A radiation-controlled molecular switch for use in gene therapy of cancer.
Ionising radiation induces the expression of a number of radiation-responsive genes and there is current interest in exploiting this to regulate the expression of exogenous therapeutic genes in gene therapy strategies for cancer. However, the radiation-responsive promoters used in these approaches are often associated with low and transient levels of therapeutic gene expression. We describe here a novel radiation-triggered molecular switching device based on promoter elements from the radiation-responsive Egr-1 gene and the cre-LoxP site-specific recombination system of the P1 bacteriophage. Using this system, a single, minimally toxic dose of radiation induced cre-mediated excision of a lox-P flanked stop cassette in a silenced expression vector and this resulted in amplified levels of CMV-promoter-driven expression of the exogenous tumour-sensitising gene, HSV-tk. This strategy could be used in combination with targeted delivery and tumour-specific promoters to elicit the tumour-targeted and prolonged expression of a variety of tumour-sensitising genes and provide an unprecedented level of control and tumour selectivity.
Cancer Research Campaign Section of Genome Damage and Repair, Paterson Institute for Cancer Research, Christie Hospital (NHS) Trust, Manchester, UK.
S D
SD
Scott
B
B
Marples
J H
JH
Hendry
L S
LS
Lashford
M J
MJ
Embleton
R D
RD
Hunter
A
A
Howell
G P
GP
Margison
D000998:Antiviral Agents / Q000627:therapeutic use; D002455:Cell Division / Q000187:drug effects; D003587:Cytomegalovirus / Q000235:genetics; D005434:Flow Cytometry; D015774:Ganciclovir / Q000627:therapeutic use; D015870:Gene Expression; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods*; D049452:Green Fluorescent Proteins; D006801:Humans; D019426:Integrases / Q000235:genetics*; D008164:Luminescent Proteins / Q000235:genetics; D009369:Neoplasms / Q000532:radiotherapy / Q000628:therapy*; D011401:Promoter Regions, Genetic; D018139:Simplexvirus / Q000201:enzymology*; D013937:Thymidine Kinase / Q000235:genetics*; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000528:radiation effects; D014764:Viral Proteins
D000998:Antiviral Agents; D008164:Luminescent Proteins; D014764:Viral Proteins; D049452:Green Fluorescent Proteins; D013937:Thymidine Kinase; C045073:Cre recombinase; D019426:Integrases; D015774:Ganciclovir