circRNA_0073453-miRNA-146a-5p调控胃癌间质干细胞旁分泌IL-8促进胃癌转移及机制研究

Circular RNA (circRNA) is a hot molecule in the field of tumor research, however, it is not clear whether it regulates microenvironment cells to play a pro-tumor role and the molecular mechanism. We have found that gastric cancer mesenchymal stem cells (GC-MSC) in microenvironmental cells can promote the migration and invasion of gastric cancer cells by paracrine IL-8. Whether there is circRNA regulating the expression of IL-8 in GC-MSC can promote gastric cancer and its mechanism is worthy of further study. This study have found that circRNA_0073453 expression was up-regulated in GC-MSC by microarray screening, biological information analysis and functional detection,which might targeting regulate the expression and secretion of IL-8 through sponge adsorption miRNA-146a-5p. Therefore, this study will use gene intervention, FISH, RNA pull down and other cellular and molecular biological techniques, combined with the in vitro and in vitro cell and animal metastasis model, investigate the mechanism of circRNA_0073453-miRNA-146a-5p regulating GC-MSC paracrine IL-8 in promoting gastric cancer metastasis. Meanwhile，to detect the expression of circRNA_0073453-miRNA-146a-5p in clinical tissue and serum samples that will provide potential molecular targets for the diagnosis and treatment of gastric cancer metastasis, which has important scientific significance and clinical research value.

环状RNA（circRNA）是肿瘤领域研究的热点分子，但其是否调控微环境细胞发挥促肿瘤作用及分子机制尚不清楚。课题组前期发现微环境细胞胃癌间质干细胞（GC-MSC）能旁分泌IL-8促胃癌细胞迁移、侵袭。GC-MSC中是否存在circRNA调控IL-8表达发挥促胃癌作用及机制值得深入研究。芯片筛选、生物信息分析及功能检测等发现circRNA_0073453在GC-MSC中表达上调，其可能通过海绵吸附miRNA-146a-5p靶向调控IL-8的表达与分泌。基于此，本研究将采用基因干预、FISH、RNA pull down等细胞与分子生物学技术，结合体内外细胞与动物转移模型进一步深入探讨circRNA_0073453-miRNA-146a-5p调控GC-MSC旁分泌IL-8促进胃癌转移及其分子机制。同时结合临床组织及血清标本检测，为胃癌转移诊疗提供潜在分子靶标，具有重要的科学意义和临床研究价值。

环状RNA（circRNA）已然成为目前肿瘤关注非编码RNA研究领域的重要热点分子。肿瘤组织和肿瘤细胞中circRNAs的相继鉴定及功能学研究证实其广泛参与肿瘤的发生发展调控，但其在微环境细胞中是否异常表达及广泛介导微环境细胞促肿瘤及相关分子机制有待深入研究。前期课题组研究发现胃癌微环境细胞GC-MSCs显著促进胃癌转移，芯片检测筛选发现GC-MSCs存在着大量异常表达circRNAs。基于此，本项目重点研究并阐释异常表达circRNAs如何调控GC-MSCs促胃癌转移功能及分子机制并评估其调控相关信号轴分子临床意义及预后判断价值，同时增加胃癌组织异常表达circRNA研究并寻找转移调控关键分子并阐明其分子调控机制。主要的研究发现：① circ_0073453通过吸附miR-146a-5p靶向调控IL-8介导GC-MSCs增强胃癌细胞迁移、侵袭能力和诱导胃癌细胞表达PD-L1抵抗细胞毒性CD8+ T细胞杀伤发生免疫逃逸。② circ_0024107海绵吸附miR-5572和miR-6855-5p上调CPT1A表达促进GC-MSCs 脂肪酸氧化（FAO）代谢重编程；信号轴分子在胃癌组织和GC-MSCs中异常表达且与胃癌淋巴结转移及预后相关。③在胃癌组织异常表达上调的hsa_circRNA_101996与胃癌转移和不良预后有关；hsa_circRNA_101996海绵吸附miR-143上调TET2，其通过去甲基化上调MMP2/MMP9表达增强胃癌细胞侵袭能力；体内靶向抑制hsa_circRNA_101996显著抑制胃癌生长及转移。本项目从微环境细胞和胃癌细胞异常表达circRNAs角度结合代谢重编程、免疫逃逸及表观遗传学调控阐明胃癌转移分子机制，有望为胃癌转移诊疗及预后判断提供潜在分子靶标。