[New therapeutic strategy against colon cancer based on a tumor-specific approach]

To develop a new therapy against colon cancer, we investigated two kinds of strategy using a cancer-specific approach. First, we employed the Cre/loxP regulation system to enhance the specific expression by carcinoembryonic antigen (CEA) promotor in CEA-producing tumor cells, and examined whether sufficient enhancement to transcriptional activity of CEA promotor, which maintains its specificity in vitro and in vivo, could be obtained. Next, using dendritic cells pulsed with HLA-A24 epitope peptides of CEA, we performed a Phase I study of active immunotherapy in patients with advanced colon cancer. These results suggest that the newly developed therapy for colon cancer is a promising strategy; however, minor modification may be necessary.