Guo Yarong, Chai Bao, Jia Junmei, Yang Mudan, Li Yanjun, Zhang Rui, Wang Shunmin, Xu Jun
Department of Oncology, The First Affiliated Hospital of Shanxi Medical University, Taiyuan, 030001, Shanxi, China.
Department of Gastroenterology, Shanxi Academy of Medical Science, Shanxi Bethune Hospital, Taiyuan, 030032, Shanxi, China.
Cell Biosci. 2021 Apr 15;11(1):73. doi: 10.1186/s13578-021-00585-6.
Dysregulation of KLF7 participates in the development of various cancers, but it is unclear whether there is a link between HCC and aberrant expression of KLF7. The aim of this study was to investigate the role of KLF7 in proliferation and migration of hepatocellular carcinoma (HCC) cells.
CCK8, colony growth, transwell, cell cycle analysis and apoptosis detection were performed to explore the effect of KLF7, VPS35 and Ccdc85c on cell function in vitro. Xenografted tumor growth was used to assess in vivo role of KLF7. Chip-qPCR and luciferase reporter assays were applied to check whether KLF7 regulated VPS35 at transcriptional manner. Co-IP assay was performed to detect the interaction between VPS35 and Ccdc85c. Immunohistochemical staining and qRT-PCR analysis were performed in human HCC sampels to study the clinical significance of KLF7, VPS35 and β-catenin.
Firstly, KLF7 was highly expressed in human HCC samples and correlated with patients' differentiation and metastasis status. KLF7 overexpression contributed to cell proliferation and invasion of HCC cells in vitro and in vivo. KLF7 transcriptional activation of VPS35 was necessary for HCC tumor growth and metastasis. Further, co-IP studies revealed that VPS35 could interact with Ccdc85c in HCC cells. Rescue assay confirmed that overexpression of VPS35 and knockdown of Ccdc85c abolished the VPS35-medicated promotion effect on cell proliferation and invasion. Finally, KLF7/VPS35 axis regulated Ccdc85c, which involved in activation of β-catenin signaling pathway, confirmed using β-catenin inhibitor, GK974. Functional studies suggested that downregulation of Ccdc85c partly reversed the capacity of cell proliferation and invasion in HCC cells, which was regulated by VPS35 upregulation. Lastly, there was a positive correlation among KLF7, VPS35 and active-β-catenin in human HCC patients.
We demonstrated that KLF7/VPS35 axis promoted HCC cell progression by activating Ccdc85c-medicated β-catenin pathway. Targeting this signal axis might be a potential treatment strategy for HCC.
KLF7的失调参与多种癌症的发展，但KLF7异常表达与肝癌（HCC）之间是否存在联系尚不清楚。本研究旨在探讨KLF7在肝癌（HCC）细胞增殖和迁移中的作用。
进行CCK8、集落生长、transwell、细胞周期分析和凋亡检测，以探讨KLF7、VPS35和Ccdc85c对体外细胞功能的影响。采用异种移植瘤生长评估KLF7的体内作用。应用芯片-qPCR和荧光素酶报告基因检测来检查KLF7是否以转录方式调节VPS35。进行免疫共沉淀试验以检测VPS35与Ccdc85c之间的相互作用。在人肝癌样本中进行免疫组织化学染色和qRT-PCR分析，以研究KLF7、VPS35和β-连环蛋白的临床意义。
首先，KLF7在人肝癌样本中高表达，且与患者的分化和转移状态相关。KLF7过表达促进了体外和体内肝癌细胞的增殖和侵袭。KLF7对VPS35的转录激活是肝癌肿瘤生长和转移所必需的。此外，免疫共沉淀研究表明，VPS35可与肝癌细胞中的Ccdc85c相互作用。挽救试验证实，VPS35过表达和Ccdc85c敲低消除了VPS35介导的对细胞增殖和侵袭的促进作用。最后，使用β-连环蛋白抑制剂GK974证实，KLF7/VPS35轴调节Ccdc85c，其参与β-连环蛋白信号通路的激活。功能研究表明，Ccdc85c的下调部分逆转了VPS35上调所调节的肝癌细胞增殖和侵袭能力。最后，在人肝癌患者中，KLF7、VPS35和活性β-连环蛋白之间存在正相关。
我们证明KLF7/VPS35轴通过激活Ccdc85c介导的β-连环蛋白途径促进肝癌细胞进展。靶向该信号轴可能是肝癌的一种潜在治疗策略。
