Nanocapsules for transposon therapy in cancer

Viral vectors are used in more than 70% of current gene therapy trials. However, immunogenicity, oncogenicity, and poor tumor transfection efficiencies present significant barriers to clinical success. Sleeping Beauty Transposon (SBT) technology, combined with a targeted, tumor-penetrating, non-viral gene transfer system, offers an alternative approach for therapeutic transgene production with low toxicity. We have developed a non-viral, sub-50 nm capsule formulation platform that condenses and encapsulates macromolecules in protein/peptide capsules for targeted drug delivery. In vitro, we have demonstrated nanocapsule uptake is receptor-mediated via caveolae, supporting the possibility of efficient tumor-targeting and intracellular delivery. In vivo, we have demonstrated the potential of nanocapsules for systemic, targeted, tumor-penetrating delivery of oligonucleotides, and produced expression of SBT plasmids for reporter and therapeutic genes. We propose to demonstrate feasibility of nanoencapsulated SBT plasmids for use in targeted treatment of advanced prostate cancer, by comparing the biodistribution of three nanocapsule coating proteins for tumor-targeting in a syngeneic, orthotopic model of prostate cancer. We will select the most promising coating for future testing with a transposon plasmid being developed to generate siRNA against hyaluronan receptors CD44 and RHAMM-1, which have been shown to play major roles in prostate cancer metastasis and tumor survival.