s was analyzed in tissue culture; viability varied from 2 to 6 days. Consequently, to ensure that cell death was due to virally induced lysis and release of progeny virus and was not due to spontaneous lysis 14709329 of the surgical material, a 24 hr endpoint was selected. Six tumor samples were collected and punch cultures from tumor and normal sections were generated and exposed to either Ad5 or ColoAd1. To determine each viruses’ ability to replicate, lyse and release infectious virus, supernatant was collected 24 hr post-infection and assayed for the 5 A Novel Virus for Colon Cancer presence of progeny virus. As seen in ColoAd1 can be armed without compromising potency Armed GDC0973 oncolytic viruses seek to complement the potency of the oncolytic virus by the addition of therapeutic transgenes. In this approach it is important that a therapeutic transgene insertion site within the viral genome be identified that does not compromise the life cycle and therefore the potency of the virus. Unlike Ad5, where the biology and description of insertion sites compatible with the viral life-cycle are well described, ColoAd1 represents a novel agent that is primarily derived from the poorly 
studied Ad11p genome. Consequently, a transposon-based system that can scan the genome for insertion sites in a non-prejudiced fashion was utilized for the identification of compatible transgene insertion sites Given that the viral genome coding capacity of the human Ad is constrained a consensus splice acceptor site was placed upstream of the transgene, eliminating the need for an exogenous promoter and linking expression to an endogenous ColoAd1 promoter. To enhance the ability to identify transgene expressing ColoAd1 variants, GFP was chosen as the transgene. A number of viral isolates were generated and then screened for potency and a virus termed ColoAd1-GFP was selected based on equivalent potency to the parent ColoAd1. Past studies using a splice acceptor-based expression cassette demonstrated that expression occurred late in the viral life cycle and was dependent upon viral DNA replication. Linking therapeutic transgene expression to the selectivity of the virus has a A Novel Virus for Colon Cancer significant safety advantage over traditional constitutive expression systems since gene expression would be limited and dependent upon the tumor selectivity of the viral system. To determine the GFP expression kinetics from ColoAd1-GFP, HT-29 cells were infected in the presence or absence of AraC, a compound which inhibits viral replication. As seen in expression occurs late in the viral life cycle and is linked to viral replication. Discussion In the present study we established conditions that select potent viral agents, without bias towards any mechanism, from a pool of 7 A Novel Virus for Colon Cancer Ad serotypes representing Ad subgroups BF. This method, which is a highly accelerated version of the natural selection of viruses, can be applied to any virus and any cancer type of choice. Using this process, we generated and characterized ColoAd1, a novel Ad3/Ad11p chimeric oncolytic virus for the treatment of human colon cancer and, potentially, other indications. This virus 18690793 was shown to be more potent and have a larger therapeutic window than Ad5 and the most clinically advanced oncolytic virus Onyx-015. Futhermore, ColoAd1 demonstrated increased potentcy in an intravenous tumor model and on tumor explants.This virus has several changes relative to the parent Ad11p
