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.

2.50
Hdl Handle:
http://hdl.handle.net/10541/74021
Title:
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.
Authors:
Marignol, Laure; Foley, Ruth; Southgate, Thomas D; Coffey, Mary; Hollywood, Donal; Lawler, Mark
Abstract:
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. 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. 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. CONCLUSIONS: This strategy thus has the potential to sensitize the hypoxic compartment of prostate tumours and improve the outcome of current therapies.
Affiliation:
Department of Haematology and Academic Unit of Clinical and Molecular Oncology, Institute of Molecular Medicine, St James's Hospital and Trinity College Dublin, Dublin, Ireland. marignol@tcd.ie
Citation:
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. 2009, 11 (2):169-79 J Gene Med
Journal:
The Journal of Gene Medicine
Issue Date:
Feb-2009
URI:
http://hdl.handle.net/10541/74021
DOI:
10.1002/jgm.1281
PubMed ID:
19051213
Type:
Article
Language:
en
ISSN:
1521-2254
Appears in Collections:
All Paterson Institute for Cancer Research; Biological Immune and Gene Therapy Group

Full metadata record

DC FieldValue Language
dc.contributor.authorMarignol, Laure-
dc.contributor.authorFoley, Ruth-
dc.contributor.authorSouthgate, Thomas D-
dc.contributor.authorCoffey, Mary-
dc.contributor.authorHollywood, Donal-
dc.contributor.authorLawler, Mark-
dc.date.accessioned2009-07-15T16:20:12Z-
dc.date.available2009-07-15T16:20:12Z-
dc.date.issued2009-02-
dc.identifier.citationHypoxia 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. 2009, 11 (2):169-79 J Gene Meden
dc.identifier.issn1521-2254-
dc.identifier.pmid19051213-
dc.identifier.doi10.1002/jgm.1281-
dc.identifier.urihttp://hdl.handle.net/10541/74021-
dc.description.abstractBACKGROUND: 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. 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. 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. CONCLUSIONS: This strategy thus has the potential to sensitize the hypoxic compartment of prostate tumours and improve the outcome of current therapies.en
dc.language.isoenen
dc.subjectCell Line Tumouren
dc.subjectProstatic Canceren
dc.subject.meshCell Hypoxia-
dc.subject.meshCell Line, Tumor-
dc.subject.meshCell Survival-
dc.subject.meshCytosine Deaminase-
dc.subject.meshFlucytosine-
dc.subject.meshGene Therapy-
dc.subject.meshGenetic Vectors-
dc.subject.meshHumans-
dc.subject.meshMale-
dc.subject.meshProstatic Neoplasms-
dc.subject.meshRadiation Tolerance-
dc.subject.meshResponse Elements-
dc.subject.meshTransfection-
dc.titleHypoxia 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.en
dc.typeArticleen
dc.contributor.departmentDepartment of Haematology and Academic Unit of Clinical and Molecular Oncology, Institute of Molecular Medicine, St James's Hospital and Trinity College Dublin, Dublin, Ireland. marignol@tcd.ieen
dc.identifier.journalThe Journal of Gene Medicineen
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