Adenovirus-mediated cytosine deaminase/5-fluorocytosine suicide gene therapy of human hepatoblastoma in vitro.
BACKGROUND
Multidrug resistance is a key factor for the sobering outcome of relapsed and metastatic human hepatoblastoma (HB). Gene directed treatment approaches were recently identified as possible treatment options against advanced HB, in which standard chemotherapy regimens are partially insufficient. The aim of this study was to systematically analyze the effects of suicide gene therapy in three HB cell lines using a yeast-derived cytosine deaminase (YCD)-combined yeast uracil phosphoribosyltransferase (YUPRT)-based adenovirus-mediated gene transfer.


METHODS
YCD and YUPRT were fused to form the bifunctional suicide gene SuperCD. Adeonoviral vectors were used for transduction. Tumor cells transduced at MOI 50 were incubated with 5-fluorocytosine (5-FC) in ascending concentrations.


RESULTS
Transduction rates were 87.8% (+6.7) in the mixed HB cell line HUH6, 98.6% (+1.4) in the epithelial HB cell line HepT1 and 93.6% (+0.6) in the multifocal HB embryonal cell line HepT3, respectively. In HepT3 and HepT1 cells suicide gene therapy with SuperCD/5-FC was highly effective leading to HB cell damage far above those of application of the prodrug 5-FC only. In HUH6 cells the approach had no effect due to a lack in activity of the CMV promoter being employed for transcription of the SuperCD transgene.


CONCLUSIONS
Assuming employment of fully active promoters, the SuperCD/5-FC approach may serve as a potentially useful anti-tumor strategy against advanced HB.
Warmann
Steven W
SW
Department of Pediatric Surgery, University Children's Hospital Tübingen, Tübingen, Germany. steven.warmann@med.uni-tuebingen.de
Armeanu
Sorin
S
Heigoldt
Heike
H
Ruck
Peter
P
Vonthein
Reinhard
R
Heitmann
Heike
H
Seitz
Guido
G
Lemken
Marie-Luise
ML
Bitzer
Michael
M
Fuchs
Jörg
J
Lauer
Ulrich M
UM
D000256:Adenoviridae / Q000235:genetics*; D000970:Antineoplastic Agents / Q000008:administration & dosage; D045744:Cell Line, Tumor; D043525:Cytosine Deaminase / Q000008:administration & dosage*; D005437:Flucytosine / Q000008:administration & dosage*; D005455:Fluorescent Antibody Technique; D005472:Fluorouracil / Q000008:administration & dosage; D041722:Genes, Transgenic, Suicide; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors; D018197:Hepatoblastoma / Q000235:genetics / Q000628:therapy*; D006801:Humans; D066298:In Vitro Techniques; D008113:Liver Neoplasms / Q000235:genetics / Q000628:therapy*; D014161:Transduction, Genetic
D000970:Antineoplastic Agents; D005437:Flucytosine; D043525:Cytosine Deaminase; D005472:Fluorouracil