Wang Hongming, Xue Weishuang, Ouyang Wunyu, Jiang Xiaoze, Jiang Xuejun
Department of Otolaryngology, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning, China.
Department of Neurology, The First Affiliated Hospital of China Medical University, Shenyang, Liaoning, China.
J Cancer. 2020 Feb 10;11(9):2529-2539. doi: 10.7150/jca.30995. eCollection 2020.
SIX1 overexpression has been reported in several cancers. However, its involvement in head and neck squamous cell carcinoma (HNSCC) remains unclear. In this study we investigated the clinical significance and biological roles of SIX1 in HNSCC. SIX1 expression was upregulated in HNSCC and correlated with TNM stage and nodal metastasis. Analysis of TCGA dataset demonstrated that high SIX1 expression correlated with poor patient prognosis. Overexpression of SIX1 in the Fadu cell line upregulated cell proliferation, colony formation, glucose uptake and ATP production. In contrast, SIX1 depletion in the Detroit562 cell line downregulated cell proliferation, colony formation, glucose uptake and ATP production. We analyzed a series of genes involved in glucose metabolism and found that SIX1 overexpression upregulated GLUT3, an important glucose transporter, at both mRNA and protein levels. Using the TRANSFAC database, we found that SIX1 had potential binding sites on the GLUT3 promoter, which was validated by chromatin immunoprecipitation (ChIP) assays. Next, we focused on miR-23a-3p, which could target SIX1 in HNSCC cells. The miR-23a-3p mimic downregulated SIX1 expression while the miR-23a-3p inhibitor upregulated SIX1 expression. The binding of miR-23a-3p to the 3'-UTR of SIX1 was confirmed using the luciferase reporter assay. Analysis of TCGA dataset showed a negative correlation between the miR-23a-3p and SIX1. Furthermore, the miR-23a-3p mimic inhibited cell proliferation, ATP production and glucose uptake, which could be rescued by transfection with the SIX1 plasmid. In summary, our study demonstrated that SIX1 facilitated HNSCC cell growth through regulation of GLUT3 and glucose uptake. miR-23a-3p targeted the SIX1/GLUT3 axis and suppressed glucose uptake and proliferation in HNSCC.
已有报道称SIX1在多种癌症中过表达。然而，其在头颈部鳞状细胞癌（HNSCC）中的作用仍不清楚。在本研究中，我们调查了SIX1在HNSCC中的临床意义和生物学作用。SIX1在HNSCC中表达上调，并与TNM分期和淋巴结转移相关。对TCGA数据集的分析表明，SIX1高表达与患者预后不良相关。在Fadu细胞系中过表达SIX1可上调细胞增殖、集落形成、葡萄糖摄取和ATP生成。相反，在Detroit562细胞系中敲低SIX1可下调细胞增殖、集落形成、葡萄糖摄取和ATP生成。我们分析了一系列参与葡萄糖代谢的基因，发现SIX1过表达在mRNA和蛋白质水平上均上调了重要的葡萄糖转运蛋白GLUT3。使用TRANSFAC数据库，我们发现SIX1在GLUT3启动子上有潜在的结合位点，这通过染色质免疫沉淀（ChIP）实验得到了验证。接下来，我们聚焦于miR-23a-3p，它可以在HNSCC细胞中靶向SIX1。miR-23a-3p模拟物下调SIX1表达，而miR-23a-3p抑制剂上调SIX1表达。使用荧光素酶报告基因实验证实了miR-23a-3p与SIX1的3'-UTR结合。对TCGA数据集的分析显示miR-23a-3p与SIX1之间呈负相关。此外，miR-23a-3p模拟物抑制细胞增殖、ATP生成和葡萄糖摄取，而转染SIX1质粒可挽救这些作用。总之，我们的研究表明SIX1通过调节GLUT3和葡萄糖摄取促进HNSCC细胞生长。miR-23a-3p靶向SIX1/GLUT3轴并抑制HNSCC中的葡萄糖摄取和增殖。
