Effective treatment of small murine hepatocellular carcinoma by dendritic cells

Hepatocellular carcinoma (HCC) is a common malignancy with a poor prognosis. This investigation examined whether dendritic cell-based immunotherapy can treat murine HCC effectively. Bone marrow-derived dendritic cells were propagated from C57BL/10J mice in GM-CSF (4 ng/mL) and interleukin (IL)-4 (1, 000 μ/mL). The dendritic cells were pulsed with a Hepal-6 lysate overnight and employed to treat murine HCC. For in vivo study, HCC was created by inoculation of hepal-6, 5 × 10⁵ cells, in the flank of C57BL/10J mice. HCC were categorized into small (3 × 3-mm) and large (5 × 5-mm) tumors. These HCC were treated by dendritic cells intravenously, twice at weekly intervals. The results revealed that lymphocytes could be gathered around small HCC after administration of Hepal-6 lysate-pulsed dendritic cells. Seven of 12 (58.3%) small HCC could be eradicated completely by dendritic cellbased immunotherapy, and 33.3% of the small tumors responded to immunotherapy partially which were held in a stable condition for 34.0 ± 7.4 days before the tumors regrew. For large HCC, lymphocytes did not gather around the tumors, and the tumors cannot be eradicated effectively by dendritic cells. However, dendritic cell-based immunotherapy could slow down the growth rate of large tumors (116.2 ± 91.4 mm³ vs. 234.0 ± 149.1 mm³ of the control on day 7, P =. 043; and 280.3 ± 224.7 mm³ vs. 870.0 ± 418.9 mm³ of the control on day 17, P <. 001). Conclusively, dendritic cells pulsed with a Hepal-6 lysate can be employed to treat small HCC in vivo effectively. However, the efficacy of dendritic cell-based immunotherapy decreases while tumors grow.