Isolated limb perfusion based anti-p21ras gene therapy in a rat rhabdomyosarcoma.
BACKGROUND
Inhibition of ras oncogene is a promising new strategy. Gene therapy against ras proved successful in human and murine tumour cell lines. Previously we demonstrated effective targeted transfection of tumour in a rat model by using an isolated limb perfusion (ILP) for the delivery of adenoviral vectors.


METHODS
This study explores the anti-tumour activity of an adenoviral construct encoding an intracellular single-chain antibody (scFv) against p21ras (Y28). In order to determine the influence of the ras status on the efficacy of the scFv, we used a wild-type rat rhabdomyosarcoma and its ras-oncogene transfectant, for in vitro studies. In vivo we used the ILP delivery method to study anti-tumour activity on established limb tumours.


RESULTS
In vitro studies demonstrated an inhibition of growth caused by the Y28 construct. No significant difference between transfected and wild-type cell lines could be demonstrated. Upon ILP, homogeneous transduction was observed in 5% of tumour cells. Perfusion with the Y28 construct, however, did not result in any additional anti-tumour activity compared to controls.


CONCLUSIONS
Despite in vitro activity and in vivo transfection, no significant tumour response could be detected using anti-p21ras gene therapy in this ILP-tumour model.
Erasmus University Medical Centre-Daniel den Hoed Cancer Centre, Department of Surgical Oncology, PO Box 520,1 3008 AE Rotterdam, The Netherlands.
Boudewijn
B
Van Etten
Sandra T
ST
Van Tiel
Gisela
G
Ambagtsheer
Alexander M M
AM
Eggermont
Timo L M
TL
Ten Hagen
D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D000918:Antibody Specificity; D045744:Cell Line, Tumor; D010478:Chemotherapy, Cancer, Regional Perfusion; D011905:Genes, ras / Q000235:genetics; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors / Q000008:administration & dosage / Q000235:genetics; D007128:Immunoglobulin Fragments / Q000235:genetics / Q000276:immunology; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics*; D051381:Rats; D012208:Rhabdomyosarcoma / Q000235:genetics / Q000628:therapy*; D014162:Transfection
D007128:Immunoglobulin Fragments; C055966:immunoglobulin Fv; D016283:Proto-Oncogene Proteins p21(ras)