Department of Oncology and Hematology, Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, P. R. China.
Department of Epidemiology and Public Health, School of Medicine, Yale University, New Haven, Connecticut, USA.
Kaohsiung J Med Sci. 2019 Aug;35(8):459-466. doi: 10.1002/kjm2.12089. Epub 2019 May 15.
The current study aims to evaluate the mechanism of apoptotic protease activating factor-1 (Apaf-1) in hepatocellular carcinoma (HCC) cells by verifying the regulation of the wnt/beta-catenin signaling pathway via Apal-1. Our data showed that transfection with Ad-Apaf-1 could inhibit the activity of a lymphoid enhancer factor (LEF) luciferase plasmid activated by β-catenin. Overexpressing Apaf-1 could suppress the β-catenin-induced LEF luciferase activity in a dose-dependent manner. Western blot assays demonstrated that the overexpression of Apaf1 significantly suppressed the expression of Wnt/β-catenin signaling-related proteins. Further study demonstrated that Apaf-1 suppressed HepG2 cell migration, invasion, and viability. Knocking down the expression of Apaf-1 activated the wnt/β-catenin pathway in HepG2 cells. In contrast, silencing β-catenin decreased the activation of wnt/β-catenin, even in the presence of si-Apaf-1. Cell cycle distribution analysis demonstrated a decrease in the number of cells in the G0/G1 phase in the Apaf-1 silencing group. In contrast, knocking down the expression of β-catenin increased the number of cells in the G0/G1 phase, even in the presence of si-Apaf-1. In summary, the Apaf-1-mediated suppression of HepG2 cell malignancy is achieved by inhibiting the wnt/β-catenin pathway.
本研究旨在通过验证 Apaf-1 对 wnt/β-catenin 信号通路的调节作用，来评估凋亡蛋白酶激活因子-1（Apaf-1）在肝癌（HCC）细胞中的作用机制。我们的数据表明，转染 Ad-Apaf-1 可以抑制β-catenin 激活的淋巴增强因子（LEF）荧光素酶质粒的活性。过表达 Apaf-1 可以以剂量依赖的方式抑制β-catenin 诱导的 LEF 荧光素酶活性。Western blot 分析表明，Apaf1 的过表达显著抑制了 Wnt/β-catenin 信号通路相关蛋白的表达。进一步的研究表明，Apaf-1 抑制 HepG2 细胞的迁移、侵袭和活力。敲低 Apaf-1 的表达可激活 HepG2 细胞中的 wnt/β-catenin 通路。相反，沉默β-catenin 即使在存在 si-Apaf-1 的情况下，也能降低 wnt/β-catenin 的激活。细胞周期分布分析表明，Apaf-1 沉默组 G0/G1 期细胞数量减少。相反，敲低β-catenin 即使在存在 si-Apaf-1 的情况下，也能增加 G0/G1 期细胞数量。总之，Apaf-1 通过抑制 wnt/β-catenin 通路抑制 HepG2 细胞的恶性行为。
