Targeting Malic Enzyme 3 as a Synthetic Lethality Target in Pancreatic Cancer

将苹果酸酶 3 作为胰腺癌的合成致死靶点

• 批准号: 10241331
• 负责人: Prasenjit Dey
• 金额: $ 24.9万
• 依托单位: ROSWELL PARK CANCER INSTITUTE CORP
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-09-01 至 2022-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10241331
• 关键词: 3-Dimensional; 5' -AMP-activated protein kinase; Address; Affect; Allosteric Site; Attention; Binding; Biological Assay; Biological Models; Branched-Chain Amino Acids; Bypass; CRISPR/Cas technology; Catabolism; Cell Death; Cell Survival; Cells; Collection; Computer Models; Data; Databases; Dimerization; Drug Design; Enzymes; Event; Extinction (Psychology); Future; Genes; Genetic Transcription; Genome; Genomics; Glutamates; Glutamine; Goals; Grant; Housekeeping; Housekeeping Gene; In Vitro; Individual; Investigation; Lead; MADH4 gene; Maintenance; Malignant Neoplasms; Malignant neoplasm of pancreas; Mediating; Metabolic; Mitochondria; Modeling; Molecular; Molecular Target; NADP; Natural regeneration; Neoplasm Metastasis; Nitrogen; Nucleotide Biosynthesis; Oncogenes; Outcome; Pancreatic Ductal Adenocarcinoma; Patients; Pharmaceutical Preparations; Play; Production; Protein Isoforms; Proteins; Regulation; Resistance; Role; Route; SRE-1 binding protein; Site; Site-Directed Mutagenesis; Specificity; Structure; Survival Rate; System; Testing; Tetanus Helper Peptide; Therapeutic; Tumor Burden; Tumor Suppressor Genes; Validation; alpha ketoglutarate; amino group; base; branched-chain-amino-acid transaminase; cancer survival; computer cluster; experimental study; gain of function mutation; genomic locus; high end computer; high throughput screening; in silico; in vivo; in vivo Model; inhibitor/antagonist; insight; malic enzyme; metabolic abnormality assessment; metabolomics; molecular targeted therapies; mouse model; mutant; nucleobase; pancreatic ductal adenocarcinoma cell; precision medicine; small molecule; therapeutic target; therapy resistant; tumor; tumor progression; uptake; virtual screening

Project Summary/Abstract Pancreatic ductal adenocarcinoma (PDAC) is the most common cancer of the pancreas and 5-year survival rate for PDAC patients is a dreadful ~6%. PDAC genome sustains frequent deletion of tumor suppressor gene loci, most notably SMAD4, which is homozygously deleted in approximately 30% of cases. As loss of neighboring housekeeping genes can confer collateral lethality, I sought to determine whether loss of the metabolic gene malic enzyme (ME) 2 in the SMAD4 locus would create a cancer-specific metabolic vulnerability upon targeting its paralogous isoform ME3. Using in vitro and in vivo model system, I demonstrated that ME3 depletion in ME2 null PDAC cells causes cell death. Mechanistically, integrated metabolomic and molecular investigation of mitochondrial ME-deficient cells revealed diminished NADPH production and consequent high ROS which activates AMP activated protein kinase (AMPK), and which in turn suppresses BCAT2 (Branched chain amino acid transaminase 2) gene via sterol regulatory element-binding protein 1 (SREBP1)-directed transcription. BCAT2 catalyzes the transfer of the amino group from branched chain amino acids (BCAA) to alpha-ketoglutarate (αKG) thereby regenerating glutamate, which functions in part to support de novo nucleobase synthesis. In summary, this data shows that mitochondrial ME is required for pancreatic cancer survival and can be exploited as vulnerability for treatment. The goal of the project is to determine the druggability of ME in PDAC. In order to achieve this goal, I propose the following: 1) Systematic validation of Malic Enzyme as a therapeutic target in pancreatic cancer, 2) Mechanistic understanding of metabolic deregulation upon ME3 extinction; 3) Identification of selective ME3 inhibitors. By addressing the above aim, I will gain further insights into the structural features of ME3 and generate a blueprint for rational drug design to target ME3. Moreover, I will also identify the potential resistance or metabolic bypass mechanism of ME3 treatment by tracing metabolites such as BCAA and glutamine. Moreover, my unique understanding of the BCAA regulation will identify new avenues for targeting surrogate target of ME3. Finally, will undertake structure-function analysis of ME3 and validate the top hits identified by in-silico analysis.

项目概要/摘要 胰腺导管腺癌 (PDAC) 是最常见的胰腺癌症，5 年生存率 PDAC 患者的发病率高达 6% 左右。 PDAC基因组持续频繁缺失抑癌基因 位点，最显着的是 SMAD4，它在大约 30% 的病例中被纯合删除。由于损失 相邻的管家基因可以赋予附带致死性，我试图确定是否失去了 SMAD4 基因座中的代谢基因苹果酸酶 (ME) 2 将产生癌症特异性代谢 针对其旁系同源异构体 ME3 的漏洞。使用体外和体内模型系统，我 证明 ME2 缺失的 PDAC 细胞中 ME3 耗尽会导致细胞死亡。机械化、一体化 线粒体 ME 缺陷细胞的代谢组学和分子研究显示 NADPH 减少 产生并随后激活 AMP 激活蛋白激酶 (AMPK) 的高 ROS，进而激活 AMP 激活蛋白激酶 (AMPK) 通过甾醇调节元件结合抑制 BCAT2（支链氨基酸转氨酶 2）基因 蛋白 1 (SREBP1) 指导的转录。 BCAT2 催化氨基从支链转移 链氨基酸（BCAA）转化为α-酮戊二酸（αKG），从而再生谷氨酸，谷氨酸在 部分支持从头核碱基合成。总之，该数据表明线粒体 ME 是必需的 胰腺癌的生存率，并可作为治疗的脆弱性。该项目的目标是 确定 ME 在 PDAC 中的成药性。为了实现这一目标，我提出以下建议：1）系统化 验证苹果酸酶作为胰腺癌治疗靶点，2) 机制理解 ME3 灭绝时代谢失调； 3）选择性ME3抑制剂的鉴定。通过解决 为了实现上述目标，我将进一步深入了解ME3的结构特征，并生成合理的蓝图 针对 ME3 的药物设计。此外，我还将确定潜在的阻力或代谢旁路 通过追踪支链氨基酸和谷氨酰胺等代谢物来了解 ME3 治疗的机制。而且，我独特的 了解 BCAA 法规将确定针对 ME3 替代靶标的新途径。最后， 将进行 ME3 的结构功能分析并验证通过计算机分析确定的热门命中。