Intranasal therapy with an adenoviral vector containing the murine interleukin-12 gene eradicates osteosarcoma lung metastases

The purpose of these studies was to determine the effect of adenovirus-medi ated interleukin-12 (IL-12) gene transfer on the growth and development of osteosarcoma (OS) lung metastases in nude mice. A nude mouse model was prod uced by repetitive cycling of human SAGS OS cells through the lung, The res ultant SAOS-LM6 cell line produced microscopic lung metastases by 5-6 weeks after i.v. injection of the tumor cells, with visible lung metastases pres ent 8 weeks after injection. Transfection of SAOS-LM6 cells with a plasmid containing the murine IL-12 gene resulted in a decrease in metastatic poten tial. Animals injected with IL-12-transfected clones had fewer metastases c ompared with mice injected with SAOS-LM6 cells transfected with a control p lasmid, Furthermore, nasal delivery of an adenoviral vector containing the murine IL-12 gene resulted in the inhibition of pulmonary metastases, Toget her, these data indicate that IL-12 may be an effective agent against OS an d that nasal delivery may offer a unique way to deliver the gene to the loc al tumor environment, potentially decreasing systemic toxic effects.