Department of Thyroid Surgery, Henan Provincial People's Hospital, Zhengzhou, Henan 450000, P.R. China.
Int J Oncol. 2019 Nov;55(5):988-1002. doi: 10.3892/ijo.2019.4868. Epub 2019 Sep 4.
Anaplastic thyroid carcinoma (ATC) has a poor prognosis due to its resistance to all conventional treatments. The long non‑coding RNA (lncRNA) nuclear paraspeckle assembly transcript 1 (NEAT1) serves a critical role in cancer chemoresistance; however, whether NEAT1 is associated with chemoresistance of ATC remains unclear. In the present study, reverse transcription‑quantitative PCR assays were performed to detect the expression levels of NEAT1, microRNA (miR)‑9‑5p and sperm‑associated antigen 9 (SPAG9). Western blot analysis was conducted to assess the protein expression levels of p62, microtubule‑associated proteins 1A/1B light chain 3B and SPAG9. Cell proliferation was detected using the Cell Counting kit‑8 assay, and cell apoptosis was determined by flow cytometry. Dual‑luciferase reporter and RNA immunoprecipitation assays were performed to verify the interaction between NEAT1 and miR‑9‑5p, or miR‑9‑5p and SPAG9. Furthermore, an animal model was used to investigate the regulatory effects of NEAT1 on cisplatin (DDP)‑resistance in tumors in vivo. The present results demonstrated that NEAT1 was upregulated in ATC tissues and cell lines, and NEAT1 silencing resulted in decreased DDP‑resistance of ATC cells. In addition, NEAT1 suppressed miR‑9‑5p expression by binding to miR‑9‑5p and SPAG9 was a direct target of miR‑9‑5p. miR‑9‑5p overexpression sensitized ATC cells to DDP. Notably, NEAT1 silencing exerted its inhibitory effect on DDP‑resistance of ATC via the miR‑9‑5p/SPAG9 axis in vitro and in vivo. In conclusion, the present study demonstrated that NEAT1 silencing ameliorated DDP‑resistance of ATC, at least in part by reducing miR‑9‑5p sponging and regulating SPAG5 expression; therefore, NEAT1 may be considered a potential therapeutic target of ATC.
间变性甲状腺癌 (ATC) 对所有常规治疗均具有耐药性，因此预后较差。长链非编码 RNA (lncRNA) 核斑蛋白组装转录本 1 (NEAT1) 在癌症化疗耐药性中发挥着关键作用；然而，NEAT1 是否与 ATC 的化疗耐药性有关尚不清楚。在本研究中，采用逆转录定量 PCR 法检测 NEAT1、微小 RNA (miR)-9-5p 和精子相关抗原 9 (SPAG9) 的表达水平。采用 Western blot 分析检测 p62、微管相关蛋白 1A/1B 轻链 3B 和 SPAG9 的蛋白表达水平。采用细胞计数试剂盒-8 检测细胞增殖，采用流式细胞术检测细胞凋亡。采用双荧光素酶报告基因和 RNA 免疫沉淀实验验证 NEAT1 与 miR-9-5p 或 miR-9-5p 与 SPAG9 之间的相互作用。此外，还构建了体内动物模型，以研究 NEAT1 对体内肿瘤顺铂 (DDP) 耐药性的调控作用。结果表明，NEAT1 在 ATC 组织和细胞系中上调，沉默 NEAT1 可降低 ATC 细胞的 DDP 耐药性。此外，NEAT1 通过与 miR-9-5p 结合抑制 miR-9-5p 的表达，而 SPAG9 是 miR-9-5p 的直接靶基因。miR-9-5p 过表达可使 ATC 细胞对 DDP 敏感。值得注意的是，NEAT1 沉默通过 miR-9-5p/SPAG9 轴在体外和体内对 ATC 的 DDP 耐药性发挥抑制作用。综上所述，本研究表明，沉默 NEAT1 可改善 ATC 的 DDP 耐药性，至少部分是通过减少 miR-9-5p 海绵作用和调节 SPAG9 表达来实现的；因此，NEAT1 可能是 ATC 的潜在治疗靶点。
