Purine Synthesis Inhibitors with Selective Folate Receptor Tumor Transport

具有选择性叶酸受体肿瘤转运的嘌呤合成抑制剂

• 批准号: 8810225
• 负责人: Charles E. Dann
• 金额: $ 55.82万
• 依托单位: DUQUESNE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-02-05 至 2017-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8810225
• 关键词: 4-Aminobenzoic Acid; 5' -AMP-activated protein kinase; Affinity; Aminopterin; Anabolism; Antineoplastic Agents; Binding; Blood Circulation; Breast; Cell Death; Cell Line; Cells; Cervical; Chemotherapy-Oncologic Procedure; Chinese Hamster; Clinical; Clinical Trials; Collaborations; Coupled; Crystallization; Development; Dose-Limiting; Drug Design; Drug Transport; Drug usage; Endometrial; Enzymes; Equilibrium; Evaluation; Exhibits; Failure; Folic Acid; Folic Acid Antagonists; Glycine; Goals; Hamsters; Hand; Health; Human; Hydroxymethyltransferases; Implant; In Situ; In Vitro; Intracellular Transport; Kidney; Label; Lead; Literature; Lometrexol; Lung; Malignant Neoplasms; Malignant neoplasm of ovary; Measures; Metabolic; Metabolism; Methotrexate; Modeling; Molecular; Molecular Target; Non-Small-Cell Lung Carcinoma; Normal Cell; Nucleosides; Nucleotide Biosynthesis; Nucleotides; Ovarian; Ovary; Partner in relationship; Pathway interactions; Patients; Pattern; Pemetrexed; Pharmaceutical Preparations; Pharmacology; Property; Protons; Pteridines; Purine Nucleotides; Purines; Radiolabeled; Raltitrexed; Recombinants; Resistance; Ribonucleotides; Roentgen Rays; SCID Mice; SKOV3 cells; SLC19A1 gene; Series; Signal Transduction; Specificity; Staging; Structural Biologist; Structure; System; Testing; Thiophenes; Thymidylate Synthase; Toxic effect; Treatment Failure; Tumor Cell Line; analog; antitumor agent; apical membrane; base; cancer cell; cancer therapy; cellular targeting; chemotherapeutic agent; cytotoxic; cytotoxicity; design; drug development; efficacy trial; folate-binding protein; glycine amide; human FRAP1 protein; imidazole-4-carboxamide; imidazolecarboxamide; improved; in vivo; inhibitor/antagonist; killings; kinase inhibitor; nano; neoplastic cell; novel; overexpression; polyglutamate; purine; radiotracer; receptor expression; subcutaneous; tumor; tumor specificity; tumor xenograft; uptake

DESCRIPTION (provided by applicant): The failure of cancer chemotherapy can be attributed in large measure to a lack of tumor selectivity of chemotherapeutic agents. Currently approved antitumor antifolates, methotrexate, pemetrexate, raltitrexed and pralatrexate, are all transported by the ubiquitous, reduced folate carrier (RFC) into both tumor and normal host cells, and hence are nonselective for tumor cells and are consequently toxic. If an agent could selectively attack only cancer cells, a qualitative and not just a quantitative difference between cancer cells and normal cells would be at hand for exploitation. We have discovered compounds that specifically target tumor cells by selective transport by folate receptor (FR) -? and -?. These are folic acid transport systems (almost) exclusively expressed by several tumor cells (e.g., ovarian, non-small cell lung cancer, endometrial, renal, breast, cervical, lung) but nt normal cells. Our compounds, once selectively transported into tumors, target the de novo purine nucleotide biosynthesis pathways dependent on folate, i.e. glycinamide ribonucleotide formyltransferase (GARFTase) or 5-amino-4- imidazolecarboxamide ribonucleotide (AICAR) formyltransferase (AICARFTase). These are both novel enzyme targets, as there are no known clinical agents that target de novo purine biosynthesis as their primary mechanism of action. Antipurine antifolates are cytotoxic independent of p53 status. Selectivity of antipurine agents can result from the loss of purine salvage in a large number of human tumors. Inhibition of AICARFTase causes an accumulation of AICAR (ZMP) that, via AMPK, inhibits mTOR, resulting in an additional mechanism of cytotoxic antitumor activity. The goal of this proposal is to optimize our lead structures for tumor specificity via FR? and -? over RFC, and GARFTase or AICARFTase inhibitory activities. In Aim 1, we will synthesize novel analogs from 16 series (two in each series) based on structure-activity profiles of our lead compounds. In Aim 2, we will evaluate compounds from Aim 1 for cytotoxicity in isogenic hamster and human tumor cell line models with established RFC and FR expression, and will identify molecular mechanisms including cellular targets by nucleoside protection, in situ metabolic labeling, analysis of intracellular metabolites, and studies with isolated enzymes. Additional studies will characterize transport properties of the novel analogs with FRs vis ¿ vis RFC, polyglutamate synthesis, and mechanisms of cell death. In Aim 3, we will determine in vivo efficacies of the most potent FR-targeted GARFTase or AICARFTase inhibitors by in vivo toxicity and efficacy trials in FR-expressing human tumor implants in SCID mice. Finally, in Aim 4, we will determine X-ray crystal structures of the most potent and selective analogs with FR? and/or -?, as well as GARFTase or AICARFTase. All the Specific Aims will be performed concurrently from year 1 to year 5. Collectively, our studies will afford a molecular understanding of the interactions of nove analogs with FRs and enzyme targets to guide the design of selective analogs. We anticipate advancing one or more of our novel folate analogs with optimized FR-selective antitumor agents to clinical trials to be used alone or in combination with other agents.

描述（申请人提供）：癌症化疗的失败在很大程度上可归因于化疗药物缺乏肿瘤选择性。目前批准的抗肿瘤抗叶酸药物，甲氨蝶呤、培美曲沙、雷替曲塞和普拉曲沙，均通过普遍存在的还原叶酸载体（RFC）转运至肿瘤和正常宿主细胞中，因此对肿瘤细胞没有选择性，因此具有毒性。如果一种试剂可以选择性地只攻击癌细胞，那么癌细胞和正常细胞之间的定性差异（而不仅仅是定量差异）就可以被利用。我们发现了通过叶酸受体 (FR) 选择性转运来特异性靶向肿瘤细胞的化合物 -?和 -？。这些叶酸转运系统（几乎）仅由几种肿瘤细胞（例如卵巢癌、非小细胞肺癌、子宫内膜癌、肾癌、乳腺癌、宫颈癌、肺癌）表达，但正常细胞不表达。我们的化合物一旦选择性转运到肿瘤中，就会靶向依赖叶酸的从头嘌呤核苷酸生物合成途径，即甘氨酰胺核糖核苷酸甲酰基转移酶（GARFTase）或5-氨基-4-咪唑甲酰胺核糖核苷酸（AICAR）甲酰基转移酶（AICARFTase）。这些都是新的酶靶标，因为没有已知的临床药物以从头嘌呤生物合成为主要作用机制。安替嘌呤抗叶酸药物的细胞毒性与 p53 状态无关。抗嘌呤药物的选择性可能是由于大量人类肿瘤中嘌呤补救措施的丧失所致。抑制 AICARFTase 会导致 AICAR (ZMP) 积累，通过 AMPK 抑制 mTOR，从而产生细胞毒性抗肿瘤活性的额外机制。该提案的目标是通过 FR 优化我们的肿瘤特异性先导结构？和 -？ RFC、GARFTase 或 AICARFTase 抑制活性。在目标 1 中，我们将根据先导化合物的结构活性特征合成 16 个系列（每个系列两个）的新型类似物。在目标 2 中，我们将评估目标 1 中的化合物在已建立 RFC 和 FR 表达的同基因仓鼠和人类肿瘤细胞系模型中的细胞毒性，并将确定分子机制，包括通过核苷保护、原位代谢标记、细胞内代谢物分析和分离酶研究来确定细胞靶点。其他研究将表征新型类似物与 FR 相对于 RFC 的转运特性、聚谷氨酸合成和细胞死亡机制。在目标 3 中，我们将通过在 SCID 小鼠中表达 FR 的人类肿瘤植入物中进行体内毒性和功效试验，确定最有效的 FR 靶向 GARFTase 或 AICARFTase 抑制剂的体内功效。最后，在目标 4 中，我们将确定 FR? 最有效和选择性类似物的 X 射线晶体结构？和/或-？，以及GARFTase或AICARFTase。所有具体目标将从第一年到第五年同时进行。总的来说，我们的研究将从分子角度理解新型类似物与 FR 和酶靶点的相互作用，以指导选择性类似物的设计。我们预计将一种或多种新型叶酸类似物与优化的 FR 选择性抗肿瘤药物一起推进到临床试验中，以单独使用或与其他药物联合使用。