Abstract:

Objective　To investigate the effect of long noncoding RNA (lncRNA) POTEM-4 on the malignant biological behaviors of thyroid cancer cells and its mechanism of action. Methods　The research was from March 2024 to January 2025. The GEO database was used to analyze the expression of POTEM-4 in thyroid cancer tissues. The expression levels of POTEM-4 in thyroid cancer cell lines KTC-1, 8505C, FTC-133, and SW579 were detected by the quantitative real-time polymerase chain reaction (qPCR). POTEM-4 low-expression plasmid and negative control plasmid were transfected into the FTC-133 cells, respectively, and named as an sh-POTEM-4 group and an sh-NC group. The effects of low-expression POTEM-4 on the proliferation and invasion of the FTC-133 cells were detected by the clone formation assay and Transwell assay, respectively. The bioinformatics technology and dual luciferase reporter assay were used to verify the targeting effect of POTEM-4 and miR-363-3p in the FTC-133 cells. The effect of low-expression POTEM-4 on the expression of miR-363-3p was detected by qPCR. The effect of low-expression POTEM-4 on the expression of the NF-κB signaling pathway proteins p65, p50, tumor necrosis factor receptor-associated factor 2 (TRAF2), and tumor necrosis factor receptor-associated factor 6 (TRAF6) was detected by Western blot. The statistical methods used were t test and one-way analysis of variance. Results　POTEM-4 was highly expressed in the thyroid cancer tissues (P<0.01). The expression levels of POTEM-4 in the KTC-1, 8505C, FTC-133, and SW579 cells were significantly higher than that in the thyroid epithelial HTori-3 cells (all P<0.01). POTEM-4 low-expression plasmid could effectively reduce the expression of POTEM-4 in the FTC-133 cells (t=16.320, P<0.01). The numbers of clones formed in the sh-POTEM-4 group and the sh-NC group were 45.52±6.17 and 149.20±12.65, respectively, indicating that the low expression of POTEM-4 inhibited the FTC-133 cells' proliferation ability (t=7.367, P<0.01). The invasion numbers of FTC-133 cells in the sh-POTEM-4 group and the sh-NC group were 38.07±10.84 and 137.30±9.31, respectively, indicating that the low expression of POTEM-4 inhibited the FTC-133 cells' invasion ability (t=6.942, P<0.01). POTEM-4 could target and bind to miR-363-3p (t=7.950, P<0.01). The low expression of POTEM-4 promoted the expression of miR-363-3p in the FTC-133 cells (t=5.840, P<0.01). Compared with those in the sh-NC group, the expression levels of p65, p50, TRAF2, and TRAF6 proteins in the NF-κB signaling pathway in the FTC-133 cells in the sh-POTEM-4 group were lower (all P<0.01). Conclusions　POTEM-4 is highly expressed in thyroid cancer. The downregulation of POTEM-4 inhibits the proliferation and invasion of FTC-133 cells by regulating the miR-363-3p/NF-κB axis.

Key words:

Thyroid cancer, Long noncoding RNA, POTEM-4, MiR-363-3p, Proliferation, Invasion

摘要：

目的　探讨长链非编码RNA（long noncoding RNA，lncRNA）POTEM-4对甲状腺癌细胞恶性生物学行为的影响及其作用机制。方法　研究时间为2024年3月至2025年1月。用GEO数据库分析POTEM-4在甲状腺癌组织中的表达。实时荧光定量聚合酶链式反应（quantitative real-time polymerase chain reaction，qPCR）检测POTEM-4在甲状腺癌细胞系KTC-1、8505C、FTC-133、SW579中的表达水平。分别转染POTEM-4低表达质粒和阴性对照质粒至FTC-133细胞，分别命名为sh-POTEM-4组和sh-NC组。采用克隆形成实验和Transwell实验分别检测低表达POTEM-4对FTC-133细胞增殖和侵袭的影响。生物信息学技术和双荧光素酶报告实验验证FTC-133细胞中POTEM-4与miR-363-3p的靶向作用。qPCR检测低表达POTEM-4对miR-363-3p表达的影响。蛋白质免疫印迹（Western blot）检测低表达POTEM-4对NF-κB信号通路蛋白p65、p50、肿瘤坏死因子受体相关因子2（tumor necrosis factor receptor-associated factor 2，TRAF2）、肿瘤坏死因子受体相关因子6（tumor necrosis factor receptor-associated factor 6，TRAF6）表达的影响。统计学方法采用t检验和单因素方差分析。结果　POTEM-4在甲状腺癌组织中呈高表达（P<0.01）。POTEM-4在KTC-1、8505C、FTC-133、SW579细胞中的表达水平均高于在甲状腺上皮HTori-3细胞中的表达水平（均P<0.01）。POTEM-4低表达质粒能有效降低FTC-133细胞中POTEM-4的表达（t=16.320，P<0.01）。sh-POTEM-4组和sh-NC组克隆形成数分别为（45.52±6.17）个和（149.20±12.65）个，表明低表达POTEM-4抑制了FTC-133细胞的增殖能力（t=7.367，P<0.01）。sh-POTEM-4组和sh-NC组FTC-133细胞侵袭数分别为（38.07±10.84）个和（137.30±9.31）个，表明低表达POTEM-4抑制了FTC-133细胞的侵袭能力（t=6.942，P<0.01）。POTEM-4能够与miR-363-3p靶向结合（t=7.950，P<0.01）。低表达POTEM-4促进了FTC-133细胞中miR-363-3p的表达（t=5.840，P<0.01）。与sh-NC组比较，sh-POTEM-4组FTC-133细胞中NF-κB信号通路p65、p50、TRAF2、TRAF6蛋白表达水平均较低（均P<0.01）。结论　POTEM-4在甲状腺癌中呈高表达，下调POTEM-4通过调控miR-363-3p/NF-κB轴抑制FTC-133细胞的增殖和侵袭。

关键词:

甲状腺癌, 长链非编码RNA, POTEM-4, miR-363-3p, 增殖, 侵袭