背景:绝大多数lncRNAs具有低表达丰度,这极大地限制了它们的功能范围和影响。作为一种高表达丰度的lncRNA,FGD5-AS1在癌症中的非ceRNA生物学功能尚不清楚。
方法:进行RNA-seq研究和染色质免疫沉淀(Chip)测定以鉴定ZEB1调节的lncRNA。RNA测序,RNA下拉,RNA免疫沉淀试验,并对FGD5-AS1在GC中的分子机制进行了研究。
结果:作为细胞中最丰富的lncRNAs之一,FGD5-AS1已被ZEB1转录激活,因此与上皮-间质转化(EMT)信号传导密切相关。临床分析显示,FGD5-AS1过表达与淋巴结转移相关,并预测GC的存活率低。功能丧失研究证实,FGD5-AS1敲低抑制GC增殖并诱导顺铂化学敏感性,细胞衰老,和GC细胞中的DNA损伤。机械上,FGD5-AS1是一种结合YBX1的lncRNA,因为其mRNA包含三个相邻的结构基序(UAAUCCCA,ACCAGCCU,和CAGUGAGC)可以被YBX1识别和绑定。这种RNA-蛋白质相互作用延长了YBX1蛋白在GC中的半衰期。此外,拯救实验表明,FGD5-AS1通过抑制YBX1细胞衰老和ROS产生来促进GC。
结论:FGD5-AS1是一种由ZEB1转录调控的细胞高丰度lncRNA。FGD5-AS1过表达通过结合和稳定YBX1蛋白抑制细胞衰老和ROS产生来促进GC进展。
BACKGROUND: The vast majority of lncRNAs have low expression abundance, which greatly limits their functional range and impact. As a high expression abundance lncRNA, FGD5-AS1\'s non-ceRNA biological function in cancer is unclear.
METHODS: RNA-seq studies and chromatin immunoprecipitation (Chip) assays were performed to identify ZEB1-regulated lncRNAs. RNA sequencing, RNA pulldown, RNA Immunoprecipitation assays, and rescue assays were conducted to explore the molecular mechanisms of FGD5-AS1 in GC.
RESULTS: As one of the most abundant lncRNAs in cells, FGD5-AS1 has been shown to be transcriptionally activated by ZEB1, thus closely related to epithelial-mesenchymal transition (EMT) signaling. Clinical analysis showed that FGD5-AS1 overexpression was clinically associated with lymph node metastasis, and predicted poor survival in GC. Loss-of-function studies confirmed that FGD5-AS1 knockdown inhibited GC proliferation and induced cisplatin chemosensibility, cell senescence, and DNA damage in GC cells. Mechanismically, FGD5-AS1 is a YBX1-binding lncRNA due to its mRNA contains three adjacent structural motifs (UAAUCCCA, ACCAGCCU, and CAGUGAGC) that can be recognized and bound by YBX1. And this RNA-protein interaction prolonged the half-life of the YBX1 protein in GC. Additionally, a rescue assay showed that FGD5-AS1 promotes GC by repressing cell senescence and ROS production via YBX1.
CONCLUSIONS: FGD5-AS1 is a cellular high-abundant lncRNA that is transcriptionally regulated by ZEB1. FGD5-AS1 overexpression promoted GC progression by inhibiting cell senescence and ROS production through binding and stabilizing the YBX1 protein.