Low-dose simultaneous delivery of adenovirus encoding hepatocyte growth factor and vascular endothelial growth factor in dogs enhances liver proliferation without systemic growth factor elevation.
BACKGROUND
Hepatocyte growth factor (HGF) and vascular endothelial growth factor (VEGF) gene transfer proved to enhance liver regeneration. However, elevation of their plasma levels may induce potentially serious distant effects such as tumorigenesis or proliferative retinopathy.


OBJECTIVE
This study was performed to examine whether simultaneous administration of low-dose adenovirus encoding HGF and VEGF genes in dogs will stimulate liver proliferation but without inducing liver toxicity or systemic elevation of HGF and VEGF levels.


METHODS
Adult dogs received an intravenous injection of low-dose adenoviral vectors encoding human HGF and VEGF (HGF/VEGF), beta-galactosidase (lacZ) or phosphate-buffered saline (PBS). Liver proliferation was measured using the proliferating cell nuclear antigen (PCNA) immunostaining labelling index. HGF and VEGF plasma concentrations and transaminases were repeatedly measured. Transgene expression was evaluated using reverse-transcription polymerase chain reaction.


RESULTS
Human HGF and VEGF expressions were detected only in the liver of HGF/VEGF dogs at day 2 after injection but declined at sacrifice (day 7). No expression was detected in the liver of the lacZ or PBS groups. Plasma levels of HGF and VEGF were not statistically different from those in the lacZ group (P=0.81, P=0.22 respectively). The PCNA labelling index was five-fold higher in the HGF/VEGF group compared with the lacZ group (P<0.01). No immunostaining was detected in the PBS group. Transaminases were only elevated (P<0.01) in the lacZ group compared with the other groups.


CONCLUSIONS
We showed that simultaneous administration of low-dose adenoviral vectors encoding human HGF and VEGF genes can induce transgene expression and liver proliferation without liver toxicity or systemic growth factor elevation.
Atta
Hussein M
HM
Department of Surgery, Faculty of Medicine, Minia University, Minia, Egypt. attahm@ems.org.eg
Al-Hendy
Ayman
A
Salama
Salama A
SA
Shaker
Olfat G
OG
Hammam
Olfat A
OA
D000256:Adenoviridae / Q000235:genetics*; D000410:Alanine Transaminase / Q000097:blood; D000469:Alkaline Phosphatase / Q000097:blood; D000818:Animals; D001219:Aspartate Aminotransferases / Q000097:blood; D049109:Cell Proliferation; D004285:Dogs; D015316:Genetic Therapy / Q000009:adverse effects / Q000379:methods*; D005822:Genetic Vectors; D017228:Hepatocyte Growth Factor / Q000096:biosynthesis* / Q000097:blood / Q000235:genetics; D006801:Humans; D007275:Injections, Intravenous; D008099:Liver / Q000378:metabolism* / Q000473:pathology; D008115:Liver Regeneration; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D013997:Time Factors; D014161:Transduction, Genetic; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis* / Q000097:blood / Q000235:genetics
C066855:HGF protein, human; D018809:Proliferating Cell Nuclear Antigen; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D017228:Hepatocyte Growth Factor; D001219:Aspartate Aminotransferases; D000410:Alanine Transaminase; D000469:Alkaline Phosphatase