环状RNA编码蛋白调控FOXC1活性对神经母细胞瘤天冬氨酸代谢的作用及机制研究

天冬氨酸促进神经母细胞瘤(NB)增殖及侵袭，但代谢基因表达调控机制不明。我们发现：转录因子叉头框C1(FOXC1)与DEAD盒RNA解旋酶5(DDX5)相互作用，促进NB天冬氨酸合成、转运基因(GOT2、SLC1A6)表达；DDX5环状RNA(circDDX5)编码蛋白(DDX5-326aa)能结合FOXC1，降低GOT2及SLC1A6启动子活性。据此提出“DDX5-326aa通过拮抗DDX5与FOXC1相互作用，抑制GOT2、SLC1A6表达及天冬氨酸代谢”假说。本项目拟解析NB中FOXC1结合DDX5、招募组蛋白乙酰化酶对GOT2及SLC1A6表达、天冬氨酸代谢的影响；观测FOXC1与DDX5-326aa、DDX5相互作用；明确circDDX5编码蛋白调控FOXC1活性对GOT2及SLC1A6表达、NB天冬氨酸代谢、增殖及侵袭转移的作用，阐明天冬氨酸代谢调控机理，为NB治疗提供新思路。

Aspartate promotes the proliferation and invasion of neuroblastoma (NB), while the mechanisms regulating its metabolic gene expression still remain elusive. Our results showed that transcription factor forkhead box C1 (FOXC1) was able to interact with DEAD box RNA helicase 5 (DDX5), and facilitate the expression of aspartate biosynthesis and transport genes, glutamic-oxaloacetic transaminase 2 (GOT2) and solute carrier family 1 member 6 (SLC1A6) in NB. Meanwhile, DDX5-326aa, a protein encoded by DDX5-derived circular RNA (circDDX5), bound to FOXC1 and inhibited the promoter activity of GOT2 and SLC1A6. Therefore, we hypothesized that DDX5-326aa might suppress expression of GOT2 and SLC1A6 and aspartate metabolism via repressing the interaction between DDX5 and FOXC1. This project is proposed to investigate the binding of FOXC1 to DDX5, subsequent recruitment of histone acetyltransferase, and their effects on GOT2 and SLC1A6 expression as well as aspartate metabolism in NB. The interaction of FOXC1 with DDX5-326aa or DDX5 will be explored, while the effects of DDX5-326aa-regulated FOXC1 activity on expression of GOT2 and SLC1A6, aspartate metabolism, proliferation, invasion, and metastasis of NB will also be clarified. This study will elucidate the regulatory mechanisms of aspartate metabolism, and provide novel strategies for the treatment of NB.