Department of Obstetrics and Gynecology, Weihai Center Hospital, Weihai, Shandong, China.
Shandong First Medical University, Taian, Shandong, China.
Arch Biochem Biophys. 2021 Sep 15;708:108925. doi: 10.1016/j.abb.2021.108925. Epub 2021 May 21.
Cervical squamous cell carcinoma (SCC) is a common subtype of cervical cancer. Circular RNAs (circRNAs) have been demonstrated as vital regulators in gene regulation and malignant tumor progression. Therefore, the precise role of circular RNA salt overly-sensitive 2 (circSOS2) was investigated in SCC.
The relative expression levels of circSOS2, microRNA-543 (miR-543), and Fibronectin type III domain containing 3B (FNDC3B) were determined by real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot assays. The correlation between percent survival times of SCC patients and circSOS2 level was presented by Kaplan-Meier Plotter analysis. The cell proliferation was measured by MTT and colony-forming assays. Flow cytometry assay was used to assess apoptosis and cell cycle distribution. The migration and invasion were measured by transwell assay. The glycolysis was analyzed by extracellular acidification rate (ECAR) assay, Glucose Assay Kit, and Lactate Assay Kit. The interaction relationship between miR-543 and circSOS2 or FNDC3B was analyzed by dual-luciferase reporter, RNA immunoprecipitation (RIP), and RNA pull-down assays. A xenograft experiment was established to clarify the functional role of circSOS2 inhibition in viv.
CircSOS2 was highly expressed in SCC tissues and cells; besides, its expression level was closely associated with poor prognosis. Loss-of-functional experiments revealed that suppression of circSOS2 repressed proliferation, cell cycle process, migration, invasion, and glycolysis while induced apoptosis in SCC cells, which was overturned by inhibition of miR-543. In addition, miR-543 was downregulated and negatively correlated with circSOS2 expression in SCC tissues. We also found that overexpression of miR-543 impeded proliferation, cell cycle process, migration, invasion, and glycolysis while induced apoptosis in SCC cells by targeting FNDC3B. The silencing of circSOS2 impeded tumorigenesis in vivo.
CircSOS2 conferred an oncogenic function in SCC by regulation of proliferation, cell cycle, apoptosis, migration, invasion, and glycolysis of SCC cells, which was contributed to its interactions with miR-543 and FNDC3B.
宫颈鳞状细胞癌（SCC）是宫颈癌的常见亚型。环状 RNA（circRNA）已被证明是基因调控和恶性肿瘤进展的重要调节剂。因此，本研究旨在探讨环状 RNA 盐过度敏感 2（circSOS2）在 SCC 中的精确作用。
采用实时定量聚合酶链反应（RT-qPCR）和 Western blot 检测 circSOS2、微小 RNA-543（miR-543）和 Fibronectin type III domain containing 3B（FNDC3B）的相对表达水平。采用 Kaplan-Meier Plotter 分析 SCC 患者的生存百分率与 circSOS2 水平的相关性。采用 MTT 和集落形成实验检测细胞增殖。采用流式细胞术检测细胞凋亡和细胞周期分布。采用 Transwell 实验检测细胞迁移和侵袭。通过细胞外酸化率（ECAR）测定、葡萄糖测定试剂盒和乳酸测定试剂盒分析糖酵解。采用双荧光素酶报告、RNA 免疫沉淀（RIP）和 RNA 下拉实验分析 miR-543 与 circSOS2 或 FNDC3B 的相互作用关系。建立异种移植实验以阐明 circSOS2 抑制在体内的功能作用。
circSOS2 在 SCC 组织和细胞中高表达；此外，其表达水平与不良预后密切相关。功能丧失实验表明，circSOS2 抑制可抑制 SCC 细胞的增殖、细胞周期进程、迁移、侵袭和糖酵解，而诱导 SCC 细胞凋亡，而 miR-543 的抑制则逆转了这一过程。此外，在 SCC 组织中 miR-543 下调且与 circSOS2 表达呈负相关。我们还发现，miR-543 通过靶向 FNDC3B 抑制 SCC 细胞的增殖、细胞周期进程、迁移、侵袭和糖酵解，诱导细胞凋亡。circSOS2 的沉默抑制了体内肿瘤的发生。
circSOS2 通过调节 SCC 细胞的增殖、细胞周期、凋亡、迁移、侵袭和糖酵解，发挥致癌作用，这归因于其与 miR-543 和 FNDC3B 的相互作用。
