Recent evidences demonstrate that dysregulated expression of microRNA-320d (miR-320d) has been associated with several cancer development and progression. However the effect of miR-320d on gastric cardiac adenocarcinoma (GCA) and the association of miR-320d with its potential gene target FoxM1 remain unclear. Here, we evaluated expression profile of miR-320d and FoxM1 in 60 human GCA tissues and GCA cell lines (OE-19 and SK-GT2). Immunohistochemistry, qualitative PCR and western-blotting were performed in GCA tissues to detect the expression level of miR-320d and FoxM1. CCK-8, transwell, wound-healing assays, and in vivo experiments were conducted using GCA cells that treated with miR-320d mimics or inhibitors to evaluate the biological functions of miR-320d. Luciferase reporter assay was conducted to confirm possible binding sites of FoxM1 for miR-320d. Compared with paired non-cancerous tissues, it showed that miR-320d expression was significantly decreased in GCA specimens (P < 0.0001), while FoxM1 was significantly upregulated in GCA tissues (P < 0.0001). Modulating miR-320d function by transfection of miR-320 mimics or inhibitor led to inhibition or promotion of GCA cell proliferation and invasion, thus regulating tumor progression in GCA-tumor bearing mice. The mechanism analysis of miR-320d/FoxM1 showed that FoxM1 has two miR-320d binding sites in its 3′-untranslated region (3′-UTR), that contributes to regulation of the cell biological behaviors. Taken together, our data suggested that miR-320d acts as a tumor suppressor in GCA by directly targeting FoxM1 and thus potentially serves as a biomarker for anti-GCA therapy in GCA patients.

中文翻译：

---

MicroRNA-320d通过促进FoxM1调节肿瘤的生长和侵袭，并预测胃gastric门腺癌的不良预后。

最近的证据表明，microRNA-320d（miR-320d）的表达失调与几种癌症的发生和发展有关。但是，尚不清楚miR-320d对胃a门腺癌（GCA）的作用以及miR-320d与其潜在基因靶标FoxM1的关联。在这里，我们评估了miR-320d和FoxM1在60个人的GCA组织和GCA细胞系（OE-19和SK-GT2）中的表达谱。在GCA组织中进行免疫组织化学，定性PCR和western-blotting检测miR-320d和FoxM1的表达水平。使用经miR-320d模拟物或抑制剂处理的GCA细胞进行CCK-8，transwell，伤口愈合试验和体内实验，以评估miR-320d的生物学功能。进行荧光素酶报告基因测定以确认FoxM1可能与miR-320d结合。与配对的非癌组织相比，它表明在GCA标本中miR-320d表达显着降低（P <0.0001），而FoxM1在GCA组织中显着上调（P <0.0001）。通过转染miR-320模拟物或抑制剂来调节miR-320d功能可抑制或促进GCA细胞增殖和侵袭，从而调节荷瘤GCA小鼠的肿瘤进程。对miR-320d / FoxM1的机理分析表明，FoxM1在其3'-非翻译区（3'-UTR）中具有两个miR-320d结合位点，有助于调节细胞生物学行为。在一起