外泌体包裹lncTh17DI在胃癌微环境Th17细胞分化中的调控作用和机制研究

Th17 cells play an important role in the development of gastric cancer, which was mediated by the elevated level of inflammation in the tumor microenvironment. The mechanism of Th17 differentiation regulation is one of the key issues. Great attention has been paid to the communication between tumor cells and the microenvironment, which was mediated by exosomes and their associated package molecules. The role of exosomes derived from gastric cancer cells in the regulation of Th17 differentiation remains unknown. We focused on the epigenetic regulation of Th17 differentiation in gastric cancer microenvironment in our previous Youth Program. On this basis, we enriched exosomes derived from gastric cancer cells to perform high-throughput sequencing. The results showed that long non-coding RNA lnc AK037891 was significantly enriched in exosomes derived from gastric cancer cells. When the exosomes were co-cultured with CD4+T cells, we found that lnc AK037891 could enter T cells. More surprisingly, the differentiation of Th17 cells was dramatically enhanced. Therefore, we named lnc AK037891 as lncTh17DI (differentiation inducer). Accordingly, we aim to explore the role of lncTh17DI packaged in the exosomes derived from gastric cancer cells in the regulation of Th17 differentiation, so as to suggest new mechanisms and intervention targets for gastric cancer.

胃癌微环境中Th17细胞在促进肿瘤微环境炎症及其介导的胃癌进展中发挥重要作用，肿瘤微环境中Th17的分化调控机制是其中关键的科学问题。肿瘤细胞相关外泌体及其包裹分子在肿瘤细胞和微环境细胞间的通讯目前受广泛关注，胃癌相关外泌体在微环境Th17细胞分化中的作用目前未知。申请人前期青年项目关注胃癌微环境中Th17细胞分化的表观遗传调控机制，在此基础上，我们富集胃癌细胞外泌体并进行高通量测序，发现胃癌细胞外泌体中长链非编码RNA lnc AK037891显著富集。将上述富集的外泌体加入CD4+T细胞培养，发现lnc AK037891能够进入T细胞，并导致Th17分化增加，因此，我们将此lncRNA命名为lncTh17DI。据此，本工作拟探求胃癌外泌体包裹lncTh17DI在胃癌微环境Th17细胞分化中的调控作用和机制，以期提出胃癌肿瘤微环境形成新机制和干预潜在靶点。

胃癌微环境中Th17细胞在促进肿瘤微环境炎症及其介导的胃癌进展中发挥重要作用，肿瘤微环境中Th17的分化调控机制是其中关键的科学问题。肿瘤细胞相关外泌体及其包裹分子在肿瘤细胞和微环境细胞间的通讯目前受广泛关注，胃癌相关外泌体在微环境Th17细胞分化中的作用目前未知。申请人前期青年项目关注胃癌微环境中Th17细胞分化的表观遗传调控机制，在此基础上，我们富集胃癌细胞外泌体并进行高通量测序，发现胃癌细胞外泌体中长链非编码RNA lncAK037891显著富集。将上述富集的外泌体加入CD4+T细胞培养，发现lncAK037891能够进入T细胞，并导致Th17分化增加，因此，我们将此lncRNA命名为lncTh17DI。本项目研究中，我们首先检测并证实了临床胃癌组织与癌旁对照组织中lncTh17DI的表达差异。体外构建lncTh17DI慢病毒并成功转染胃癌BGC-823细胞，与CD4+T细胞共培养，发现lncTh17DI可以进入CD4+T细胞。进而，我们构建了lncTh17DI低表达的慢病毒载体并成功转染CD4+T细胞，发现阻断lncTh17DI表达后，IL-17的表达显著下调，提示lncTh17DI能够促进CD4+T细胞向Th17方向分化。.在前期成功构建阿霉素及紫杉醇诱导胃癌细胞衰老模型的基础上，发现二甲双胍能够剂量依赖性的抑制阿霉素诱导的胃癌细胞衰老及其伴随的SASP效应。通过对二甲双胍经典药理学机制的分析，推测化疗诱导的细胞衰老及SASP效应可能与氧化应激及UPR相关。通过对UPR经典活化通路的检测，发现在衰老模型中PERK通路处于激活状态，而另外两条通路ATF6α和IRE1处于非激活状态；阻断PERK通路能够一直紫杉醇诱导的胃癌细胞衰老，同时伴随SASP因子的表达下调，提示PERK通路的激活可能参与了化疗诱导的胃癌细胞衰老及SASP效应。.该研究有助于深入认识肿瘤细胞与微环境中免疫细胞的相互作用方式，进一步完善肿瘤免疫编辑理论体系，揭示化疗诱导的细胞衰老及SASP效应的分子机制，为临床逆转胃癌化疗耐药提供新思路。.相关研究成果已发表学术论文7篇，其中SCI论文4篇，获批国家实用新型专利1项。.