Department of Interventional Radiology, The First Affliated Hospital of Soochow University, Suzhou, China.
Department of Interventional Radiology, Huaian Hospital of Huaian City, Huaian, China.
J Cell Biochem. 2018 Dec;119(12):10327-10337. doi: 10.1002/jcb.27375. Epub 2018 Aug 20.
Epidermal growth factor-like domain multiple 7 (EGFL7) is an important sport stimulating factor and motility related factors significantly enhanced the tumor cell metastasis and overexpressed in many cancers, including hepatocellular carcinoma (HCC), associated with tumorigenesis. However, the molecular mechanism by which EGFL7 regulates HCC cell proliferation and apoptosis and the correlation between EGFL7 and cyclin-dependent kinases regulatory subunit 2 (CKS2), which is essential for biological function, have not fully explained. In this study, EGFL7 and CKS2 expression in patients with HCC was measured by real-time polymerase chain reaction and immunohistochemistry. After HCC cells respectively transfected with pLKO.1-EGFL7-shRNA, pLVX-Puro-EGFL7 recombined vector or CKS2 small interfering RNA, cell counting kit-8 and flow cytometry was performed to examine the cell proliferation and apoptosis, respectively, and the expression of β-catenin, CKS2, CDK2, and cleaved caspase-3 was measured by Western blot analysis. We found that EGFL7 and CKS2 were overexpressed in HCC tissues and a positive correlation was found between them. EGFL7 knockdown markedly inhibited proliferation and promoted apoptosis of HCC cells, along with decreased expression of CKS2 and CDK2, but increased cleaved caspase-3 expression, while EGFL7 overexpression showed an opposite effect. EGFL7 silencing in nude mice also showed decreased tumor growth and altered protein expression similar to its effect in HCC cells in vitro. Importantly, CKS2 silencing significantly inhibited EGFL7-induced HCC cell proliferation and protein expression, and Wnt/β-catenin signaling pathway inhibitor IWR-1-endo significantly inhibited CKS2 expression in HCC cells. Taken together, EGFL7 promotes HCC cell proliferation and inhibits cell apoptosis through increasing CKS2 expression by activating Wnt/β-catenin signaling.
表皮生长因子样域蛋白 7（EGFL7）是一种重要的运动刺激因子和运动相关因子，它显著增强了肿瘤细胞的转移能力，并且在包括肝细胞癌（HCC）在内的许多癌症中过度表达，与肿瘤发生有关。然而，EGFL7 调节 HCC 细胞增殖和凋亡的分子机制以及 EGFL7 与细胞周期蛋白依赖性激酶调节亚基 2（CKS2）之间的相关性，CKS2 对于生物功能至关重要，但尚未完全阐明。在这项研究中，通过实时聚合酶链反应和免疫组织化学检测 HCC 患者中 EGFL7 和 CKS2 的表达。分别转染 HCC 细胞 pLKO.1-EGFL7-shRNA、pLVX-Puro-EGFL7 重组载体或 CKS2 小干扰 RNA 后，通过细胞计数试剂盒-8 和流式细胞术分别检测细胞增殖和凋亡，通过 Western blot 分析检测 β-连环蛋白、CKS2、CDK2 和 cleaved caspase-3 的表达。我们发现 EGFL7 和 CKS2 在 HCC 组织中过度表达，并且它们之间存在正相关。EGFL7 敲低显著抑制 HCC 细胞的增殖并促进其凋亡，同时降低 CKS2 和 CDK2 的表达，但增加 cleaved caspase-3 的表达，而 EGFL7 过表达则表现出相反的效果。在裸鼠中沉默 EGFL7 也显示出肿瘤生长减少和蛋白表达改变，与体外对 HCC 细胞的作用相似。重要的是，沉默 CKS2 显著抑制了 EGFL7 诱导的 HCC 细胞增殖和蛋白表达，Wnt/β-连环蛋白信号通路抑制剂 IWR-1-endo 显著抑制了 HCC 细胞中 CKS2 的表达。总之，EGFL7 通过激活 Wnt/β-连环蛋白信号通路增加 CKS2 的表达来促进 HCC 细胞增殖并抑制细胞凋亡。
