Hypoxia response element-driven cytosine deaminase/5-fluorocytosine gene therapy system:a highly effective approach to overcome the dynamics of tumour hypoxia and enhance the radiosensitivity of prostate cancer cells in vitro


Autoria(s): Marignol, Laure; Foley, Ruth; Southgate, Thomas D; Coffey, Mary; Hollywood, Donal; Lawler, Mark; Lawler, Mark
Data(s)

01/02/2009

Resumo

<p>BACKGROUND: We proposed to exploit hypoxia-inducible factor (HIF)-1alpha overexpression in prostate tumours and use this transcriptional machinery to control the expression of the suicide gene cytosine deaminase (CD) through binding of HIF-1alpha to arrangements of hypoxia response elements. CD is a prodrug activation enzyme, which converts inactive 5-fluorocytosine to active 5-fluorouracil (5-FU), allowing selective killing of vector containing cells.</p><p>METHODS: We developed a pair of vectors, containing either five or eight copies of the hypoxia response element (HRE) isolated from the vascular endothelial growth factor (pH5VCD) or glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (pH8GCD) gene, respectively. The kinetics of the hypoxic induction of the vectors and sensitization effects were evaluated in 22Rv1 and DU145 cells in vitro.</p><p>RESULTS: The CD protein as selectively detected in lysates of transiently transfected 22Rv1 and DU145 cells following hypoxic exposure. This is the first evidence of GAPDH HREs being used to control a suicide gene therapy strategy. Detectable CD levels were sustained upon reoxygenation and prolonged hypoxic exposures. Hypoxia-induced chemoresistance to 5-FU was overcome in both cell lines treated with this suicide gene therapy approach. Hypoxic transfectants were sensitized to prodrug concentrations that were ten-fold lower than those that are clinically relevant. Moreover, the surviving fraction of reoxygenated transfectants could be further reduced with the concomitant delivery of clinically relevant single radiation doses.</p><p>CONCLUSIONS: This strategy thus has the potential to sensitize the hypoxic compartment of prostate tumours and improve the outcome of current therapies.</p>

Identificador

http://pure.qub.ac.uk/portal/en/publications/hypoxia-response-elementdriven-cytosine-deaminase5fluorocytosine-gene-therapy-system(e18fdc4a-62b3-4cb8-acc5-0ffbc936139a).html

http://dx.doi.org/10.1002/jgm.1281

Idioma(s)

eng

Direitos

info:eu-repo/semantics/restrictedAccess

Fonte

Marignol , L , Foley , R , Southgate , T D , Coffey , M , Hollywood , D , Lawler , M & Lawler , M 2009 , ' Hypoxia response element-driven cytosine deaminase/5-fluorocytosine gene therapy system : a highly effective approach to overcome the dynamics of tumour hypoxia and enhance the radiosensitivity of prostate cancer cells in vitro ' The Journal of Gene Medicine , vol 11 , no. 2 , pp. 169-79 . DOI: 10.1002/jgm.1281

Palavras-Chave #Cell Hypoxia #Cell Line, Tumor #Cell Survival #Cytosine Deaminase #Flucytosine #Genetic Therapy #Genetic Vectors #Humans #Male #Prostatic Neoplasms #Radiation Tolerance #Response Elements #Transfection
Tipo

article