title: Inhibition of retinoblastoma in vitro and in vivo with conditionally replicating oncolytic adenovirus H101.
abstract: OBJECTIVE
  To determine the therapeutic effect of oncolytic adenovirus H101 on retinoblastoma in vitro and in vivo.
  
  
  METHODS
  The expression of coxsackievirus-adenovirus receptor (CAR) in human retinoblastoma cell line HXO-RB(44) was determined by RT-PCR, Western blot, immunofluorescence, and immunocytochemistry staining. Appropriate multiplicity of infection was determined using flow cytometry in retinoblastoma cells with green fluorescent protein-expressing adenovirus (AdGFP). The viability of HXO-RB(44) cells treated with H101 or AdGFP was measured using a cell counting kit-8-based procedure. Viral proliferation in vitro was measured by end point dilution titration and real-time PCR. Cell cycle and apoptotic activity of HXO-RB(44) were analyzed by flow cytometry. NOD-SCID mice bearing retinoblastoma xenografts were treated with intratumoral injection of H101, AdGFP, or PBS. Tumor volume and survival time were recorded. Immunohistochemistry for adenoviral fiber protein and Western blot for adenoviral Hexon protein of retinoblastoma xenografts were performed to evaluate H101 virus replication in vivo.
  
  
  RESULTS
  HXO-RB(44) cells expressed CAR and were sensitive to adenoviral infection. HXO-RB(44) cells treated with H101 had reduced cell viability compared with AdGFP-treated cells (P < 0.01). Abundant replication of H101 in HXO-RB(44) cells resulted in G(2)/M-phase arrest and finally tumor cell lysis, but the apoptosis pathway was not activated. Tumor-bearing mice treated with H101 had reduced tumor burdens and prolonged survival times compared with PBS and AdGFP controls (both P < 0.01). Immunohistochemical and Western blot examination revealed widespread replication of H101 within the tumor.
  
  
  CONCLUSIONS
  These results suggest that H101 effectively inhibits the growth of retinoblastoma cells in vitro and in mice and may serve as a novel therapy for retinoblastoma.
authors.affiliation: Department of Ophthalmology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, P R China.
authors.forename: Xin
authors.initials: X
authors.lastname: Song
authors.forename: Yixiong
authors.initials: Y
authors.lastname: Zhou
authors.forename: Renbing
authors.initials: R
authors.lastname: Jia
authors.forename: Xiaofang
authors.initials: X
authors.lastname: Xu
authors.forename: Haibo
authors.initials: H
authors.lastname: Wang
authors.forename: Jifan
authors.initials: J
authors.lastname: Hu
authors.forename: Shengfang
authors.initials: S
authors.lastname: Ge
authors.forename: Xianqun
authors.initials: X
authors.lastname: Fan
mesh_terms: D000256:Adenoviridae / Q000502:physiology*; D000818:Animals; D015153:Blotting, Western; D002453:Cell Cycle; D005434:Flow Cytometry; D019084:Fluorescent Antibody Technique, Indirect; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D050130:Oncolytic Virotherapy; D050504:Oncolytic Viruses / Q000502:physiology; D019572:Retinal Neoplasms / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D012175:Retinoblastoma / Q000401:mortality / Q000473:pathology / Q000628:therapy*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015996:Survival Rate; D014407:Tumor Cells, Cultured; D014779:Virus Replication; D023041:Xenograft Model Antitumor Assays