涎腺ACC细胞外泌体传递非编码RNA恶性转化雪旺细胞表达嗜神经侵袭特性的机制研究

Tumor-derived exosomes are important carrier for materials exchange and information communication between cancer and adjacent normal cells. Exosomes, which contain numerous bioactive compounds, regulate the signaling network and malignant transformation in target cells. The applicant found that tumor-derived exosomes selectively accumulated some genetic materials and protein in our research. By further identification of the key signaling compounds, we propose the hypothesis that salivary adenoid cystic carcinoma cells introduce non-coding RNA (miRNA and lncRNA) into Schwann's cells by secreting exosomes. The miRNA and lncRNA in exosomes induce malignant transformation of Schwann's cells through inducing changes in epigenetic, transcriptional and post-transcriptional levels. These changes will improve the neural invasion and tumor progression of ACC. We planned in this project to identify the relationship between exosomes-mediated intracellular communication, malignant transformation of Schwann's cells and tumor progression in different models using gene microarray assay, downstream signaling pathway examination, malignant transformation assessment. These results will provide new insight into cancer therapy.

外泌体是肿瘤细胞与邻近细胞进行物质交换和信息交流的重要载体，其丰富的信号物质影响目标细胞的信号网络和生物学转化。我们前期研究发现肿瘤细胞外泌体特异性富集某些遗传物质和蛋白，通过深入分析其中关键信号物质，我们提出：涎腺ACC细胞可通过释放外泌体，将含有恶性信号的非编码RNA(miRNA和lncRNA)导入雪旺细胞中。外泌体中具有关键诱导能力的miRNA和lncRNA通过引起表观遗传学、转录和转录后水平改变，诱导雪旺细胞发生恶性转化，呈现ACC的嗜神经侵袭表型并促进肿瘤发展。本课题拟采用基因芯片筛选、靶基因和下游信号通路检测、恶性转化效应评估等检测方法，从分子、细胞和动物水平探讨肿瘤外泌体介导的细胞间信号传导、恶性转化神经鞘膜细胞表达嗜神经侵袭特性及其与肿瘤演进的关系，为肿瘤治疗提供新思路。

外泌体是细胞主动向胞外分泌的纳米级小囊泡，近年来研究发现肿瘤细胞可通过分泌包含多种信号物质的外泌体，影响肿瘤微环境中正常细胞的生物学功能。在本课题中，我们系统性地比较了人涎腺腺样囊性癌与正常涎腺组织来源的外泌体中的miRNA和lncRNA表达谱，发现人涎腺腺样囊性癌细胞来源的外泌体中特异性地富集多种miRNA和lncRNA，生物信息学分析发现这些异常表达的miRNA和lncRNA涉及多条肿瘤相关信号通路。通过小RNA测序技术发现RSC96雪旺细胞摄取人涎腺腺样囊性癌细胞分泌的外泌体后，可导致RSC96细胞内的小RNA表达谱出现显著变化，生物信息学分析发现变化的miRNA涉及癌症相关通路。最后，我们发现人涎腺腺样囊性癌细胞来源的外泌体可促进RSC96细胞增殖、迁移和侵袭，并诱导增殖相关标志物和外泌因子表达。我们从芯片结果中筛选出miR-762、miR-1249-3p、miR-296-5p，通过过表达实验发现这三个miRNA可能是人涎腺腺样囊性癌外泌体中的关键miRNA。通过本课题，我们获得了人涎腺腺样囊性癌外泌体中差异表达miRNA和lncRNA数据库，为深入探索涎腺腺样囊性癌嗜神经侵袭相关机制打下基础。