Development of synthetic promoters for radiationmediated gene therapy
Marples, B., Scott, S.D., Hendry, J.H., Embleton, M.J., Lashford, L.S. and Margison, G.P. (2000) Development of synthetic promoters for radiationmediated gene therapy. Gene Therapy, 7 (6). pp. 511-517. ISSN 0969-7128 (print), 1476-5462 (electronic) (doi:10.1038/sj.gt.3301116)Full text not available from this repository.
Exposure of cells to ionising radiation results in the activation of specific transcriptional control (CArG) elements within the early growth response 1 (Egr1) gene promoter, leading to increased gene expression. As part of a study investigating the potential use of these elements in radiation-controlled gene therapy vectors, we have incorporated their sequences into a synthetic gene promoter and assayed for the ability to induce expression of a downstream reporter gene following irradiation. In vector-transfected MCF-7 breast adenocarcinoma cells, the synthetic promoter was more effective than the wild-type Egr1 counterpart in up-regulating expression of the reporter gene after exposure to a single 5 Gy dose,
and equally effective as the wild-type in U87-MG glioma
cells. The level of gene expression achieved using the synthetic promoter was dependent on the inducing radiation
dose for both U87-MG and MCF-7 cells, being maximal at
3 Gy and decreasing at 5 and 10 Gy. Furthermore, induction
could be repeated by additional radiation treatments. The
latter indicates that up-regulation should be additive during fractionated radiotherapy schedules. To demonstrate the potential clinical benefit of such an approach, the synthetic promoters were also shown to drive expression of the herpes simplex virus thymidine kinase gene, leading to
enhanced cell killing in the presence of the prodrug ganciclovir (GCV) when compared with cells treated with radiation alone. Our results demonstrate that the synthetic promoter is responsive to low doses of ionising radiation and therefore isolated CArG elements function as radiation-mediated transcriptional enhancers outside their normal sequence context. The continued development and optimisation of such radiation-responsive synthetic promoters is expected to make a valuable contribution to the development of future radiation-responsive vectors for cancer gene therapy.
|Uncontrolled Keywords:||Egr1, CArG elements, GFP, gene therapy|
|Subjects:||R Medicine > RC Internal medicine > RC0254 Neoplasms. Tumors. Oncology (including Cancer)|
T Technology > TP Chemical technology
|School / Department / Research Groups:||Medway School of Pharmacy|
|Last Modified:||02 Jul 2012 15:05|
Actions (login required)