外泌体中转录因子簇通过活化c-MYC超级增强子促进鼻咽癌血管拟态及转移的机制

Distant metastasis is the main cause of death among nasopharyngeal carcinoma (NPC) patients. Studies have reported that vasculogenic mimicry (VM) is closely associated with tumor metastasis. Our studies have shown that VM has important associations with the metastasis and the prognosis of NPC; exosomes derived from NPC tissues with metastasis might promote the formation of VM; High-throughput sequencing shows that c-JUN、NACA、NME2 are highly expressed in exosomes derived from NPC tissues with metastasis; RNA-seq shows that these genes could regulate the transcript of c-MYC; the transcription of c-MYC is drived by super-enhancers. In view of this, c-JUN、NACA、NME2 in exosomes derived from NPC tissues with metastasis could activate super-enhancer–driven c-MYC to increase the transcription of c-MYC. And then the target genes of c-MYC are activated to promote VM formation and tumor metastasis. In this study, firstly, EMSA and ChIP will be used to investigate the mechanism of c-JUN、NACA and NME2 in regulating the transcription of c-MYC. Secondly, we will use cas9 to knock out super-enhancer–driven c-MYC. Furthermore, we will analyze the main part of super-enhancer in regulating the transcription of c-MYC. Lastly, we will investigate the relationship of super-enhancer–driven c-MYC with VM and the metastasis of NPC in vivo and in vitro. Our study might help to know the mechanism of exosomes in VM formation. What’s more, our research might help to clarify the mechanism of NPC metastasis.

远处转移是鼻咽癌（NPC）致死的主要因素，血管拟态(VM)与肿瘤转移密切相关。我们预实验发现VM与NPC转移及预后相关；有转移的NPC组织来源外泌体可促进VM形成；高通量组学发现转移组外泌体高表达c-JUN、NACA、NME2；二代测序分析上述基因可调控c-MYC转录活性；而c-MYC转录活性受超级增强子驱动。据此提出: NPC组织外泌体中c-JUN、NACA、NME2通过激活c-MYC关联超级增强子促进c-MYC转录活性，激活靶基因表达继而促进VM形成及肿瘤转移。本课题拟进一步通过EMSA、ChIP探究c-JUN、NACA、NME2调控c-MYC转录活性的具体机制；采用cas9敲除c-MYC超级增强子，分析外泌体中转录因子簇调控c-MYC转录的主要增强子组分，体内体外明确c-MYC超级增强子与VM及NPC转移的关系。本项目有助于深入理解外泌体调控VM的详细机制，有助于阐明NPC转移机制。