Biology of major folate transporters and STING signaling in cancer

主要叶酸转运蛋白的生物学和癌症中的 STING 信号传导

• 批准号: 10597540
• 负责人: Zhanjun Hou
• 金额: $ 7.7万
• 依托单位: WAYNE STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-04-05 至 2025-03-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10597540
• 关键词: Adenosine Monophosphate; Agonist; Anions; Area; Bacteria; Biology; CD8B1 gene; Cell membrane; Cell model; Cells; Clinical; Clinical Data; Clinical Trials; Code; Complex; Coupled; Cyclic GMP; Cytosol; DNA; Dinucleoside Phosphates; Dose; Endoplasmic Reticulum; Ensure; Environment; Epigenetic Process; Folic Acid; Folic Acid Deficiency; Frequencies; Genetic Polymorphism; Genetic Transcription; Genomics; Goals; Human; Immune; Immune checkpoint inhibitor; Infection; Infiltration; Inflammatory Response; Interferon Type I; Interferons; Investigational Drugs; Lesion; Lymphoma; Malignant Neoplasms; Mammalian Cell; Methotrexate; Molecular; Mus; Pathway interactions; Patients; Pemetrexed; Periodicity; Phase I Clinical Trials; Physiological; Positioning Attribute; Post-Transcriptional Regulation; Protons; Publishing; Radiation therapy; Regulation; Reporting; Research; Role; SLC19A1 gene; Signal Transduction; Solid Neoplasm; Source; Specificity; Stimulator of Interferon Genes; Structure; Substrate Specificity; System; T-Lymphocyte; Tetrahydrofolates; Therapeutic; Therapeutic Effect; Tissues; Tumor Immunity; analog; cancer cell; cancer immunotherapy; checkpoint therapy; clinical efficacy; clinical translation; cytokine; ds-DNA; extracellular; folate-binding protein; human tissue; immunogenicity; improved; inhibitor therapy; innate immune sensing; insight; neoplastic cell; novel; overexpression; pharmacologic; pre-clinical; preclinical study; promoter; protein protein interaction; response; sensor; success; symporter; tool; tumor; tumor growth; uptake

ABSTRACT In mammalian cells, cyclic dinucleotides (CDNs) act as prominent danger signals that are sensed by the innate immune sensor, stimulator of interferon genes (STING). Activation of STING elicits a signaling cascade that culminates in the induction of type I interferons (IFNs) and various cytokines, thereby promoting a powerful inflammatory response. Mammalian cells are able to produce their own CDNs, catalyzed by the cyclic guanosine monophosphate–adenosine monophosphate (GMP-AMP) synthase (cGAS), which is activated by double-strand DNAs to synthesize the eukaryotic CDN, 2′3′-cGAMP. Beyond intracellular CDNs, STING-activating CDNs can originate from extracellular sources, such as therapeutic CDNs, cGAMP produced by tumor cells, and CDNs from extracellular bacteria. The role of the cGAS-STING pathway in anti-tumor immunity supports the use of STING agonists as cancer therapeutics. Inspired by the discovery that 2′3′-cGAMP activates human STING to initiate robust downstream IFN signaling, STING-activating agents (mostly 2′3′-cGAMP analogues) were synthesized. Direct pharmacologic activation of STING was shown to restrict tumor growth by a T cell-driven tumor regression mechanism and to enhance immunogenicity. Administration of cGAMP in tumor-bearing mice also potentiated the therapeutic effects of immune-checkpoint inhibitors and radiotherapy. Based on results with CDN analogs in mice, two phase I clinical trials were initiated for the intra-tumoral delivery of STING agonists (ADU-S100 and MK-1454) to solid tumors and lymphomas. Despite the impressive anti-tumor activity of STING agonists in mice, initial results from clinical trials of such agonists have indicated a lower efficacy in humans. The regulatory interplay among the import, export and degradation of CDNs remains an important and interesting area for future research. Exogenous 2′3′-cGAMP and synthetic CDNs, including the investigational new drug (IND) 2′3′-CDAS used in cancer immunotherapy, traverse the cell membrane through the reduced folate carrier (RFC; SLC19A1) to activate STING in target cells, and the proton-coupled folate transporter (PCFT; SLC46A1) enhances such response. RFC and PCFT are major facilitative transporters of folate in human tissues and tumors. PCFT is unique from RFC in that it has an acidic rather than neutral pH optimum. RFC and PCFT share substrates such as clinically used methotrexate and pemetrexed but also show their own unique substrate specificities. Our group has studied RFC and PCFT structure, function and regulation extensively. In this R03 application, we explore the unique biology of RFC, as well as PCFT, and STING agonists in cancer, with a goal of further understanding CDN uptake by these facilitative transporters and, by extension, improving therapeutic applications. We propose in Aim 1 to study mechanisms of CDN uptake by RFC and PCFT under physiological conditions. In Aim 2, we will study the molecular regulation of RFC in relation to CDN uptake, including transcriptional epigenetics, and the potential role of protein-protein interactions in regulating RFC. Our proposed studies are distinctive for their novelty and potential for clinical translation.

抽象的 在哺乳动物细胞中，环状二核苷酸（CDN）起到了天生感所感知的明显危险信号 免疫传感器，干扰素基因的刺激剂（STING）。激活刺激引起信号级联 最终导致I型干扰素（IFN）和各种细胞因子的诱导，从而促进了强大的 炎症反应。哺乳动物细胞能够产生自己的CDN，并由环状鸟氨酸催化 单磷酸 - 腺苷单磷酸盐（GMP-AMP）合酶（CGA），该合酶被双链激活 DNA合成真核CDN，2'3'-cgamp。除了细胞内CDN之外，激活的CDN可以 起源于细胞外来源，例如治疗性CDN，由肿瘤细胞产生的CGAMP和来自 细胞外细菌。 CGAS刺途径在抗肿瘤免疫中的作用支持刺激的使用 激动剂作为癌症治疗。受到2'3'-cgamp激活人刺的发现的启发 合成了强大的下游IFN信号传导，刺激激活剂（主要是2'3'-cgamp类似物）。 刺激的直接药理激活显示可通过T细胞驱动的肿瘤限制肿瘤的生长 回归机制并增强免疫原性。在承肿的小鼠中给予CGAMP 增强了免疫检查抑制剂和放射疗法的治疗作用。基于结果 小鼠中的CDN类似物，开始了两项I期临床试验，以进行肿瘤内刺激性激动剂的肿瘤内递送 （ADU-S100和MK-1454）用于实体瘤和淋巴瘤。尽管刺痛具有令人印象深刻的抗肿瘤活性 小鼠的激动剂，此类激动剂的临床试验的初步结果表明，人类的效率较低。 CDN的进出口，出口和降解之间的监管相互作用仍然很重要， 未来研究的有趣领域。外源2'3'-cgamp和合成CDN，包括研究 新药（IND）2'3'-CDA用于癌症免疫疗法，通过还原的细胞膜穿越细胞膜 叶酸载体（RFC; SLC19A1）激活靶细胞中的刺激，以及质子偶联的叶酸转运蛋白（PCFT； SLC46A1）增强了这种反应。 RFC和PCFT是人类组织中叶酸的主要最爱转运蛋白 和肿瘤。 PCFT是RFC独特的，因为它具有酸性而不是中性pH最佳。 RFC和PCFT 共享基材，例如临床使用的方法传记酸盐和Pemetrex，但也显示了自己独特的底物 特殊性。我们的小组已广泛研究了RFC和PCFT结构，功能和调节。在此R03中 应用，我们探讨了RFC，PCFT的独特生物学以及癌症中的激动剂，其目标 进一步了解这些友好运输者的CDN吸收，并扩展 治疗应用。我们建议在AIM 1中研究RFC和PCFT的CDN吸收机制 生理条件。在AIM 2中，我们将研究与CDN吸收相关的RFC的分子调节， 包括转录表观遗传学，以及蛋白质蛋白相互作用在RENING RFC中的潜在作用。 我们提出的研究对于它们的新颖性和临床翻译潜力而言是独特的。