Bai Lili, Sun Wangjie, Han Zhe, Tang Hua
Tianjin Life Science Research Center, Tianjin Key Laboratory of Inflammation Biology, Collaborative Innovation Center of Tianjin for Medical Epigenetics, Department of Pathogen Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin, People's Republic of China.
Cancer Manag Res. 2021 Jan 12;13:259-275. doi: 10.2147/CMAR.S289032. eCollection 2021.
To explore the role and potential mechanism of circSND1 in cervical cancer (CC).
qRT-PCR was used to determine the expression of circSND1 in tumor necrosis factor-α (TNF-α)-treated HeLa cells. CircSND1 overexpression and knockdown were performed to indicate the functional role of circSND1 in vitro and in vivo. Luciferase assay was used to analyze promoter activity. The expression and regulation of circSND1, miR-125a-3p and FUT6 were evaluated using EGFP fluorescent reporter assay and rescue experiments. Immunofluorescence and Western blot assays were used to analyze the activation of nuclear factor-κB (NF-κB).
In HeLa cells, TNF-α up-regulated the expression of circSND1 by activating the NF-κB signaling pathway. Overexpression of circSND1 significantly increased the migration and invasion and the epithelial-mesenchymal transition (EMT) process of CC cells, and promoted tumor metastasis in xenograft nude mouse model, whereas down-regulation of circSND1 exerted opposite effects. Furthermore, circSND1 enhanced the expression of FUT6 via sponging miR-125a-3p, and FUT6 activated NF-κB signaling pathway.
We found that circSND1 promoted the expression of FUT6 and the malignant behavior of cervical cancer through the ceRNA mechanism, and there was a TNF-α/NF-κB/circSND1/miR-125a-3p/FUT6/NF-κB positive feedback pathway between them, which suggests that circSND1 can be a promising prognostic marker and therapeutical target for cervical cancer.
探讨环状SND1（circSND1）在宫颈癌（CC）中的作用及潜在机制。
采用qRT-PCR检测肿瘤坏死因子-α（TNF-α）处理的HeLa细胞中circSND1的表达。进行circSND1过表达和敲低实验以表明circSND1在体外和体内的功能作用。利用荧光素酶报告基因检测分析启动子活性。通过EGFP荧光报告基因检测和拯救实验评估circSND1、miR-125a-3p和FUT6的表达及调控。采用免疫荧光和蛋白质印迹分析检测核因子-κB（NF-κB）的激活情况。
在HeLa细胞中，TNF-α通过激活NF-κB信号通路上调circSND1的表达。circSND1过表达显著增加了CC细胞的迁移、侵袭及上皮-间质转化（EMT）过程，并促进了异种移植裸鼠模型中的肿瘤转移，而circSND1下调则产生相反的作用。此外，circSND1通过吸附miR-125a-3p增强FUT6的表达，且FUT6激活NF-κB信号通路。
我们发现circSND1通过ceRNA机制促进FUT6的表达及宫颈癌的恶性行为，且它们之间存在TNF-α/NF-κB/circSND1/miR-125a-3p/FUT6/NF-κB正反馈通路，这表明circSND1有望成为宫颈癌的预后标志物和治疗靶点。
