MYCN drives a ferroptotic vulnerability in neuroblastoma

项目概述：细胞凋亡是一种程序性细胞死亡，长期以来一直受到重视， 是癌细胞的标志近年来，靶向凋亡途径的药物，如FDA- 已批准的BCL-2抑制剂维奈托克已经彻底改变了具有特定 针对这一途径的脆弱性。一种不同的程序性细胞死亡途径，铁凋亡，最近 被发现了解哪些癌症可能容易诱导铁凋亡， 靶向分子的参与可能会导致新一波成功的癌症治疗。MYCN扩增 神经母细胞瘤（NB）是儿科癌症中最致命的亚型之一。在这里，我们证明， 扩增的MYCN驱动NB中异常的铁捕获程序并增加细胞内半胱氨酸 生物合成和硒代半胱氨酸依赖通过多种机制解毒活性氧 物种（ROS）的积累作为高细胞铁的结果。这些MYCN导向的结果 变化是对谷胱甘肽/谷胱甘肽过氧化物酶的遗传或药物靶向的合成致死性 4（GPX 4）途径导致铁凋亡细胞死亡。这笔赠款旨在扩大我们对如何 MYCN改变半胱氨酸和硒代半胱氨酸的产生和铁凋亡诱导途径，以维持一种新的代谢途径。 抗氧化防御以及这些途径如何在药学上被利用来改善治疗 在这种恶性肿瘤中的反应。 具体目标： 目的1：描述MYCN抑制神经母细胞瘤中铁下垂的能力 目的2：MYCN扩增的神经母细胞瘤中合成致死性铁凋亡抗性机制的鉴定 目的3：在MYCN扩增的神经母细胞瘤小鼠模型中，评估新型铁结合疗法 研究设计：使用充分表征的等基因细胞系和患者来源的异种移植细胞培养物，我们将 动员硒代半胱氨酸生物合成（Copeland）、泛酸激酶抑制剂（Rock）方面的专业知识， 铁凋亡途径调节剂的基因组筛选（Olzmann），以更好地定义铁凋亡的脆弱性， MYCN扩增的NB和发现新的致敏剂，以铁蛋白诱导剂在MYCN扩增的NB。目标 这些实验的目的不仅是更好地了解MYCN癌基因如何劫持半胱氨酸， 生产硒代半胱氨酸是为了防御氧化表型，但也是为了创造新的治疗方法 以在MYCN扩增的NB中创建更好的抗铁凋亡方法。为此，我们将与我们的临床前 小鼠模型专家（Koblinski）和NB临床研究者（Glod），以建立 合成致命的新疗法进入临床难治性NB患者。

Project Summary: Apoptosis is a type of programmed cell death and has for a long time been appreciated to be a hallmark of cancer cells. In recent years, drugs targeting the apoptotic pathway, such as the FDA- approved BCL-2 inhibitor, venetoclax, have revolutionized therapy in cancers which have a particular vulnerability to targeting this pathway. A different programmed cell death pathway, ferroptosis, has recently been discovered. Understanding which cancers may be vulnerable to the induction of ferroptosis and which targetable molecules are involved could lead to a new wave of successful cancer therapy. MYCN-amplified neuroblastoma (NB) is one of the deadliest subtypes of pediatric cancer. Here in, we demonstrate that amplified MYCN drives an aberrant iron capture program in NB and increases intracellular cysteine biosynthesis and selenocysteine dependence through multiple mechanisms to detoxify reactive oxygen species (ROS) accumulation as a result of high cellular iron. The consequence of these MYCN-directed changes is a synthetic lethality to genetic or pharmaceutical targeting of the glutathione/glutathione peroxidase 4 (GPX4) pathway resulting in ferroptotic cell death. This grant aims to expand our understanding of how MYCN alters cysteine and selenocysteine production and ferroptotic inducing pathways to sustain an antioxidant defense and how these pathways may be exploited pharmaceutically to improve therapeutic responses in this recalcitrant tumor type. Specific Aims: Aim 1: Characterize the ability of MYCN to suppress ferroptosis in neuroblastoma Aim 2: Identification of synthetic lethal ferroptosis resistance mechanisms in MYCN-amplified neuroblastoma Aim 3: In MYCN-amplified neuroblastoma mouse models, evaluate novel ferroptotic combination therapies Study Design: Using well characterized isogenic cell lines and patient-derived xenograft cell cultures, we will mobilize expertise in selenocysteine biosynthesis (Copeland), pantothenate kinase inhibitors (Rock), and genomic screening of ferroptotic pathway modifiers (Olzmann) to better define the ferroptotic vulnerability in MYCN-amplified NB and to uncover novel sensitizers to ferroptotic inducers in MYCN-amplified NB. The goal of these experiments is to not only better understand how the MYCN oncogene hijacks cysteine for selenocysteine production to mount a defense against an oxidized phenotype, but to create new therapeutics to create better anti-ferroptotic approaches in MYCN-amplified NB. To this end, we will work with our preclinical mouse model expert (Koblinski) and a NB clinical investigator (Glod) to build the preclinical evidence of synthetic lethal new therapies into the clinic for refractory NB patients.