Zou Y, Guo C-G, Zhang M-M
Department of Radiology, Women's Hospital, Zhejiang University, School of Medicine, Hangzhou, China.
Eur Rev Med Pharmacol Sci. 2015 Dec;19(24):4751-61.
Hepatocellular carcinoma (HCC) is one of the most common malignant tumors in China. Hepatic arterial chemoembolization transcatheter (TACE) is one of the main treatment methods for liver cancer. However, the long-term therapeutic effect of HCC after TACE is still unsatisfactory, postoperative recurrence and metastasis rate is still very high. Furthermore, TACE operation due to liver cancer tissue ischemia and hypoxia will lead to up-regulation of vascular endothelial growth factor (VEGF) expression. In the current study, we investigated the effects of suppressed VEGF on HCC and its molecular mechanism provided a basis for targeting angiogenesis.
We established rabbits primary HCC model by in situ embedding the VX2 subcutaneous transplantation tumor. Conventional Seldinger femoral artery and hepatic artery catheterization method were used to select the catheter over the tumor-bearing hepatic artery. The different groups were divided into TACE operation, and the experimental group was performed with the VEGF-siRNA molecular preparation in the catheter. 64-slice spiral CT were used to perfusion imaging of liver cancer model before and after TACE operation. We further assessed the efficiency of VEGF silencing and its influence on VX2 cells. The expression of VEGF mRNA and protein were detected by RT-PCR and Western blotting, respectively. Intratumoral microvessel density (MVD), VEGF and CD34 were evaluated by immunohistochemistry. We detected the cell apoptotic by immunofluorescence and flow cytometry.
Our findings indicated that VEGF-siRNA-2# could effectively suppress the expression of VEGF expression, inhibited the proliferation capability and promoted apoptosis of VX2 cells in vitro. Silencing of VEGF expression also suppress HCC tumor growth and reduce HCC angiogenesis in rabbits primary HCC model in vivo. Furthermore, We found that phosphoinositide 3-kinase (PI3K) and protein kinase B (AKT) activation were considerably reduced while inhibition VEGF expression in VX2 cells.
Our data demonstrated that VEGF silencing could suppress cells proliferation, promote cells apoptosis and reduce HCC angiogenesis through inactivation of VEGF/PI3K/AKT signaling pathway.
肝细胞癌（HCC）是中国最常见的恶性肿瘤之一。经导管肝动脉化疗栓塞术（TACE）是肝癌的主要治疗方法之一。然而，TACE术后HCC的长期治疗效果仍不尽人意，术后复发和转移率仍然很高。此外，TACE手术因肝癌组织缺血缺氧会导致血管内皮生长因子（VEGF）表达上调。在本研究中，我们探讨了抑制VEGF对HCC的影响及其分子机制，为靶向血管生成提供依据。
通过原位植入VX2皮下移植瘤建立兔原发性HCC模型。采用传统的Seldinger股动脉和肝动脉插管方法，将导管选至荷瘤肝动脉上方。将不同组分为TACE手术组，实验组在导管内注入VEGF-siRNA分子制剂。采用64层螺旋CT对TACE手术前后的肝癌模型进行灌注成像。我们进一步评估了VEGF沉默的效率及其对VX2细胞的影响。分别采用RT-PCR和Western blotting检测VEGF mRNA和蛋白的表达。通过免疫组化评估瘤内微血管密度（MVD）、VEGF和CD34。通过免疫荧光和流式细胞术检测细胞凋亡情况。
我们的研究结果表明，VEGF-siRNA-2#能有效抑制VEGF的表达，在体外抑制VX2细胞的增殖能力并促进其凋亡。在兔原发性HCC模型体内，沉默VEGF表达也能抑制HCC肿瘤生长并减少HCC血管生成。此外，我们发现抑制VX2细胞中VEGF表达时，磷酸肌醇3激酶（PI3K）和蛋白激酶B（AKT）的激活明显降低。
我们的数据表明，VEGF沉默可通过使VEGF/PI3K/AKT信号通路失活来抑制细胞增殖、促进细胞凋亡并减少HCC血管生成。
