背景:转录因子SIX2在几种肿瘤中的作用已被鉴定。然而,其在胃癌(GC)进展中的作用尚未揭示。我们的目标是探索SIX2对GC细胞干性的影响和潜在机制。
方法:采用慢病毒感染在GC细胞中建立SIX2或PFN2的稳定表达。进行了功能增益和功能丧失实验,以检测干性标记的变化,流式细胞术配置文件,肿瘤球体形成,和肿瘤启动能力。ChIP,RNA测序,组织微阵列,并进行了生物信息学分析,以揭示SIX2和PFN2之间的相关性。通过组织微阵列分析阐明了SIX2/PFN2环介导作用的潜在机制,RNA稳定性分析,IP-MS,免疫共沉淀,和抑制JNK信号通路。
结果:SIX2增强了GC细胞的干性。机械上,SIX2直接与PFN2的启动子结合并促进PFN2活性。PFN2,反过来,通过招募RNA结合蛋白YBX-1促进SIX2的mRNA稳定性,随后激活下游MAPK/JNK途径。
结论:这项研究揭示了SIX2在控制GC细胞干细胞中的作用,定义负责这种调节的新型SIX2/PFN2调节环。这表明靶向SIX2/PFN2环用于GC处理的潜力(图形摘要)。
BACKGROUND: The roles of the transcriptional factor SIX2 have been identified in several tumors. However, its roles in gastric cancer (GC) progression have not yet been revealed. Our objective is to explore the impact and underlying mechanisms of SIX2 on the stemness of GC cells.
METHODS: Lentivirus infection was employed to establish stable expression SIX2 or PFN2 in GC cells. Gain- and loss-of-function experiments were conducted to detect changes of stemness markers, flow cytometry profiles, tumor spheroid formation, and tumor-initiating ability. ChIP, RNA-sequencing, tissue microarray, and bioinformatics analysis were performed to reveal the correlation between SIX2 and PFN2. The mechanisms underlying the SIX2/PFN2 loop-mediated effects were elucidated through tissue microarray analysis, RNA stability assay, IP-MS, Co-Immunoprecipitation, and inhibition of the JNK signaling pathway.
RESULTS: The stemness of GC cells was enhanced by SIX2. Mechanistically, SIX2 directly bound to PFN2\'s promoter and promoted PFN2 activity. PFN2, in turn, promoted the mRNA stability of SIX2 by recruiting RNA binding protein YBX-1, subsequently activating the downstream MAPK/JNK pathway.
CONCLUSIONS: This study unveils the roles of SIX2 in governing GC cell stemness, defining a novel SIX2/PFN2 regulatory loop responsible for this regulation. This suggests the potential of targeting the SIX2/PFN2 loop for GC treatment (Graphical Abstracts).