Non-Invasive Imaging of Oncolytic Virotherapy by Genetic Capsid Labeling – Dynamic Monitoring of Virotherapy

Aims: Conditionally replicative adenoviruses represent a promising strategy to address the limited efficacy and safety issues associated with conventional cancer treatment. Despite rapid translation into human clinical trials and demonstrated safety, the fundamental properties of oncolytic adenovirus replication, spread and host-vector interactions in vivo have not been completely evaluated. Methods: We developed a noninvasive dynamic monitoring system to detect adenovirus replication. We constructed capsid-labeled E1/E3-deleted, wild-type adenoviruses and a conditionally replicative adenovirus by fusing the minor capsid protein IX with red fluorescent proteins mRFP. Virus DNA replication, encapsidation, cytopathic effect, thermostability were analyzed using real-time quantitative polymerase chain reaction, cell viability (MTS) assay, and fluorescence microscopy. Adenovirus replication was dynamically monitored with a fluorescence noninvasive imaging system. Results: The red fluorescence label had little effect on viral DNA replication and cytopathic effect. Conclusions: Genetic capsid labeling provides a promising approach for the dynamic assessment of oncolytic adenovirus function in vivo.

Imaging - Virotherapy - Breast Cancer - Oncolysis