Esophageal cancer (EC) is one of the most common aggressive malignant diseases worldwide. miR-28-5p plays important regulatory roles in many cancers including human EC. However, the molecular mechanism and potential role of miR-28-5p in EC remain uncertain. In this study, qRT-PCR and western blot analysis revealed that miR-28-5p expression was up-regulated and metastasis suppressor-1 (MTSS1) was down-regulated in EC tissues relative to matched para-cancer tissues. Cell counting kit-8 (CCK-8) assay demonstrated that miR-28-5p mimics increased cell viability, and miR-28-5p inhibitor decreased it. Flow cytometry (FCM) assay indicated that miR-28-5p mimics promoted cell cycle entry, while miR-28-5p inhibitor reduced it and induced cell apoptosis. Moreover, miR-28-5p mimics up-regulated the expressions of cyclin A, cyclin dependent kinase 2 (CDK2), cyclin D1, and cyclin E but down-regulated the expressions of cleaved caspase-3 and cleaved caspase-9, which was abolished by miR-28-5p inhibitor. Furthermore, luciferase reporter assay verified that miR-28-5p directly targeted MTSS1 3′UTR and down-regulated its expression. MTSS1 overexpression in TE-1 cells inhibited cell proliferation and promoted apoptosis induced by miR-28-5p mimics, whereas silencing of MTSS1 reversed cell progression induced by miR-28-5p inhibitor. We also demonstrated that miR-28-5p could promote esophageal tumor formation in vivo. Hematoxylin–eosin staining, immunohistochemistry, and TUNEL assays confirmed that miR-28-5p antagomir inhibited cell growth and accelerated apoptosis. Our results suggest that miR-28-5p may induce cell proliferation and suppress apoptosis to promote EC tumor formation via decreasing MTSS1 expression. Thus, miR-28-5p may be a potential target for human EC therapy.

中文翻译：

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miR-28-5p靶向MTSS1来调节食道癌中的细胞增殖和凋亡。

食道癌（EC）是全球最常见的侵袭性恶性疾病之一。miR-28-5p在包括人类EC在内的许多癌症中起着重要的调节作用。然而，miR-28-5p在EC中的分子机制和潜在作用仍然不确定。在这项研究中，qRT-PCR和蛋白质印迹分析表明，相对于匹配的癌旁组织，EC组织中的miR-28-5p表达上调，而转移抑制因子1（MTSS1）下调。细胞计数试剂盒8（CCK-8）分析表明，miR-28-5p模拟物可提高细胞活力，而miR-28-5p抑制剂可降低其活力。流式细胞仪（FCM）分析表明，miR-28-5p模仿物促进细胞周期进入，而miR-28-5p抑制剂降低其诱导细胞凋亡。此外，miR-28-5p上调了细胞周期蛋白A，细胞周期蛋白依赖性激酶2（CDK2）的表达，细胞周期蛋白D1和细胞周期蛋白E但下调了被miR-28-5p抑制剂消除的caspase-3和caspase-9的表达。此外，荧光素酶报告基因测定证实了miR-28-5p直接靶向MTSS1 3'UTR并下调了其表达。TE-1细胞中MTSS1的过表达抑制miR-28-5p模拟物诱导的细胞增殖并促进细胞凋亡，而沉默MTSS1则逆转miR-28-5p抑制剂诱导的细胞进程。我们还证明了miR-28-5p可以促进食道肿瘤的形成 TE-1细胞中MTSS1的过表达抑制miR-28-5p模拟物诱导的细胞增殖并促进细胞凋亡，而沉默MTSS1则逆转miR-28-5p抑制剂诱导的细胞进程。我们还证明了miR-28-5p可以促进食道肿瘤的形成 TE-1细胞中MTSS1的过表达抑制miR-28-5p模拟物诱导的细胞增殖并促进细胞凋亡，而沉默MTSS1则逆转miR-28-5p抑制剂诱导的细胞进程。我们还证明了miR-28-5p可以促进食道肿瘤的形成体内。苏木精-伊红染色，免疫组化和TUNEL分析证实miR-28-5p antagomir抑制细胞生长并加速细胞凋亡。我们的结果表明，miR-28-5p可能通过降低MTSS1表达来诱导细胞增殖并抑制细胞凋亡，从而促进EC肿瘤的形成。因此，miR-28-5p可能是人类EC治疗的潜在靶标。