title: Suppression of angiogenesis and tumor growthin vitroandin vivousing an anti-angiopoietin-2 single-chain antibody.
abstract: Hepatocellular carcinomas (HCCs) are tumors with a highly developed vascular architecture. HCC cells require access to blood vessels for growth and metastasis; therefore, the inhibition of angiogenesis represents a potential therapeutic target for HCC that may reduce the mortality and morbidity from HCC. Various attempts to develop an anti-angiogenic therapy have been made in past decades; however, modest results have been achieved in clinical trials and the challenge of HCC treatment remains. Single-chain antibodies (scFv) are characterized by low molecular weight, low immunogenicity, high penetration and a short half-life, and are easy to produce on a large scale by genetic engineering. Accordingly, an scFv against a specific angiogenic regulator, such as angiopoietin (Ang), may be a promising anti-angiogenic therapy for HCC. Our previous study indicated that an imbalanced expression of angiopoietin-2 (Ang-2) vs. angiopoietin-1 (Ang-1) in HCCs contributes to initiation of neovascularization and promotes the angiogenesis and progression of HCCs. Therefore, we suggest that specific Ang-2-targeting interventions may be valuable in the treatment of HCC via remodeling the neovascular network and changing the tumor microenvironment. In this study, a prokaryotic expression vector of Ang-2 was constructed and purified human Ang-2 protein was isolated. An scFv against human Ang-2 (scFv-Ang2) was identified and purified via phage display technology, and the effects of scFv-Ang2in vitroandin vivoon HCC in nude mice were evaluated. The results show that scFv-Ang2 inhibits vascular endothelial growth factor (VEGF) and Ang-2 induces the proliferation, migration and tubule formation of human umbilical vein endothelial cells (HUVECs)in vitro. In thein vivoassay, statistical indices, including tumor weight and volume, metastases to lungs, CD31 expression and the microvessel density (MVD) count in the scFv-Ang2-treated group of mice were significantly lower than those in the control group (P<0.05). In conclusion, the successfully generated scFv-Ang2 showed significant inhibitory effects on the angiogenesis and tumor growth of human HCCin vitroandin vivo.
authors: Hepatobiliary & Pancreatic Unit, Department of General Surgery, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, P.R. China.
authors: Zhong-Lin
authors: ZL
authors: Zhang
authors: Department of General Surgery, Branch Hospital in Fengxian of Shanghai No. 6 People's Hospital, Shanghai 201406, P.R. China.
authors: Ji-Fa
authors: JF
authors: Zhang
authors: Hepatobiliary & Pancreatic Unit, Department of General Surgery, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, P.R. China.
authors: Yu-Feng
authors: YF
authors: Yuan
authors: Hepatobiliary & Pancreatic Unit, Department of General Surgery, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, P.R. China.
authors: Yue-Ming
authors: YM
authors: He
authors: Hepatobiliary & Pancreatic Unit, Department of General Surgery, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, P.R. China.
authors: Quan-Yan
authors: QY
authors: Liu
authors: Hepatobiliary & Pancreatic Unit, Department of General Surgery, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, P.R. China.
authors: Xiao-Wen
authors: XW
authors: Mao
authors: Hepatobiliary & Pancreatic Unit, Department of General Surgery, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, P.R. China.
authors: Yong-Biao
authors: YB
authors: Ai
authors: Hepatobiliary & Pancreatic Unit, Department of General Surgery, Zhongnan Hospital of Wuhan University, Wuhan, Hubei 430071, P.R. China.
authors: Zhi-Su
authors: ZS
authors: Liu
keywords: angiopoietin-2; liver tumor; neovascularization; phage display peptide library; single-chain antibody