Therapeutic Targeting of Novel Antifolates to Solid Tumors via Folate Receptor

新型抗叶酸药物通过叶酸受体靶向治疗实体瘤

• 批准号: 8257420
• 负责人: Shermaine Kimberly Mitchell
• 金额: $ 3.66万
• 依托单位: WAYNE STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-03-01 至 2015-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8257420
• 关键词: Adverse effects; Alimta; Apical; Architecture; Biological; Biological Models; Blood; Bone Marrow; Brain; Carrier Proteins; Clinical Trials; Coupled; Cytotoxic agent; DNA; DNA biosynthesis; Development; Diagnostic Neoplasm Staging; Disease; Drug Delivery Systems; Educational process of instructing; Epithelial ovarian cancer; Europe; Exhibits; Fellowship; Folate; Folic Acid; Folic Acid Antagonists; Generations; Hematopoietic Neoplasms; Image; In Vitro; Intervention; Intracellular Membranes; Lead; Malignant Neoplasms; Malignant neoplasm of ovary; Mammalian Cell; Mesothelioma; Metabolism; Methods; Methotrexate; Non-Small-Cell Lung Carcinoma; Normal Cell; Normal tissue morphology; Nucleotide Biosynthesis; Nucleotides; Operative Surgical Procedures; Ovarian Carcinoma; Ovary; Pathway interactions; Patients; Pattern; Pemetrexed; Pharmaceutical Preparations; Population; Process; Production; Protons; Purine Nucleotides; Purines; Pyrimidine; Pyrimidine Nucleotides; Reaction; Reporting; Research; SLC19A1 gene; Series; Signal Pathway; Solid; Solid Neoplasm; Staging; System; Therapeutic; Time; Toxic effect; Transmembrane Transport; Tumor stage; Uterus; Water-Soluble Vitamin; anticancer research; apical membrane; base; basolateral membrane; career; chemotherapy; cofactor; cytotoxic; design; folate-binding protein; human FOLR1 protein; human FRAP1 protein; in vivo; in vivo Model; inhibitor/antagonist; interest; killings; mTOR Signaling Pathway; membrane polarity; neoplastic cell; new therapeutic target; novel; nucleotide metabolism; ovarian neoplasm; overexpression; purine; receptor; receptor density; tool; treatment strategy; tumor; tumor specificity; uptake

Antifolates such as methotrexate were originally developed as valuable chemotherapy agents to treat hematopoietic malignancies. More recently, newer antifolates were developed for treating solid tumors. Pemetrexed (Pmx, Alimta) was approved in 2004 for treating non-small cell lung cancer and mesothelioma. While Pmx shows antitumor activity, this agent lacks tumor selectivity and induces toxicity. The latter has been attributed to intracellular membrane transport of Pmx by Reduced Folate Carrier (RFC). RFC is a ubiquitously expressed folate facilitative transport protein that is present in both tumor and normal cells such as bone marrow. Folate Receptors (FRs) are an alternative mechanism for internalizing (anti)folates. FR¿, unlike other folate transport proteins is only expressed basolaterally and is exposed to circulating blood in tumors, in contrast to its apical localizationin normal tissues. In conjunction with this abnormal cellular architecture in tumors, FR¿ is also overexpressed in a variety of malignancies including those of the ovaries, uterus and brain. Approximately 90% of epithelial ovarian cancers have been reported to exhibit elevated expression of FR¿ with receptor densities correlating to tumor grade and stage. I hypothesize that the differential expression of FR¿ in solid (ovarian) tumor cells enables tumor targeting of novel cytotoxic antifolates, reflecting selectivity for cellular uptake by FR¿ over RFC. I further hypothesize that novel FR¿ antifolate substrates that inhibit de novo purine nucleotide biosynthesis show tumor selectivity due to the absence of purine salvage and/or indirectly target downstream AMPK and mTOR signaling pathways. Antifolate therapeutics directed to FR¿ and to specific folate-dependent intracellular targets will induce selective killing of tumor cells and reduce toxicity. To investigate this hypothesis, I propose the following specific aims: (Aim 1) to develop novel solid tumor-targeted antifolate therapeutics with selective membrane transport by FR¿ over RFC that target de novo purine nucleotide biosynthesis and downstream signaling pathways (e.g., AMPK, mTOR); and (Aim 2) to identify determinants of cytotoxic activity and selectivity for the aforementioned solid tumor targeted agents in in vitro and in vivo model systems. To complete these aims, I will screen a series of rationally designed folate analogs and determine their antiproliferative and cytotoxic potencies via purine nucleotide depletion and their preferred mechanisms of membrane transport. I will establish their detailed mechanisms including cellular metabolism, intracellular targets, and impact on downstream signaling pathways. I will determine cellular determinants of drug activity including the impact of purine salvage and the presence or absence of other folate transport systems on drug activity. Finally I will establish in vivo efficacies within the broader context of these cellular determinants. Curren treatment strategies for late stage ovarian cancer are often ineffective and are associated with toxic side effects. Hence, there is a compelling rationale for developing newer FR-targeted therapies for treating ovarian carcinomas.

抗染料（如方法二羟基）最初是作为有价值的化学疗法剂而开发的，用于治疗造血性恶性肿瘤。最近，开发了用于治疗实体瘤的较新的抗染料。 Pemetrexed（PMX，Alimta）于2004年批准用于治疗非小细胞肺癌和间皮瘤。虽然PMX表现出抗肿瘤活性，但该剂缺乏肿瘤选择性和诱导的毒性。后者归因于叶酸载体（RFC）的细胞内膜转运。 RFC是一种普遍表达的叶酸基本转运蛋白，在肿瘤和正常细胞（例如骨髓）中呈现。叶酸受体（FRS）是内化（抗）叶酸的替代机制。与其他叶酸转运蛋白不同，与其他叶酸转运蛋白不同，与其正常组织的顶端定位相比，肿瘤中的血液循环。结合肿瘤中这种异常的细胞结构，Fr fr在包括卵巢，子宫和大脑在内的各种恶性肿瘤中也过表达。据报道，大约90％的上皮卵巢癌表现出升高的FR表达，受体密度与肿瘤级和阶段相关。我假设在固体（卵巢）肿瘤细胞中FR的差异表达能够靶向新型的细胞毒性抗染料，从而反映了Fr fr froof to rfc对细胞摄取的选择性。我进一步假设抑制从头嘌呤核卫星生物合成的新型抗叶酸底物显示出由于缺乏嘌呤打捞和/或间接靶向下游AMPK和mTOR信号通路，因此显示出肿瘤的选择性。针对FR的抗叶酸疗法和特定的叶酸依赖性细胞内靶标将诱导肿瘤细胞和 降低毒性。为了研究这一假设，我提出了以下特定目的：（目标1）通过fr fr fr fr的RFC开发新型的实体瘤抗卵巢疗法，而靶向从Novo De Nevo purine purine Not Purine Noto-Otide生物合成和下游信号通路（例如Ampk，mtor）； （AIM 2）确定在体外和体内模型系统中大约实体肿瘤靶向剂的细胞毒性活性和选择性的确定性。为了完成这些目标，我将筛选一系列理性设计的叶酸类似物，并通过嘌呤核卫星部署及其对膜运输的首选机制来确定它们的抗增殖和细胞毒性电位。我将建立他们的详细机制，包括细胞代谢，细胞内靶标以及对下游信号通路的影响。我将确定药物活性的细胞确定，包括购买打捞的影响以及其他叶酸转运系统对药物活性的影响。最后，我将在这些细胞决定剂的更广泛背景下建立体内效率。晚期卵巢癌的Curren治疗策略通常无效，并且与毒性副作用有关。因此，有一个令人信服的理由，用于开发新的FR靶向疗法来治疗卵巢癌。