This Article Full Text Full Text (PDF) Supplementary Data Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Hingorani, M. Articles by Harrington, K. J. Search for Related Content PubMed PubMed Citation Articles by Hingorani, M. Articles by Harrington, K. J.

Inhibition of Repair of Radiation-Induced DNA Damage Enhances Gene Expression from Replication-Defective Adenoviral Vectors

¹ Targeted Therapy Team, The Institute of Cancer Research; ² Centre for Molecular Oncology, Queen Mary's School of Medicine and Dentistry; ³ Head and Neck Unit, Royal Marsden Hospital, London, United Kingdom; ⁴ KuDOS Pharmaceuticals Ltd., Cambridge, United Kingdom; ⁵ Medway School of Pharmacy, University of Kent, Kent, United Kingdom; ⁶ University of Surrey, Guildford, United Kingdom; ⁷ St. James's University Hospital, Leeds, United Kingdom; and ⁸ Molecular Medicine Program, Mayo Clinic, Rochester, Minnesota

Requests for reprints: Kevin J. Harrington, Targeted Therapy Laboratory, The Institute of Cancer Research, Chester Beatty Laboratories, Cancer Research UK Centre for Cell and Molecular Biology, 237 Fulham Road, London SW3 6JB, United Kingdom. Phone: 20-7153-5157; Fax: 20-7808-2235; E-mail: kevinh{at}icr.ac.uk.

Key Words: adenovirus • DNA repair • double-strand breaks • gene expression • MAP kinase

Radiation has been shown to up-regulate gene expression from adenoviral vectors in previous studies. In the current study, we show that radiation-induced dsDNA breaks and subsequent signaling through the mitogen-activated protein kinase (MAPK) pathway are responsible, at least in part, for this enhancement of transgene expression both in vitro and in vivo. Inhibitors of ataxia-telangiectasia–mutated, poly(ADP-ribose) polymerase–mutated, and DNA-dependent protein kinase (DNA-PK)–mediated DNA repair were shown to maintain dsDNA breaks (H2AX foci) by fluorescence-activated cell sorting and microscopy. Inhibition of DNA repair was associated with increased green fluorescent protein (GFP) expression from a replication-defective adenoviral vector (Ad-CMV-GFP). Radiation-induced up-regulation of gene expression was abrogated by inhibitors of MAPK (PD980059 and U0126) and phosphatidylinositol 3-kinase (LY294002) but not by p38 MAPK inhibition. A reporter plasmid assay in which GFP was under the transcriptional control of artificial Egr-1 or cytomegalovirus promoters showed that the DNA repair inhibitors increased GFP expression only in the context of the Egr-1 promoter. In vivo administration of a water-soluble DNA-PK inhibitor (KU0060648) was shown to maintain luciferase expression in HCT116 xenografts after intratumoral delivery of Ad-RSV-Luc. These data have important implications for therapeutic strategies involving multimodality use of radiation, targeted drugs, and adenoviral gene delivery and provide a framework for evaluating potential advantageous combinatorial effects. [Cancer Res 2008;68(23):9771–8]

This article has been cited by other articles:

				I. Peerlinck, A. Merron, P. Baril, S. Conchon, P. Martin-Duque, C. Hindorf, J. Burnet, M. Quintanilla, M. Hingorani, R. Iggo, et al. Targeted Radionuclide Therapy Using a Wnt-Targeted Replicating Adenovirus Encoding the Na/I Symporter Clin. Cancer Res., November 1, 2009; 15(21): 6595 - 6601. [Abstract] [Full Text] [PDF]