Cancer Targeted Gene Therapy for Inhibition of Melanoma Lung Metastasis with eIF3i shRNA Loaded Liposomes

Eukaryotic translation initiation factors 3i (eIF3i) is a proto-oncogene that is overexpressed in various tumors, reducing its expression by eIF3i shRNA is a promising strategy to inhibit tumor growth or metastasis. Tumor cell is the target of eIF3i shRNA so that tumor-site accumulation could be important for fulfilling its therapeutic effect. Thus, the iRGD modified liposome (R-LP) was rationally synthesized to enhance the antitumor effect by active targeted delivery of eIF3i shRNA to B16F10 melanoma cells. R-LP encapsulating eIF3i shRNA gene (R-LP/sheIF3i) were prepared by a film dispersion method. The transfection experiment proves that R-LP could effectively transfect B16F10 cells. R-LP/sheIF3i notably restrained the migration, invasion, and adhesion of melanoma cells in vitro. In a mouse model of lung metastasis, R-LP/sheIF3i administered by intravenous injection suppressed pulmonary metastasis of melanoma by dramatically downregulated eIF3i expression and subsequently inhibiting tumor neovascularization and tumor cells proliferation in vivo. Our results provide a basis for tumor cells targeting strategies to reduce the expression of eIF3i by RNAi in the treatment of tumor metastasis.