Hyperpolarized 13C probes for the one carbon metabolism

用于一碳代谢的超极化 13C 探针

• 批准号: 10647293
• 负责人: Zoltan Kovacs
• 金额: $ 45.1万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10647293
• 关键词: Adult; Anabolism; Attention; Back; Biochemical Pathway; Biological; Cancer Patient; Carbon; Cell Culture Techniques; Cell Proliferation; Cell physiology; Cells; Chemicals; Citric Acid Cycle; Communities; Cytoplasm; Cytosol; Development; Enzymes; Excretory function; Folic Acid; Formates; Funding; Generations; Glycine; Glycine Hydroxymethyltransferase; Glycolysis; Hematoma; Human; Image; In Vitro; Label; Magnetic Resonance Imaging; Malignant Neoplasms; Metabolic; Metabolism; Mitochondria; Monitor; Neoplasm Metastasis; Nuclear; Nucleotide Biosynthesis; Nucleotides; Organ; Oxidoreductase; Pathway interactions; Pattern; Phospholipids; Polyamines; Primary carcinoma of the liver cells; Process; Production; Prognosis; Proliferating; Rattus; Reaction; Relaxation; Role; Running; S-Adenosylhomocysteine; S-Adenosylmethionine; Serine; Signal Transduction; Source; Testing; Tetrahydrofolates; Time; Tissues; Tracer; Visualization; Warburg Effect; Xenograft procedure; cancer cell; cancer type; clinical translation; experience; hepatoma cell; imaging modality; in vivo; liver cancer model; magnetic resonance spectroscopic imaging; non-invasive imaging; nucleotide metabolism; overexpression; preservation; real time monitoring; tumor

Abstract One-carbon metabolism is a network of fundamental metabolic and biosynthetic pathways that occur in the cytoplasm and the mitochondria. Central to one-carbon metabolism is the folate cycle. This involves the activation and transfer of serine hydroxymethyl group to tetrahydrofolate intermediates and eventually formate, which is then converted back into serine to via the same intermediates. The folate cycle provides activated one carbon units for the biosynthesis of a variety of biomolecules necessary for normal cellular function and proliferation, most importantly, nucleotides. The activity of one-carbon metabolism is upregulated in cancer cells to support high rates of proliferation. The folate cycle is highly compartmentalized with separate sets of enzymes in the cytosol and in the mitochondria. When there is an increased need for one-carbon units for nucleotide biosynthesis, the cytosolic and mitochondrial folate cycles run in the opposite direction. The mitochondrial folate pathway produces formate, which is transported into the cytosol where it enters the folate cycle to produce activated one-carbon units for biosynthesis. In many types of cancer cells, the mitochondrial formate production exceeds the biosynthetic demand. Excess formate is excreted from these cells in a process known as formate overflow. Despite its great biological importance and central role in cancer, currently there is no clinically translatable, non–invasive imaging method for the real time monitoring of one carbon metabolism and formate overflow in vivo. In this R21 application we propose to use deuterated, 13C-labeled serines as hyperpolarized 13C-tracers to monitor one carbon metabolic activity and formate overflow in vivo by 13C magnetic resonance spectroscopic imaging. As serine is the main source of one carbon units, 13C-labeled serines are ideal probes for the mitochondrial folate cycle. Aim 1 will focus on the synthesis and in vitro characterization of deuterated, 13C-labeled serines as hyperpolarized 13C probes for the one carbon metabolism. In Aim 2, we will test the hyperpolarized probes in hepatoma cell cultures and in vivo in normal and orthotopic xenograft rat model for hepatocellular carcinoma. By the end of the two year funding period we expect to have demonstrated that upregulated mitochondrial folate pathway can be visualized in hepatoma bearing rats by 13C magnetic resonance spectroscopic imaging.

摘要 一碳代谢是一个基本的代谢和生物合成途径的网络， 细胞质和线粒体。一碳代谢的核心是叶酸循环。这涉及 丝氨酸羟甲基的活化和转移为四氢叶酸中间体并最终形成甲酸盐， 然后通过相同的中间体将其转化回丝氨酸。叶酸循环提供激活的 用于生物合成正常细胞功能所必需的各种生物分子的碳单元， 增殖，最重要的是核苷酸。一碳代谢的活性在癌症中上调 细胞以支持高增殖率。叶酸循环是高度区室化的，具有独立的组， 细胞质和线粒体中的酶。当对一碳单位的需求增加时， 在核苷酸生物合成中，胞质和线粒体叶酸循环以相反的方向运行。的 线粒体叶酸途径产生甲酸，甲酸被转运到胞质溶胶中，在胞质溶胶中进入叶酸 循环以产生用于生物合成的活性一碳单元。在许多类型的癌细胞中，线粒体 甲酸盐的生产超过了生物合成的需求。过量的甲酸盐从这些细胞中排出， 称为甲酸盐溢流。尽管它在癌症中具有重要的生物学意义和核心作用，但目前 没有临床上可转换的、非侵入性的成像方法用于真实的时间监测一碳代谢 和体内甲酸盐溢出。在该R21应用中，我们提出使用氘代的13 C标记的丝氨酸作为 超极化~（13）C示踪剂在体内监测一碳代谢活性和甲酸盐溢出 磁共振波谱成像由于丝氨酸是一个碳单元的主要来源，13 C-标记的 丝氨酸是线粒体叶酸循环的理想探针。目标1将集中在合成和体外 氘代13 C标记的丝氨酸作为一个碳原子的超极化13 C探针的表征 新陈代谢.在目标2中，我们将在肝癌细胞培养物和正常人体内测试超极化探针。 和肝细胞癌的原位异种移植大鼠模型。在两年的资助期结束时，我们 我希望已经证明，上调的线粒体叶酸途径可以在肝癌中可视化 13 C磁共振波谱成像。