Nucleic Acids Research Advance Access published online on May 14, 2009
Nucleic Acids Research, doi:10.1093/nar/gkp374
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Methods Online |
p53-dependent antiviral RNA-interference facilitates tumor-selective viral replication
1Department of Gastroenterology, Hepatology and Endocrinology, Medical School Hannover, Carl Neuberg Str. 1, 30625 Hannover, Germany and 2Department of Microbiology, University of Iowa, 51 Newton Road, Iowa City, IA 52242, USA
*To whom the correspondence should be addressed. Tel: +49 511 532 9401; Fax: +49 511 532 2021; Email: kuehnel.florian{at}mh-hannover.de
Correspondence may also be addressed to Stefan Kubicka. Tel: +49 511 532 6766; Fax: +49 511 532 2021; Email: kubicka.stefan{at}mh-hannover.de
Received November 13, 2008. Accepted April 24, 2009.
RNA-interference (RNAi) is a potent tool for specific gene silencing. In this study, we developed an adenovirus for conditional replication in p53-dysfunctional tumor cells that uses p53-selective expression of a microRNA-network directed against essential adenoviral genes. Compared to a control virus that expressed a scrambled microRNA-network, antiviral RNAi selectively attenuated viral replication in cells with transcriptionally active p53, but not in p53-dysfunctional tumor cells where both viruses replicated equivalently. Since these results were confirmed by an in vivo comparison of both viruses after infection of p53-knockout and normal mice, we could demonstrate that attenuated replication was indeed a result of p53-selective exhibition of antiviral RNAi. Addressing the therapeutic applicability, we could show that the application of RNAi-controlled virus efficiently lysed p53-dysfunctional tumors in vitro and in vivo but resulted in drastically reduced load of virus-DNA in the liver of treated mice. We have generated a broadly applicable adenovirus for selective destruction of p53-dysfunctional tumors and thereby demonstrate that virus-encoded RNAi-networks represent an efficient and versatile tool to modify viral functions. RNAi-networks can be applied to all transcriptionally regulated DNA-viruses to remodulate viral tropism and thus provide means to generate specifically replicating vectors for clinical applications.