As a malignant tumor, gastric cancer (GC) is closely related with gastric mucosa and has a high mortality in the world. Since microRNA (miRNA) has become more and more important in tumor research, we intend to find out the functional role and mechanism of miR-511-5p in GC. Firstly, miR-511-5p level was examined in human GC cell lines and tissues, and its effect on cell migration and invasion of BGC-823 or HGC-27 cells was tested by migration assay and transwell assay. Then, we confirmed the association between miR-511-5p and p21 activated kinase 2 (PAK2) by the luciferase reporter assay, and further assessed their role in cell migration and invasion. Moreover, we verified the function of miR-511-5p and PAK2 in epithelial–mesenchymal transition (EMT). In our study, miR-511-5p was downregulated in GC cell lines and tissues, and inversely associated with PAK2. Luciferase reporter assay confirmed that miR-511-5p could bind to PAK2. MiR-511-5p mimics significantly upregulated E-cadherin and downregulated N-cadherin, Vimentin and Snail, and consequently inhibited cell migration and invasion. However, reintroduction of PAK2 reversed the inhibitory function of miR-511-5p on BGC-823 and HGC-27 cells. Our research suggested that tumor-suppressive function of miR-511-5p in GC was inhibited by PAK2, and miR-511-5p/PAK2 axis may serve as a new strategy in GC management.

胃癌（GC）作为一种恶性肿瘤，与胃黏膜密切相关，在世界范围内具有较高的死亡率。由于microRNA（miRNA）在肿瘤研究中越来越重要，我们打算找出miR-511-5p在GC中的功能作用和机制。首先，在人GC细胞系和组织中检测miR-511-5p水平，并通过迁移试验和transwell试验检测其对BGC-823或HGC-27细胞迁移和侵袭的影响。然后，我们通过荧光素酶报告基因分析证实了 miR-511-5p 和 p21 活化激酶 2 (PAK2) 之间的关联，并进一步评估了它们在细胞迁移和侵袭中的作用。此外，我们验证了 miR-511-5p 和 PAK2 在上皮间质转化 (EMT) 中的功能。在我们的研究中，miR-511-5p 在 GC 细胞系和组织中被下调，并与 PAK2 负相关。荧光素酶报告基因分析证实 miR-511-5p 可以与 PAK2 结合。MiR-511-5p 模拟显着上调 E-cadherin 并下调 N-cadherin、Vimentin 和 Snail，从而抑制细胞迁移和侵袭。然而，重新引入 PAK2 逆转了 miR-511-5p 对 BGC-823 和 HGC-27 细胞的抑制功能。我们的研究表明 miR-511-5p 在 GC 中的抑癌功能被 PAK2 抑制，miR-511-5p/PAK2 轴可能作为 GC 管理的新策略。PAK2 的重新引入逆转了 miR-511-5p 对 BGC-823 和 HGC-27 细胞的抑制功能。我们的研究表明 miR-511-5p 在 GC 中的抑癌功能被 PAK2 抑制，miR-511-5p/PAK2 轴可能作为 GC 管理的新策略。PAK2 的重新引入逆转了 miR-511-5p 对 BGC-823 和 HGC-27 细胞的抑制功能。我们的研究表明 miR-511-5p 在 GC 中的抑癌功能被 PAK2 抑制，miR-511-5p/PAK2 轴可能作为 GC 管理的新策略。