Department of Radiotherapy, The Affiliated Cancer Hospital of Nanjing Medical University & Jiangsu Cancer Hospital & Jiangsu Institute of Cancer Research, Nanjing, China.
J Cell Biochem. 2019 Apr;120(4):6250-6263. doi: 10.1002/jcb.27912. Epub 2018 Oct 25.
MicroRNA-32 (miR-32) functioned as a tumor oncogene in some cancer, which control genes involved in important biological and pathological functions and facilitate the tumor growth and metastasis. However, the role of miR-32 modulates esophageal squamous cell carcinoma (ESCC) malignant transformation has not been clarified. Here, we focused on the function and the underlying molecular mechanism of miR-32 in ESCC. Results discovered a significant increased expression of miR-32 in ESCC tissues and cells. Downregulation of miR-32 inhibited the migration, invasion, adhesion of ESCC cell lines (EC9706 and KYSE450), and the levels of EMT protein in vitro. In vivo, miR-32 inhibitors decrease tumor size, tumor weight, and the number of metastatic nodules. Hematoxylin and eosin (H&E) results revealed that inhibition of miR-32 attenuate lung metastasis. Immunohistochemistry and immunofluorescence assay showed increased level of E-cadherin and decreased level of N-cadherin and Vimentin with treatment of miR-32 inhibitors. Furthermore, miR-32 targeted the 3'-untranslated region (3'-UTR) of CXXC5, and inhibited the level of mRNA and protein of CXXC5. There is a negative correlation between the expressions of CXXC5 and miR-32. Then, after EC9706 and KYSE450 cells cotransfected with si-CXXC5 and miR-32 inhibitors, the ability of cell migration, invasion, and adhesion was significantly reduced. In addition, the protein expression of EMT and TGF-β signaling was also depressed. Collectively, these data supply an insight into the positive role of miR-32 in ESCC progression and metastasis, and its biological effects may attribute the inhibition of TGF-β signaling mediated by CXXC5.
微小 RNA-32（miR-32）在某些癌症中作为肿瘤癌基因发挥作用，其控制参与重要生物学和病理学功能的基因，并促进肿瘤生长和转移。然而，miR-32 调节食管鳞状细胞癌（ESCC）恶性转化的作用尚未阐明。在这里，我们专注于 miR-32 在 ESCC 中的功能和潜在分子机制。结果发现 miR-32 在 ESCC 组织和细胞中表达显著增加。下调 miR-32 抑制 ESCC 细胞系（EC9706 和 KYSE450）的迁移、侵袭和黏附，以及 EMT 蛋白的水平在体外。在体内，miR-32 抑制剂可减少肿瘤大小、肿瘤重量和转移结节数量。苏木精和伊红（H&E）结果显示，抑制 miR-32 可减轻肺转移。免疫组化和免疫荧光分析显示，miR-32 抑制剂处理后 E-钙黏蛋白水平升高，N-钙黏蛋白和波形蛋白水平降低。此外，miR-32 靶向 CXXC5 的 3'-非翻译区（3'-UTR），并抑制 CXXC5 的 mRNA 和蛋白水平。CXXC5 和 miR-32 的表达呈负相关。然后，在 EC9706 和 KYSE450 细胞共转染 si-CXXC5 和 miR-32 抑制剂后，细胞迁移、侵袭和黏附的能力显著降低。此外，EMT 和 TGF-β 信号通路的蛋白表达也受到抑制。总之，这些数据提供了 miR-32 在 ESCC 进展和转移中的积极作用的深入了解，其生物学效应可能归因于 CXXC5 介导的 TGF-β 信号抑制。
