Targeting Serine and Glycine Metabolic Vulnerabilities in Melanoma Brain Metastasis

针对黑色素瘤脑转移中的丝氨酸和甘氨酸代谢漏洞

• 批准号: 10439744
• 负责人: Victoria Margarita Osorio Vasquez
• 金额: $ 4.68万
• 依托单位: NEW YORK UNIVERSITY SCHOOL OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-07-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10439744
• 关键词: Amino Acids; Antioxidants; Brain; Brain Neoplasms; CRISPR/Cas technology; Cell Line; Cell Proliferation; Cells; Cerebrospinal Fluid; Citric Acid Cycle; Clinical; Consumption; Cranial Irradiation; DNA; Data; Dependence; Disease; Doxycycline; Environment; Enzymes; Exhibits; Exposure to; Extracellular Space; Glucose; Glycine; Glycolysis; Growth; Heart; Human; Hydroxymethyltransferases; In Vitro; Injections; Knowledge; Label; Lesion; Luciferases; Lymphoma cell; MEL Gene; Measures; Melanoma Cell; Membrane Lipids; Metabolic; Metabolic Pathway; Metastatic Melanoma; Metastatic malignant neoplasm to brain; Methyltransferase; Mitochondria; Monitor; Mortality Determinants; Mus; Neoplasm Metastasis; Neurotransmitters; Nude Mice; Nutrient; Pathway interactions; Patient-Focused Outcomes; Patients; Phosphoglycerate dehydrogenase; Plasma; Prognosis; Proteins; Proxy; RNA; Research; Serine; Skin Cancer; Survival Rate; System; Testing; Therapeutic; Time; Tumor Burden; bioluminescence imaging; cancer cell; cell growth; conditional knockout; design; experimental study; extracellular; immune checkpoint blockade; improved; in vivo; inhibitor; knock-down; malignant breast neoplasm; melanoma; metabolomics; mortality; new therapeutic target; novel; novel therapeutics; pancreatic cancer cells; prevent; prophylactic; response; small molecule; small molecule inhibitor; standard of care; therapy design; tumor

Project Summary Brain metastases (BM) are a major contributor to mortality in melanoma. BM are found in 44% of Stage IV melanoma patients resulting in a median survival of 4 months and a 5-year survival rate of less than 20%. The poor prognosis of brain metastatic melanoma is due in part to the lack of therapies that provide an effective and durable response. There are no therapies specifically designed to target brain metastases. The brain microenvironment, relative to blood plasma, is unique because it has low concentrations of amino acids. Amongst the most changed amino acids are serine and glycine. The plasma concentration of serine is 114 µM and decreases to 24 µM in the cerebrospinal fluid (CSF), a proxy for amino acid concentrations in the brain. Glycine levels also decrease from 232 µM in plasma to 5 µM in CSF. We have made media that mimics CSF serine and glycine concentrations. My preliminary data shows that two human melanoma cell lines, A375 and SK-MEL-28, have increased serine and glycine synthesis in CSF environments. This suggests that cells become dependent on synthesizing serine and glycine and can be targeted to decrease the viability of melanoma cells. The first and rate-limiting step of serine synthesis is catalyzed by phosphoglycerate dehydrogenase (PHGDH) and can be inhibited using small molecule inhibitors, PH719 and PH755. Glycine is made from serine by serine hydroxy methyltransferase 1/2 (SHMT1/2) and can be targeted by the small molecule inhibitors SHIN1 and AGF347. My initial experiments demonstrate that melanoma cells are sensitized to these serine and glycine synthesis inhibitors in CSF conditions. These data suggest that mice with melanoma BM treated with either PHGDH or SHMT1/2 inhibitors may have decreased brain tumor burden and that this could provide a novel target for patients with BM who otherwise have limited therapeutic options. To determine if our in vitro data are applicable in vivo, we will establish melanoma brain metastases by intracardiac injection of GFP-luciferase-labeled melanoma cell lines into the hearts of NCr-Foxn1nu (Nude) mice. The growth of these cells in mice will be monitored using bioluminescence imaging (IVIS). We will use doxycycline inducible deletion of PHGDH and SHMT1/2 to determine if upon deletion of these enzymes there a reduction in brain lesions. The findings from this study will provide knowledge about the implications of the serine and glycine synthesis pathway in amino acid depleted environments like the brain and provide novel therapeutic targets for BM to improve patient outcomes.

项目摘要 脑转移瘤(BM)是导致黑色素瘤死亡的主要因素。44%的分期中可发现骨髓 IV型黑色素瘤患者的中位生存期为4个月，5年生存率不到20%。 脑转移性黑色素瘤预后不良的部分原因是缺乏有效的治疗方法。 和持久的反应。目前还没有专门针对脑转移瘤的治疗方法。大脑 相对于血浆，微环境是独一无二的，因为它含有较低浓度的氨基酸。 变化最大的氨基酸是丝氨酸和甘氨酸。丝氨酸血药浓度为114微米 并在脑脊液(CSF)中减少到24微米，这是大脑中氨基酸浓度的替代指标。 甘氨酸水平也从血浆中的232微米降至脑脊液中的5微米。我们已经制作了模仿脑脊液的媒体 丝氨酸和甘氨酸浓度。 我的初步数据显示，两个人类黑色素瘤细胞系，A375和SK-MEL-28，已经增加 脑脊液环境中丝氨酸和甘氨酸的合成。这表明细胞变得依赖于合成 丝氨酸和甘氨酸，并可靶向降低黑色素瘤细胞的活力。第一个也是限速 丝氨酸合成步骤是由磷酸甘油酸脱氢酶(PHGDH)催化的，可以用 小分子抑制剂，PH719和PH755。甘氨酸是丝氨酸通过丝氨酸羟甲基转移酶合成的 1/2(SHMT1/2)，可被小分子抑制剂SHIN1和AGF347靶向。我最初的实验 证明黑色素瘤细胞对脑脊液中的丝氨酸和甘氨酸合成抑制物敏感 条件。这些数据表明，患有黑色素瘤BM的小鼠接受PHGDH或SHMT1/2抑制剂治疗 可能减轻了脑肿瘤负担，这可能为患有BM的患者提供了一个新的靶点 否则，治疗选择有限。为了确定我们的体外数据是否适用于体内，我们将 心内注射绿色荧光素酶标记黑色素瘤细胞系建立黑色素瘤脑转移模型 进入NCR-Foxn1nu(裸)小鼠的心脏。这些细胞在小鼠体内的生长将通过 生物发光成像(IVIS)。我们将使用多西环素诱导PHGDH和SHMT1/2的缺失来 确定删除这些酶后，脑部病变是否减少。 这项研究的发现将提供关于丝氨酸和甘氨酸的含义的知识。 在氨基酸缺乏的环境中的合成途径，如大脑，并提供新的治疗靶点 BM以改善患者的预后。