Intranasal administration of CpG DNA lipoplex prevents pulmonary metastasis in mice

Synthetic oligodeoxynucleotides containing CpG motifs (CpG DNA) can activate immunocompetent cells which offer the potential advantage of antitumor activity. In this study, we used cationic liposomes to complex with CpG DNA (CpG DNA lipoplex) to prevent pulmonary metastasis following intranasal administration in mice. Intranasal administration of CpG DNA lipoplex prior to challenge with both colon26/Luc and B16F10 cells significantly prevented the proliferation of tumor cells, and the survival time of the mice receiving CpG DNA lipoplex was prolonged. After intranasal administration, [32P] CpG DNA lipoplex mainly distributed in nose and lung and induced higher IFN-γ production in the lung. These results suggest that intranasal administration of CpG DNA lipoplex has a significant effect on preventing pulmonary metastasis in mice.