在我们先前的研究中,MiR-494-5p的表达已被认为与结直肠癌(CRC)及其转移有关。然而,缺乏对这种miR在CRC中的分子介导作用的功能研究.本研究中的计算机模拟分析揭示了JAK1的3'UTR内的推定结合序列。在培养的CRC中miR-494-5p的过表达显着降低了含有野生型JAK1-3UTR的报告质粒的荧光素酶活性,被种子序列突变废除。此外,miR-494-5p在CRC细胞系中的过表达导致JAK1表达的显著降低,扩散,体外迁移,和入侵。通过用抑制内源性miR-494-5p的特异性双链RNA共转染消除了这些作用。此外,IL-4诱导的迁移,入侵,过表达miR后,JAK1、STAT6和AKT蛋白的磷酸化降低,表明这种miR影响CRC中最重要的途径之一。Kaplan-Meier绘图仪分析显示具有高JAK1表达的患者显示降低的存活率。一起,这些数据表明miR-494-5p在翻译水平以及迁移和侵袭中物理抑制JAK1的表达,支持miR-494-5p作为早期肿瘤抑制因子和CRC早期转移步骤抑制剂的假设。
MiR-494-5p expression has been suggested to be associated with colorectal cancer (CRC) and its metastases in our previous studies. However, functional investigations on the molecule-mediating actions of this miR in CRC are lacking. In silico analysis in the present study revealed a putative binding sequence within the 3\'UTR of
JAK1. Overexpression of miR-494-5p in cultured CRC significantly reduced the luciferase activity of a reporter plasmid containing the wild-type
JAK1-3\'UTR, which was abolished by seed sequence mutation. Furthermore, the overexpression of miR-494-5p in CRC cell lines led to a significant reduction in
JAK1 expression, proliferation, in vitro migration, and invasion. These effects were abolished by co-transfection with a specific double-stranded RNA that inhibits endogenous miR-494-5p. Moreover, IL-4-induced migration, invasion, and phosphorylation of
JAK1, STAT6, and AKT proteins were reduced after an overexpression of this miR, suggesting that this miR affects one of the most essential pathways in CRC. A Kaplan-Meier plotter analysis revealed that patients with high
JAK1 expression show reduced survival. Together, these data suggest that miR-494-5p physically inhibits the expression of JAK1 at the translational level as well as in migration and invasion, supporting the hypothesis of miR-494-5p as an early tumor suppressor and inhibitor of early steps of metastasis in CRC.