Targeting Glutamine Uptake via ASCT2 Inhibition in MYCN-amplified Neuroblastomas

神经母细胞瘤（NB）是儿童最常见的颅外实体瘤。约25%的NBs和近一半的高风险NBs存在mycn扩增。N-MYC是一种驱动癌细胞生长、血管生成和代谢的原癌基因。谷氨酰胺代谢异常是myc驱动的癌症的一个标志。N-MYC增强谷氨酰胺转运蛋白ASCT2的表达。ASCT2已被证明对体外mycn扩增的NB细胞存活和体内皮下异种移植物形成至关重要。我们的中心假设是，通过ASCT2的异常谷氨酰胺摄取对mycn扩增的NB原发肿瘤的生长和转移至关重要。我们将利用CRISPR-Cas9敲除和V-9302（一种小分子ASCT2抑制剂），在mycn扩增NB的3-D类器官和患者来源的原位异种移植（PDOX）模型中确定ASCT2在NB中的关键作用。稳定同位素分解代谢组学将用于定义在ASCT2阻断存在下激活以维持NB存活的异常代谢途径。我们还将利用无偏倚的CRISPR-Cas9谱系辍学筛选来确定ASCT2抑制所揭示的代谢脆弱性，以评估mycn扩增的NB细胞的双重合成致死性。

Neuroblastoma (NB) is the most common extracranial solid tumor in children. MYCN-amplification is present in ~25% of NBs and nearly half of all high-risk NBs. N-MYC is a proto-oncogene that drives cancer cell growth, angiogenesis, and metabolism. Aberrant glutamine metabolism is a hallmark of MYC-driven cancers. N-MYC enhances expression of the glutamine transporter, ASCT2. ASCT2 has been shown to be critical for MYCN-amplified NB cell survival in vitro and in subcutaneous xenograft formation in vivo. Our central hypothesis is that aberrant glutamine uptake via ASCT2 is critical for MYCN-amplified NB primary tumor growth and metastasis. We will define the critical role of ASCT2 in NB utilizing CRISPR-Cas9 knockout and V-9302, a small molecule ASCT2 inhibitor, in 3-D organoid and patient-derived orthotopic xenograft (PDOX) models of MYCN-amplified NB. Stable-isotope resolved metabolomics will be used to define aberrant metabolic pathways activated to sustain NB survival in the presence of ASCT2 blockade. We will also seek to define metabolic vulnerabilities uncovered by ASCT2 inhibition utilizing an unbiased CRISPR-Cas9 lineage dropout screen to assess for dual synthetic lethality in MYCN-amplified NB cells.