title: AAV-mediated human PEDF inhibits tumor growth and metastasis in murine colorectal peritoneal carcinomatosis model.
abstract: BACKGROUND
  Angiogenesis plays an important role in tumor growth and metastasis, therefore antiangiogenic therapy was widely investigated as a promising approach for cancer therapy. Recently, pigment epithelium-derived factor (PEDF) has been shown to be the most potent inhibitor of angiogenesis. Adeno-associated virus (AAV) vectors have been intensively studied due to their wide tropisms, nonpathogenicity, and long-term transgene expression in vivo. The objective of this work was to evaluate the ability of AAV-mediated human PEDF (hPEDF) as a potent tumor suppressor and a potential candidate for cancer gene therapy.
  
  
  METHODS
  Recombinant AAV2 encoding hPEDF (rAAV2-hPEDF) was constructed and produced, and then was assigned for in vitro and in vivo experiments. Conditioned medium from cells infected with rAAV2-hPEDF was used for cell proliferation and tube formation tests of human umbilical vein endothelial cells (HUVECs). Subsequently, colorectal peritoneal carcinomatosis (CRPC) mouse model was established and treated with rAAV2-hPEDF. Therapeutic efficacy of rAAV2-hPEDF were investigated, including tumor growth and metastasis, survival time, microvessel density (MVD) and apoptosis index of tumor tissues, and hPEDF levels in serum and ascites.
  
  
  RESULTS
  rAAV2-hPEDF was successfully constructed, and transmission electron microscope (TEM) showed that rAAV2-hPEDF particles were non-enveloped icosahedral shape with a diameter of approximately 20 nm. rAAV2-hPEDF-infected cells expressed hPEDF protein, and the conditioned medium from infected cells inhibited proliferation and tube-formation of HUVECs in vitro. Furthermore, in CRPC mouse model, rAAV2-hPEDF significantly suppressed tumor growth and metastasis, and prolonged survival time of treated mice. Immunofluorescence studies indicated that rAAV2-hPEDF could inhibit angiogenesis and induce apoptosis in tumor tissues. Besides, hPEDF levels in serum and ascites of rAAV2-hPEDF-treated mice were significant higher than those in rAAV2-null or normal saline (NS) groups.
  
  
  CONCLUSIONS
  Thus, our results suggest that rAAV2-hPEDF may be a potential candidate as an antiangiogenic therapy agent.
authors.affiliation: State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, and School of Life Sciences, Sichuan University, Chengdu 610041, P.R. China.
authors.forename: Qin Jie
authors.initials: QJ
authors.lastname: Wu
authors.forename: Chang Yang
authors.initials: CY
authors.lastname: Gong
authors.forename: Shun Tao
authors.initials: ST
authors.lastname: Luo
authors.forename: Dong Mei
authors.initials: DM
authors.lastname: Zhang
authors.forename: Shuang
authors.initials: S
authors.lastname: Zhang
authors.forename: Hua Shan
authors.initials: HS
authors.lastname: Shi
authors.forename: Lian
authors.initials: L
authors.lastname: Lu
authors.forename: Heng Xiu
authors.initials: HX
authors.lastname: Yan
authors.forename: Sha Sha
authors.initials: SS
authors.lastname: He
authors.forename: Dan Dan
authors.initials: DD
authors.lastname: Li
authors.forename: Li
authors.initials: L
authors.lastname: Yang
authors.forename: Xia
authors.initials: X
authors.lastname: Zhao
authors.forename: Yu Quan
authors.initials: YQ
authors.lastname: Wei
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage*; D015153:Blotting, Western; D002277:Carcinoma / Q000473:pathology / Q000556:secondary / Q000628:therapy*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004195:Disease Models, Animal; D005136:Eye Proteins / Q000008:administration & dosage*; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors; D051379:Mice; D008807:Mice, Inbred BALB C; D055806:Microvessels / Q000473:pathology; D009362:Neoplasm Metastasis; D009389:Neovascularization, Pathologic / Q000188:drug therapy; D009414:Nerve Growth Factors / Q000008:administration & dosage*; D010534:Peritoneal Neoplasms / Q000473:pathology / Q000628:therapy*; D015843:Serpins / Q000008:administration & dosage*; D000099174:Pigment Epithelium-Derived Factor
chemical_list: D000970:Antineoplastic Agents; D005136:Eye Proteins; D009414:Nerve Growth Factors; D015843:Serpins; D000099174:Pigment Epithelium-Derived Factor