Thyroid cancer (TC) is the most common endocrine malignant disease with a rising morbidity year by year. Accumulating studies have shown that microRNAs (miRNAs) play a regulatory role in the progression of various tumors, but the molecular regulatory mechanism of miR-196a-2 in TC is still unknown. qRT-PCR was employed to measure the expression of miR-196a-2 and NRXN1 mRNA in TC cells, while western blot was used to detect the protein expression of NRXN1. CCK-8, colony formation and flow cytometry assays were used to measure cell proliferation and apoptosis of TC cells. Dual-luciferase reporter gene assay was used to predict and verify the targeted binding relationship between miR-196a-2 and NRXN1. Our study results manifested that miR-196a-2 was dramatically overexpressed in cells of TC, while NRXN1 was lowly expressed. miR-196a-2 could promote cell proliferation and inhibit cell apoptosis of TC. Additionally, miR-196a-2 could also target and inhibit the expression of NRXN1. Silencing NRXN1 could reverse the inhibitory effect of miR-196a-2 downregulation on cell proliferation of TC, as well as the promoting effect on cell apoptosis. In a conclusion, we found that miR-196a-2 could promote cell proliferation and inhibit cell apoptosis of TC by targeting NRXN1. Therefore, miR-196a-2/NRXN1 is potential to be a molecular therapeutic target for TC.

中文翻译：

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miR-196a-2通过靶向NRXN1促进甲状腺癌恶性进展

甲状腺癌（TC）是最常见的内分泌恶性肿瘤，发病率逐年上升。越来越多的研究表明，微小RNA（miRNA）在多种肿瘤的进展中发挥着调控作用，但miR-196a-2在TC中的分子调控机制仍不清楚。qRT-PCR检测TC细胞中miR-196a-2和NRXN1 mRNA的表达，Western blot检测NRXN1蛋白的表达。使用CCK-8、集落形成和流式细胞术测定TC细胞的细胞增殖和凋亡。双荧光素酶报告基因检测用于预测和验证miR-196a-2与NRXN1之间的靶向结合关系。我们的研究结果表明，miR-196a-2在TC细胞中显着高表达，而NRXN1低表达。miR-196a-2能够促进TC细胞增殖并抑制细胞凋亡。此外，miR-196a-2还可以靶向并抑制NRXN1的表达。沉默NRXN1可以逆转miR-196a-2下调对TC细胞增殖的抑制作用，以及对细胞凋亡的促进作用。总之，我们发现miR-196a-2可以通过靶向NRXN1促进TC细胞增殖并抑制细胞凋亡。因此，miR-196a-2/NRXN1有可能成为TC的分子治疗靶点。