Targeting antioxidant vulnerabilities in KEAP1/NRF2 mutant NSCLC

转录因子NRF2是细胞氧化还原平衡的中央调节因子。NRF2基因突变及其阴性 在15-34%的非小细胞肺癌(NSCLC)中发现了调节因子Keap1。这些突变的结果是 NRF2的结构性激活和一组NRF2靶基因的慢性诱导，从而产生抗性 化疗/放射治疗。尽管以NRF2为靶点具有巨大的治疗潜力，但目前还没有有效的策略 抑制致病的Keap1/NRF2信号转导的后果。因此，至关重要的是要确定和 了解Keap1/NRF2突变NSCLC的脆弱性以开发有效的治疗方法 这些突变。NRF2控制许多抗氧化酶的转录，从而调节 活性氧物种的解毒。然而，在很大程度上还不清楚哪种特定的抗氧化剂。 酶可以在治疗上靶向逆转NRF2/Keap1突变对 氧化应激，化疗/放射治疗的关键介体。谷胱甘肽(GSH)/GSH还原酶(GSR)和 硫氧还蛋白(TXN)/硫氧还蛋白还原酶(TXNRD)是两种平行的、补偿硫醇依赖的抗氧化剂 关键调节和维持细胞硫醇氧化还原动态平衡和蛋白质二硫醇/二硫键的途径 平衡。我的初步结果表明，GSR和TXNRD1都是由NRF2激活强烈诱导的 并导致了对抗氧化剂治疗的内在抵抗力。然而，它们在不同的领域发挥着独特的作用 细胞隔间。具体地说，NRF2诱导的GSR作用于保护线粒体免受氧化，而 TXNRD1保护胞浆。此外，TXNRD1上调与抑制其他 提示NRF2的激活导致了硒分布的不平衡。给出了钥匙 硒蛋白在氧化还原生物学中的作用，氧化还原生物学是氧化还原诱导不同硒蛋白产生的开关 NRF2激活可能会导致具有治疗潜力的NRF2活动性非小细胞肺癌的新的脆弱性。这项建议 旨在通过定义GSR如何贡献的机制基础来进一步加强这些观察 NRF2介导的抗氧化性，并利用不平衡的硒蛋白翻译来 为Keap1/NRF2突变的非小细胞肺癌制定有效的治疗策略。我们追求以下具体目标 目的：1.研究GSR在NRF2介导的氧化应激抵抗中的作用。目标2. 明确NRF2在非小细胞肺癌中作为硒蛋白质组调节器的作用。知识和科学专长 我从这些拟议的研究中学到的东西将有助于我过渡到一个独立的职位。我的长期生活 目标是研究癌症中的抗氧化酶，主要集中在硒蛋白上。除 科学目标，我已经概述了一个详细的职业发展计划，以获得领导一个 研究实验室，建立强大的研究计划。我将进行拟议的研究并进行 在我的指导委员会的指导下制定了培训计划。我会走上优秀的学术道路 莫菲特癌症中心为实现这些目标提供了环境，并过渡到一个独立的位置。

The transcription factor NRF2 is a central regulator of cellular redox balance. Mutations in NRF2 and its negative regulator KEAP1 are found in 15-34% of non-small cell lung cancer (NSCLC). The result of these mutations is constitutive NRF2 activation and chronic induction of a battery of NRF2 target genes, which confers resistance to chemo/radiation therapy. While targeting NRF2 holds great therapeutic potential, there is no effective strategy to inhibit the consequences of pathogenic KEAP1/NRF2 signaling. It is therefore critical to identify and understand vulnerabilities of KEAP1/NRF2 mutant NSCLC to develop effective therapies for patients harboring these mutations. NRF2 controls the transcription of many antioxidant enzymes, thereby regulating the detoxification of reactive oxygen species. However, it remains largely unknown which specific antioxidant enzymes can be therapeutically targeted to reverse the profound resistance of NRF2/KEAP1 mutations to oxidative stress, the key mediator of chemo/radiation therapy. Glutathione (GSH)/GSH reductase (GSR) and thioredoxin (TXN)/thioredoxin reductase (TXNRD) are two parallel, compensating thiol-dependent antioxidant pathways that critically regulate and maintain cellular thiol redox homeostasis and protein dithiol/disulfide balance. My preliminary results indicate that both GSR and TXNRD1 are strongly induced by NRF2 activation and contribute to the intrinsic resistance to the pro-oxidant therapies. However, they play unique roles in different cellular compartments. Specifically, NRF2 induced GSR acts to protect mitochondria from oxidation, while TXNRD1 protects the cytosol. Further, TXNRD1 upregulation is associated with the suppression of other selenoproteins, suggesting that NRF2 activation causes an imbalance in selenium distribution. Given the key role of selenoprotein in redox biology, the switch in the production of the different selenoproteins induced by NRF2 activation may create novel vulnerabilities of NRF2 active NSCLC with therapeutic potential. This proposal is designed to further strengthen these observations by defining the mechanistic basis of how GSR contributes to NRF2-mediated resistance to oxidative stress, and to leverage the imbalanced selenoprotein translation to develop potent therapeutic strategies for KEAP1/NRF2 mutant NSCLC. The following specific aims are pursued in this application: Aim 1. Investigate the role of GSR in NRF2-mediated resistance to oxidative stress. Aim 2. Define the role of NRF2 as a modulator of the selenoproteome in NSCLC. The knowledge and scientific expertise that I acquire from these proposed studies will facilitate my transition to an independent position. My long-term goal is to study the antioxidant enzymes in cancer, with a major focus on selenoproteins. In addition to the scientific goal, I have outlined a detailed career development plan to obtain skillsets that are key for leading a research laboratory and establishing a strong research program. I will conduct the proposed research and carry out the training plan under the guidance of my mentoring committee. I will embark on the excellent academic environment provided by Moffitt Cancer Center to achieve these goals and transition to an independent position.