Thyroid Diseases Department, Shandong Provincial ENT Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250022, P.R. China.
Otolaryngology Department, Traditional Chinese Medicine Hospital of Juxian, Rizhao, Shandong 276599, P.R. China.
Mol Med Rep. 2020 Oct;22(4):2723-2732. doi: 10.3892/mmr.2020.11343. Epub 2020 Jul 15.
Thyroid carcinoma (THCA) is a malignant tumor of the endocrine system. Previous studies have revealed the vital roles of microRNAs (miRNAs/miRs) in THCA procession. The present study aimed to explore the effects of miR‑15b‑5p on the progression of THCA and its targeting mechanism. The data of THCA and healthy samples were firstly collected from starbase2.0 and used to analyze the relationship of miR‑15b‑5p with THCA. Dual‑luciferase assay was performed to detect the direct interaction between miR‑15b‑5p and the predicted target gene GDP dissociation inhibitor 2 (GDI2). The effects of miR‑15b‑5p and GDI2 on the overall survival of patients with THCA were analyzed using Kaplan‑Meier analysis with log rank test. Cell Counting Kit‑8 and Transwell assays were conducted to assess the impacts of miR‑15b‑5p and GDI2 on the proliferation and invasion of THCA cells. Reverse transcription‑quantitative PCR and western blot analyses were performed to analyze the expression levels of the related miRNAs and proteins, respectively. miR‑15b‑5p was found to be downregulated both in THCA tissues and cells, and the low expression of miR‑15b‑5p was associated with the short overall survival time of patients. Moreover, the upregulation or downregulation of miR‑15b‑5p could inhibit or enhance the proliferation and invasion of THCA cells, respectively. miR‑15b‑5p reduced the protein expression levels of matrix metalloproteinase (MMP)2 and MMP9, which were related to cell invasion. Furthermore, GDI2, which was enhanced in THCA and related to the poor prognosis of patients with THCA, was identified as the target gene of miR‑15b‑5p and negatively regulated by miR‑15b‑5p. Additional experiments demonstrated that GDI2 overexpression could significantly reduce the antitumor effect of miR‑15b‑5p and its inhibitory action on the expression levels of MMP2 and MMP9. Thus, the results indicated a potential tumor suppressive role of miR‑15b‑5p in THCA, which was mainly exerted by targeting GDI2 and modulating MMP2 and MMP9. These findings will increase the understanding on the pathogenesis of THCA and provide novel candidates for THCA therapy.
甲状腺癌（THCA）是内分泌系统的一种恶性肿瘤。先前的研究表明，微小 RNA（miRNA/miRs）在 THCA 进程中发挥着重要作用。本研究旨在探讨 miR-15b-5p 对 THCA 进展的影响及其靶向机制。首先从 starbase2.0 收集 THCA 和健康样本的数据，用于分析 miR-15b-5p 与 THCA 的关系。通过双荧光素酶报告基因实验检测 miR-15b-5p 与预测靶基因 GDP 解离抑制剂 2（GDI2）之间的直接相互作用。通过 Kaplan-Meier 分析和对数秩检验分析 miR-15b-5p 和 GDI2 对 THCA 患者总生存时间的影响。通过细胞计数试剂盒-8 和 Transwell 实验评估 miR-15b-5p 和 GDI2 对 THCA 细胞增殖和侵袭的影响。通过逆转录-定量 PCR 和 Western blot 分析分别检测相关 miRNA 和蛋白的表达水平。发现 miR-15b-5p 在 THCA 组织和细胞中均下调，miR-15b-5p 的低表达与患者总生存时间短有关。此外，上调或下调 miR-15b-5p 分别可以抑制或增强 THCA 细胞的增殖和侵袭。miR-15b-5p 降低了与细胞侵袭相关的基质金属蛋白酶（MMP）2 和 MMP9 的蛋白表达水平。此外，在 THCA 中上调并与 THCA 患者预后不良相关的 GDI2 被鉴定为 miR-15b-5p 的靶基因，并受 miR-15b-5p 负调控。进一步的实验表明，GDI2 过表达可显著降低 miR-15b-5p 的抗肿瘤作用及其对 MMP2 和 MMP9 表达水平的抑制作用。因此，研究结果表明 miR-15b-5p 在 THCA 中发挥潜在的肿瘤抑制作用，主要通过靶向 GDI2 并调节 MMP2 和 MMP9 来发挥作用。这些发现将增加对 THCA 发病机制的认识，并为 THCA 治疗提供新的候选药物。
