文章：

circSFMBT1通过靶向miR-330-5p/PAK1轴促进胰腺癌的生长和转移

circSFMBT1 promotes pancreatic cancer growth and metastasis via targeting miR-330-5p/PAK1 axis 

原文发布日期：2020-08-28 

英文摘要：

Pancreatic cancer (PC) is one of the most common and lethal cancers that affects millions of people around the world. The prognosis of PC is poor with very limited effective treatments. Here, we fully investigated the function and underlying mechanism of circSFMBT1 (hsa_circ_0066147) in PC. Real-time quantitative PCR, Western blotting, and immunohistochemistry were used to examine levels of circSFMBT1, miR-330-5p, PAK1 (p21-activated kinase 1), or proliferation/metastasis-related proteins. Colony formation assay, flow cytometry, and transwell assay detected the roles of circSFMBT1 and miR-330-5p in cell apoptosis, proliferation, migration, and invasion of PC cells, respectively. Dual luciferase assay and RNA immunoprecipitation were used to validate the interactions of circSFMBT1/miR-330-5p and miR-330-5p/PAK1. Fluorescence in situ hybridization was performed to examine the subcellular localization of circSFMBT1 and miR-330-5p. Subcutaneous tumor growth was monitored in nude mice and in vivo metastasis was examined as well following injection of PC cells into the tail vein. This study demonstrated that circSFMBT1 and PAK1 were up-regulated in PC tissues and cells, while miR-330-5p was down-regulated. circSFMBT1 directly bound miR-330-5p and inhibited its expression. In addition, circSFMBT1 promoted proliferation, migration, and invasion of PC cells through up-regulating proliferation-related proteins and down-regulating apoptosis-related proteins via miR-330-5p. miR-330-5p directly bound PAK1 mRNA and suppressed proliferation, migration, invasion, and epithelial–mesenchymal transition process via targeting PAK1 in PC cells. Further, knockdown circSFMBT1 increased miR-330-5p level, but decreased PAK1 expression and repressed tumor growth and metastasis in vivo. Taken together, circSFMBT1 promotes proliferation and metastasis of PC via regulating miR-330-5p/PAK1 pathway as a miR-330-5p sponge. 

摘要翻译： 

胰腺癌（PC）是全球范围内最常见且致死率极高的恶性肿瘤之一，其预后较差且有效治疗手段极为有限。本研究深入探讨了环状RNA circSFMBT1（hsa_circ_0066147）在胰腺癌中的功能及潜在作用机制。通过实时定量PCR、蛋白质印迹法和免疫组化技术检测circSFMBT1、miR-330-5p、PAK1（p21激活激酶1）及增殖/转移相关蛋白的表达水平；采用集落形成实验、流式细胞术和Transwell实验分别验证circSFMBT1与miR-330-5p对胰腺癌细胞凋亡、增殖、迁移和侵袭能力的影响；双荧光素酶报告基因实验与RNA免疫沉淀实验证实了circSFMBT1/miR-330-5p及miR-330-5p/PAK1之间的相互作用；荧光原位杂交技术用于确定circSFMBT1与miR-330-5p的亚细胞定位。通过裸鼠皮下成瘤实验和尾静脉注射癌细胞模型评估体内肿瘤生长与转移情况。

研究结果表明：circSFMBT1与PAK1在胰腺癌组织及细胞中显著高表达，而miR-330-5p呈现低表达状态。circSFMBT1可直接结合miR-330-5p并抑制其表达，通过miR-330-5p介导的上调增殖相关蛋白和下调凋亡相关蛋白机制，促进胰腺癌细胞的增殖、迁移和侵袭。miR-330-5p能直接靶向PAK1 mRNA，通过抑制PAK1表达进而阻遏胰腺癌细胞的增殖、迁移、侵袭及上皮-间质转化进程。值得注意的是，敲低circSFMBT1可提高miR-330-5p水平，降低PAK1表达，并显著抑制体内肿瘤生长和转移。综上所述，circSFMBT1作为miR-330-5p分子海绵，通过调控miR-330-5p/PAK1信号通路促进胰腺癌的增殖与转移。

原文链接：

circSFMBT1 promotes pancreatic cancer growth and metastasis via targeting miR-330-5p/PAK1 axis