食管癌外泌体中的lncRNAs的筛选鉴定及功能和机制研究

Esophageal carcinoma is one of the most fatal malignant tumors in China, and metastasis is the key factor of its prognosis. In recent years, lncRNAs have been investigated as a research hotspots with biological functions in tumorigenesis. Meanwhile, it has been proved that exosome plays an important role in the progression of tumor, but the function and molecular mechanism of lncRNAs in exosome remains unclear. We have found that the exosomes secreted by highly invasive esophageal cancer cells have the ability to enhance the migration of vascular endothelial cells. Moreover, 1184 lncRNAs have been identified in the exosome secreted from highly invasive esophageal cancer cells compared with poorly invasive esophageal cancer cells by RNA sequencing. These findings indicate that the lncRNAs in the exosomes may play important roles in the metastasis of tumor cells, which is still understudied by now. Here, by comparing the lncRNAs in the exosomes of highly and poorly invasive esophageal cancer cell lines, we plan to identify the metastasis-related lncRNAs within the exosomes, in vivo and in vitro, study the functions and molecular mechanism of the lncRNAs in the tumor microenvironment and identify the molecules that specific interation with these lncRNAs.

食管癌是我国发病率和死亡率较高的恶性肿瘤之一，远处转移是影响其预后的主要因素。近年来，lncRNA在肿瘤中的功能及机制研究成为热点。研究表明外泌体在恶性肿瘤的发展过程中发挥重要作用，但其中lncRNA在肿瘤微环境中的功能及分子机制仍不清楚。通过Transwell模型和划痕实验，我们发现高侵袭性食管癌细胞株的外泌体能够促进血管内皮细胞的迁移能力；通过高通量测序技术，我们筛选出高侵袭性肿瘤细胞外泌体中特异表达的lncRNA共1184条。因此推测外泌体中的lncRNA在介导肿瘤转移过程中可能发挥重要作用，而这方面的研究目前尚属空白。本课题拟通过筛选和鉴定外泌体中与肿瘤转移相关的lncRNA，通过体外细胞培养和体内动物荷瘤鼠模型验证外泌体lncRNA对食管癌体内转移的调控，阐明其对肿瘤微环境中其他细胞的调控作用，并通过寻找与lncRNA相互作用的分子，进一步探讨lncRNA的作用机制。

食管癌是我国发病率和死亡率较高的恶性肿瘤之一，远处转移是影响其预后的主要因素。但其中外泌体包裹的lncRNA在肿瘤微环境中的功能及分子机制仍不清楚。按照原计划，我们成功建立和优化了食管癌外泌体的研究体系。通过对外泌体测序数据以及细胞的转录组测序的整合，对外泌体包裹的lncRNA特征进行了鉴定，并对外泌体包裹的mRNA的参与的信号通路进行了分析。同时，我们对高转移性食管癌细胞外泌体对低转移性细胞的影响进行了鉴定。并且成功的筛选和鉴定出一系列在高转移性食管癌外泌体中表达的lncRNA以及circRNA。此外，进一步的对其中的PCAT1和FULN这两个外泌体包裹的lncRNA在食管癌转移中的功能和机制在体内和体外进行了深入研究。综上，本课题已通过细胞系及食管癌组织鉴定出在转移中起到关键调控的外泌体包裹的lncRNA，并对其关键机制进行了阐明。在此基础上已发表研究论文3篇，本研究为液体活检对食管癌进行早期诊断以及预后判断提供了前期基础。