NEAT1募集剪接蛋白PTBP1参与AKT1剪接成熟调节脑胶质瘤免疫抑制机制的研究

NEAT1 is an oncogenic gene in glioma, which accelerates the growth, invasion and anti-apoptosis in glioma. However, its potential mechanism regulating glioma immunosuppression remains to be mined. Our bioinformatic analysis revealed that NEAT1 was closed to immunosuppression in glioma. PTBP1 which is a splicing protein could bind NEAT1 and AKT1 through ChIRP-MS and CLIP-Seq assays. PTBP1 expression differed significantly in WHO grade and the highest expression was observed in GBM (WHO IV). High expression of PTBP1 resulted in a significantly shorter overall survival time. On the basis of our previous results, we mainly focus on the immunosuppressive role of NEAT1 in gliomas, and will carry out the following work: (1) to investigate the lncRNA and RBP complex composing of NEAT1, NONO and PSF participate in the recruitment of splicing protein PTBP1 in glioma; (2) to explore the effect of PTBP1 on the malignant biological behaviors such as proliferation and invasion of glioma in vitro and in vivo; (3) to confirm the effect that NEAT1 participates in the splicing and maturation of AKT1 through recruiting PTBP1; (4) to illustrate the mechanism NEAT1 participates in immunosuppression of glioma by mediating AKT1 splicing and maturation via PTBP1 to enhance epigenetic transcription regulation; (5) to further prove that NEAT1 involves in immunosuppression of glioma by mediating AKT1 splicing and maturation via PTBP1 to epigenetic transcription regulation in vivo. Our work would provide theoretical and experimental basis for the research of NEAT1 for immunosuppression of glioma.

脑胶质瘤中lncRNA NEAT1是重要的致癌基因。申请人前期通过生物信息学发现NEAT1与脑胶质瘤免疫抑制密切相关，利用ChIRP-MS实验发现NEAT1能结合剪接蛋白PTBP1，公开数据分析发现PTBP1与脑胶质瘤级别以及预后有相关性，通过CLIP-Seq实验发现PTBP1可同时与pre-AKT1和NEAT1结合。本研究将进一步探索脑胶质瘤中NEAT1参与募集PTBP1的机制；体内外实验明确PTBP1对脑胶质瘤恶性生物学行为的影响；研究脑胶质瘤中NEAT1募集剪接蛋白PTBP1参与AKT1剪接成熟的机制；解析NEAT1/PTBP1/AKT1轴参与脑胶质瘤的免疫抑制的机制；体内实验验证NEAT1募集PTBP1经AKT1调节脑胶质瘤免疫抑制的机制。本研究可揭示NEAT1募集剪接蛋白PTBP1参与AKT1剪接成熟介导脑胶质瘤免疫抑制的分子机制，为脑胶质瘤免疫治疗提供新的理论和实验依据。

肿瘤免疫抑制微环境形成是引起肿瘤患者预后差得主要原因。本课题以肿瘤免疫抑制微环境为重点研究对象，依托高通量检测、生物学技术等方法阐明了肿瘤免疫微环境对肿瘤恶性生物学行为的影响。本项目已按计划完成所有研究内容，取得创新型研究成果，其中研究内容主要集中在以下几个方面：1.申请人利用流式细胞术、原位肿瘤模型等实验揭示了在胶质母细胞瘤中EMP3可抑制T细胞杀伤肿瘤细胞的活性以及在肿瘤组织中的浸润水平，敲除EMP3后可以增加PD-1抑制剂的疗效，研究结果提示了EMP3是肿瘤免疫微环境的重要因子之一，EMP3有望成为胶质母细胞瘤患者评价预后及指导治疗的新靶标。2.通过PCR、Co-IP等实验揭示了在肿瘤细胞中RNA结合蛋白参与转录后调控及其在PD-1 mRNA稳定性中的作用，研究成果揭示了mRNA转录后修饰的一种全新机制。在本课题的支持下，已发表SCI 研究性论文2篇（影响因子均大于10分），会议摘要1篇。