抑制剂的集中库。从这项工作中得到的抑制剂可能对鼠疫耶尔森氏菌作为生物恐怖剂的使用具有治疗价值。