Institute for Regenerative Medicine, Yanbian University College of Medicine, Yanji, 133002, Jilin Province, PR China.
Institute for Regenerative Medicine, Yanbian University College of Medicine, Yanji, 133002, Jilin Province, PR China; Department of Pathology, Yanbian University College of Medicine, Yanji, 133002, Jilin Province, PR China.
Exp Cell Res. 2020 Apr 1;389(1):111861. doi: 10.1016/j.yexcr.2020.111861. Epub 2020 Jan 22.
SET domain-containing 5 (SETD5) is an uncharacterized member of the protein lysine methyltransferase family. Although it was reported that SETD5 gene mutations are associated with the several types of human cancer, its functional role in esophageal squamous cell carcinoma (ESCC) progression has not been fully elucidated. In the present study, we used tissue samples from 147 patients with ESCC and ESCC cell lines to determine the clinicopathological significance of SETD5 in ESCC and its effects on ESCC stemness. We performed immunohistochemical staining, immunofluorescence imaging, and tumor sphere formation, colony formation, flow cytometry, wound healing, Transwell, and western blotting assays. SETD5 expression was upregulated in ESCC tissue and associated with primary tumor (pT) stage, clinical stage, lymph node metastasis, shorter overall survival rate, and disease-free survival rate. Cox regression analyses indicated that SETD5 is an independent poor prognostic factor of ESCC. In addition, SETD5 expression was correlated with cancer stemness-related protein, hypoxia-inducible factor-1α (HIF-1α), and CD68 expression. Moreover, immunofluorescence analysis revealed that SETD5 was co-localized with CD44 and SOX2 in TE10 and TE11 cells and that exposing cells to cobalt chloride increased HIF-1α, SETD5, and stemness-related protein expression in a time-dependent manner. Furthermore, SETD5 expression was significantly correlated with the expression of cell cycle-related genes and PI3K/Akt signaling pathway-related proteins. Finally, knocking down SETD5 downregulated the expression of stemness-related and PI3K/Akt signaling pathway proteins, while inhibiting tumor spheroid formation, cell proliferation, migration, and invasion in ESCC cells. These results indicate that SETD5 expression is associated with cancer stemness and that SETD5 is a potential prognostic biomarker and therapeutic target for ESCC.
SET 结构域包含蛋白 5（SETD5）是蛋白赖氨酸甲基转移酶家族的一个未被描述的成员。尽管有报道称 SETD5 基因突变与几种人类癌症有关，但它在食管鳞状细胞癌（ESCC）进展中的功能作用尚未完全阐明。在本研究中，我们使用了来自 147 名 ESCC 患者和 ESCC 细胞系的组织样本，以确定 SETD5 在 ESCC 中的临床病理意义及其对 ESCC 干性的影响。我们进行了免疫组织化学染色、免疫荧光成像以及肿瘤球体形成、集落形成、流式细胞术、划痕愈合、Transwell 和 Western blot 分析。SETD5 在 ESCC 组织中表达上调，并与原发肿瘤（pT）分期、临床分期、淋巴结转移、总生存率和无病生存率降低相关。Cox 回归分析表明，SETD5 是 ESCC 的一个独立不良预后因素。此外，SETD5 表达与癌症干性相关蛋白、缺氧诱导因子-1α（HIF-1α）和 CD68 表达相关。此外，免疫荧光分析显示，SETD5 在 TE10 和 TE11 细胞中与 CD44 和 SOX2 共定位，并且用氯化钴处理细胞可使 HIF-1α、SETD5 和干性相关蛋白的表达呈时间依赖性增加。此外，SETD5 表达与细胞周期相关基因和 PI3K/Akt 信号通路相关蛋白的表达显著相关。最后，敲低 SETD5 下调了干性相关和 PI3K/Akt 信号通路蛋白的表达，同时抑制了 ESCC 细胞的肿瘤球体形成、细胞增殖、迁移和侵袭。这些结果表明，SETD5 表达与癌症干性有关，SETD5 是 ESCC 的一个潜在预后生物标志物和治疗靶点。
