OBJECTIVETo investigate the inhibitory effect of DNA vaccine immunization on neu-overexpressed melanoma growth in prophylactic treatment and anti-lung-metastasis experiments in C57BL/6 mice.

METHODSpcDNA-neu transfected into B16F10 with transfection reagent Fugene 6, neu-overexpressed cell clone B16F10-neu was selected with limited dilution method. The growth curve was drawn to analyse its proliferating character in vitro. With Helios gene gun system, DNA vaccine pWRG-neu was immunized to 8-week-old C57BL/6 mice in the shaved abdominal skin for 3 times at two-weekly interval. After immunization, the life span was analyzed. Using MTT assay, the cytolysis activity of the DNA immunized mice spleen cells was compared.

RESULTSOne clone of neu-overexpressed B16F10-neu was selected and its proliferating character was the same as B16F10 and B16F10-pcDNA. In prophylactic, treatment and anti-lung-metastasis experiments, gene gun-mediated pWRG-neu immunization could exhibit antitumor effects. The growth and metastasis of neu-overexpressed melanoma was reduced dramatically. The spleen cells of the immuned mice showed cytotoxic T lymphocyte (CTL) activity.

CONCLUSIONGene gun-mediated gene transfer is effective and practicable. DNA vaccine pWRG-neu is potent in preventing subsequent tumor cells challenge, inhibiting the tumor growth and metastasis.