title: Systemic adenoviral gene delivery to orthotopic murine breast tumors with ablation of coagulation factors, thrombocytes and Kupffer cells.
abstract: BACKGROUND
  Rapid clearance of adenoviruses from blood by macrophage lineage cells of the liver and spleen, and binding to platelets, hinder their successful systemic use for cancer gene therapy. Vitamin K dependent coagulation factors are important mediators for the adenovirus liver tropism. Here we aim to determine the effects of coagulation factor, thrombocyte and liver macrophage (Kupffer cell) ablation on biodistribution of serotype 5 adenoviruses in mice with orthotopic breast tumors.
  
  
  METHODS
  Prior to intravenous injection of adenoviruses, mice bearing orthotopic breast tumors were pretreated with warfarin to inhibit vitamin K dependent coagulation factor synthesis, an anti-platelet antibody causing thrombocytopenia or an inhibitor of the Kupffer cell scavenger receptor or their combination. Virus availability in blood after injection was determined from blood samples and transgene expression in tissues analyzed 72 hours afterwards with In Vivo Imaging and luciferase assays.
  
  
  RESULTS
  Warfarin pretreatment reduced gene delivery to liver, spleen and lung. Kupffer cell ablation increased persistence of adenoviruses in blood but didn't affect biodistribution significantly. Depletion of Kupffer cells combined with thrombocytopenia doubled the systemic gene delivery of 5/3 chimeric adenovirus to tumors (p < 0.05). Triple ablation of platelets, Kupffer cells and coagulation factors increased the tumor to liver ratio of systemic adenovirus gene delivery by 81% (p < 0.05).
  
  
  CONCLUSIONS
  Depletion of coagulation factors can reduce transduction of liver, spleen and lung. Kupffer cell depletion is the most feasible method of increasing amount adenovirus in systemic blood flow and in combination with ablation of thrombocytes can increase the transduction of adenovirus to tumors.
authors: Cancer Gene Therapy Group, Molecular Cancer Biology Program and Transplantation Laboratory, Haartman Institute, University of Helsinki, Finland.
authors: Anniina
authors: A
authors: Koski
authors: Maria
authors: M
authors: Rajecki
authors: Kilian
authors: K
authors: Guse
authors: Anna
authors: A
authors: Kanerva
authors: Ari
authors: A
authors: Ristimäki
authors: Sari
authors: S
authors: Pesonen
authors: Sophie
authors: S
authors: Escutenaire
authors: Akseli
authors: A
authors: Hemminki
mesh_terms: D000256:Adenoviridae / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D001779:Blood Coagulation Factors / Q000037:antagonists & inhibitors; D001792:Blood Platelets / Q000187:drug effects; D005260:Female; D007728:Kupffer Cells / Q000187:drug effects; D008325:Mammary Neoplasms, Experimental / Q000235:genetics* / Q000378:metabolism / Q000628:therapy; D051379:Mice; D050130:Oncolytic Virotherapy / Q000379:methods; D050504:Oncolytic Viruses / Q000235:genetics*; D014161:Transduction, Genetic; D014859:Warfarin / Q000494:pharmacology
chemical_list: D001779:Blood Coagulation Factors; D014859:Warfarin