Department of Internal Medicine and Endocrinology, Medical University of Warsaw, Banacha 1a, 02-097 Warsaw, Poland.
Faculty of Medicine, Medical University of Warsaw, Żwirki i Wigury 61, 02-091 Warsaw, Poland.
Int J Mol Sci. 2021 Jun 4;22(11):6067. doi: 10.3390/ijms22116067.
NIS is a potent iodide transporter encoded by the gene. Its expression is reduced in papillary thyroid carcinoma (PTC). In this study we analyzed the impact of miR-181a-5p on NIS expression in the context of PTC. We used real-time PCR to analyze the expression of and miR-181a-5p in 49 PTC/normal tissue pairs. Luciferase assays and mutagenesis were performed to confirm direct binding of miR-181a-5p to the 3'UTR of and identify the binding site. The impact of modulation of miR-181a-5p using appropriate plasmids on endogenous NIS and radioactive iodine accumulation was verified. We confirmed downregulation of and concomitant upregulation of miR-181a-5p in PTC. Broadly used algorithms did not predict the binding site of miR-181a-5p in 3'UTR of , but we identified and confirmed the binding site through mutagenesis using luciferase assays. In MCF7 and HEK293-flhNIS cell lines, transfection with mir-181a-expressing plasmid decreased endogenous , whereas silencing of miR-181a-5p increased it. We observed similar tendencies in protein expression and radioactive iodine accumulation. This study shows for the first time that miR-181a-5p directly regulates expression in the context of PTC and may decrease efficacy of radioiodine treatment. Accordingly, miR-181a-5p may serve as an emerging target to enhance the efficacy of radioactive iodine therapy.
NIS 是一种由 基因编码的强效碘转运蛋白。它在甲状腺乳头状癌（PTC）中的表达减少。在这项研究中，我们分析了 miR-181a-5p 在 PTC 背景下对 NIS 表达的影响。我们使用实时 PCR 分析了 49 对 PTC/正常组织中 和 miR-181a-5p 的表达。进行了荧光素酶测定和突变分析以确认 miR-181a-5p 与 3'UTR 的直接结合，并确定结合位点。使用适当的质粒对 miR-181a-5p 的调节对内源性 NIS 和放射性碘积累的影响进行了验证。我们证实了 PTC 中 的下调和 miR-181a-5p 的伴随上调。广泛使用的算法没有预测 miR-181a-5p 在 3'UTR 中的结合位点，但我们通过荧光素酶测定中的突变分析确定并证实了该结合位点。在 MCF7 和 HEK293-flhNIS 细胞系中，转染表达 miR-181a 的质粒会降低内源性 ，而 miR-181a-5p 的沉默则会增加其表达。我们在蛋白表达和放射性碘积累方面观察到了类似的趋势。这项研究首次表明，miR-181a-5p 在 PTC 背景下直接调节 表达，可能降低放射性碘治疗的疗效。因此，miR-181a-5p 可能成为增强放射性碘治疗疗效的新兴靶标。
