1. ¹Genelux Corporation, San Diego Science Center, San Diego, CA, USA
2. ²Department of Biochemistry, University of Würzburg, Würzburg, Germany
3. ³Centre for Human Genetics, University of Bremen, Bremen, Germany
4. ⁴Small Animal Clinic, University of Veterinary Medicine, Hannover, Germany
5. ⁵Virchow Center for Experimental Biomedicine, University of Würzburg, Würzburg, Germany
6. ⁶Institute for Molecular Infection Biology, University of Würzburg, Würzburg, Germany

Correspondence: Professor AA Szalay, Genelux Corporation, San Diego Science Center, 3030 Bunker Hill Street, San Diego, CA 92109, USA. E-mail: aaszalay@genelux.com

⁷These three authors contributed equally to this work.

Received 18 April 2008; Revised 24 June 2008; Accepted 31 July 2008; Published online 24 October 2008.

Abstract

Mammary cancers together with cancers of the skin account for about 60% of the total cancers occurring in dogs. The veterinary options for therapeutic management of canine mammary cancer are limited and prognosis for such patients is poor. In this study, we analyzed the functionality of the oncolytic vaccinia virus strain GLV-1h68 as a possible therapeutic agent for canine mammary cancer. Cell culture data demonstrated that GLV-1h68 efficiently infected and destroyed cells of the canine mammary adenoma cell line ZMTH3. Furthermore, after systemic administration this attenuated vaccinia virus strain primarily replicated in canine tumor xenografts in nude mice. The efficient tumor colonization process resulted in inhibition of tumor growth and drastic reduction of tumor size. This is the first report demonstrating that vaccinia virus is an effective tool for the therapy of canine mammary cancers, which might next be applied to dogs with breast tumors.