Abstract
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.
Original language | English (US) |
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Pages (from-to) | 812-823 |
Number of pages | 12 |
Journal | Journal of Gastrointestinal Surgery |
Volume | 8 |
Issue number | 7 |
DOIs | |
State | Published - 2004 |
Externally published | Yes |
Keywords
- Flk-1
- Gene therapy
- Herpes simplex virus
- Hypoxia-inducible factor 1
- Vascular endothelial growth factor
ASJC Scopus subject areas
- Surgery
- Gastroenterology