a Department of Oral and Maxillofacial Surgery , The Second Affiliated Hospital of Harbin Medical University , Harbin , China.
b Department of Neurosurgery , The Fourth Affiliated Hospital of Harbin Medical University , Harbin , China.
Cell Adh Migr. 2018 May 4;12(3):236-246. doi: 10.1080/19336918.2017.1365992. Epub 2017 Nov 13.
Previous studies indicate that TGFBR3 (transforming growth factor type III receptor, also known as betaglycan), a novel suppressor of progression in certain cancers, is down-regulated in tongue squamous cell carcinoma (TSCC). However, the role of this factor as an upstream regulator in TSCC cells remains to be elucidated. The present study was designed to elucidate whether TGFBR3 gene expression is regulated by two microRNA molecules, miR-19a and miR-424. The study also aimed to determine if these microRNAs promote migration of CAL-27 human oral squamous cells. Immunohistochemistry (IHC) and western blot analyses demonstrated that TGFBR3 protein levels were dramatically down-regulated in clinical TSCC specimens. Conversely, bioinformatics analyses and qRT-PCR results confirmed that both miR-19a and miR-424 were markedly up-regulated in clinical TSCC specimens. In this study, we observed that transfection of a TGFBR3-containing plasmid dramatically inhibited epithelial-to-mesenchymal transition (EMT) and migration in CAL-27 cells. Co-immunoprecipitation analyses also revealed that TGFBR3 forms a complex with the β-arrestin 2 scaffolding protein and IκBα. Furthermore, overexpression of TGFBR3 decreased p-p65 expression and increased IκBα expression; these effects were subsequently abolished following knockdown of β-arrestin 2. Moreover, over-expression of miR-19a and miR-424 promoted migration and EMT in CAL-27 cells. We also observed that the promotion of EMT by miR-19a and miR-424 was mediated by the inhibition of TGFBR3. Our study provides evidence that miR-19a and miR-424 play important roles in the development of TSCC. These results expand our understanding of TGFBR3 gene expression and regulatory mechanisms pertaining to miRNAs.
先前的研究表明，TGFBR3（转化生长因子 III 型受体，也称为β糖蛋白）是某些癌症进展的新型抑制剂，在舌鳞状细胞癌（TSCC）中下调。然而，该因子作为 TSCC 细胞上游调节剂的作用仍有待阐明。本研究旨在阐明 TGFBR3 基因表达是否受两种 microRNA 分子，miR-19a 和 miR-424 的调控。该研究还旨在确定这些 microRNAs 是否促进 CAL-27 人口腔鳞状细胞的迁移。免疫组织化学（IHC）和 Western blot 分析表明，TGFBR3 蛋白水平在临床 TSCC 标本中明显下调。相反，生物信息学分析和 qRT-PCR 结果证实，miR-19a 和 miR-424 在临床 TSCC 标本中均明显上调。在这项研究中，我们观察到转染含有 TGFBR3 的质粒可显著抑制 CAL-27 细胞的上皮间质转化（EMT）和迁移。共免疫沉淀分析还表明，TGFBR3 与β-arrestin 2 支架蛋白和 IκBα 形成复合物。此外，TGFBR3 的过表达降低了 p-p65 的表达并增加了 IκBα 的表达；随后敲低β-arrestin 2 后，这些作用被消除。此外，miR-19a 和 miR-424 的过表达促进了 CAL-27 细胞的迁移和 EMT。我们还观察到，miR-19a 和 miR-424 通过抑制 TGFBR3 促进 EMT。我们的研究提供了证据表明，miR-19a 和 miR-424 在 TSCC 的发展中起重要作用。这些结果扩展了我们对 TGFBR3 基因表达和 miRNA 调节机制的理解。
