Herpes simplex virus amplicon delivery of a hypoxia-inducible angiogenic inhibitor blocks capillary formation in hepatocellular carcinoma.
Tumor hypoxia induces vascular endothelial growth factor (VEGF) expression, which stimulates tumor angiogenesis. The VEGF pathway is inhibited by soluble VEGF receptors (soluble fetal liver kinase-1 [sFlk-1]) that bind VEGF and block its interaction with endothelial cells. Herpes simplex virus (HSV)-derived amplicons are replication-incompetent viruses used for gene delivery. We attempt to attenuate angiogenesis and inhibit hepatoma growth through amplicon-mediated expression of sFlk-1 under hypoxic control. A multimerized hypoxia-responsive enhancer (10xHRE) was cloned upstream of the sFlk-1 gene (10xHRE/sFlk-1). An amplicon expressing 10xHRE/sFlk-1 was genetically engineered (HSV10xHRE/sFlk-1). SK-HEP-1 human hepatoma cells were transduced with HSV10xHRE/sFlk-1 and incubated in normoxia (21% O2) or hypoxia (1% O2). Human umbilical vein endothelial cell assay evaluated capillary inhibition. Western blot assessed sFlk-1 expression. SK-HEP-1 flank tumors (n = 24) in athymic mice were treated with HSV10xHRE/sFlk-1. Media from hypoxic SK-HEP-1 transduced with HSV10xHRE/sFlk-1 yielded an 80% reduction in capillary formation (P < 0.005), whereas normoxic SK-HEP-1 yielded a 25% reduction (P < 0.05). Western blot of SK-HEP-1 transduced with HSV10xHRE/sFlk-1 demonstrated greater sFlk-1 expression in hypoxia vs. normoxia. SK-HEP-1 tumors treated with HSV10xHRE/sFlk-1 yielded a 72% reduction in volume vs. the control group (P < 0.000001). HSV amplicon-mediated delivery of a hypoxia-inducible soluble VEGF receptor substantially reduces new vessel formation and tumor growth in hepatoma.
Pin
Richard H
RH
Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, New York, USA.
Reinblatt
Maura
M
Bowers
William J
WJ
Federoff
Howard J
HJ
Fong
Yuman
Y
D020533:Angiogenesis Inhibitors / Q000494:pharmacology*; D000818:Animals; D015153:Blotting, Western; D006528:Carcinoma, Hepatocellular / Q000098:blood supply*; D015687:Cell Hypoxia; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000235:genetics; D005822:Genetic Vectors / Q000235:genetics; D018257:Helix-Loop-Helix Motifs / Q000235:genetics; D006801:Humans; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D008113:Liver Neoplasms / Q000098:blood supply*; D051379:Mice; D008819:Mice, Nude; D009687:Nuclear Proteins / Q000235:genetics; D040262:Receptors, Vascular Endothelial Growth Factor / Q000378:metabolism; D018139:Simplexvirus / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics
D020533:Angiogenesis Inhibitors; D004268:DNA-Binding Proteins; C497442:HIF1A protein, human; D051793:Hypoxia-Inducible Factor 1; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D009687:Nuclear Proteins; D014157:Transcription Factors; D040262:Receptors, Vascular Endothelial Growth Factor