Department of Diagnostic Radiology, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, China; Department of Medical Technology, Xi'an Medical University, Xi'an, 710061, China.
Department of Medical Technology, Xi'an Medical University, Xi'an, 710061, China.
Biochem Biophys Res Commun. 2019 Jan 29;509(1):8-15. doi: 10.1016/j.bbrc.2018.11.121. Epub 2018 Dec 20.
NHERF1/EBP50 is a PDZ-scaffold protein initially identified as an organizer and modulator of transporters and channels at the apical side of epithelia via actin-binding ezrin-moesin-radixin proteins. Presently, hepatocellular carcinoma (HCC) is one of the most deadly cancers in the world and has no effective therapeutic strategies. In the present study, we attempted to explore the role of NHERF1 in regulating liver cancer progression. The results indicated that NHERF1 was significantly expressed in liver tumor samples compared to the corresponding adjacent normal tissues. HCC patients with low NHERF1 exhibited better survival rate. Additionally, repressing NHERF1 expression markedly down-regulated the cell proliferation. G0/G1 transition was highly induced by NHERF1 knockdown, accompanied with reduced expressions of Cyclin D1 and cyclin-dependent kinase 4 (CDK4), as well as the enhanced expression of p27, phosphatase and tensin homolog (PTEN) and p53. Moreover, NHERF1 suppression significantly induced apoptosis in liver cancer cells by promoting the activation of Caspase-3 and poly (ADP-ribose) polymerase (PARP). We also observed a remarkable increase of reactive oxygen species (ROS) production in NHERF1-knockdown cells, along with c-Jun-N-terminal kinase (JNK) phosphorylation. Importantly, suppressing ROS production abolished NHERF1 knockdown-induced JNK activation. Moreover, cell cycle-regulatory proteins meditated by NHERF1 knockdown in liver cancer cells were abrogated by the pre-treatment of ROS scavenger. Further, restraining ROS generation also diminished NHERF1 knockdown-induced apoptosis. In vivo, we also found that NHERF1 knockdown markedly reduced the tumor growth. In conclusion, the results suggested that NHERF1 played an essential role in regulating liver cancer progression, and repressing NHERF1 expression exhibited significant anticancer effects via the induction of G0/G1 phase arrest, apoptosis and ROS generation.
NHERF1/EBP50 是一种 PDZ 支架蛋白，最初被鉴定为上皮细胞顶侧的转运体和通道的组织者和调节剂，通过与肌动蛋白结合的 ezrin-moesin-radixin 蛋白。目前，肝细胞癌（HCC）是世界上最致命的癌症之一，尚无有效的治疗策略。在本研究中，我们试图探讨 NHERF1 在调节肝癌进展中的作用。结果表明，NHERF1 在肝癌组织样本中的表达明显高于相应的相邻正常组织。NHERF1 低表达的 HCC 患者的生存率更高。此外，抑制 NHERF1 的表达显著下调了细胞增殖。NHERF1 敲低诱导 G0/G1 期过渡，伴随着 Cyclin D1 和细胞周期蛋白依赖性激酶 4（CDK4）的表达减少，以及 p27、磷酸酶和张力蛋白同源物（PTEN）和 p53 的表达增强。此外，NHERF1 抑制通过促进 Caspase-3 和多聚（ADP-核糖）聚合酶（PARP）的激活，显著诱导肝癌细胞凋亡。我们还观察到 NHERF1 敲低细胞中活性氧（ROS）的产生显著增加，同时 c-Jun-N 末端激酶（JNK）磷酸化。重要的是，抑制 ROS 产生消除了 NHERF1 敲低诱导的 JNK 激活。此外，ROS 清除剂预处理消除了 NHERF1 敲低后对肝癌细胞中细胞周期调节蛋白的抑制作用。此外，抑制 ROS 生成也减弱了 NHERF1 敲低诱导的凋亡。在体内，我们还发现 NHERF1 敲低显著降低了肿瘤生长。总之，结果表明 NHERF1 在调节肝癌进展中起重要作用，抑制 NHERF1 的表达通过诱导 G0/G1 期阻滞、细胞凋亡和 ROS 生成显示出显著的抗癌作用。
