Investigation of NRF2-Dependent Metabolic Liabilities

代谢重新编程发生在肿瘤发生过程中，并有望用于癌症治疗。然而， 控制这些代谢改变的潜在机制及其对肿瘤维持的贡献 通常都是缺乏的。在15%-34%的非小细胞肺癌中发现NRF2及其负调控因子Keap1的突变 细胞肺癌(NSCLC)，并导致结构性的NRF2活性。许多受NRF2监管的过程集中在 氨基酸合成抗氧化剂谷胱甘肽的生产与利用 半胱氨酸、甘氨酸和谷氨酸。在我们之前的工作中，我们发现谷胱甘肽的合成对 NRF2在肿瘤发生过程中的促增殖作用。此外，我们发现NRF2促进新陈代谢 重新布线以增加甘氨酸的利用率，以支持谷胱甘肽的合成。要定义NRF2如何构成 活性诱导代谢重新编程以支持GSH合成，我们产生了基因工程， 癌症突变NRF2D29H和KEAP1R554Q的条件性敲入小鼠模型。我们的预赛 对NRF2调节代谢的分析表明，半胱氨酸双加氧酶(CDO1)限制谷胱甘肽 由NRF2产生，产生有毒副产品，在肿瘤形成期间被沉默。我们已经建立了一个 分析含硫代谢物的代谢组学平台和基因工程NRF2 和Keap1突变的肺癌小鼠模型进行体内研究，现在准备定义肿瘤 CDO1及其代谢产物在肺肿瘤发生中的抑制作用 在目标1中，我们将研究CDO1是否通过以下方式拮抗NRF2调节的抗氧化反应 半胱氨酸消耗殆尽。 在目标2中，我们将检测CDO1表达对具有NRF2活性的细胞的选择性毒性 副产品生产。 在目标3中，我们将使用我们的基因工程技术研究CDO1缺失是否促进肺肿瘤的发生 Keap1和NRF2突变的小鼠肺肿瘤模型和患者肿瘤样本。 该项目的最终目标和总体影响是将CDO1描述为一种新的代谢易感性 对于具有NRF2/Keap1突变的肿瘤，以便为患者确定治疗干预的机会 这些突变目前缺乏有针对性的治疗。

Metabolic reprogramming occurs during tumorigenesis and holds promise for cancer therapy. However, the underlying mechanisms that control these metabolic alterations and their contribution to tumor maintenance are generally lacking. Mutations in NRF2 and its negative regulator KEAP1 are found in 15-34% of non-small cell lung cancer (NSCLC) and lead to constitutive NRF2 activity. Many NRF2-regulated processes center on the production and utilization of the antioxidant glutathione, which is synthesized from the amino acids cysteine, glycine and glutamate. In our previous work, we found that glutathione synthesis was critical for the pro-proliferative effects of NRF2 during tumor initiation. Furthermore, we found that NRF2 promotes metabolic rewiring to increase glycine availability to support glutathione synthesis. To define how constitutive NRF2 activity induces metabolic reprogramming to support GSH synthesis, we generated genetically engineered, conditional knock-in mouse models of the cancer mutations NRF2D29H and KEAP1R554Q. Our preliminary analysis of NRF2-regulated metabolism indicates that cysteine dioxygenase (CDO1) limits glutathione production by NRF2, produces toxic byproducts, and is silenced during tumorigenesis. We have established a metabolomics platform for the analysis of sulfur-containing metabolites, and a genetically engineered NRF2 and KEAP1 mutant lung cancer mouse models for in vivo studies and are now poised to define the tumor suppressive role of CDO1 and its metabolites during lung tumorigenesis. In Aim 1 we will examine the whether CDO1 antagonizes the NRF2-regulated antioxidant response by depleting cysteine. In Aim 2 we will examine the selective toxicity of CDO1 expression to cells with NRF2 activity due to toxic byproduct production. In Aim 3 we will examine whether CDO1 loss promotes lung tumorigenesis using our genetically engineered KEAP1 and NRF2 mutant mouse lung tumor models and patient tumor samples. The ultimate goal and the overall impact of this project are to characterize CDO1 as a novel metabolic liability for tumors with NRF2/KEAP1 mutations in order to define opportunities for therapeutic intervention for patients with these mutations, which currently lack targeted therapy.