Fundamental studies of targeting cancer chemotherapy against choriocarcinoma--application of liposome

For the fundamental study of the targeting cancer chemotherapy against choriocarcinoma using the anti-human chorionic gonadotropin beta subunit (hCG beta) antibody-conjugated-liposome containing anticancer drugs, we evaluated the specific accumulation of the antibody to the choriocarcinoma tissue and the uptake of liposome by choriocarcinoma cells. In vivo, the mice bearing human choriocarcinoma were injected anti-hCG beta antibody (30 micrograms/body) and the localization of the antibody in the tumor and other mouse organs were investigated by the PAP method. The antibody specifically accumulated to the choriocarcinoma tissue within 4 hours after the injection of the antibody, and gradually increased. In vitro, cultured BeWo cells were exposed to the liposome containing adriamycin, the antibody conjugated liposome containing adriamycin or the adriamycin alone, respectively, for 2 hours. Then the uptake of the adriamycin by the tumor cells was studied under fluorescent microscopy. The nuclear accumulation of adriamycin was clearly observed in the tumor cells exposed to the liposome containing adriamycin or the antibody conjugated liposome containing adriamycin, whereas only faint cytoplasmic accumulation of the adriamycin without any nuclear accumulation was observed in the cells exposed to the adriamycin alone. These results indicate that the liposome is a good carrier of anticancer drugs for immunotargeting chemotherapy.