Background and Purpose: Ovarian cancer is the most frequent cause of death from gynecologic malignancy. Recently, immunotherapies have been suggested as ways to treat this malignancy. However, the ideal of immunotherapy has not been realized yet in ovarian cancer patients. Therefore, we investigated effects of monocyte-derived dendritic cells (mono DCs) and new-generation DCs subset (new DCs) on an ID8 orthotropic mouse model of ovarian cancer.

Methods: Mono DCs were prepared from bone marrow of C57BL/6 mice. We isolated monocyte from bone marrow by monocyte isolation kit. Isolated monocyte was incubated for 7 days with IL-4 and GM-CSF. In addition, monocytes were pulsed with LPS and ID8 tumor lysate while incubating. Likewise new DCs were isolated from bone marrow of C57BL/6 mice. We isolated lineage negative cells from bone marrow using lineage cell depletion kit. Isolated cells were incubated with IL-4 and GM-CSF; also the cells were pulsed by ID8 tumor lysate and Rg3, which is a ginsenoside. Orthotropic model of ID8 was made on C57BL/6 mice. We injected 5x106 cells into peritoneal cavity. 4 weeks after cell injection, mice were grouped into three groups, which were vehicle, mono DCs and new DCs. Mice were injected with mono DCs and new DCs. 5x106 cells of DCs were injected 1 time/week for three weeks. One week later, mice were sacrificed and organs were harvested such as peritoneum, phren, ovary and tumor mass for histologic analysis.

Results: DCs treated groups showed lower ascites formation than vehicle group. Ascites were fewest in new DCs group. Survival rate was lowest in vehicle group. Each survival rate is 0% in vehicle, 63% in new DCs and 80% in mono DCs. Also tumor growth at ovary was more decreased in mono DCs and new DCs group. In addition, mono DCs-treated mice showed low level of metastasis to other organs.

Conclusion: Immunotherapy with dendritic cells showed inhibition of tumor growth and metastasis on mouse ovarian cancer. These results indicated that DCs treatments are able to be a potential therapy for ovarian cancer. It also could have synergy with the combined treatment of existing anticancer drugs. However, there are several limitations such as a relatively high dose of DCs and the procedure of isolating DCs needed large amount of bone marrow. We will continue to study and improve these issues.

Citation Format: Min-Je Kim, Joo-won Kim, Ju-hyun Kim, Young-Jae Lee, Shin-Wha Lee, Yong-Man Kim. Immunotherapy with dendritic cells inhibited tumor growth on an ID8 orthotropic mouse model of ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 119.