Yang Sheng-Li, Ren Quan-Guang, Zhang Tao, Pan Xiaoli, Wen Lu, Hu Jian-Li, Yu Chao, He Qian-Jin
Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China.
Department of Gastroenterology and Hepatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430022, P.R. China.
Oncol Rep. 2017 Jan;37(1):348-356. doi: 10.3892/or.2016.5211. Epub 2016 Nov 2.
Increasing evidence has demonstrated that Notch genes, including Notch1, Notch2, Notch3 and Notch4, are involved in carcinogenesis. However, the expression and regulation of Notch genes in hepatocellular carcinoma (HCC) tissues have not been fully investigated. In the present study, immunohistochemical and quantitative real-time PCR (qPCR) analyses were performed to examine the expression of Notch genes in normal human liver, HBV-related HCC and paired peritumoral tissues. Additionally, qPCR and western blotting were utilized to investigate the impact of hepatitis B virus X protein (HBx) and hypoxia‑inducible factor-1α (HIF-1α) on the regulation of Notch gene expression. The immunohistochemical and qPCR results showed that the expression levels of Notch1, Notch3 and Notch4 were significantly higher in HCC tissues than the levels in peritumoral and normal liver tissues. However, no significant difference in Notch2 expression was found between HCC and peritumoral tissues. Among the four Notch genes, immunohistochemical analyses found that only the increased level of Notch3 in HCC tissues was positively correlated with vascular invasion of liver cancer (P<0.05). Moreover, we found that overexpression of both HBx and HIF-1α increased the expression of Notch1, Notch3 and Notch4 in HepG2 and Bel-7404 cell lines. In summary, the present study demonstrated that Notch1, Notch3 and Notch4 were upregulated in HCC tissues and that HBx and HIF-1α may be the factors that cause the overexpression of Notch genes. Furthermore, the increased expression of Notch3 was closely related to the vascular invasiveness of HCC.
越来越多的证据表明，Notch基因，包括Notch1、Notch2、Notch3和Notch4，参与了肿瘤发生。然而，Notch基因在肝细胞癌（HCC）组织中的表达和调控尚未得到充分研究。在本研究中，进行了免疫组织化学和定量实时PCR（qPCR）分析，以检测Notch基因在正常人肝脏、HBV相关HCC及配对的癌旁组织中的表达。此外，利用qPCR和蛋白质印迹法研究乙型肝炎病毒X蛋白（HBx）和缺氧诱导因子-1α（HIF-1α）对Notch基因表达调控的影响。免疫组织化学和qPCR结果显示，HCC组织中Notch1、Notch3和Notch4的表达水平显著高于癌旁和正常肝脏组织中的水平。然而，HCC与癌旁组织之间Notch2表达无显著差异。在这四个Notch基因中，免疫组织化学分析发现，仅HCC组织中Notch3水平的升高与肝癌的血管侵犯呈正相关（P<0.05）。此外，我们发现HBx和HIF-1α的过表达均增加了HepG2和Bel-7404细胞系中Notch1、Notch3和Notch4的表达。总之，本研究表明Notch1、Notch3和Notch4在HCC组织中上调，且HBx和HIF-1α可能是导致Notch基因过表达的因素。此外，Notch3表达的增加与HCC的血管侵袭性密切相关。
