Targeting Ral GTPases in Bladder Cancer

靶向 Ral GTP 酶治疗膀胱癌

• 批准号: 8745033
• 负责人: DAVID ROSS
• 金额: $ 29.48万
• 依托单位: UNIVERSITY OF TX MD ANDERSON CAN CTR
• 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/8745033
• 关键词: Affinity; Allosteric Site; Animal Model; Binding; Binding Sites; Biological Assay; Biological Markers; Bladder; Cancer cell line; Cells; Chemicals; Clinical; Complement; Computer Simulation; Databases; Development; Disease; Docking; Drug Kinetics; Embryo; Enzyme-Linked Immunosorbent Assay; Evaluation; Fibroblasts; Funding; Gene Expression Profile; Generations; Goals; Growth; Guanosine Triphosphate; Guanosine Triphosphate Phosphohydrolases; Human; Immunohistochemistry; In Vitro; Inhibitory Concentration 50; Libraries; Lung; Malignant Neoplasms; Malignant neoplasm of pancreas; Malignant neoplasm of prostate; Malignant neoplasm of urinary bladder; Measures; Mediating; Metastatic Neoplasm to the Lung; Modeling; Molecular; Molecular Conformation; Molecular Target; Mus; NMR Spectroscopy; Neoplasm Metastasis; Nuclear Magnetic Resonance; Nucleotides; Pathway interactions; Patients; Pharmaceutical Chemistry; Phase I Clinical Trials; Positioning Attribute; Process; Progression-Free Survivals; Property; Proteins; Radical Cystectomy; Research; Series; Signal Pathway; Site; Solid; Structure; Therapeutic; Transitional Cell Carcinoma; Translating; Translations; Treatment Efficacy; Urogenital Cancer; Visceral; Work; Xenograft Model; anti-cancer therapeutic; base; cancer cell; cancer type; clinically significant; combinatorial; design; effective therapy; efficacy evaluation; gemcitabine; high risk; human tissue; improved; in vivo; inhibitor/antagonist; interest; member; metastatic process; monolayer; novel; paralogous gene; preclinical evaluation; programs; response; screening; small molecule; success; therapeutic target; three-dimensional modeling; tumor

The last major advance in the treatment of metastatic bladder cancer (BC) took place in 1997 with the advent of gemcitabine. Despite this advance, visceral metastases are usually fatal. The overall goal of the proposed studies is to develop small molecule inhibitors that block a critical node in the metastatic process. We found that Rai GTPases serve as the molecular switches of a therapeutically tractable signaling pathway that allows UC cells to grow in the lung, the most common visceral metastatic site. The clinical significance of this pathway and validity of Rai as a therapeutic target is supported by finding that high Rai expression in tumors places patients at higher risk for metastasis and the requirement of Rai expression for lung metastasis to occur in animal models of UC. Our Guiding Hypothesis for this application is that small molecules targeting Rai provide effective therapy for metastatic UC. With support from the MD Anderson Bladder SPORE Developmental Research Program (DRP), we evaluated >500K compounds for their ability to bind RalA or RalB in computational and combinatorial screens and selected 99 "hits". These were evaluated in a series of secondary assays allowing us to select Rai Binding Compound (RUC)8 and 10 to be pursued in this application. RUC8 and 10 were selected because they: 1) inhibit RalA to RalBPI binding in human UC cells and RalA induced spreading in murine embryo fibroblasts; 2) inhibit in vitro monolayer growth (IC50 0.5-1.9 pM) of human UC cells; 3) bind RalB directly by nuclear magnetic resonance (NMR) spectroscopy; and 4) have good pharmacokinetic (PK) properties in mice (Cmax 1.3-23 pM, T1/2 3.7-4.6 hrs). To develop this novel class of agents we propose the following Specific Aims: Aim 1: Characterize higher potency 2nd generation compounds based on RUC8 and 10 using medicinal chemistry, computational fragment-based design, and similarity search of chemical databases. In the unlikely situation that higher potency compounds are not found in Aim 1, we will pursue Aim 2 and 3 using RUC8 and 10, given their adequate IC50 and in vivo PK. Aim 2: Evaluate 2nd generation compounds for their in vivo therapeutic efficacy in novel human UC models of visceral metastasis. Aim 3: Develop predictive biomarkers of response to antlRal therapeutics in human tissues that will position us for Phase 1 trials by end of this project. Documented interest by Astra Zeneca in our work improves overall chances for success in translating our novel Rai inhibitors into the clinical setting as anticancer therapeutics.

上一次治疗转移性膀胱癌(BC)的重大进展发生在1997年吉西他滨的出现。尽管有这样的进展，内脏转移通常是致命的。拟议研究的总体目标是开发小分子抑制剂，阻断转移过程中的一个关键节点。我们发现，RAI GTP酶作为治疗上易处理的信号通路的分子开关，允许UC细胞在肺中生长，肺是最常见的内脏转移部位。这一途径的临床意义和RAI作为治疗靶点的有效性得到了以下发现的支持：肿瘤中RAI的高表达使患者有更高的转移风险，以及在UC动物模型中肺转移需要RAI的表达。我们对这一应用的指导性假设是靶向RAI的小分子为转移性UC提供了有效的治疗方法。在MD Anderson膀胱孢子发育研究计划(DRP)的支持下，我们在计算和组合筛选中评估了&gt；500K化合物与Rala或RalB结合的能力，并选择了99个“Hit”。在一系列二次化验中对这些进行了评估，使我们能够选择在本申请中要追求的RAI结合化合物(RUC)8和10。选择RUC8和RUC10是因为它们：1)抑制Rala与人UC细胞的RalBPI结合，并抑制Rala诱导的小鼠胚胎成纤维细胞的扩散；2)抑制人UC细胞的体外单层生长(IC50 0.5-1.9 pm)；3)通过核磁共振(NMR)直接结合RalB；以及4)在小鼠体内具有良好的药代动力学(PK)特性(Cmax 1.3-23 pm，T1/2 3.7-4.6小时)。为了开发这类新的试剂，我们提出了以下具体目标：目标1：利用药物化学、基于计算片段的设计和化学数据库的相似性搜索来表征基于RUC8和10的更高效力的第二代化合物。在不太可能的情况下，在目标1中没有发现更高效力的化合物，我们将使用RUC8和10来实现目标2和3，因为它们有足够的IC50和体内PK。目的：评价第二代化合物对新型人UC内脏转移模型的体内治疗效果。目标3：在人体组织中开发对抗肿瘤治疗反应的预测性生物标记物，这将使我们在该项目结束时进入第一阶段试验。阿斯特拉捷利康对我们工作的兴趣被记录在案，这提高了将我们的新型RAI抑制剂作为抗癌疗法转化为临床环境的总体成功机会。