GENE DELIVERY INTO MALIGNANT-CELLS IN-VIVO BY A CONJUGATED ADENOVIRUSDNA COMPLEX/

Current viral delivery systems suffer from disadvantages that may limi t the rate at which therapeutic gene expressing constructs can be test ed both in vitro and in vivo. In this study, our focus was to develop a simple gene delivery system for the rapid and reproducible testing o f therapeutic genes in cancer cells both in vitro and in vivo. We repo rt here that a delivery system based on using a conjugated adenovirus in complex form with a DNA plasmid can be used for not only delivering genes in vitro but also for efficient and reproducible delivery in vi vo. Replication defective adenoviral particles were chemically modifie d by covalent attachment of poly-L-lysine (PLL) to the viral capsid, a llowing for direct interaction with DNA. The adenovirus/PLL conjugate (Adv/PLL) was used to deliver the plasmid pCMV/beta-gal to several dif ferent cancer cell lines (i.e., lung, cervical) in vitro and resulted in transduction efficiencies as high as 52% as determined by histochem ical staining. On direct intralesional injection of the Adv/PLL/DNA co mplex into subcutaneous tumors, transduction efficiencies greater than 35% could also be achieved. As a result, this system provides a simpl e method for delivering and testing therapeutic genes in cells both in vitro and in vivo, prior to the further development of gene therapy v ectors for both malignant and benign disease.