Department of Gastroenterology and Hepatology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, P.R. China.
Oncol Rep. 2014 Feb;31(2):933-9. doi: 10.3892/or.2013.2917. Epub 2013 Dec 12.
Hepatocellular carcinoma (HCC) is a highly lethal cancer with increasing worldwide incidence, and there are few therapeutics options available for patients with HCC. Thus, novel therapeutic targets for this disease are desperately needed. Chronic infection with hepatitis B virus (HBV) is the major risk factor for the development of HCC, while hepatitis B virus X protein (HBx) is essential for HBV-associated HCC. Based on our previous studies showing that HBx promoted hepatocarcinogenesis of the human non-tumor hepatic cell line L02 and activated Notch1 signaling, Notch1 short hairpin RNA (shRNA) was utilized to inhibit Notch1 mRNA in the present study. We observed that Notch1 shRNA inhibited cell proliferation together with decreased activity of the Notch1 pathway in vitro, and also markedly suppressed tumor formation of L02/HBx cells in a BALB/c nude mouse model in vivo. Furthermore, the blockade of Notch1 was capable of arresting the cell cycle in the G0/G1 phase through the downregulation of CyclinD1, CDK4, E2F1 and the upregulation of p21 and Rb, while all of these factors were involved in the CyclinD1/CDK4 pathway. Inhibition of Notch1 by shRNA markedly promoted the apoptosis of L02/HBx cells via the caspase-9-caspase-3 pathway. These data suggest that inhibition of Notch1 impairs the growth of human HBx-transformed L02 cells, and Notch1 may be a putative therapeutic target for human HBx-associated HCC.
肝细胞癌（HCC）是一种具有高致死率的癌症，其全球发病率正在不断上升，而 HCC 患者的治疗选择非常有限。因此，迫切需要针对这种疾病的新治疗靶点。慢性乙型肝炎病毒（HBV）感染是 HCC 发展的主要危险因素，而乙型肝炎病毒 X 蛋白（HBx）是 HBV 相关 HCC 的关键因素。基于我们之前的研究表明 HBx 促进了人非肿瘤肝细胞系 L02 的肝癌发生，并激活了 Notch1 信号通路，本研究利用 Notch1 短发夹 RNA（shRNA）抑制 Notch1 mRNA。我们观察到 Notch1 shRNA 在体外抑制细胞增殖并降低 Notch1 通路的活性，并且还显著抑制了体内 BALB/c 裸鼠模型中 L02/HBx 细胞的肿瘤形成。此外，通过下调细胞周期蛋白 D1（CyclinD1）、细胞周期蛋白依赖性激酶 4（CDK4）、E2F1 和上调 p21 和 RB，Notch1 的阻断能够将细胞周期阻滞在 G0/G1 期，而所有这些因素都参与了 CyclinD1/CDK4 通路。Notch1 shRNA 的抑制通过 caspase-9-caspase-3 通路显著促进了 L02/HBx 细胞的凋亡。这些数据表明，抑制 Notch1 可损害人 HBx 转化的 L02 细胞的生长，Notch1 可能是人类 HBx 相关 HCC 的潜在治疗靶点。
