Antitumor effects induced by dendritic cell-based immunotherapy against established pancreatic cancer in hamsters.

Because the prognosis of patients with pancreatic cancer is very poor, development of a novel approach for treatment of this disease is vital. In the present study, we investigated the effect of dendritic cell (DC)-based immunotherapy against established syngeneic hamster pancreatic cancer named HPD1NR. Hamster enriched DCs were prepared from bone marrow (BM) by a culture for 7 days in the presence of mouse GM-CSF and mouse IL-4, and characterized by the expression of specific DC markers (DEC205, DC-SIGN) mRNA using in situ hybridization (ISH). DCs pulsed with tumor lysate and N-[1-(2,3-dioleoyloxy)propyl]-N,N,N-trimethylammonium methylsulfate (DOTAP) or DCs alone were injected s.c. weekly into HPD1NR-bearing hamsters three times. Tumor growth was significantly inhibited by 82% in hamsters treated with tumor lysate and DOTAP-pulsed DCs when compared with the PBS vehicle-treated group. These findings suggest that DC-based immunotherapy may be a useful approach for the treatment of pancreatic cancers.