Targeting adenovirus to the serotype 3 receptor increases gene transfer efficiency to ovarian cancer cells.
Gene delivery efficiency in clinical cancer gene therapy trials with recombinant adenoviruses (Ads) based on serotype 5 (Ad5) has been limited partly because of variable expression of the primary Ad5 receptor, the coxsackie and adenovirus receptor (CAR), on human primary cancer cells. As a means of circumventing CAR deficiency, Ad vectors have been retargeted by creating chimeric fibers possessing knob domains of alternate Ad serotypes. In this study, we have constructed an Ad5-based vector, Ad5/3luc1, with a chimeric fiber protein featuring a knob domain derived from Ad3. This virus is retargeted to the Ad3 receptor and, therefore, has different tissue tropism. A novel knob binding assay was used to measure expression of CAR and the Ad3 receptor. Further, to evaluate the correlation of receptor expression and infectivity by Ad, a panel of ovarian cancer cell lines and purified primary cancer cells were infected with Ad5luc1 and Ad5/3luc1 at 50, 200, and 1000 viral particles/cell. Our results confirm that Ad5/3luc1 is retargeted to the Ad3 receptor. Furthermore, the Ad3 receptor is present at higher levels than CAR on ovarian adenocarcinoma cells. Also, the amount of binding to primary receptor appears to be the major factor determining the efficiency of transgene expression. The Ad5/3 chimera displays enhanced infectivity for ovarian cancer cell lines and purified primary tumor cells, which could translate into increased efficacy in clinical trials.
Kanerva
Anna
A
Division of Human Gene Therapy, Departments of Medicine, Pathology, and Surgery and the Gene Therapy Center, University of Alabama at Birmingham, 35294-3300, USA.
Mikheeva
Galina V
GV
Krasnykh
Victor
V
Coolidge
Candace J
CJ
Lam
John T
JT
Mahasreshti
Parameshwar J
PJ
Barker
Shannon D
SD
Straughn
Michael
M
Barnes
Mack N
MN
Alvarez
Ronald D
RD
Hemminki
Akseli
A
Curiel
David T
DT
D000230:Adenocarcinoma / Q000628:therapy*; D000256:Adenoviridae / Q000235:genetics*; D001667:Binding, Competitive; D062727:Coxsackie and Adenovirus Receptor-Like Membrane Protein; D004770:Enterovirus / Q000235:genetics*; D005260:Female; D005434:Flow Cytometry; D018014:Gene Transfer Techniques; D015316:Genetic Therapy; D005822:Genetic Vectors / Q000235:genetics; D006801:Humans; D008156:Luciferases / Q000235:genetics; D010051:Ovarian Neoplasms / Q000628:therapy*; D011991:Receptors, Virus / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000235:genetics; D014407:Tumor Cells, Cultured; D014764:Viral Proteins / Q000378:metabolism
C568771:CLMP protein, human; D062727:Coxsackie and Adenovirus Receptor-Like Membrane Protein; D011991:Receptors, Virus; D011993:Recombinant Fusion Proteins; D014764:Viral Proteins; D008156:Luciferases